Autoantibodies to chromatin: prevalence and clinical significance in juvenile rheumatoid arthritis

OBJECTIVE: To determine the prevalence of anti-chromatin antibodies (Abs) in juvenile rheumatoid arthritis (JRA) and to assess any association between the presence of anti-chromatin Abs and clinical subsets of the disease. METHODS: IgG anti-chromatin Abs and anti-extractable nuclear antigens (ENA) Abs were detected by an enzyme-linked immunosorbent assay (ELISA), and antinuclear Abs (ANA) by indirect immunofluorescence in sera of 89 children with JRA. Ten children with systemic, 32 with polyarticular and 47 with pauciarticular disease onset (uveitis occurred in 17/47 children) were studied. As a control group, 12 sera of patients suffering from idiopathic uveitis and 31 age- and-sex-matched healthy children (HC) were examined. RESULTS: Abs to chromatin were detected in 14/47 (29.8%) of children suffering from pauciarticular onset JRA and in this group the higher prevalence of anti-chromatin Abs has been found in children with chronic uveitis (p = 0.002). Anti-chromatin positivity was observed in 2/10 (20%) of systemic and in 3/32 (9.3%) of polyarticular onset JRA. Furthermore, none of the patients with idiopathic uveitis and HC had Abs to chromatin. anti-chromatin Abs titers remained relatively stable over a 6-month control period. CONCLUSION: Our results confirm previous data about the presence of circulating anti-chromatin Abs in juvenile arthritis. Interestingly, anti-chromatin Abs were significantly higher in the group of patients with pauciarticular onset with past or present history of uveitis, than in patients without ocular involvement. A long-term follow-up study could be useful to demonstrate the potential utility of these autoantibodies in diagnosing, classifying and treating children affected.     

Age-specific effects of juvenile rheumatoid arthritis-associated HLA alleles.

OBJECTIVE: To define the onset and duration of effect of the HLA alleles that are associated with disease susceptibility and protection in juvenile rheumatoid arthritis (JRA) and 2 of its subtypes. METHODS: We typed 680 patients with JRA and 254 ethnically matched unrelated controls for HLA class I and II genes. The frequency of each allele was calculated for each of the age-at-onset, onset type, and sex categories and plotted against the allele frequency in the control population. Survival analysis (with onset of disease as the terminating event) was used to calculate the age by which 50% (St0.5) and 80% (St0.2) of the children with particular alleles and combinations of alleles develop disease. This allele-specific survival analysis also allowed for the comparison of the overall survival functions for the various JRA subtype and sex categories. RESULTS: Certain alleles are strongly associated with early susceptibility to pauciarticular JRA, including HLA-A2, DR8, DR5, and DPB1*0201. Fifty percent of the children carrying at least 1 of these alleles had disease onset prior to their third birthday. Among children who carried HLA-A2 and any 2 HLA-DR alleles (DR3, DR5, DR6, or DR8), the median age at the onset of pauciarticular disease was 2.7 years. Combinations of A2 and DPB1*0201 and one DR allele narrowed the window further to a median age at onset of 2.4 years. B27 and DR4 were associated with protection early in life but with increased risk later in childhood, with St0.5 values of 7.3 and 6.6 years, respectively, for pauciarticular JRA and St0.5 values of 10.2 and 10.7 years, respectively, for polyarticular JRA. Sex strongly influenced the age at which many of the alleles have their effect. CONCLUSION: These data define at what age and for how long various HLA alleles influence susceptibility and protection (window-of-effect) in patients with JRA. In addition, these data establish more clearly the boundaries of ages-at-onset for 2 of the subtypes of the disease.     

DNA analysis of HLA-DR, DQ, and DP alleles in children with polyarticular juvenile rheumatoid arthritis.

HLA-DR, DQ and DP alleles were determined by restriction fragment length polymorphism analysis and oligonucleotide probe hybridization of polymerase chain reaction amplified genomic DNA in 94 Caucasian children with polyarticular juvenile rheumatoid arthritis (JRA) [13 rheumatoid factor (RF)+ and 81 RF-] and 100 healthy controls. HLA-DRw8, DQw4, DQA1*0401, DQB1*0402 were increased in frequency in those patients with RF seronegative disease, with highest frequencies seen in patients with young age at onset (< 5 years of age). These findings were similar to what we observed in children with pauciarticular JRA, especially those with young age at onset. DPB1*0301 was also found in increased frequency in the RF- group, and in particular those seronegative for antinuclear antibody. In contrast to what is observed in patients with pauciarticular JRA, the frequency of DPB1*0201 was not increased in any polyarticular JRA patient group. These data suggest that polyarticular JRA shares many genetic features with pauciarticular JRA.     

Sexual maturation in Egyptian boys and girls with juvenile rheumatoid arthritis

Children with juvenile rheumatoid arthritis (JRA) exhibit a compromised growth status while information concerning the pattern of their sexual maturity is scant. The aim of the current work was to study sexual maturity in boys and girls with JRA. The study included eighty JRA patients they were 45 male and 35 female and eighty age- and sex-matched normal children served as controls. Development of genitalia was evaluated as per sexual maturity rating criteria given by Tanner score. Development of hair (pubic, axillary and facial) and age of monarch to JRA females were noted The mean (±SD) age of appearance of genitalia stage G-2 in boys with systemic onset JRA (12.0 ± 0.3 years) was earlier when compared with pauciarticular (12.60 ± 0.93 years) and polyarticular (13.39 ± 0.93 years) JRA but delayed for all types of JRA when compared with controls (10.06 ± 0.63 years). In comparison with female groups, the mean (±SD) age of appearance of genitalia stage G-2 with systemic onset JRA (12.0 ± 0.4 years) was also earlier when compared with pauciarticular (12.68 ± 1.09 years) and polyarticular (13.72 ± 0.39 years). Age of menarche delayed in all JRA female patients. None of the study group reach stage G-5 of genitalia development. The timing of initiation of sexual maturity in boys and girls with JRA delayed and this delay variable according to disease subtype.     

Growth patterns in juvenile rheumatoid arthritis

OBJECTIVE: To define patterns of growth in juvenile rheumatoid arthritis (JRA) and to evaluate possible associated clinical and laboratory correlates. METHODS: The study population comprised 67 children with JRA who had been followed for 5 years or longer and whose follow-up period did not extend beyond 18 years of age. Height and weight z scores were calculated with reference to age-related standards for each of the annual follow-up intervals and correlated with JRA subtype, the presence of rheumatoid factor (RF), the erythrocyte sedimentation rate (ESR), alkaline phosphatase level (ALP) and medication history. RESULTS: Initial height-for-age (HAZ) scores for pauciarticular, polyarticular and systemic JRA onset groups (PaJRA, PoJRA and SJRA respectively) were +0.27, -0.07 and +0.40 respectively. A significantly lower HAZ score in the SJRA population compared to the PaJIA population first became apparent at year 2 and the difference was maintained throughout the 9-year follow-up period. A significantly lower HAZ score in the SJRA population compared to the PoJRA population first became apparent at year 6 and the difference was maintained until the ninth year. During the 9-year follow-up period, RF-positive children tended to have negative HAZ scores whereas RF-negative children tended to have positive HAZ scores. The SJRA onset group displayed significantly lower HAZ scores, as compared to the HAZ score at onset, for 7 of the 9 subsequent follow-up intervals. Only 2 patients had heights < 2SD below the mean at final determination. Delay in generalized linear growth occurred predominantly in the SJRA population and to a lesser degree in those with PoJRA associated with RF positivity. CONCLUSIONS: Delay in linear growth occurs in some children with JRA. Patients with pauciarticular and RF-negative polyarticular disease can have growth patterns similar to normal children. Children with RF-positive polyarticular and systemic JRA have more significant growth retardation that occasionally can be sustained and extreme.     

Circulating immune complexes and antinuclear antibodies in juvenile rheumatoid arthritis

Materials with the Clq binding properties of soluble immune complexes (IC) were found in sera from 11 of 51 consecutive (22%) children with juvenile rheumatoid arthritis (JRA) and in 17 of 20 adults with active sero-positive rheumatoid arthritis (RA). IC appeared more frequently in children with systemic onset disease whereas antinuclear antibody (ANA) was found more frequently in sera from those with pauciarticular disease. Only 3 JRA sera contained anti-immunoglobulin (rheumatoid factor); those 3 also had high Clq binding activities. Seven of 50 patients (14%) carried HLA-B27 but B27 was not associated with high Clq binding activity or presence of ANA. The presence of free ANA more frequently in children with mild disease and IC more frequently in children with relatively severe disease suggests that children with systemic JRA may have a relative defect in antibody-forming capacity or reticuloendothelial function which results in decreased clearance of circulating IC. Alternatively, systemic, polyarticular, and pauciarticular JRA may represent a spectrum of clinically similar diseases resulting from different etiologic agents.     

Early predictors of longterm outcome in patients with juvenile rheumatoid arthritis: subset-specific correlations

OBJECTIVE: To determine early predictors of longterm outcome in juvenile rheumatoid arthritis (JRA) in a multicenter cohort. METHODS: Patients were selected if they were > or = 8 years of age; the onset of arthritis occurred > or = 5 years before study; and a diagnosis of JRA was made at a participating center. Outcome variables were scores on self-administered Childhood Health Assessment Questionnaires (CHAQ) and active disease duration. Possible explanatory variables assessed included characteristics present at onset, HLA alleles, in particular the rheumatoid arthritis associated shared epitope (RASE), and radiographic indicators of joint damage within 2 years of onset. Data for 393 patients were available. Multivariate analyses were performed for the total group and for each onset subtype. RESULTS: Male sex correlated with worse disability in systemic onset JRA but less disability in RF negative, and a shorter active disease duration in RF positive polyarticular onset JRA. Positive antinuclear antibody correlated with a longer active disease duration in patients with pauciarticular onset JRA. Younger age at onset predicted longer active disease duration in pauciarticular and RF negative polyarticular, and a shorter active disease duration in systemic onset JRA. Residence on a reserve, rather than native North American race, correlated with worse disability. The RASE correlated with less disability in systemic JRA; but no correlation with outcome was evident for patients with rheumatoid factor positive polyarticular JRA. CONCLUSION: Variables predictive of longterm outcome in JRA are specific for each onset subtype. The most important early predictors were age at onset and sex of the patient. Place of residence may have a greater effect on disability than race. RASE may associate with a more favorable outcome in systemic onset disease.     

Use of the HEp-2 cell substrate in the detection of antinuclear antibodies in juvenile rheumatoid arthritis

Presence and titer of antinuclear antibodies (ANA) were determined in 217 juvenile rheumatoid arthritis (JRA) patients, by indirect immunofluorescence using HEp-2 cells as substrate. Positive ANA titers (greater than or equal to 1:40) were present in 131 (60%) of the JRA patients. All 3 JRA onset types demonstrated increased percentages of ANA positivity compared with healthy children. Sixty-seven percent of the patients in the polyarticular onset group had positive titers; titers were positive in 62% of the pauciarticular onset group and in 32% of the systemic onset group. ANA were also found in 45% of control patients with other connective tissue diseases. In JRA patients, the speckled pattern occurred most commonly (72%). Fourteen patients (8 with pauciarticular onset and 6 with polyarticular onset) had iridocyclitis; all of them had high titers (greater than or equal to 1:80) of ANA. The use of HEp-2 cells provided a sensitive substrate for detecting ANA in JRA. It proved to be of value in differentiating JRA patients from healthy controls, but not from patients with other connective tissue diseases.     

The immunogenetics of juvenile rheumatoid arthritis.

Recent major advances in understanding the genetic structure of the human leukocyte antigen (HLA) region and how HLA molecules contribute to immune responses have been paralleled by more precise identification of specific HLA genes conferring susceptibility to the various forms of juvenile rheumatoid arthritis (JRA). This article presents current models for HLA-associated autoimmune disease susceptibility and summarizes the HLA Class II alleles currently known to be associated with JRA: primarily DR8, DR5, DR6, and DPw2.1 in pauciarticular onset JRA; and DR4 in rheumatoid factor-positive polyarticular onset JRA. Rheumatoid factor-negative polyarticular onset JRA and systemic onset JRA are variously associated with several of these same genes. Gene interactions and the clinical utility of HLA typing in this disease are also discussed.     

Predicting outcome at the knee in juvenile rheumatoid arthritis

This study was undertaken to correlate long-term severe radiographic changes with clinical profiles in an attempt to identify a group of patients at risk. Knee radiographs of 100 juvenile rheumatoid arthritis (JRA) patients with 1-20 years of follow-up studies were reviewed for changes leading to severe disability. Eighteen children had evidence of destructive changes an average of 4.3 years after onset of JRA. 23 patients had reactive changes superimposed on destructive changes seen 9.7 years after onset of disease. 92% of the children with reactive and destructive knee changes had radiographic evidence of significant JRA at another joint. Polyarticular disease with significant JRA involvement of another joint seems to indicate a group of children at higher risk for destructive and reactive changes at the knee.     

Antibody to streptococcal cell wall peptidoglycan-polysaccharide polymers in sera of patients with juvenile rheumatoid arthritis but absent in isolated immune complexes

Sera of 88 children with juvenile rheumatoid arthritis (JRA) (10 seropositive, polyarticular onset, 29 seronegative, polyarticular onset, 32 pauciarticular onset, and 17 systemic onset) were evaluated for the presence of serum antibodies to streptococcal cell wall peptidoglycan-polysaccharide polymers (PG-PSP). Immune complexes (IC) isolated by the antihuman IgM (HIgM) affinity column method were also evaluated for the presence of antibodies to PG-PSP. Forty-one of 88 patients with JRA (7 of 10 seropositive, polyarticular onset, 11 of 29 seronegative, polyarticular onset, 16 of 32 pauciarticular onset, and 7 of 17 systemic onset) showed elevated levels of antibodies to PG-PSP in their sera. IgM rheumatoid factors (RF) were demonstrated in 70/88 isolated IC fractions of patients with JRA and IgG RF in 7; however, none of the patients demonstrated the presence of antibodies to PG-PSP in their isolated IC fractions from the anti-HIgM affinity column. These data indicate that antibodies are produced to PG-PSP in all JRA onset types, but they are not constituents of isolated IC by the anti-HIgM affinity column method.     

Antibodies to histones H1 and H5 in sera of patients with juvenile rheumatoid arthritis

The specificity of juvenile rheumatoid arthritis (JRA) sera for histone subclasses was examined by immunoblotting. Antibodies to H1 alone were found in 4 of 21 pauciarticular-onset JRA sera, 4 of 19 polyarticular-onset JRA sera, and 2 of 11 systemic-onset JRA sera. Antibodies to H5 alone were found in 1 of 21 pauciarticular JRA sera, 1 of 19 polyarticular JRA sera, and 3 of 11 systemic JRA sera. Antibodies to both H1 and H5 were found in 4 of 21 pauciarticular JRA sera, 4 of 19 polyarticular JRA sera, and 1 of 11 systemic JRA sera. Antibodies to the core histones (H2A and H2B) were found in 1 of 21 pauciarticular JRA sera, 1 of 19 polyarticular JRA sera, and no systemic JRA sera. No reactivity to histones was observed in 30 sera from age-matched children with nonrheumatic diseases. The presence of H1 and H5 antibodies did not correlate with antinuclear antibody titers or with a homogeneous pattern of immunofluorescence. The predominance of H1 and H5 antibodies and relative absence of antibodies binding to core histones in JRA contrast with findings in adult systemic lupus erythematosus. Further, the presence of antibodies to H5 alone in some of the JRA patients indicates that the immune response in these patients is directed to determinants that are not shared by sequences of mammalian proteins.     

Polymorphism in the MHC-encoded LMP7 gene: association with JRA without functional significance for immunoproteasome assembly.

OBJECTIVE: To determine if a polymorphism in the immunoproteasome subunit LMP7 was associated with juvenile rheumatoid arthritis (JRA) and had functional significance. METHODS: The frequency of LMP7QQ+ vs QQ- (QK and KK genotypes) among 207 patients with JRA and 50 controls was determined. JRA subtypes were pauciarticular (53%), polyarticular (33%), and systemic (14%). Onset was before age 6 (early onset) in 60% of patients. The functional significance of the LMP7 polymorphism was determined by comparing incorporation of LMP7Q vs LMP7K into proteasomes. RESULTS: There was an increased frequency of LMP7QQ in patients vs controls (73 vs 56%; p = 0.016), mainly due to the pauciarticular and systemic JRA subtypes (p = 0.037), and more pronounced in early onset disease (77 vs 56%; p = 0.006). The association persisted with stratification for HLA-DR5(11) and -DPB 1 *0201 (p = 0.002 and 0.013). We found no difference in the relative incorporation of LMP7Q and LMP7K into proteasomes. CONCLUSIONS: These results support an association between LMP7QQ homozygosity and JRA, particularly early onset disease. The difference persists with stratification, at least for DR5(11) and DPB1*0201, suggesting that this effect is unlikely to be due to linkage disequilibrium with HLA alleles known to be associated with early onset pauciarticular JRA. Importantly, as there does not appear to be functional significance associated with the LMP7 polymorphism, this may be a marker for another as yet unidentified susceptibility locus.     

The immunologic and clinical associations of the split products of C3 in plasma in juvenile rheumatoid arthritis.

A qualitative counterimmunoelectrophoretic assay for the complement activation products C3c and C3d was used to study plasma from children with juvenile rheumatoid arthritis (JRA) and other rheumatic diseases. Positive tests for C3c,d were found in all patients with active systemic lupus erythematosus (SLE), 7 of 10 patients with active systemic JRA, 16 of 29 with active polyarticular JRA, 7 of 20 with active pauciarticular JRA, and in only 2 of 20 with inactive joint disease. The incidence of positive assays for C3c,d in JRA was increased in the presence of positive latex fixation tests, antinuclear antibody tests, or elevated values for antiglobulins as determined by affinity chromatography, but these associations were not statistically significant. Three joint fluids from children with pauciarticular JRA were negative for C3c,d. These studies show that the subgroups of JRA defined by clinical criteria are heterogeneous by current laboratory parameters and that evidence implicating antigen-antibody complexes in the pathogenesis of JRA is lacking in many patients.     

The Immunologic and Clinical Associations of the Split Products of C3 in Plasma in Juvenile Rheumatoid Arthritis

A qualitative counterimmunoelectrophoretic assay for the complement activation products C3c and C3d was used to study plasma from children with juvenile rheumatoid arthritis (JRA) and other rheumatic diseases. Positive tests for C3c,d were found in all patients with active systemic lupus erythematosus (SLE), 7 of 10 patients with active systemic JRA, 16 of 29 with active polyarticular JRA, 7 of 20 with active pauciarticular JRA, and in only 2 of 20 with inactive joint disease. The incidence of positive assays for C3c,d in JRA was increased in the presence of positive latex fixation tests, antinuclear antibody tests, or elevated values for antiglobulins as determined by affinity chromatography, but these associations were not statistically significant. Three joint fluids from children with pauciarticular JRA were negative for C3c,d. These studies show that the subgroups of JRA defined by clinical criteria are heterogeneous by current laboratory parameters and that evidence implicating antigen-antibody complexes in the pathogenesis of JRA is lacking in many patients.     

Antiperinuclear factor in juvenile rheumatoid arthritis.

The serological diagnosis of juvenile rheumatoid arthritis (JRA) is difficult, with only 7-10% of patients 19S IgM rheumatoid factor positive. About 60-70% of patients are positive for hidden 19S IgM rheumatoid factor, but this test requires serum separation and is not available in most laboratories. Antiperinuclear factor has been described in both seropositive and seronegative adult patients with rheumatoid arthritis, but has not been thoroughly evaluated in children with JRA. This study determined the diagnostic sensitivity and specificity of antiperinuclear factor in patients with JRA. Serum samples from 64 children with JRA, 24 with systemic lupus erythematosus (SLE), and 24 control subjects were tested for the presence of antiperinuclear factor. A total of 10 (83%) of seropositive, polyarticular onset and six (37%) of seronegative, polyarticular onset patients with JRA were positive for antiperinuclear factor. The occurrence of antiperinuclear factor in five (19%) with pauciarticular onset and one (10%) with systemic onset (JRA) as well as in four (17%) with SLE was not increased compared with the control subjects (1/24 (4%)). These data show an overall diagnostic sensitivity and specificity of 34 and 90% respectively in this group of patients. Although less sensitive than the hidden rheumatoid factor assay, the antiperinuclear factor assay is easier to perform and may contribute to the serological diagnosis of JRA.     

Analysis of the HLA-DR gene frequencies in Japanese cases of juveniles rheumatoid arthritis and rheumatoid arthritis by oligonucleotide DNA typing

Summary HLA-DR gene frequencies in 59 Japanese children with juvenile rheumatoid arthritis (JRA) and 62 Japanese adults with rheumatoid arthritis (RA) were analyzed by oligonucleotide DNA typing. As in other studies, the frequency of DRB1*0405 in RA patients was significantly higher than in the Japanese controls. In a comparison of non-calssified JRA patients with Japanese controls, no significant differences were observed in the frequency of DR types. However, when the JRA patients were classified into four clinical types, i.e., a rheumatoid factor-positive [RF(+)] polyarticular type, a rheumatoid factor-negative [RF(-)] polyarticular type, a pauciarticular type, and a systemic onset type, DRB1*0405 was found to be significantly higher in the RF(+) polyarticular JRA patients than in the controls (P>0.05). Thus, the RF(+) polyarticular type of JRA had the same HLA association as RA. This result is consistent with the fact that both RF(+) polyarticular JRA and RA cases have a similar clinical course.     

Asymptomatic gastritis in naproxen‐treated North Indian children with juvenile rheumatoid arthritis

Aims: Nonsteroidal anti‐inflammatory drugs (NSAIDs) are the agents of choice in patients with juvenile rheumatoid arthritis (JRA). While NSAIDs have been associated with gastritis in adults with rheumatoid arthritis (RA), not much is known about children with JRA. In this prospective study we set out to evaluate 31 children with JRA, who fulfilled the diagnostic criteria given by the American College of Rheumatology (ACR). Methods: All patients had received naproxen for at least 3 months prior to their enrolment. Mean age of children was 9.02 years (range 2.5–16 years) with the male : female ratio being 1.8 : 1 (boys 20; girls 11). Eleven (35.5%) patients had polyarticular, 15 (48.4%) had pauciarticular and the remaining five (16.1%) had systemic onset JRA. Duration of disease varied from 5–84 months (mean ± 2, SD = 25.32 ± 20 months) with a mean duration of therapy of 14.19 months (range 4–72 months). Six patients had complaints of mild non‐specific upper abdominal pain. Results: On upper gastrointestinal endoscopic examination none of the children showed any significant gross findings. However, histopathology of antral biopsies showed features of active and/or chronic gastritis in almost all the patients. Helicobacter pylori was identified in 16 (51.8%) of these on hematoxylin and eosin staining and the findings were confirmed with Giemsa/Gram staining. Fourteen (85.5%) were also positive by the rapid urease test (RUT). Ten of the 16 patients with H. pylori infection showed evidence of active inflammation in the antral biopsies. Conclusions: Asymptomatic gastritis is a common finding in children with JRA who are receiving naproxen. There appears to be no correlation between the presence of H. pylori infection or histological gastritis and presence of abdominal symptoms in children with JRA.     

Does sport negatively influence joint scores in patients with juvenile rheumatoid arthritis

Summary The influence of sporting activities performed using joint protective measures on deterioration in hand and lower extremity function was evaluated over 8 years in 62 patients with juvenile rheumatoid arthritis (JRA). Sporting activities usually recommended to patients with JRA, such as cycling and swimming, did not negatively influence hand or lower extremity function as compared to a control group of patients not taking part in sporting activities. Besides cycling and swimming, other sporting activities were only performed by a minority of patients (less than 10%). Decreases in total joint scores of both the hands and lower extremities, showed significant correlations with disease duration in patients taking part and in patients not taking part in sporting activities. Polyarticular onset of disease was associated with higher total joint scores of the hands as compared to pauciarticular onset of disease. In lower extremity function, no difference was found between patients with polyarticular onset and patients with pauciarticular onset. Disease duration of longer than 10 years, accompanied by severe functional deterioration, was followed by low participation in sporting activities. Therefore, we suggest that appropriate sporting activities, such as cycling and swimming, can be advised to patients with JRA regardless of disease duration, since no negative effects were observed in our study over a period of 8 years.     

Antibodies against cyclic citrullinated peptide are associated with HLA–DR4 in simplex and multiplex polyarticular‐onset juvenile rheumatoid arthritis

Objective

Anti–cyclic citrullinated peptide (anti‐CCP) antibodies have been detected in patients with juvenile rheumatoid arthritis (JRA), particularly in those with polyarticular, rheumatoid factor (RF)‐positive JRA. Our objectives were to determine whether anti‐CCP antibodies are associated with HLA–DR4 in children with polyarticular JRA, whether anti‐CCP antibodies are associated with clinical features of disease, and whether affected sibling pairs (ASPs) with JRA are concordant for this antibody.

Methods

Stored serum samples obtained from 230 HLA‐typed patients with JRA (77 with polyarticular‐onset disease and 153 with pauciarticular‐ or systemic‐onset disease), 100 JRA ASPs, and 688 healthy children were tested for anti‐CCP antibodies and RF.

Results

Thirteen percent of the patients with polyarticular‐onset JRA and 2% of the other JRA patients exhibited anti‐CCP antibodies, compared with only 0.6% of the controls. Fifty‐seven percent of RF‐positive patients with polyarticular‐onset JRA had anti‐CCP antibodies. HLA–DR4–positive patients with polyarticular‐onset JRA were more likely to have anti‐CCP antibodies than were those without HLA–DR4 alleles (odds ratio [OR] 5.20, 95% confidence interval [95% CI] 1.30–20.9). Anti‐CCP antibodies were associated with polyarticular onset (OR 7.46, 95% CI 1.99–28.0), a polyarticular disease course (OR 9.78, 95% CI 1.25–76.7), and erosive disease (OR 14.3, 95% CI 3.01–67.9). Concordance rates for anti‐CCP antibodies among ASPs were statistically significant.

Conclusion

These data demonstrate increased anti‐CCP antibody formation in HLA–DR4–positive patients with polyarticular‐onset JRA. The overall prevalence of anti‐CCP antibodies in JRA is low, but a substantial proportion of RF‐positive patients with polyarticular‐onset JRA have these antibodies. Anti‐CCP antibodies in JRA are associated with polyarticular onset, a polyarticular course, and erosive disease.