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

Identifying acute lymphoblastic leukemia mimicking juvenile idiopathic arthritis in children

Objective

Acute lymphoblastic leukemia (ALL) may present with arthritis implying the risk of being misdiagnosed as juvenile idiopathic arthritis (JIA). The aim of this study was to identify predictors for ALL based on clinical and laboratory information.

Methods

This cross-sectional, retrospective study compared clinical presentation and laboratory results of 26 children with ALL and arthritis versus 485 children with JIA (433 non-systemic, 52 systemic JIA). Using a Bayesian score approach the findings were evaluated by calculating odds ratios (OR) and lnOR as a measure of diagnostic weight.

Results

Distinction on clinical grounds was difficult, as even a high number of joints involved did not exclude ALL. One or more hematologic cell counts were low (Hb <10 g/dL, platelet count <100 x 10⁹/L, neutrophil count < 1.0 x 10⁹/L) in 92% with ALL, 25% with systemic JIA and 10% with non-systemic JIA. Neutropenia and thrombocytopenia had the highest ORs of 128 (95% CI 43–387) and 129 (95% CI 26–638), each giving a diagnostic weight of 4. The estimated risks of ALL were 0.2% with normal cell counts and 9%, 67% and 100% when one, two or three cell lines were affected.

Conclusion

A simple count of cell lines with low counts can serve as a basic diagnostic strategy. Children with tri- or bilinear involvement should be referred to a bone marrow, and those with unilinear involvement a thorough screen for further evidence of ALL (organomegaly, ESR, LDH, uric acid, and blood smear).

Heavy metals in fish and its association with autoimmunity in the development of juvenile idiopathic arthritis: a prospective birth cohort study

BACKGROUND

The etiology of Juvenile Idiopathic Arthritis (JIA) is poorly understood. The purpose of this study was to examine the possible influence of early nutrition on later development of JIA.

METHODS

In a population-based prospective birth cohort of 15,740 children we collected nutritional data, including fish consumption, and biological samples during pregnancy, at birth and at different ages. 16 years after study inclusion we identified 42 children with JIA, of whom 11 were positive for Antinuclear Antibodies (ANA). Heavy metals were analysed in cord blood of all 42 JIA patients and 40 age and sex-matched controls. A multivariable logistic regression model, adjusted for relevant factors, was used as well as Mann-Whitney U-test.

RESULTS

Fish consumption more than once a week during pregnancy as well as during the child's first year of life was associated with an increased risk of JIA (aOR 4.5 (1.95-10.4); p < 0.001 and aOR 5.1 (2.1-12.4) p < 0.001) and of ANA-positivity (aOR 2.2 (1.4-3.6); p = 0.002 and p < 0.001). Concentrations of Al, Cd, Hg and Li in cord blood were significantly higher in the JIA-group than in controls. The ANA-positive, all of whom had consumed fish >once/week their first year, had significantly higher concentrations of Al (p < 0.001), Cd (p = 0.003), and Li (p < 0.001) in cord blood than controls. Frequency of fish consumption correlated with concentrations of Cd (p = 0.003), Li (p = 0.015) and Hg (p = 0.011).

CONCLUSIONS

Moderate exposure to heavy metals, associated with fish consumption, during pregnancy and early childhood may cause effects on the immune system of the offspring, resulting in ANA positivity and JIA.

Remission rate is not dependent on the presence of antinuclear antibodies in juvenile idiopathic arthritis

Recently, it has been hypothesized that the subcategories of the ILAR classification of juvenile idiopathic arthritis (JIA) are not homogeneous, and that the presence of antinuclear antibodies (ANA) should lead to a separate entity. Therefore, the aim of this study was to evaluate ANA positivity as a predictor of achieving remission. A retrospective single-center cohort study including all JIA patients diagnosed between January 2000 and May 2014. A minimum follow-up of 1 year was required plus the ANA status. ANA positivity was defined as at least two positive results with a titer ≥1:160. Demographic and clinical features were collected. Remission at last follow-up was defined by the Wallace criteria. A total of 625 patients met the inclusion criteria and 230 (37%) were found ANA positive. Analysis showed no difference in remission rate between ANA-positive and ANA-negative patients. Additionally, joint count at diagnosis and at last follow-up were comparable in both groups. ANA positivity was correlated to a female predominance and young age at diagnosis (p < 0.001). Remission rates are not different in ANA-positive patients than in ANA-negative patients. This does not support the hypothesis to possibly divide JIA patients based on their ANA status.

Any increased risk of autoimmune disease?

Autoimmune diseases such as systemic lupus erythematosus (SLE) are known to have a strong genetic component, therefore the risk of autoimmune disease might be increased in family members of patients with SLE. However, there are currently no data that support a higher incidence of autoimmune disorders in the offspring of SLE patients. Babies with neonatal lupus are not at increased risk to develop SLE in later life, but a continued follow-up is suggested, especially prior to adolescence and if the mother herself has an autoimmune disease.

Review for the generalist: The antinuclear antibody test in children - When to use it and what to do with a positive titer

The antinuclear antibody test (ANA) is a much overused test in pediatrics. The ANA does have a role in serologic testing but it should be a very limited one. It is often ordered as a screening test for rheumatic illnesses in a primary care setting. However, since it has low specificity and sensitivity for most rheumatic and musculoskeletal illnesses in children, it should not be ordered as a screening test for non-specific complaints such as musculoskeletal pain. It should only be used as a diagnostic test for children with probable Systemic Lupus Erythematosus (SLE) or Mixed Connective Tissue Disease, (MCTD) and other possible overlap-like illnesses. Such children should have developed definite signs and symptoms of a disease before the ANA is ordered. This review presents data supporting these conclusions and a review of the ANA literature in adults and children.By limiting ANA testing, primary care providers can avoid needless venipuncture pain, unnecessary referrals, extra medical expenses, and most importantly, significant parental anxieties. It is best not to do the ANA test in most children but if it ordered and is positive in a low titer (<1:640), the results can be ignored if the child is otherwise well and does not have other features of a systemic illness.

Biomarkers of Chronic Uveitis in Juvenile Idiopathic Arthritis: Predictive Value of Antihistone Antibodies and Antinuclear Antibodies

Objective.

To study the predictive value of antinuclear autoantibody (ANA) tests and antihistone antibodies (AHA) as risk factors for development of chronic asymptomatic uveitis of insidious onset in juvenile idiopathic arthritis (JIA).

Methods.

ANA by indirect immunofluorescence using HEp-2 cells (IF-ANA), ELISA for ANA (E-ANA), and AHA were analyzed in sera of 100 children with recent-onset JIA and in 58 control sera. Clinical features, including age at onset, JIA subgroup, and presence of uveitis, were recorded in this prospective population-based cohort study.

Results.

E-ANA was positive in 4 of the 100 sera, and was not associated with uveitis. Chronic uveitis developed in 16 children with JIA: in 14 of 68 positive for IF-ANA ≥ 80, and in 13 of 44 positive for AHA ≥ 8 U/ml. IgM/IgG AHA were found in higher proportions in children with uveitis (mean 12.4 U/ml) than in those with JIA and no uveitis (mean 6.9 U/ml) or in healthy controls (mean 4.3 U/ml).

Conclusion.

No association was found between E-ANA and uveitis, and most IF-ANA-positive sera were E-ANA-negative. E-ANA is not clinically relevant in this setting and should never be used to determine frequencies of eye examinations to detect new uveitis in JIA. AHA ≥ 8 U/ml, IF-ANA titer ≥ 320, and young age at onset of arthritis were significant predictors for development of chronic uveitis. The diagnostic value of AHA ≥ 8 U/ml as a biomarker of chronic uveitis in JIA is very similar to IF-ANA ≥ 80.

Long term prognosis of children born to lupus patients

OBJECTIVE

To determine the long term prognosis of children of patients with systemic lupus erythematosus (SLE).

METHODS

Children of patients with SLE were invited to attend our clinic for physical examination and laboratory tests. A total of 195 children (aged 4 months to 26 years; male = 82, female = 113) were examined in 1991, 1995, 1997, and 1998.

RESULTS

Two cases were diagnosed as SLE at the first visit and were excluded from the second visit. A significantly higher percentage (52/195 (27%)) of patients were positive for antinuclear antibodies (ANA) at a cut off serum dilution of 1/40 compared with controls (4/57 (7%)). ANA were detected more frequently in female subjects than in men (p<0.05). Forty four subjects were examined on more than two occasions. Nine of the 10 patients who were positive for ANA at the second visit were girls aged 4-8 years. The incidence of anti-DNA and antiphospholipid antibodies in children of patients with SLE was similar to that in the controls.

CONCLUSIONS

The finding that children, especially girls, born to maternal lupus patients had a high positive rate for ANA suggests that a genetic factor is involved in SLE pathogenesis. Longitudinal observation of these patients may provide important clinical information and clues to the pathogenesis of SLE.

Murine animal models of systemic sclerosis

Animal models of systemic connective tissue diseases have provided valuable insights into the causative mechanisms and the pathogenesis of these diseases, and have provided the means to test potentially useful therapeutic interventions. Although numerous animal models for systemic sclerosis (SSc) have been described, the most extensively studied are murine. One advantage of murine animal models is the large body of genetic information available for the mouse that is not available for other species. No animal model described to date reproduces precisely all manifestations of SSc. However, all animal models display tissue fibrotic changes similar to those present in SSc. The prudent interpretation of the results obtained from the study of animal models has provided substantial and valuable information about the pathogenesis of the human disease.

Prevalence and clinical significance of anti-cyclic citrullinated peptide antibodies in juvenile idiopathic arthritis

BACKGROUND

Antibodies against cyclic citrullinated peptide (anti-CCP) are considered to be specific for rheumatoid arthritis (RA).

OBJECTIVE

To assess the clinical significance of anti-CCP in a cohort of patients with juvenile idiopathic arthritis (JIA).

METHODS

Anti-CCP were tested by an enzyme linked immunosorbent assay (ELISA) in serum samples from 109 patients with JIA (30 boys, 79 girls), with a mean age of 8.7 years (range 0.6-20.3) and mean disease duration of 3.6 years (range 3 months to 15.6 years). As control groups, anti-CCP were also tested in sera of 30 healthy children, 25 patients with juvenile onset systemic lupus erythematosus (SLE), and 50 adult patients (30 with RA, 20 with SLE).

RESULTS

Positive anti-CCP values were found in sera of two patients with JIA (2%), one with polyarthritis, and one with oligoarthritis. Statistical analysis showed that anti-CCP were not associated with the presence of antinuclear antibodies, raised erythrocyte sedimentation rate, or erosions. In the control groups, none of the patients with juvenile onset SLE and only one of 20 adults with SLE were positive for anti-CCP, but 19/30 (63%) adults with RA showed anti-CCP positivity.

CONCLUSIONS

Anti-CCP can be detected in children with JIA, but are less frequently present than in adults with RA.

Juvenile chronic arthritis profile in Greek children

BACKGROUND

Juvenile chronic arthritis (JCA) is the commonest autoimmune rheumatic disease in childhood and presents different clinical subtypes. Juvenile chronic arthritis is considered to be of a polygenic nature and its genetic background is still under investigation. The clinical profile of JCA in the Greek population has not been studied completely. This study retrospectively analyzed the clinical and immunological features of JCA in Greek children presented between 1989 and 1994. Human leukocyte antigen (HLA)-positive or -negative associations in the different clinical subtypes were also detected. The findings of this study were correlated with those reported from other populations.

METHODS AND RESULTS

Antinuclear antibodies (ANA) anti-ds DNA and anti-extractable nuclear antigen antibodies were estimated by immunofluorescent and ELISA assays. Human leukocyte antigen typing was performed by microlymphocytotoxicity, using immunobeads. The peak ages of JCA onset were between 2 and 5 years and also between 9 and 12 years. There was a high female predominance in pauciarticular and polyarticular groups. The most common disease was pauciarticular (58.7%) followed by systemic (25%) arthritis. The incidence of eye involvement was 12.5% and presented only in the pauciarticular group. Overall, ANA positivity was 53.7%, increasing to 90% in pauciarticular cases associated with chronic uveitis. In the early onset (EOPA) pauciarticular subtype, positive-HLA associations with alleles DR11 and DR8 were shown. In the late onset pauciarticular (LOPA) group only B27 allele was increased.

CONCLUSIONS

The results of this retrospective study did not reveal major differences between JCA in Greek children compared with other Caucasian series.

Clinical significance of the antinuclear antibody test in selected children with idiopathic thrombocytopenic purpura

PURPOSE

To determine the clinical significance of the antinuclear antibody (ANA) test in selected children with idiopathic thrombocytopenic purpura (ITP).

METHODS

The study was conducted through retrospective chart review and long-term follow-up by telephone interview.

RESULTS

Of 87 children with ITP who had an ANA performed, 25 had a positive titer (median = 1:160, range: 1:40 to 1:2,560). Children with a positive ANA were more likely to be older girls who developed chronic ITP, but there was no correlation with family history of autoimmune disease, initial hemoglobin concentration, or initial platelet count. With an average follow-up of more than 5 years, more children with a positive ANA developed further autoimmune symptoms than those with a negative ANA (36% vs. 0%, p < 0.001). Nine children with a positive ANA developed additional autoimmune symptoms, including five with clinical criteria sufficient for the diagnosis of systemic lupus erythematosus (SLE). Autoantibodies to dsDNA were more prevalent in the children with progression of autoimmune symptoms (57% vs. 0%, p = 0.04). The presence of any autoantibody in addition to the ANA, including dsDNA, SS-A/Ro, SS-B/La, Smith Antigen (Sm), nuclear ribonucleoprotein (nRNP), or cardiolipin was more common in children who had further autoimmune symptoms (75% vs. 0%, p = 0.003).

CONCLUSIONS

The ANA is a useful screening test in a subset of children with ITP, especially older girls with chronic ITP, who are at risk for the development of generalized autoimmune disease. Children with ITP and a positive ANA should receive careful follow-up.

Juvenile rheumatoid arthritis: The Saudi Experience

We retrospectively studied the charts of 115 Arab children with juvenile rheumatoid arthritis (JRA), all of whom satisfied the American College of Rheumatology (ACR) criteria for JRA. They were followed between 1978 and 1993 at King Faisal Specialist Hospital and Research Centre and King Khalid University Hospital in Riyadh, Saudi Arabia. All patients were followed up for at least 18 months. The female to male ratio was 1.2:1, and the mean age of onset of the disease was six years. Ninety of the patients were Saudis and the remainder were Middle Eastern Arabs. The mode of onset was systemic in 44%, polyarticular in 30%, and periarticular in 26%. Chronic uveitis was found in only two of the children (1.7%). Antinuclear antibody (ANA) was determined in 96 patients and was positive in 29 (30%). Amyloidosis was not detected in this study population. The clinical and laboratory manifestations of this disease are presented. This review shows that the spectrum of clinical presentation differs in Arab children from those in the West. Systemic and polyarticular onset subtypes were more common, and the incidence of uveitis and amyloidosis was lower. Whether this reflects a genuine difference in the pattern of the disease, or is due to bias in referral pattern, remains to be detected. The answer is currently being sought through an ongoing prospective study.

Immunopathogenesis of juvenile rheumatoid arthritis: role of T cells and MHC

Juvenile rheumatoid arthritis (JRA) is defined as chronic arthritis of unknown etiology appearing in patients less than 16 years of age. The disease is heterogeneous and is classified as pauciarticular, polyarticular, or systemic-onset disease. A few lines of evidence suggest that T cells are involved in the pathogenesis of the disease. T cells infiltrating the synovial membrane bear markers of activation and produce cytokines. The association of particular subtypes of JRA with certain HLA class II alleles provides strong evidence in favor of T cell involvement through an HLA-peptide-T cell receptor complex. Limited data from a few patients with JRA on T cell receptor transcripts from synovial membrane or synovial fluid cells point towards oligoclonality. This further supports the concept that T cells infiltrating the synovial membrane or extravasating into synovial fluid in patients with JRA reflect antigen-driven T cell proliferation.

Autoantibody studies in juvenile rheumatoid arthritis

Early studies showed few immunologic abnormalities in juvenile rheumatoid arthritis (JRA) patients. There were no specific laboratory markers useful for diagnosis and assessment of the course of disease in JRA. Previous work showed an association of antinuclear antibodies (ANA) with early-onset pauciarticular disease and iridocyclitis. Similarly, the presence of 19S immunoglobulin (Ig) M rheumatoid factors (RF) was associated with late-onset polyarticular disease in girls. More recent studies have detected many unique autoantibodies. Newer assays show 19S IgM RF in up to 35% of JRA patients, although still mainly in girls with late-onset polyarticular disease. Hidden 19S IgM RF can be shown in up to 75% of JRA patients using different procedures, primarily in those with active polyarticular-or pauciarticular-onset disease. Immune complexes have been detected in JRA patients by means of different techniques; their presence usually correlates with active disease. Studies on a specific ANA in JRA have shown no common extractable nuclear antigen, but antihistone antibodies have been found in up to 75% of cases, again mainly in those with pauciarticular onset and iritis. Finally, a variety of unusual immunologic proteins have also been detected, including anti-ocular, anti-cellular, anti-cardiolipin, anti-perinuclear factor, and anti-collagen antibodies. This review evaluates the significance of these antibodies that can now be found in JRA.

Hyperprolactinemia in systemic lupus erythematosus: association with disease activity

This study was designed to determine the prevalence and clinical significance of hyperprolactinemia in systemic lupus erythematosus (SLE) and other rheumatic diseases. Basal levels of prolactin were determined in 130 nonselected sera from patients with rheumatic diseases including 45 with SLE, 31 with rheumatoid arthritis, 23 with osteoarthritis, 18 with fibromyalgia, and 13 with polymyalgia rheumatica. Serum samples of 28 healthy subjects were used as normal controls. Serum prolactin was measured by radioimmunoassay. ANA, anti-DNA, RNP, Sm, Ro, La, and anticardiolipin antibodies were determined by standard techniques. Elevated serum levels of prolactin (PRL greater than 20 ng/ml) were found in a subset of SLE patients. In addition, a direct correlation with clinical disease and serological (ANA) activity was also found. These findings suggest a potential role for this immunoregulatory hormone in SLE pathogenesis.

Cytotoxic effects of rheumatoid arthritis sera on chondrocytes

Human sera from patients with rheumatoid arthritis (RA) and also from healthy donors were found to be toxic to cultured chondrocytes. Immunoglobulins were found to bind to the surface of cultured cells and cells in chicken sternal cartilage, as detected by indirect immunofluorescence. In vitro, cell detachment from the substrate was caused by the incubation of chondrocyte monolayers with 5 per cent and less RA serum. Serum treatment caused cytotoxic degradation of the cells. This could be quantified by a chromium release assay. Heat inactivation of the serum abolished the cytotoxicity. The extent of the cytotoxic reaction was related to the complement content of the serum and also to the intensity of the disease, as determined by the Ritchie-index. Other cell types, as chondrosarcoma cells, normal fibroblasts and corneal epithelium, were not affected by RA sera.

Antinuclear antibodies using HEp-2 cells in normal children and in children with common infections

Antinuclear antibody (ANA) immunofluorescence tests, using HEp-2 cells, were performed on 100 children without a history of connective tissue disease. Eighteen (18%) were positive at titres greater than or equal to 1:40, nine (9%) being greater than 1:160. Interlaboratory variability was demonstrated with some specimens. No association with possible intercurrent infection was found to account for positive results. Of 44 children with proven infections five (11%) were positive. Antinuclear antibody may be found in some normal children when using the sensitive HEp-2 cell substrate, and in the absence of clinical features should not necessarily suggest the presence of a connective tissue disease.

Autoantibodies in patients with juvenile chronic arthritis and their immediate family relatives

Antibodies to nuclear antigens were assessed in 23 children with juvenile chronic arthritis (JCA) and 66 of their first degree relatives. Serum samples from 16 patients with JCA (70%) and nine relatives (14%) had antinuclear antibodies by indirect immunofluorescence. Antibodies against nuclear antigens in rabbit thymus extract or an erythroblastoid cell line (K562) were detected by countercurrent immunoelectrophoresis and immunoblotting in 16 patients (70%) and 39 family relatives (59%). Immunoblotting did not show any banding patterns common to all patients with JCA, though bands in the 43-45 kD range were detected in 5/23 patients. Anticardiolipin antibodies were found in 7/23 patients. In total, 18/20 families (90%) had members other than the probands with detectable autoantibodies. In five families immunoblotting showed common banding patterns between the probands and other members. This suggests that there might be an inherited trend towards autoimmune responses in some families of patients with JCA.

Psoriatic arthritis in children

A proposed definition of juvenile psoriatic arthritis (JPsA) was used to identify definite or probable JPsA in 35 children. Definite JPsA (24 patients) was defined as arthritis associated, but not necessarily coincident, with a typical psoriatic rash, or arthritis plus at least 3 of 4 minor criteria: dactylitis, nail pitting, psoriasis-like rash, or family history of psoriasis. Probable JPsA (11 patients) was defined as arthritis plus 2 of the minor criteria. In 33 of 35 patients, the onset of arthritis was pauciarticular, but the disease followed a polyarticular course in 23 of 35. Chronic anterior uveitis (6 of 35), antinuclear antibodies (22 of 35), anticollagen antibodies (10 of 35), HLA-DR4 (2 of 28), and HLA-DR8 (5 of 28) occurred with frequencies similar to those seen in patients with juvenile rheumatoid arthritis. JPsA may have more in common with juvenile rheumatoid arthritis than with the seronegative spondylarthropathies with which it is traditionally associated.

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.

Juvenile rheumatoid arthritis. Monocyte dysfunction in selected patients

The in vitro parameters of cell-mediated immunity were studied in 20 children with an established diagnosis of Juvenile rheumatoid arthritis (JRA) (age range 4-15 years) and 23 age- and sex-matched healthy children. (No attempt was made to correlate the observed changes with clinical course or treatment). We are not certain, at this time, of clinical relevancy or the generalizability of the findings. The normal level of T-lymphocytes (CD3+) and normal proportions of CD4+ and CD8+ lymphocytes were seen in children with JRA. The in vitro response of lymphocytes to T-cell mitogen phytohemagglutinin (PHA) also was normal. The suppressor activity of JRA monocytes was essentially the same as controls. In contrast, monocytes from patients with JRA showed the following: decreased expression of receptors for Fc part of IgG immunoglobulin (FcR), diminished nitro blue tetrazolium (NBT) reduction activity, and depressed expression of Ia.7 major histocompatibility complex (MHC) class II determinants. This indicates that certain monocyte functions in selected patients with a variety of manifestations of JRA are depressed.

Immunoregulatory aberrations in patients with polyarticular juvenile rheumatoid arthritis

The presence of hypergammaglobulinemia and various circulating autoantibodies in children with polyarticular juvenile rheumatoid arthritis (JRA) implies an immunoregulatory disorder. We report here experiments planned to elucidate the underlying cellular aberrations in this disease. Twelve children with polyarticular JRA were studied. Percentages of Leu-1, Leu-2, and Leu 3 T cells were comparable to those of normal individuals. Immunofluorescent double staining studies demonstrated elevated numbers of activated (DR+) T cells of both Leu-2 and Leu-3 phenotype. B cells characterized both phenotypically (Leu-12) and functionally (as spontaneous plaque-forming cells, PFC) were elevated. In vitro PFC responses to pokeweed mitogen (PWM) and Epstein-Barr virus (EBV) were diminished. The levels of concanavalin A-induced suppressor cells of the PWM-stimulated PFC responses were comparable to control values. In contrast, the EBV-associated suppressor T cells were significantly impaired in both EBV-seropositive and EBV-seronegative patients. These studies indicate that peripheral blood B-cell activity is abnormal in polyarticular JRA. Defective T-cell responses in vitro suggest that this may be due to disruption of normal regulatory circuits between B and T cells and may contribute to the pathogenesis of this disease.

Autoantibody profile in juvenile chronic arthritis

Patients with juvenile chronic arthritis (JCA) may be subdivided into a minority, who carry IgM rheumatoid factor and have erosive polyarthritis resembling adult rheumatoid arthritis, and the majority (90%), who are seronegative by conventional means. Between 30 and 60% of patients with JCA have positive antinuclear antibodies (ANAs) according to the choice of substrate for indirect immunofluorescence. The importance of ANAs is the frequent development of associated asymptomatic chronic iridocyclitis, which may impair vision causing worse handicap than the arthritis, which remains predominantly pauciarticular in two thirds of these young children. ANA positive patients rarely possess antibodies to deoxyribonucleic acid (DNA) or extractable nuclear antigens (ENA), and current studies suggest that several different nuclear antigens, including histones, may be involved.

Incidence and prevalence of juvenile chronic arthritis: a population survey

In a population based epidemiological survey of juvenile chronic arthritis (JCA), performed in Western Sweden in 1983, an incidence of 12/100,000 was found. The estimated prevalence was 56/100,000. Subgroup distribution showed a preponderance of mono- and pauciarticular forms. The peak age of onset was between 0 and 4 years of age. Girls predominated over boys in a ratio of 3:2. Overall, 30% were antinuclear antibody (ANA) positive, 9% rheumatoid factor (RF) positive, and eye involvement occurred in 10% of the children. The results suggest differences in population based studies of JCA compared with previously reported hospital based series.

Immunological abnormalities in juvenile chronic arthritis

The immunological alterations that have been reported in juvenile chronic arthritis are reviewed. Their role in patient management and classification as well as their possible etiopathogenetic relevance are discussed.

Cellular immunity in patients with systemic juvenile rheumatoid arthritis

We studied the cellular immune responses in 10 patients with systemic form of juvenile rheumatoid arthritis. The numbers of peripheral T lymphocytes and their helper/inducer and cytotoxic/suppressor subpopulation were within normal levels. Activated T lymphocytes (DR+) were slightly increased but not at statistically significant levels. In contrast to the T cells, B lymphocytes were increased; both the percentage of B cells (B1+) and the number of cells spontaneously secreting IgG, IgA, and IgM were increased. Stimulation of peripheral mononuclear cells in vitro with pokeweed mitogen induced poor plaque-forming cell responses, which were partially improved upon removal of monocytes. The presence of concanavalin A in the cultures led to complete suppression. We conclude that patients with systemic JRA are characterized primarily by B-cell rather than T-cell abnormalities.