The Pediatric Rheumatology European Society/American College of Rheumatology/EuropeanLeague Against Rheumatism ProvisionalClassification Criteria for Juvenile Systemic SclerosisFRANCESCO ZULIAN,1 PATRICIA WOO,2 BALU H. ATHREYA,3 RONALD M. LAXER,4

THOMAS A. MEDSGER, JR.,5 THOMAS J. A. LEHMAN,6 MARCO MATUCCI CERINIC,7

GIORGIA MARTINI,1 ANGELO RAVELLI,8 RICARDO RUSSO,9 RUBEN CUTTICA,10

SHEILA KNUPP FEITOSA DE OLIVEIRA,11 CHRISTOPHER P. DENTON,12 FRANCO COZZI,1

IVAN FOELDVARI,13AND NICOLINO RUPERTO,8 FOR THE PEDIATRIC RHEUMATOLOGY EUROPEAN

SOCIETY/AMERICAN COLLEGE OF RHEUMATOLOGY/EUROPEAN LEAGUE AGAINST RHEUMATISMAD HOC COMMITTEE ON CLASSIFICATION CRITERIA FOR JUVENILE SYSTEMIC SCLEROSIS

This criteria set has been approved by the American College of Rheumatology (ACR) Board of Directorsas Provisional. This signifies that the criteria set has been quantitatively validated using patient data,but it has not undergone validation based on an external data set. All ACR-approved criteria sets areexpected to undergo intermittent updates.

Objective. To develop criteria for the classification of systemic sclerosis (SSc) in children (juvenile SSc).Methods. The study consisted of 3 phases: 1) collection of data on the signs and symptoms of actual patients with juvenileSSc that are useful for defining involvement of a particular organ; 2) selection of the parameters essential for theclassification of juvenile SSc and preparation of a set of provisional classification criteria (PCC) using 2 Delphi surveys;3) consensus conference consisting of 2 steps: discussion and rating of clinical profiles of 160 patients with definitejuvenile SSc, possible juvenile SSc, or other fibrosing diseases as “having or not having juvenile SSc,” using nominalgroup technique, and defining those PCC with the best statistical performance and highest face validity by using theclinical profiles of patients with definite juvenile SSc as the gold standard.Results. In phase 1, 55 centers submitted clinical data on 153 patients with juvenile SSc. A total of 48 signs and symptomswere derived from these patient data and were used to define 9 organ system categories (cutaneous, vascular, gastroin-testinal, respiratory, renal, cardiac, neurologic, musculoskeletal, and serologic). During phase 2, these were reduced to21 criteria (3 major criteria [Raynaud’s phenomenon, proximal skin sclerosis/induration of the skin, and sclerodactyly]and 18 minor criteria) and combined to generate 86 different PCC. At the consensus conference, these 86 definitions weretested on the case profiles of 127 patients with juvenile SSc. The PCC with the highest ranking were proximal sclerosis/induration and at least 2 minor criteria.Conclusion. These provisional classification criteria for juvenile SSc will help standardize the conduct of clinicalresearch, epidemiologic and outcome studies, and therapeutic trials.

KEY WORDS. Scleroderma; Systemic sclerosis; Children; Classification criteria; Organ involvement.

INTRODUCTION

Juvenile scleroderma syndromes are a group of rare con-ditions including juvenile systemic sclerosis (SSc), mixed

connective tissue disease (MCTD), and overlap syndromesthat result in varying degrees of fibrosis of the skin andinternal organs, with onset in children and adolescentsyounger than age 16 years. At present, there are no univer-

Supported by Il Volo Association for Childhood Rheu-matic Diseases and the Veneto Region.

1Francesco Zulian, MD, Giorgia Martini, MD, PhD, FrancoCozzi, MD: University of Padua, Padua, Italy; 2Patricia Woo,FRCP, PhD: Great Ormond Street Hospital, London, UK;3Balu H. Athreya, MD: Alfred I. duPont Hospital for Children,Wilmington, Delaware; 4Ronald M. Laxer, MD, FRCP: Hospitalfor Sick Children, Toronto, Canada; 5Thomas A. Medsger, Jr.,

MD, University of Pittsburgh, Pittsburgh, Pennsylvania;6Thomas J. A. Lehman, MD: Hospital for Special Surgery,New York, New York; 7Marco Matucci Cerinic, MD: Univer-sity of Florence, Florence, Italy; 8Angelo Ravelli, MD, Nico-lino Ruperto, MD, MPH: IRCCS G. Gaslini, Genova, Italy;9Ricardo Russo, MD: Hospital de Pediatria Juan P. Garra-han, Buenos Aires, Argentina; 10Ruben Cuttica, MD: Hospi-tal General de Ninos Pedro de Elizalde, Buenos Aires, Ar-

Arthritis & Rheumatism (Arthritis Care & Research)Vol. 57, No. 2, March 15, 2007, pp 203–212DOI 10.1002/art.22551© 2007, American College of Rheumatology

ORIGINAL ARTICLE

203

sally accepted nomenclature and classification criteria forjuvenile SSc.

Classification criteria for SSc in adults were establishedin 1980 and include the presence of 1 major criterion,namely symmetrical thickening of the skin proximal tothe metacarpophalangeal (MCP) or metatarsophalangeal(MTP) joints, or 2 or more minor criteria, including sclero-dactyly, digital pitting scars or loss of substance from thefinger pad, and bibasilar pulmonary fibrosis (1). More re-cently, LeRoy and Medsger introduced the concept of earlyscleroderma, defined as the presence of Raynaud’s phe-nomenon (RP) plus either scleroderma-type nailfold cap-illary changes or SSc-selective serum autoantibodies (2).Although that concept is still being debated, the group ofpatients with early scleroderma is quite important in pro-spective population-based studies, particularly studies inchildren in whom one of the subtypes of juvenile SSc maydevelop during extended followup.

In children, the relative rarity SSc, its heterogeneity, andthe difficulty in separating juvenile SSc–like conditionsfrom non-juvenile SSc–like conditions such as fasciitisand phenylketonuria point to the need for developingacceptable criteria for the diagnosis and classification ofjuvenile SSc. The lack of such criteria may in fact lead toinclusion of nonhomogeneous groups of patients in clini-cal trials, with the associated risk of reporting bias, ambig-uous interpretation of results, and inability to comparetherapies. We undertook this study, sponsored by the Pe-diatric Rheumatology European Society, in order to de-velop uniform nomenclature and criteria for the classifi-cation of patients with juvenile SSc, based on their clinicaland laboratory features.

PATIENTS AND METHODS

General methodology. The study was conducted by us-ing the Delphi technique and nominal group technique(NGT), both of which are well-recognized consensus for-mation methodologies specifically designed to combinejudgments from a group of experts in a particular field(3,4). The Delphi technique (used in phases 1 and 2 of thestudy) utilizes a series of defined questionnaire-based sur-veys, while NGT (applied in phase 3) is a structured face-to-face meeting designed to facilitate reaching consensus.These techniques have been used to develop diagnosticcriteria or outcome measures for several diseases (5–10).

Consensus formation methodology was designed so thateach step was based on the results of the previous steps.The study was performed in 3 phases.

Phase 1. Data collection. Information on demographic,clinical, and laboratory features of patients with onset ofSSc before age 16 years was retrospectively collected frompatients seen at 270 pediatric rheumatology centers inEurope (n � 166), North America (n � 42), South America(n � 28), Asia (n � 30), Australia (n � 2), and Africa (n �2). These centers were identified from the mailing lists ofthe Pediatric Rheumatology European Society and the Pe-diatric Rheumatology International Trials Organization.

A standardized case report form was developed for col-lection of data. Demographic information (sex, age at thefirst signs or symptoms of the disease, and age at diagnosis)was collected. Participants were asked to use the followingguidelines to define organ involvement at the time of di-agnosis (Table 1). Skin involvement was determined bythe presence of skin induration proximal or distal to theMCP and MTP joints, edema, calcinosis, or sclerodactyly.Peripheral vascular system involvement was defined asthe presence of any 1 of the following: RP, digital ulcers,telangiectasias, abnormal nailfold capillaries, and capil-laroscopy findings (such as megacapillaries and avascularareas). Respiratory involvement was defined as the pres-ence of any 1 of the following: dyspnea, lung fibrosis (onchest radiograph or high-resolution computed tomographyscan), reduced diffusing capacity for carbon monoxide(DLco) and forced vital capacity, or pulmonary hyperten-sion (assessed by echocardiography). Cardiac disease in-cluded any 1 of the following: arrhythmias, pericardialeffusion, heart failure, palpitation, chest pain, dizziness,presyncope/syncope, edema, and venous congestion. Mus-culoskeletal involvement was defined by the presence ofmyositis, myopathy, arthritis, arthralgia, or tendon frictionrubs. Gastrointestinal tract symptoms consisted of dyspha-gia, gastroesophageal reflux, heartburn, intestinal disten-tion, vomiting, diarrhea, constipation, or weight loss. Re-nal disease was identified by the presence of a raisedcreatinine level or urea serum level, abnormal results ofurinalysis, renal crisis, or persistent arterial hypertension.Nervous system involvement was determined by the re-port of seizures, peripheral neuropathy, headache, carpaltunnel syndrome, or neuroimaging abnormalities.

Data were also collected for serum autoantibodies, spe-cifically antinuclear antibodies (ANA), anticentromere an-tibodies (ACA), anti–topoisomerase I (Scl-70) antibodies,antifibrillarin, anti–PM-Scl, anti–fibrillin, or anti–RNApolymerase I/III antibodies. The normal ranges of labora-tory standards for each participating center were used todetermine abnormal values. Since all clinical informationwas anonymously collected from the patient charts, insti-tutional review board approval was required from only afew centers, mainly in North America. Data were storedelectronically on a secure computer network, according tolocally applicable guidelines, in the participating centers.

Participants were asked to report data on patients with adiagnosis of SSc based on the American College of Rheu-matology (ACR; formerly, the American Rheumatism As-

gentina; 11Sheila Knupp Feitosa de Oliveira, MD: Institutode Puericultura e Pediatria Martagao Gesteira, Rio de Ja-neiro, Brazil; 12Christopher P. Denton, PhD, MRCP: RoyalFree and University College Medical School, London, UK;13Ivan Foeldvari, MD: Ak Eilbek, Hamburg, Germany.

The American College of Rheumatology is an indepen-dent, professional, medical, and scientific society, whichdoes not guarantee, warrant, or endorse any commercialproduct or service.

Address correspondence to Francesco Zulian, MD, Diparti-mento di Pediatria, Universita di Padua, Via Giustiniani 3,35128 Padua, Italy. E-mail: zulian@pediatria.unipd.it.

Submitted for publication May 17, 2006; accepted in revisedform October 19, 2006.

204 Zulian et al

sociation) preliminary criteria (1). Information on patientswith overlap syndrome and MCTD was also collected.Before the analysis was completed, the principal investi-gators at the participating centers were asked to verify theaccuracy of the classification of their patients.

Phase 2. Selection of classification criteria. Using thedata collected in phase 1, questionnaires were developedand mailed to 14 experienced adult and pediatric rheuma-tologists in 7 countries. Ten were pediatric rheumatolo-gists who had contributed a consistent number of patientsto phase 1 and/or had actively participated in the planningof the study, and 4 were adult rheumatologists selected onthe basis of their clinical and research expertise in juvenileSSc.

In the first Delphi survey, these experts were asked todefine in detail the signs and symptoms that, in theiropinion, were most useful in defining involvement of aspecific organ system, alone or in combination, and rankthem. Since the number of items was different for eachorgan, the mean score obtained for each organ was dividedby the number of variables considered for that organ, inorder to make the scores comparable. This weighted scorerepresented the overall judgment of the importance of asign or symptom in defining involvement of a particularorgan.

In the second survey, the experts were asked to selectthe signs and symptoms that were strongly suggestive ofthe diagnosis of juvenile SSc and were therefore essentialfor classification of juvenile SSc. The rate of choice, rep-resenting the percentage of experts judging a particularsign or symptom as essential, was multiplied by theweighted score to obtain the final score. Among the vari-ables with the highest final scores, those with a prevalence�50% at the time of diagnosis, based on our patient pop-ulation, were selected as provisional major criteria and theremaining variables were listed as minor criteria (Table 2).

In order to mimic as much as possible the diagnosticprocess used when assessing a patient with juvenile SSc, aset of 86 provisional classification criteria (PCC) defini-tions consisting of major and minor criteria was generatedby the steering committee. These PCC were selected on thebasis of a logic combination of major and minor criteria,taking into consideration either the various clinical pic-tures presented at diagnosis by the patients collected inphase 1 or the personal experience of the experts.

The PCC were grouped under 3 headings: generic defi-nitions, specific definitions, and historic definitions. Ge-neric definitions included the presence of 1, 2, or 3 majorcriteria, with a combination of 1 or more minor criteria(definitions 1–27). An example of a generic definition is asfollows: definition 11 — presence of 2 major criteria and atleast 1 minor criterion. Specific definitions included thepresence of 1 or 2 specific (e.g., proximal sclerosis/indu-ration) major criteria with a combination of minor criteria(definitions 28–81). An example of a specific definition isas follows: definition 53 — presence of RP and proximalsclerosis/induration and at least 1 minor criterion. A groupof 5 historic definitions were obtained from the literature(definitions 82–86) (1,2).

Phase 3. Consensus conference. After the completion ofphase 2, a consensus conference was held, with the fol-lowing objectives: 1) using nominal group technique, ratethe profiles of real patients as having or not having juve-nile SSc, 2) evaluate the set of PCC using the clinical

Table 1. Signs and symptoms of juvenile systemicsclerosis (SSc) that were identified in phase 1 and

evaluated in phase 2 of the study*

Organ system Sign or symptom

1. Cutaneous EdemaSclerosis/indurationSclerodactylyCalcinosis

2. Peripheral vascular Raynaud’s phenomenonDigital ulcersNailfold capillary changesNailfold capillaroscopy findingsTelangiectasias

3. Gastrointestinal DysphagiaHeartburnIntestinal distentionVomitingDiarrheaConstipationGastroesophageal refluxWeight loss

4. Cardiac Congestive heart failurePalpitationsChest painDizzinessPresyncope/syncopeEdemaVenous congestionArrhythmiasPericardial effusion

5. Renal Renal crisisNew-onset hypertensionAbnormal serum creatinine valueAbnormal serum urea valueAbnormal urinalysis results

6. Respiratory DyspneaLung fibrosis (HRCT/radiography)Reduced FVC �80%Reduced DLco �80%Pulmonary arterial hypertension

7. Neurologic Nerve involvementSeizuresNeuroimaging abnormalitiesHeadacheCarpal tunnel syndrome

8. Musculoskeletal ArthritisArthralgiasTendon friction rubsMyositisMyopathy

9. Serologic Antinuclear antibodiesSSc-selective autoantibodies†

* HRCT � high-resolution computed tomography; FVC � forcedvital capacity; DLco � diffusing capacity for carbon monoxide.† Selective autoantibodies are anticentromere, anti–topoisomeraseI, antifibrillarin, anti–PM-Scl, antifibrillin, or anti–RNA polymeraseI or III.

Classification Criteria for Juvenile Systemic Sclerosis 205

profiles of patients considered to be the gold standardbased on the consensus of experts, and 3) define the PCCthat had the best statistical performance and highest facevalidity.

Rate patient profiles. The profiles of the patients testedat the consensus conference were based on real data col-lected from patients in phase 1, with emphasis placed ondata from patients in whom the diagnosis was more diffi-cult due to incomplete clinical manifestations. Profiles ofpatients with confounding diseases such as juveniledermatomyositis, juvenile systemic lupus erythemato-sus (SLE), overlap syndrome, MCTD, localized sclero-derma, and other fibrosing conditions were also in-cluded (Table 3). Experts were asked to individually rateeach patient as having or not having juvenile SSc, basedon the profiles provided. If �80% consensus for a par-ticular patient was not achieved, the patient was dis-cussed by the entire group and a second vote was taken.If �80% consensus was still not attained, the patientprofile was declared indefinable. Patient profiles forwhich �80% physician consensus was achieved wereused as the gold standard for the next phase (evaluationof the PCC).

Evaluating the PCC. Classification of individual pa-tients as having or not having juvenile SSc using the 86candidate criteria sets was compared with classification byphysician consensus (gold standard). For each possible setof criteria, chi-square tests with 1 degree of freedom wereperformed and the corresponding P values were deter-mined, and sensitivity (ability of the criteria to identify apatient who had been classified by the physicians as hav-ing juvenile SSc as having juvenile SSc), specificity (abil-

ity of the criteria to identify a patient who was not classi-fied as having juvenile SSc by the physicians as not havingjuvenile SSc), percent false positive (number of patientsfalsely identified as having juvenile SSc by the criteriadivided by the total number of patients identified as juve-nile SSc � 100), and percent false negative (number ofpatients falsely identified as not having juvenile SSc by thecriteria divided by the total number of patients identifiedas not having juvenile SSc � 100), and the area under thecurve (AUC) value were calculated. As a measure of agree-ment between the physicians’ evaluation and the potentialcriteria, we used the Cohen kappa value (11) with cutoffsas proposed by Landis and Kock (12) (i.e., 0.01–0.2 �slight, 0.2–0.4 � fair, 0.4–0.6 � moderate, 0.6–0.8 �substantial, 0.8–1 � almost perfect agreement). Kappa val-ues �0.7 were considered evidence of substantial agree-ment, and the PCC with those values were selected forfurther consideration.

PCC definitions with highest face validity. The statisti-cal evaluations described above (including the evaluationswith low statistical performance) were presented and fullyexplained to the consensus participants. The consensusconference attendees were asked to decide which of thejuvenile SSc PCC definitions that performed best from astatistical point of view in the earlier step were mostcredible and easiest to use (face validity) in current clini-cal practice. Attendees were asked to rank the 5 best def-initions from 1 (lowest) to 5 (highest). In order to combinethe consensus evaluation with the statistical performance,the face validity rankings were multiplied by Cohen’skappa values to obtain the final PCC ranking.

Table 2. Major and minor criteria for the classification of juvenile systemic sclerosis (SSc)*

Signs and symptomsWeighted

scoreRate ofchoice

Finalranking

Prevalence atdiagnosis

Criteriaclassification

Raynaud’s phenomenon 98.6 1 98.6 0.76 MajorSkin sclerosis/induration 91.1 0.93 84.7 0.66 MajorSclerodactyly 75 1 75 0.55 MajorPulmonary fibrosis (radiography, HRCT) 90 0.93 83.7 0.20 MinorRenal crisis 75.7 0.93 70.4 0.01 MinorSSc-selective autoantibodies 78.6 0.86 67.6 0.33 MinorGastroesophageal reflux 85.7 0.79 67.7 0.13 MinorPulmonary hypertension 64.3 0.86 55.3 0.05 MinorTendon friction rubs 70 0.21 14.7 0.06 MinorNailfold capillary abnormalities 64.3 0.71 45.7 0.48 MinorAntinuclear antibodies 71.4 0.57 40.7 0.77 MinorDysphagia 80.3 0.5 40.2 0.13 MinorArrhythmias 67.4 0.57 38.4 0.02 MinorCarpal tunnel syndrome 74.3 0.5 37.2 0.01 MinorReduced DLco 62.8 0.21 13.2 0.17 MinorArthritis 70 0.43 30.1 0.18 MinorHeart failure 61.1 0.43 26.3 0.03 MinorDigital tip ulcers 62.8 0.36 22.6 0.35 MinorNew-onset hypertension 62.8 0.36 22.6 0.01 MinorMyositis 65.7 0.21 13.8 0.15 MinorPeripheral neuropathy 68.6 0.21 14.4 0.01 Minor

* Weighted score � sum of the scores attributed to a sign or symptom/ maximal hypothetical score obtainable for that particular parameter � 100. Rateof choice � percentage of experts considering a particular sign or symptom essential for the diagnosis. Final rank � weighted score � rate of choice.HRCT � high-resolution computed tomography; DLCO � diffusing capacity for carbon monoxide.

206 Zulian et al

RESULTS

Clinical features of juvenile SSc at the time of diagnosis.During the period from January 2002 to June 2003, 55centers (32 European, 8 North American, 11 South Amer-ican, and 4 Asian) contributed data on 153 patients withjuvenile SSc. There were 120 female patients (78.4%) and33 male patients (21.6%), with a female to male ratio of3.6:1.

At the time of diagnosis of juvenile SSc, RP was the mostfrequently reported clinical manifestation (76%), followedby skin induration (66%), sclerodactyly (55%), digital tipulcers (35%), lung fibrosis (20%), arthritis (18%), myositis(15%), dysphagia (13%), gastroesophageal reflux (13%),tendon friction rubs (6%), pulmonary hypertension (5%),heart failure (3%), arrhythmias (2%), renal crisis (1%),carpal tunnel syndrome (1%), new-onset hypertension(1%), and peripheral neuropathy (1%). Nailfold capillarychanges were reported in 48% of the patients, and reducedDLCO was reported in 17%.

Among the characteristic autoantibodies, ANA werepositive in 77% of the patients, SSc-selective autoantibod-ies were positive in 33% of the patients (anti–Scl-70 24%,ACA 5%, anti–PM-Scl 3%, others 1%). In comparison

with the adult form, juvenile SSc appeared less severe, hadless internal organ involvement (particularly at the time ofdiagnosis), and had a less characteristic immunologic pro-file. A more comprehensive description of the clinical andimmunologic features of the juvenile SSc cohort in thisstudy, along with a comparison of clinical features of adultSSc patients, has been reported in a separate article (13).

Classification criteria selection. In the first Delphi sur-vey, the investigators defined 48 signs and symptoms,grouped into 9 organ systems (cutaneous, peripheral vas-cular, gastrointestinal, cardiac, renal, respiratory, neuro-logic, musculoskeletal, and serologic) (Table 1). Thesevariables were weighted on the basis of their importance indefining involvement of a particular organ. Specifically,the investigators were asked to rank the parameters byassigning a score of 1 to the variable that is least importantin defining involvement of a particular organ and assign-ing the highest score to the most important variable. Vari-ables that were not considered important were assigned ascore of 0.

Because the number of items for each organ system wasdifferent, in order to make the scores comparable, the scoreobtained by the 14 investigators was divided by the max-

Table 3. Clinical characteristics of 160 patient profiles tested at the consensus conference*

Disease Clinical subtypeNo. of

patients Clinical features (no. of patients)

Systemic sclerosis 100 Skin induration (76), RP (75), sclerodactyly (52),digital tip ulcers (30), pulmonary involvement(17), arthritis (16), myositis (12), dysphagia(13), GER (15), nailfold capillary changes (44),tendon friction rubs (5), cardiac involvement(3), renal involvement (1), carpal tunnelsyndrome (1), peripheral neuropathy (1), ANA(80), anti–Scl-70 (20), ACA (5), anti–PM-Scl(3)

Overlap syndrome SLE/juvenile DM 5 Myositis (5), pulmonary involvement (2),calcinosis (1), RP (3), ANA (5)

SLE/JIA 2 Arthritis (2), RP (2), ANA (2), RF (1)Juvenile SSc/JIA 3 Arthritis (3), RP (2), ANA (3), sclerodactyly (1)Juvenile SSc/juvenile DM 10 Myositis (10), pulmonary involvement (5),

sclerodactyly (2), calcinosis (1), RP (8), ANA(8)

Mixed connective tissue disease 15 Arthritis (3), sclerodactyly (3), renalinvolvement (5), RP (10), pulmonaryinvolvement (3), ANA (15), RNP (15)

Localized scleroderma Linear scleroderma 5 RP (2), GER (3), ANA (5), anti–PM-Scl (1)Pansclerotic morphea 1 Skin sclerosis/induration, ANADeep morphea 1 Arthritis, RP, ANAEosinophilic fasciitis 3 Skin sclerosis/induration (3), ANA (2)

SLE 5 RP (3), renal involvement (3), pulmonaryinvolvement (1), arthritis (1), ANA (5)

Dermatomyositis 5 Myositis (5), pulmonary involvement (2), ANA(1)

Miscellaneous Progeria 1 Skin sclerosis/induration, arthritisPrimary pulmonary hypertension 1 Pulmonary involvement, ANAErythropoietic protoporphyria 1 Sclerodactyly, arthritisConnective tissue nevus 2 Skin sclerosis/induration (2), GER (1), ANA (1)

* RP � Raynaud’s phenomenon; GER � gastroesophageal reflux; ANA � antinuclear antibodies; ACA � anticentromere antibodies; SLE � systemiclupus erythematosus; DM � dermatomyositis; JIA � juvenile idiopathic arthritis; RF � rheumatoid factor; SSc � systemic sclerosis.

Classification Criteria for Juvenile Systemic Sclerosis 207

imal hypothetical score obtainable for involvement of aparticular organ. This ratio was then multiplied by 100 toobtain a weighted score that represented the overall judg-ment of the importance of a sign or symptom in defininginvolvement of a particular organ (Table 2). For example, 5signs/symptoms were associated with peripheral vascularinvolvement; therefore, the maximal hypothetical scoreobtainable would be 70 (5 [maximal score] � 14 [numberof experts]). The total score for RP was 69, representing aweighted score of 98.6.

The percentage of experts who considered a particularparameter as essential for classification of juvenile SScrepresented the rate of choice. The combination of theweighted score with the rate of choice for each parameterresulted in the final ranking. Recalling the above example,the entire panel of experts considered RP to be essential forthe diagnosis of juvenile SSc, and thus the rate of choicefor RP was 1 and the final ranking for RP was 98.6. Twenty-one of the initial 48 signs and symptoms were chosen asessential for the diagnosis of juvenile SSc by at least 20%of the investigators. Detailed definitions of the signs andsymptoms are presented in Appendix A.

As shown in Table 2, the parameters with the highestfinal rankings were RP, proximal skin sclerosis/indura-tion, pulmonary fibrosis, sclerodactyly, and renal crisis.Only 3 of these signs/symptoms, RP, proximal skin scle-rosis/induration, and sclerodactyly, were present in �50%of the patients at the time of diagnosis and were thereforeconsidered to be potential major criteria. The remaining 18parameters, grouped in 8 categories, were considered to bepotential minor criteria (Table 2).

Consensus conference phase. The consensus confer-ence, held in Padua, Italy on June 3–6, 2004, was attendedby the same 14 clinicians who participated in phase 2.Two authors (NR, FZ) with expertise in nominal groupprocess and statistical analysis served as facilitators.

At the consensus conference, the clinical profiles of 160actual patients with a variety of diagnoses were evaluated.One hundred profiles were from patients with juvenile SScselected from the series of 153 patient profiles collected inphase 1 of the study. The additional 60 patients werecontrols and included those with conditions overlappingjuvenile SSc. The clinical characteristics of the patientsevaluated at the consensus conference are summarized inTable 3. Consensus of �80% was achieved for 127 of 160(79%) patients, with 70 of 127 patients (55%) judged ashaving juvenile SSc, and 57 of 127 patients (45%) judgedas not having juvenile SSc. No consensus was reached in33 of 160 patients (21%).

All 70 patients for whom there was consensus on thediagnosis of juvenile SSc belonged to the original group of100 patients collected in phase 1 of the study. Among theother 30 original patients with juvenile SSc, 12 werejudged by the investigators as not having juvenile SSc, andthe diagnoses in 18 patients were undefined. This is un-derstandable, because patients with classic juvenile SScwere defined in phase 1, according to the 1980 ACR crite-ria (1). These criteria do not necessarily include the pres-ence of proximal skin sclerosis/induration but can be met

just by the presence of 2 or more minor criteria, such assclerodactyly, digital pitting scars, and bibasilar pulmo-nary fibrosis. In fact, among the 12 children judged as nothaving juvenile SSc, 5 had sclerodactyly, RP, and arthritis,5 had digital pitting scars with sclerodactyly, and 2 hadpulmonary fibrosis and were ANA-positive. None of the 60controls were classified as having juvenile SSc (45 wereclassified as not having the disease, and 15 were unde-fined).

The 127 patients for whom the investigators reachedagreement were then used as the gold standard to test theset of PCC. Ten of the 86 PCC for juvenile SSc showed aCohen’s kappa value �0.7; their corresponding chi-squarevalues, P values, sensitivity, specificity, percent false-pos-itive and false-negative rates, AUC value, and kappa sta-tistics are shown in Table 4. Statistical evaluations for alldefinitions considered were fully presented to the consen-sus participants to guide their final face validity choice.The participants were then asked to choose and rank thosedefinitions that, in their opinion, were the more useful inclinical practice, reasonable, and easy to use.

Finally, the ranking of the 5 best definitions on facevalidity was multiplied by Cohen’s kappa value to obtainthe final ranking. As shown in Table 4, the PCC definitionwith the highest score was the presence of proximal skinsclerosis/induration and at least 2 minor criteria. On thebasis of this result, both RP and sclerodactyly should beconsidered minor criteria. The definitions that scored sec-ond highest (RP and skin sclerosis/induration and at least1 minor criterion) and third highest (RP and skin sclerosis/induration and at least 2 minor criteria) were very similarto the first choice because they all include skin sclerosis/proximal induration and at least 1 minor criteria, indicat-ing the convergent validity of the process. The final pro-visional criteria for the classification of juvenile SSc thatresulted from this multiphase study are summarized inTable 5.

DISCUSSION

The purpose of our study was to develop uniform nomen-clature and criteria for classification of patients with juve-nile SSc on the basis of their clinical and laboratory fea-tures. The study was conducted by using the Delphitechnique and the NGT, both of which are well-recognizedconsensus formation methodologies specifically designedto combine judgments from a group of experts.

The rigorous procedure followed in this study is consis-tent with the guidelines recently proposed by the ACRSubcommittee on Classification and Response Criteria (14)and was applied for the first time for the standardization ofcriteria to evaluate the response to therapy in juvenile SLE(15). With a standardized scientific approach, conductedwith the support of evidence-based collection of data froma large multicenter international database, we were able topropose classification criteria for juvenile SSc to be usedboth in current clinical practice and in research settings toclassify patients more homogeneously worldwide. Thesecriteria were essentially defined by the presence of proxi-mal sclerosis/induration of the skin and at least 2 minor

208 Zulian et al

criteria chosen from a list of 20 that are grouped in 9categories of organ system involvement (Table 5).

Until now, pediatricians, rheumatologists, and derma-tologists have used adult criteria for SSc, particularly theACR preliminary classification criteria proposed in 1980(1), along with the more recent suggestion to add criteriafor classification of early or pre-SSc (i.e., before skinchanges are evident) (2) systemic sclerosis. The ACR pre-liminary set of criteria included the presence of a majorcriterion defined as the symmetric thickening of skin prox-imal to the MCP and MTP joints or 2 or more minor criteriaincluding sclerodactyly, digital pitting scars or loss of sub-stance from the finger pad, and bibasilar pulmonary fibro-sis (1). Recent improvement in our ability to evaluatepatients with RP using widefield nailfold microscopyand more precise autoimmune serologic studies has per-mitted identification of many patients with features ofSSc who did not satisfy the ACR preliminary criteria butwho, during long-term followup, developed definite SSc(2,16). Both of these definitions were tested in our study,but their performance in distinguishing children withjuvenile SSc from those without juvenile SSc was notsatisfactory.

The classification criteria proposed in this study aremore restrictive than those for adults. In fact, the majorcriterion of proximal cutaneous sclerosis, which in adultsis enough to define a patient as having SSc, must be ac-companied by 2 other minor criteria. This is of particularimportance to exclude some pediatric conditions such aseosinophilic fasciitis, progeria, phenylketonuria, or pan-sclerotic morphea, in which the presence of diffuselythickened skin is the cardinal clinical feature. These con-ditions may have been incorrectly classified as juvenile

SSc according to the 1980 ACR preliminary criteria. Con-versely, the minor criteria in our classification system aremore numerous and grouped into different categories oforgan system involvement. This wider range of signs andsymptoms represents a more comprehensive set of clinicaland laboratory manifestations of the disease, defines andupdates the methods to detect specific organ abnormalities(Appendix A), and introduces serologic results as an im-portant aspect for disease classification.

It has been commonly observed and recently docu-mented (17) that children with RP and capillary changes orautoantibodies do not necessarily develop juvenile SSc, atleast in the short-term followup. Therefore, the proposedcriteria for pre-SSc may have some limitations that havenot yet been adequately confirmed.

Of interest is the limited cutaneous form of SSc (lcSSc),a subtype that is diagnosed more frequently in adults. Ourprovisional classification criteria include this subtype butdo not distinguish it from diffuse cutaneous SSc. Thisdistinction is probably of limited use in children, becauselcSSc is reported infrequently before age 16 years (13,18–20). However, it has now been shown that a substantialnumber of patients with childhood-onset SSc have theirdiagnosis confirmed either during adolescence or as youngadults (20,21).

Use of clinical data from real patients in combinationwith a consensus-based methodology represents an inno-vative procedure to define classification criteria for juve-nile SSc. As mentioned above, these techniques have beenused to develop diagnostic criteria or outcome measuresfor several diseases (5–10). These new classification crite-ria, which should be validated in prospective studies, will

Table 4. Top 10 sets of classification criteria for juvenile SSc and statistical performance of the criteria as tested on 127patient profiles*

Criteria

�2 Sensitivity SpecificityFalse

negative, %False

positive, % AUC KInitialrank

FinalrankNo. Definition

37 Proximal skin sclerosis/induration and atleast 2 minor criteria

94.1 90 96 11 3 93 0.86 40 34

53 RP and proximal skin sclerosis/indurationand at least 1 minor criterion

86.9 83 100 17 0 91 0.81 37 30

54 RP and proximal skin sclerosis/indurationand at least 2 minor criteria

79 79 100 21 0 89 0.77 31 24

36 Proximal skin sclerosis/induration and atleast 1 minor criterion

96.7 94 93 7 6 94 0.87 15 13

11 Two major criteria and at least 1 minorcriterion

86.4 94 88 7 10 91 0.82 20 16

12 Two major criteria and at least 2 minorcriteria

76.7 90 88 12 10 89 0.78 15 12

38 Proximal skin sclerosis/induration and atleast 3 minor criteria

75.2 79 98 21 2 88 0.75 7 5

52 RP and proximal skin sclerosis/induration 86.9 83 100 17 0 91 0.81 5 480 Proximal skin sclerosis/induration 93.2 94 91 7 7 93 0.86 2 213 Two major criteria and at least 3 minor

criteria63.9 80 91 21 8 86 0.70 1 1

* SSc � systemic sclerosis; AUC � area under the curve; K � kappa statistic; RP � Raynaud’s phenomenon; initial rank � total score obtained bysumming the scores of the 14 experts for each of the top 10 provisional classification criteria definitions (0 � poor, 5 � good, range 0–70); final rank �initial rank � kappa statistic.

Classification Criteria for Juvenile Systemic Sclerosis 209

help standardize future research in epidemiology, clinicalfeatures, therapy, and outcomes in juvenile SSc.

ACKNOWLEDGMENTSWe would like to thank Francesca Loro, statistician (Uni-versity of Padua, Italy) and Marcia Bandeira, MD (Curitiba,Brazil) for the statistical and technical assistance duringthe consensus conference. We also thank the followinginvestigators for having contributed at various levels to thestudy: Cristina Vallongo, MD, Maria Teresa Visentin, MD(University of Padua, Padua, Italy), Estevan Castell, MD(Hospital General de Ninos Pedro de Elizalde, BuenosAires, Argentina), Anne Eberhard, MD, FRACP (SchneiderChildren’s Hospital, Manhasset, New York), Gordana Su-sic, MD (Institute of Rheumatology, Belgrade, Serbia),Galina Lyskina, MD (Hospital of Childhood Diseases, Mos-cow, Russia), Dana Nemcova, MD (First Faculty of Medi-cine and General Faculty Hospital, Praha, Czech Repub-lic), Robert Sundel, MD (Children’s Hospital MedicalCenter, Boston, MA), Fernanda Falcini, MD (Ospedale A.Meyer, Firenze, Italy), Herman Girschick, MD (Kinder-klinik der Universitat, Wuerzburg, Germany), Ana Paula

Lotito, MD (Children’s Institute of the University of SaoPaulo, Sao Paulo, Brazil), Flavio Sztajnbok, MD (HospitalUniversitario Pedro Ernesto, Rio de Janeiro, Brazil), S.Al-Mayouf, MD (King Faisal Specialist Hospital and Re-search Center, Riyadh, Saudi Arabia), Ilonka Orban, MD(National Institute of Rheumatology and Physiotherapy,Budapest, Hungary), Clodoveo Ferri, MD (University ofModena, Modena, Italy).

We also acknowledge the University of Padua, for sup-porting this study.

AUTHOR CONTRIBUTIONS

Dr. Zulian had full access to all of the data in the study andtakes responsibility for the integrity of the data and the accuracyof the data analysis.Study design. Zulian, Woo, Medsger, Lehman, Matucci Cerinic,Martini, Foeldvari, Ruperto.Acquisition of data. Zulian, Woo, Athreya, Laxer, Medsger, Leh-man, Martini, Ravelli, Russo, Cuttica, de Oliveira, Denton, Cozzi,Foeldvari.Analysis and interpretation of data. Zulian, Medsger, Lehman,Matucci Cerinic, Ruperto.Manuscript preparation. Zulian, Woo, Athreya, Laxer, Medsger,Lehman, Martini, Ravelli, Russo, Cuttica, de Oliveira, Denton,Cozzi, Foeldvari, Ruperto, Matucci Cerinic.Statistical analysis. Ruperto.Consensus conference participation. Zulian, Woo, Athreya,Laxer, Medsger, Lehman, Martini, Ravelli, Russo, Cuttica, de Ol-iveira, Denton, Cozzi, Foeldvari, Ruperto, Matucci Cerinic.

REFERENCES

1. The Subcommittee for Scleroderma Criteria of the AmericanRheumatism Association Diagnostic and Therapeutic CriteriaCommittee. Preliminary criteria for the classification of sys-temic sclerosis (scleroderma). Arthritis Rheum 1980;23:581–90.

2. LeRoy EC, Medsger TA Jr. Criteria for classification of earlysystemic sclerosis [review]. J Rheumatol 2001;28:1573–6.

3. Delbecq AL, van de Ven AH, Gustafson DH. Group techniquesfor program planning: a guide to nominal group and Delphiprocesses. 1st edition. Glenview (IL): Scott, Foresman andCompany; 1975.

4. Sniderman AD. Clinical trials, consensus conferences, andclinical practice. Lancet 1999;354:327–30.

5. Barosi G, Ambrosetti A, Finelli C, Grossi A, Leoni P, LiberatoNL, et al. The Italian Consensus Conference on DiagnosticCriteria for Myelofibrosis with Myeloid Metaplasia [review].Br J Haematol 1999;104:730–7.

6. Giannini EH, Ruperto N, Ravelli A, Lovell DJ, Felson DT,Martini A. Preliminary definition of improvement in juvenilearthritis. Arthritis Rheum 1997;40:1202–9.

7. Felson DT, Anderson JJ, Boers M, Bombardier C, Furst D,Goldsmith C, et al. American College of Rheumatology pre-liminary definition of improvement in rheumatoid arthritis.Arthritis Rheum 1995;38:727–35.

8. Hertzman PA, Clauw DJ, Duffy J, Medsger TA Jr, Feinstein AR.Rigorous new approach to constructing a gold standard forvalidating new diagnostic criteria, as exemplified by the eosi-nophilia-myalgia syndrome. Arch Int Med 2001;161:2301–6.

9. Smolen JS, Strand V, Cardiel M, Edworthy S, Furst D, Glad-man D, et al. Randomized clinical trials and longitudinalobservational studies in systemic lupus erythematosus: con-sensus on a preliminary core set of outcome domains. J Rheu-matol 1999;26:504–7.

10. Miller FW, Rider LG, Chung YL, Cooper R, Danko K, FarewellV, et al. Proposed preliminary core set measures for diseaseoutcome assessment in adult and juvenile idiopathic inflam-

Table 5. Provisional criteria for the classification ofjuvenile systemic sclerosis (SSc)*

Major criterion (required)Proximal skin sclerosis/induration of the skin

Minor criteria (at least 2 required)Cutaneous

SclerodactylyPeripheral vascular

Raynaud’s phenomenonNailfold capillary abnormalitiesDigital tip ulcers

GastrointestinalDysphagiaGastroesophageal reflux

CardiacArrhythmiasHeart failure

RenalRenal crisisNew-onset arterial hypertension

RespiratoryPulmonary fibrosis (HRCT/radiography)Decreased DLCO

Pulmonary arterial hypertensionNeurologic

NeuropathyCarpal tunnel syndrome

MusculoskeletalTendon friction rubsArthritisMyositis

SerologicAntinuclear antibodiesSSc-selective autoantibodies (anticentromere, anti–

topoisomerase I [Scl-70], antifibrillarin, anti–PM-Scl, antifibrillin or anti–RNA polymerase I or III)

* HRCT � high-resolution computed tomography; DLCO � diffusingcapacity for carbon monoxide.

210 Zulian et al

matory myopathies [review]. Rheumatology (Oxford) 2001;40:1262–73.

11. Cohen J. A coefficient of agreement for nominal scales. EducPsychol Meas 1960;20:37–46.

12. Landis JR, Kock GG. The measurement of observer agreementfor categorical data. Biometrics 1977;33:159–74.

13. Martini G, Foeldvari I, Russo R, Cuttica R, Eberhard A, RavelliA, et al. Systemic sclerosis in childhood: clinical and immu-nological features of 153 patients in an international database.Arthritis Rheum 2006;54:3971–8.

14. Classification and Response Criteria Subcommittee of theAmerican College of Rheumatology Committee on QualityMeasures. Development of classification and response criteriafor rheumatic diseases. Arthritis Rheum 2006;55:348–52.

15. Ruperto N, Ravelli A, Oliveira S, Alessio M, Mihaylova D,Pasic S, et al. The Pediatric Rheumatology International TrialsOrganization/American College of Rheumatology Provisionalcriteria for the evaluation of response to therapy in juvenilesystemic lupus erythematosus: prospective validation of thedefinition of improvement. Arthritis Rheum 2006;55:355–63.

16. Lonzetti LS, Joyal F, Raynauld JP, Roussin A, Goulet JR, RichE, et al. Updating the American College of Rheumatology

preliminary classification criteria for systemic sclerosis: ad-dition of severe nailfold capillaroscopy abnormalities mark-edly increases the sensitivity for limited scleroderma [letter].Arthritis Rheum 2001;44:735–6.

17. Nigrovic PA, Fuhlbrigge RC, Sundel RP. Raynaud’s phenom-enon in children: a retrospective review of 123 patients. Pe-diatrics 2003;111:715–21.

18. Burge SM, Ryan TJ, Dawber RP. Juvenile onset systemic scle-rosis. J R Soc Med 1984;77:793-4.

19. Larregue M, Canuel C, Bazex J, Bressieux JM, Ramdene P,Laidet B. Systemic scleroderma in children: apropos of 5cases. A review of the literature. Ann Dermatol Venereol1983;110:317–26. In French.

20. Suarez-Almazor ME, Catoggio LJ, Maldonado-Cocco JA, Cut-tica R, Garcia-Morteo O. Juvenile progressive systemicsclerosis: clinical and serologic findings. Arthritis Rheum1985;28:699–702.

21. Scalapino K, Arkachaisri T, Lucas M, Fertig N, Helfrich DJ,Londino AV Jr, et al. Childhood onset systemic sclerosis: clas-sification, clinical and serologic features, and survival incomparison with adult onset disease. J Rheumatol 2006;33:1004–13.

APPENDIX A: DESCRIPTION OF THE PRIMARY CLINICAL MANIFESTATIONS OF JUVENILESYSTEMIC SCLEROSIS (SSc)

1. Cutaneous1a. Proximal sclerosis/induration. Thickening of the skin of the fingers and skin proximal to the metacarpophalangeal

and metatarsophalangeal joints.1b. Sclerodactyly. Thickening of the skin limited to the fingers or the toes.

2. Peripheral Vascular2a. Raynaud’s phenomenon. Repeated episodes of sudden, reversible changes in the color of bilateral acral structures

(e.g., fingers, hands, toes, ears, tip of the nose, or tongue) occurring spontaneously or in response to cold or physical oremotional stress. It is characterized by an early dead-white pallor that may subsequently be followed by cyanosis (reflectingstasis in the small vessels) and erythema (reflecting reactive hyperemia) and can be associated with numbness and pain.The proximal border of the color changes is often sharply demarcated. Episodes typically last from a few minutes (�5) upto 30 minutes before the skin color becomes normal.

2b. Digital tip ulcers. Ischemic lesions resulting in loss of epidermis with exposure of the superficial dermis. They canvary from focal infarcts to extensive gangrene and are replaced by scars when healed. They should be distinguished fromnondigital tip ulcers, e.g., over the proximal interphalangeal joints, metacarpophalangeal joints, or elbows, which aremultifactorial, including ischemia, stasis, trauma, and pressure.

2c. Nailfold capillary abnormalities. The periungual nailfold is often the most obvious early site of detectable abnormalvessels. On examination with a �40 lens of an ophthalmoscope or capillary microscope, these capillaries demonstratedropout and dilation/tortuosity.

3. Gastrointestinal3a. Dysphagia. Difficulty in swallowing. Pharyngeal (proximal) dysphagia primarily affects swallowing of liquids and

results in incoordination on initiation of swallowing and nasal regurgitation of liquids. Lower esophageal (distal) dysphagiaprimarily affects swallowing of solid foods, e.g., bread or meat, and results in retrosternal discomfort during the act ofswallowing.

3b. Gastroesophageal reflux. Results in the symptom of heartburn and is demonstrated by 24-hour esophageal pHmonitoring or cine esophagography. When available, esophageal manometry is the gold standard.

4. Cardiac4a. Arrhythmias. Abnormalities on baseline standard electrocardiogram or Holter monitoring consisting of conduction

disturbances.4b. Congestive heart failure. A clinical judgment by the physician based on the presence of dyspnea, orthopnea,

increased venous pressure, tender hepatomegaly, ascites and/or pitting edema, left-sided cardiac enlargement, left-sided S3gallop sound, and reduced left ventricular ejection fraction (�50%) on echocardiogram.

5. Renal5a. Renal crisisA. Hypertensive renal crisis (fulfills both A1 and A2)

Classification Criteria for Juvenile Systemic Sclerosis 211

A1. New-onset hypertension defined as any of the following: a) systolic or diastolic blood pressure �97th percentilefor age, b) increase in systolic or diastolic blood pressure �20 mm Hg.

A2. One of the following 5 features: 1) increase in serum creatinine by 50% over baseline or serum creatinine �120%of the upper limit of normal for age; 2) proteinuria �2� by dipstick; 3) hematuria �2� by dipstick or �10 redblood cells/hpf; 4) thrombocytopenia �100,000 platelets/mm3; and 5) hemolysis defined as anemia not due toother causes and accompanied by either schistocytes or other RBC fragments seen on peripheral blood smear orincreased reticulocyte count.

B. Normotensive renal crisis (fulfills both B1 and B2)B1. Increase in serum creatinine �50% over baseline or serum creatinine �120% of the upper limit of normal for age.B2. One of the following 5 features: 1) proteinuria �2� by dipstick; 2) hematuria �2� by dipstick or �10 red blood

cells/hpf; 3) thrombocytopenia �100,000 platelets/mm3; 4) hemolysis defined as anemia not due to other causesand either schistocytes or other RBC fragments seen on peripheral blood smear or increased reticulocyte count;and 5) renal biopsy consistent with renal crisis (microangiopathy).

5b. New-onset systemic arterial hypertension. Systolic blood pressure and/or diastolic blood pressure �97th percentileoccurring after the onset of juvenile SSc.

6. Respiratory6a. Pulmonary fibrosis. Bibasilar fibrosis demonstrated on plain chest radiograph or high-resolution computed tomog-

raphy scan.6b. Reduced diffusing capacity for carbon monoxide (DLco). DLco �80% of predicted normal for age on routine

pulmonary function testing.6c. Pulmonary arterial hypertension. Pulmonary artery systolic or right ventricular systolic pressure �40 mm Hg

estimated by Doppler echocardiogram, or mean pulmonary artery pressure �25 mm Hg on right heart catheterization.

7. Neurologic7a. Nerve involvement. Cranial or peripheral neuropathies documented by nerve conduction studies.7b. Carpal tunnel syndrome. Median nerve entrapment at the wrist causing paresthesias in 1 or both hands, confirmed

by a 2-point discrimination test, positive Tinel or Phelan sign, or nerve conduction studies.

8. Musculoskeletal8a. Arthritis. Swelling and tenderness of 1 or more peripheral joints with or without increased warmth, pain, or

limitation of motion.8b. Tendon friction rubs. Leathery crepitus detected by the examining physician over sites of active or passive motion

of hands/fingers (dorsal or palmar), wrists, elbows, olecranon bursae, shoulders, knees, or ankles (anterior or posterior) anddue to fibrinous or fibrous tenosynovitis or bursitis.

8c. Myositis. Muscle inflammation characterized by proximal muscle weakness and 1 or more of the following: serummuscle enzyme elevation, electromyogram showing myopathic changes, or muscle biopsy showing myofibril degenerationand/or cellular infiltration.

9. Serologic9a. Antinuclear antibodies (ANA). Serum ANA detected in a titer of �1:80 when tested on HEp-2 cell line substrate.9b. SSc-selective autoantibodies. Any of a group of serum autoantibodies found frequently (but not exclusively) in

juvenile SSc patients. They include anticentromere, anti–topoisomerase I (Scl-70), antifibrillarin, anti–PM-Scl, antifibrillin,or anti–RNA polymerase I/III antibodies. The method of measurement and normal range should be in accord with locallaboratory standards.

212 Zulian et al