Histocompatibility antigens in childhood-onset arthritis

Diagnostic and prognostic role of synovial tissue analysis in juvenile idiopathic arthritis: a monocentric study

OBJECTIVES

This study investigates the diagnostic role of synovial tissue analysis in children presenting with arthritis and assesses its prognostic significance to predict clinical outcome in juvenile idiopathic arthritis (JIA).

METHODS

Synovial samples of paediatric patients undergoing synovial biopsy between 1995 and 2020 were analysed histologically and immunohistochemically. Relationships between histological/immunohistochemical parameters and clinical variables were assessed.

RESULTS

Synovial biopsy was performed for diagnosis in 65 cases allowing to correctly classify 79% of patients.At histological analysis on 42 JIA samples, any difference in the number of synovial lining layers, subsynovial elementary lesions, fibrin deposit, Krenn Synovitis Score, inflammatory infiltrate score and pattern emerged between JIA subsets or on treatment exposure. Synovial tissue analysis predicted outcome: higher number of synovial layers predicted worse disease course (>4 flares during follow-up; 4.5 vs 3.0, p=0.035), even after adjusting for age at diagnosis and observation time (OR 2.2, p=0.007); subjects who had switched>2 biological disease-modifying antirheumatic drugs had higher prevalence of subsynovial elementary lesions (55.6% vs 10.3%, p=0.005) and fibrin deposits in synovial lining (60.0% vs 22.6%, p=0.049), even after adjustment for observation time and age at diagnosis (OR 8.1, p=0.047). At immunohistochemistry on 31 JIA samples, higher CD3 expression was described in polyarticular compared with oligoarticular subset (p=0.040). Patients with severe disease course had higher CD20+ rate (OR 7, p=0.023), regardless of JIA subset and treatment exposure.

CONCLUSIONS

Synovial tissue analysis might support the clinicians in the diagnostic approach of paediatric patients presenting with arthritis and guide the clinical management in JIA.

Adult-Onset Still's Disease: Clinical Aspects and Therapeutic Approach

Adult-onset Still's disease (AoSD) is a rare systemic autoinflammatory disease characterized by arthritis, spiking fever, skin rash and elevated ferritin levels. The reason behind the nomenclature of this condition is that AoSD shares certain symptoms with Still's disease in children, currently named systemic-onset juvenile idiopathic arthritis. Immune dysregulation plays a central role in AoSD and is characterized by pathogenic involvement of both arms of the immune system. Furthermore, the past two decades have seen a large body of immunological research on cytokines, which has attributed to both a better understanding of AoSD and revolutionary advances in treatment. Additionally, recent studies have introduced a new approach by grouping patients with AoSD into only two phenotypes: one with predominantly systemic features and one with a chronic articular disease course. Diagnosis presupposes an extensive diagnostic workup to rule out infections and malignancies. The severe end of the spectrum of this disease is secondary haemophagocytic lymphohistiocytosis, better known as macrophage activation syndrome. In this review, we discuss current research conducted on the pathogenesis, diagnosis, classification, biomarkers and complications of AoSD, as well as the treatment strategy at each stage of the disease course. We also highlight the similarities and differences between AoSD and systemic-onset juvenile idiopathic arthritis. There is a considerable need for large multicentric prospective trials.

The assessment of the spondyloarthritis international society concept and criteria for the classification of axial spondyloarthritis and peripheral spondyloarthritis: A critical appraisal for the pediatric rheumatologist

This review refers to the origin and current state of the assessment of the SpondyloArthritis International Society (ASAS) criteria for the classification of axial and peripheral spondyloarthritis (SpA) and the possible implications in the pediatric population. The ASAS criteria evolved from the idea that the earlier the recognition of patients with ankylosing spondylitis, the better the efficacy of tumor necrosis factor blockers. Strategies included the development of new concepts, definitions, and techniques for the study of clinical signs and symptoms. Of relevance, the new definition of inflammatory back pain (IBP) and the introduction of sacroiliitis by magnetic resonance imaging represented the most important advance in the early identification of AS in the "pre-radiographic stage" of the disease. AS is considered in this paper as a disease continuum with symptoms depending on age at onset. The application of those specific strategies in children and adolescents with SpA seems limited because the most important manifestation in the early stage of disease is not IBP, but peripheral arthritis and enthesitis. In this instance, the logical approach to juvenile onset SpA according to ASAS criteria should not be through the axial criteria but rather the peripheral set of criteria.

Classification of juvenile spondyloarthritis: Enthesitis-related arthritis and beyond

Spondyloarthritis (SpA) refers to a spectrum of immune-mediated inflammatory diseases with overlapping features, which differ from other types of inflammatory arthritis in genetic predisposition, pathogenesis and outcome. SpA frequently involves the axial skeleton, and can result in abnormal bone formation with eventual ankylosis of the spine, resulting in substantial disability. SpA often begins as an 'undifferentiated' disease, the presentation of which differs in children and adults; most notably, spinal involvement is uncommon, while hip arthritis and enthesitis are frequently seen in juvenile-onset disease. Currently, the classification of SpA in adults and children is approached differently. Using the International League of Associations for Rheumatology (ILAR) system for juvenile idiopathic arthritis, most childhood SpA is classified as enthesitis-related arthritis. However, in contrast to adult SpA classification, the presence of, or a family history of, psoriasis dictates a separate category of juvenile idiopathic arthritis. More importantly, the ILAR system does not specifically recognize the presence of axial disease in juvenile SpA. Resolution of these issues will improve communication and the transitioning of patients from pediatric to adult clinics, will facilitate research in genetics and pathogenesis, and will be particularly important in the evaluation of tumor necrosis factor inhibitors and other biologic agents for early, axial SpA.

The history of pediatric rheumatology

The care and study of children with rheumatic diseases began slowly in the 19th century, with the most attention centered on rheumatic fever. Other rheumatic diseases of children received little attention until the 1940s. Rheumatic diseases taken together remain a significant cause of chronic illness in children throughout the world. A number of other conditions that masquerade as rheumatic diseases in children also demand recognition and management. Although ultimate causes and cures of childhood rheumatic diseases remain elusive, advances in therapy have improved the outlook for affected children, and advances in biomedical research are adding to our basic understanding of the disease process involved. Pediatric rheumatology has become a well-organized, although underpopulated, specialty that enhances recognition and care of affected children and contributes to basic research knowledge in infectious disease, immunology, and genetics. This review focuses most prominently on the early history of pediatric rheumatology and its development as a specialty. The recent burgeoning of new biomedical science and new means of treatment will be better told in the historical perspective of years to come.

Analysis of MHC region genetics in Finnish patients with juvenile idiopathic arthritis: evidence for different locus-specific effects in polyarticular vs pauciarticular subsets and a shared DRB1 epitope

This study used Finnish juvenile idiopathic arthritis (JIA) probands with pauciarticular and rheumatoid factor (RF) negative polyarticular subtypes of JIA to further define the genetic susceptibility to JIA. We examined 16 markers spanning an 18 cM region of chromosome 6 encompassing the MHC and surrounding genomic region in a set of 235 Finnish JIA nuclear families and 639 Finnish control individuals. Analysis by case/control association and transmission disequilibrium test (TDT) methods each demonstrated strong evidence for a susceptibility locus near the D6S2447 microsatellite (P<10(-6) for both methods) that is flanked by DQB1 and DRB1. Analysis of the DRB1 locus suggested that DRB1*0801 and DRB1*1101 rather than DQA1 or other HLA alleles may be responsible for conferring susceptibility to disease. These findings are consistent with the most compelling results of previous reports on HLA associations and suggest a JIA DRB1 shared epitope encompassing critical amino-acid residues in the third hypervariable region of this molecule. Most importantly, in pauciarticular patients, the strong association does not extend to proximal markers as it does in polyarticular patients (P<0.00001). Analysis strongly suggests that the difference is because of additional JIA susceptibility loci within the MHC being present in polyarticular RF negative patients.

The juvenile-onset spondyloarthritides

The juvenile-onset spondyloarthritides comprise a group of HLA-B27-associated disorders, which are mainly characterized by enthesitis and arthritis affecting the lower extremities, and in a variable proportion of cases, the sacroiliac and spinal joints. Additional features include a variety of extra-articular manifestations, and in some cases, bacterial infections as triggers. Except for the prevalence of some clinical features at onset and severity throughout the course of the disease, juvenile-onset SpA resemble their adult counterpart in most clinical aspects, strength of HLA-B27 association, and the role of arthritogenic bacteria in their pathogenesis. Not surprisingly, several aspects, from nomenclature to classification, and diagnostic criteria reflect to some extent those developed in the adult onset populations.

Type 1A diabetes mellitus-associated autoimmunity

Type 1A diabetes mellitus has become one of the most intensively studied autoimmune disorders, with characterized animal models and extensive prospective studies of the development of anti-islet autoimmunity. It is now possible to predict the development of type 1A diabetes mellitus, beginning with HLA-encoded genetic susceptibility, followed by the development of a series of anti-islet autoantibodies. Prediction primarily is based on the detection of multiple anti-islet autoantibodies reacting with cloned islet antigens. Multiple international workshops fostered the development of specific and sensitive radioassays for autoantibodies reacting with GAD65 (glutamic acid decarboxylase), ICA512 (also termed IA-2, a tyrosine phosphatase-like protein), and insulin. Similar high throughput radioassays have been applied using autoantigens for additional autoimmune disorders including celiac disease and Addison's disease. Relatives of patients with type 1A diabetes mellitus inherit susceptibility to express multiple autoantibodies, and a subset of autoantibody-positive individuals inherit susceptibility to progress to overt disease. This article reviews autoimmune disorders associated with type 1A diabetes mellitus.

The influence of patient characteristics, disease variables, and HLA alleles on the development of radiographically evident sacroiliitis in juvenile idiopathic arthritis

OBJECTIVE

To assess the frequency of sacroiliitis and the radiographic and clinical outcome in juvenile idiopathic arthritis (JIA) and determine patient characteristics, early disease variables, and genetic markers that predict development of sacroiliitis.

METHODS

We performed a retrospective cohort study of 314 (79%) of the 400 JIA patients first admitted to the hospital between 1980 and 1985. The participants were examined after a median disease duration of 14.9 years (range 11.7-25.1). Radiographs of the sacroiliac joints, hips, ankles, and tarsi were obtained and studied in a blinded manner by 2 radiologists. The presence of HLA-DRB1 and DPB1 alleles was determined by genotyping and that of HLA-B27 by serologic testing. Variables relating to the onset and course of the disease were obtained by chart reviews.

RESULTS

Twenty (6%) of the JIA patients developed radiographic sacroiliitis according to the New York criteria. In 9 patients (45%), sacroiliitis had not been demonstrated before the followup examination. At followup, spinal flexion (lateral and anterior) was reduced in 70-75% of patients with sacroiliitis and in 30-35% of those without sacroiliitis. Compared with the JIA patients without sacroiliitis, those with sacroiliitis more frequently had inflammatory back pain, enthesitis, radiographic changes in the hips and calcanei, erosions of any peripheral joint, and uveitis. Predictors of sacroiliitis were HLA-B27, absence of DPB1*02, hip joint involvement within the first 6 months, and disease onset after age 8 years. The following factors were more common among patients in whom sacroiliitis developed than in other JIA patients: DRB1*04, male sex, family history of ankylosing spondylitis, psoriasis, inflammatory back pain, and enthesitis within the first 6 months.

CONCLUSION

In the current study, radiographically evident sacroiliitis had developed in 6% of JIA patients after a median disease duration of 14.9 years. HLA-B27, absence of DPB1*02, late onset of disease, and early hip involvement were predictors of sacroiliitis.

Juvenile-onset spondyloarthropathies

This article discusses the clinical spectrum and characteristics of juvenile-onset spondyloarthropathies and includes a review of the demographic, clinical, radiographic (and other imaging techniques), and laboratory data of conditions, syndromes, and diseases making up this group. The pathogenic role of several factors in the context of adult-onset patients, but also in regards to studies already performed in juvenile-onset patients, is discussed.

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.

The early clinical recognition of juvenile-onset ankylosing spondylitis and its differentiation from juvenile rheumatoid arthritis

OBJECTIVE

To determine which early clinical data differentiate juvenile-onset ankylosing spondylitis (AS) from juvenile rheumatoid arthritis (JRA).

METHODS

Medical records of 35 patients with juvenile-onset AS and 75 with JRA (excluding type II pauciarticular JRA), all of whom had disease onset at age < or = 16 years, disease duration of < or = 2 1/2 years at the initial visit to the rheumatology clinic, and followup of > or = 10 years, were analyzed retrospectively with regard to features of disease found 6 months, 12 months, and 10 years after onset.

RESULTS

At 6 months, various features appeared more frequently in the juvenile-onset AS group than in the JRA group, i.e., pauciarthritis (54.3% versus 30.7%; P = 0.03, odds ratio [OR] = 2.7), enthesopathy (82.9% versus 0%; P < 0.0001, OR = 321.4), tarsal disease (71.4% versus 1.3%; P < 0.0001, OR = 185.0), and lumbar/sacroiliac symptoms (11.4% versus 0%; P = 0.02, OR = 11.9). At 12 months, the features found more frequently among juvenile-onset AS patients than JRA patients were enthesopathy (88.6% versus 4.0%; P < 0.0001, OR = 186.0), tarsal disease (85.7% versus 10.7%; P < 0.0001, OR = 50.3), and knee disease (100.0% versus 82.7%; P = 0.04, OR = 8.0). Involvement of the upper extremities (especially the hands) was found in significantly fewer juvenile-onset AS patients compared with the JRA group. Definite involvement of the spine and sacroiliitis in juvenile-onset AS occurred after a mean +/- SD of 7.3 +/- 2.0 years.

CONCLUSION

Regardless of axial disease, enthesopathy and tarsal disease in children who have arthritis of the lower, but not of the upper extremities differentiate juvenile-onset AS from JRA within 1 year of symptoms. The discriminative value of these parameters approaches that of axial disease (the gold standard) throughout the followup period.

Clinical, HLA, and roentgenological follow up study of patients with juvenile arthritis: comparison between the long term outcome of transient and persistent arthritis in children

Fifty two patients with juvenile chronic arthritis (JCA) and 22 patients with arthritis of short duration (transient arthritis, TA) were studied in a follow up investigation. Nineteen (37%) of the patients with JCA had peripheral arthritis or sequelae in the form of contractures at follow up, and in addition one patient was treated with corticosteroids. In contrast, only one (5%) of the 22 patients with TA had peripheral arthritis at follow up. Back pain or limitation, or both, was registered in many of the men. Sacroiliitis, verified by x ray, was often found both in JCA (39/46, 85%) and in TA (16/21, 76%). For JCA an association was confirmed with HLA-A2 and HLA-DRw8 and a negative association with HLA-DR4, and in pauciarticular JCA, in addition, a decrease of DR7. A new finding was a low prevalence of HLA-B27 in women with JCA and grade 3 or 4 sacroiliitis (2/14, 14%).

Atypical spondyloarthritis in children: proposed diagnostic criteria

Clinical and laboratory findings in 26 children with atypical spondyloarthritis were compared with those of 76 children with juvenile rheumatoid arthritis. The sensitivity, specificity, predictive value, and efficiency for diagnosis were calculated. The following findings (major criteria) were much more common in atypical spondyloarthritis than in juvenile rheumatoid arthritis: (1) spondyloarthritis within the family; (2) enthesopathy; (3) arthritis of digital joints; (4) sacro-iliitis; (5) presence of HLA-B27; (6) frequent recurrence of arthritis and arthralgia. Six additional findings (minor criteria) were significantly more common in atypical spondyloarthritis (SA): (1) disease onset after the age of 10 years; (2) male sex; (3) involvement of the lower extremities; (4) acute iridocyclitis or conjunctivitis; (5) arthritis of the hip joints; (6) manifestation following a history of enteritis. In the presence of 4 major criteria or 3 major and 3 minor criteria, the diagnosis of an atypical SA was established with a sensitivity of 84.6%, a specificity of 100%, and an efficiency of 96.1%.

Population genetics and molecular biology of the childhood chronic arthropathies

Recent immunogenetic studies of JRA patients have both helped to clarify subdivision into distinctive subtypes and identified those subtypes which may be related to adult rheumatic disease. Despite the variability of HLA associations from different geographic sources, a consensus appears to be emerging as to the most important associations. In addition to the HLA-DR locus, distinct associations with the HLA-DP and HLA-DQ loci have been described. Family studies have suggested an increased risk with certain haplotypes, particularly in the EOPA JRA population. Although inheritance patterns remain to be defined, recent studies with monoclonal antibodies, alloreactive T cell clones, and DNA have identified the existence of specific epitopes encoded by a variety of Ia molecules which may be more directly related to disease susceptibility. The concept of an epitope dose effect is put forward to account for the variable HLA association with disease, particularly with regard to EOPA JRA. Further developments in the definition of micropolymorphisms of Ia molecules at the genomic level as well as the possible involvement of other genetic loci, in particular T cell receptor variable gene products, should help clarify our understanding of the role of genetic factors in the aetiology of JRA. The studies of the last two decades indicate that inferences made by Carter (1969) on the 'polygenic, weakly penetrant genetic effect' in autoimmune disease are indeed applicable to JRA.

HLA-B27-associated arthropathy in childhood: long-term clinical and diagnostic outcome

We conducted HLA-B27 tissue typing assessments on 430 consecutive children whose main symptom at presentation to our clinic was arthritis/arthralgia. Eighty-five of them (20%) had the B27 antigen. Thirty-six of these children were reexamined after a mean followup period of 8.9 years. Although most had definable rheumatic diseases, only 2 met the New York criteria for ankylosing spondylitis (AS). Children with HLA-B27 and arthritis/arthralgia, although at increased risk of developing AS, have diverse diagnostic and clinical outcomes. The AS criteria used to diagnose the disease in adults may not be appropriate for use in children.

Uveitis associated with juvenile rheumatoid arthritis

Chronic nongranulomatous uveitis associated with JRA, a distinctive clinical entity occurring almost exclusively in the pediatric age group, represents an important cause of visual impairment in children. Despite continuing clarification of the clinical manifestations of this disorder, the etiology of uveitis associated with JRA remains unknown and the pathophysiology is still poorly understood. Further study of uveitis-associated JRA, by the application of improved immunologic theories and techniques, should aid in developing more effective therapeutic and preventive strategies.

Arthritis in children

Arthritis in children may result from many conditions. The rheumatic diseases, including juvenile rheumatoid arthritis, the spondyloarthropathies, rheumatic fever, lupus erythematosus, dermatomyositis, and the various vasculitis syndromes all can cause arthritis; these diseases are distinguished by their characteristic clinical appearances. Several nonrheumatic disorders such as infections, malignancies, congenital or genetic conditions, orthopedic conditions, and psychological disorders may closely simulate the various rheumatic diseases. The evaluation of children with arthritis rests chiefly on historical and physical findings; radiographs, laboratory tests, and occasionally biopsies also may be helpful. It is particularly important to identify specifically treatable diseases, such as bacterial infections or childhood malignancies, early and to avoid labeling nonrheumatic conditions as rheumatic. Accurate diagnosis of the various rheumatic disease syndromes is important for optimal therapy.

Limb pain in childhood

As the presenting complaint in 7 per cent of pediatrician visits, pain in the limbs is a common problem in childhood. It is important that the diagnosis be made expeditiously. The authors review the possible organic cause of limb pain, as well as limb pain from conversion reactions and from growing pains, giving special attention to the differential diagnosis so that appropriate treatment for the pain can be initiated.

Inherited predisposition to iridocyclitis with juvenile rheumatoid arthritis: selectivity among HLA-DR5 haplotypes

HLA-DR5 is associated with a chronic iridocyclitis and juvenile rheumatoid arthritis with onset in early childhood. Previously published data provided indirect evidence for selective linkage between two HLA-B alleles and HLA-DR5. To test this observation further, 38 families, the probands of which have chronic iridocyclitis and juvenile rheumatoid arthritis, were HLA typed so that haplotypes associated with disease could be established. HLA-DR5 was linked to HLA-Bw44 or to HLA-Bw35 and to HLA-Cw4 in the majority of haplotypes obtained in the probands. Both HLA-Bw44, -DR5 and HLA-Bw35, -Cw4, -DR5 occurred more commonly in the proband haplotypes than in the control haplotypes. The frequency of the haplotype HLA-Bw44, -DR5 was 0.133 compared with 0.007 (X2 = 27.04, P less than 10(-6] and for HLA-Bw35, -Cw4, -DR5, it was 0.093 compared with 0.11 (X2 = 13.83, P = 0.0002). The relative risks were 20.77 and 9.23, respectively, versus 3.52 for HLA-DR5 alone. HLA-Bw44 occurred much more commonly in proband HLA-DR5 haplotypes (0.455) compared with control HLA-DR5 haplotypes (0.067) (X2 = 8.26, P less than 0.01). Not all HLA-DR5-bearing haplotypes predisposed equally to chronic iridocyclitis and early-onset pauciarticular juvenile rheumatoid arthritis.

Increase of HLA-"DRw6" in patients with juvenile chronic arthritis

In 43 patients with pauciarticular and 26 patients with polyarticular juvenile chronic arthritis (JCA), an increased frequency was found for HLA-B27 (36%) in male patients with onset of the disease over 9 years of age. The antigen "DRw6" was observed in high frequency (average 57%) in all subtypes of the disease. Indications for increased frequencies were obtained for DR3 in male JCA (40%) and DR5 (42%) in female JCA patients.

HLA studies in IgM rheumatoid-factor-positive arthritis of childhood

The clinical course of children with IgM rheumatoid-factor-positive chronic arthritis closely resembles that of seropositive rheumatoid disease in adults. The frequency of HLA DR4 is known to be increased in adults with seropositive rheumatoid arthritis, but the first major report on childhood arthritis did not suggest a correlation, though only 8 seropositive cases were included. Fifty-two children with polyarthritis beginning before the age of 16 who persistently carried IgM rheumatoid factor were studied. HLA DR4 was present in 60% of these children but was found in only 29% of 93 patients with seronegative juvenile arthritis and 27% of a normal adult population. These results suggest immunogenetic similarities in patients with seropositive arthritis irrespective of age of onset.

HLA-B27-associated spondyloarthritis and enthesopathy in childhood: clinical, pathologic, and radiographic observations in 58 patients

HLA-B27 typing of all arthritic children helped to identify and focus attention on a subset whose disease was pathogenetically related to and demonstrated clinical features of ankylosing spondylitis and Reiter syndrome, but only rarely fulfilled current diagnostic criteria for those disorders (spondyloarthritis). In contrast to other forms of childhood arthritis, enthesopathy (inflammation at the sites of attachment of ligaments and tendons to bone) was a prominent feature in 75%; a family history of similar arthritis was obtained from 60%; boys were more frequently affected (2:1); urethritis, acute iritis, conjunctivitis, or keratoderma blennorrhagicum occurred at some time in 42%; and the initial attack followed an unexplained febrile illness, known dysentery or urethritis, or severe musculoskeletal trauma in 41%. The arthritis was generally pauciarticular, asymmetric, and primarily in the feet and large joints of the lower extremities. Distinctive radiographic features included periostitis, severe osteopenia, calcaneal erosions, and heel spurs; three of 58 had rapid destruction of a single joint. Only ten patients (all boys) were found to have radiographic sacroiliitis after an average of five years of disease, and only three had the Reiter triad. The lifetime risk of sacroiliitis and spinal ankylosis can only be determined by long-term follow-up of such prospectively identified groups of spondyloarthritic children.

HLA-Bw35 and prognosis in adult Still's disease

Twenty-five patients with adult Still's disease were studied to determine clinical course and possible HLA associations. Two types of disease evolution were distinguishable clinically: a self-limited remitting disease with or without recurrent cyclic exacerbations was found in 11 patients, and a persistent disease with continuous activity for more than 1 year, generally accompanied by progressive joint disease, was determined in 8. Disease course could not be classified in 6 patients. The antigen frequencies of HLA-Bw35 (40%, P less than 0.05) and Cw4 (44%, P less than 0.05) were increased in adult Still's disease as compared to controls (18% and 20%, respectively). Because HLA-Bw35 was associated with self-limited remitting type disease (P less than 0.02), this antigen may be a favorable prognostic marker in adult Still's disease.

Synovial fluid in seronegative juvenile rheumatoid arthritis: studies of immunoglobulins, complements, and alpha 2-macroglobulin

Synovial fluid of 20 children with seronegative juvenile rheumatoid arthritis (JRA) and 20 patients with other joint pathology was examined for levels of total hemolytic complement and selected components, immune complexes, and alpha 2-macroglobulin (alpha 2-M). When adjusted for total protein, synovial levels of total hemolytic complement, C3, C4, and alpha 2-M did not differ significantly in the two groups. The concentrations of IgM and IgG were elevated in the JRA synovial fluid, but immune complexes were not increased when compared with non-JRA group as determined by the Raji cell technique. alpha 2-M activity against substrates of C1 esterase was absent. therefore, evidence of specific increase in immune complexes and complement activation was sought but not found, suggesting that they may not be a major factor in the pathogenesis of seronegative, pauciarticular JRA.

Early-onset pauciarticular juvenile rheumatoid arthritis associated with human leukocyte antigen-DRw5, iritis, and antinuclear antibody

Evidence has been sought for a genetically determined predisposition among children with juvenile rheumatoid arthritis (JRA) who are also at particular risk for the development of inflammatory eye disease.45 unrelated Caucasian patients (41 female) with early-onset pauciarticular JRA were human leukocyte antigen (HLA) types. 28 of the study group were found to be HLA-DRw5 compared with 16 of 84 controls (X(2), 24.3, P = <0.001). 9 patients were HLA-DRw8 compared with 4 of 84 controls (X(2), 7.51, P = <0.01). Iritis developed in 24 of the 45 children studied, 17 of whom were typed as HLA-DRw5 when compared to controls (X(2), 26.76, P = <0.001) and 6 with iritis typed as HLA-DRw8 (X(2), 9.10, P = <0.01). Antinuclear antibody was found in the serum of 17 of the 28 patients typing as HLA-DRw5 compared with 4 of the 17 who did not have this antigen (X(2), 5.88, P = <0.02). No such association was seen in patients with HLA-DRw8. In a study of linked genes, a delta value of 0.090 was found for HLA-DRw5 with HLA-B12, of 0.070 for DRw5 with HLA-Cw4, and a value of 0.050 for DRw5 and HLA-Bw35. This suggests a linkage disequilibrium between HLA-DRw5 and these two B series alleles, a conclusion which was supported by haplotype analysis in families of 11 of the disease probands. HLA-DRw5 has not previously been reported to be increased in any rheumatic disease group. It is proposed that HLA-DRw5 is a genetic marker defining those at risk for early-onset pauciarticular JRA with iritis.

Heterogeneity of HLA associations in systemic onset juvenile rheumatoid arthritis

Two genetic markers, HLA-Bw35 and HLA-B8, are found to be associated with "febrile" or "systemic" onset juvenile rheumatoid arthritis (JRA). Evidence is presented that JRA patients are probably heterogeneous with respect to these antigens.

The pediatric arthritides

The three principal syndromes of juvenile rheumatoid arthritis have distinctive features that aid in early diagnosis and can contribute to specificity of treatment. Guidelines are given for differentiating JRA from other disorders producing joint pain.

The histocompatibility complex and rheumatic diseases

Histocompatibility typing has assumed an increasingly important role as a clinical and research tool in rheumatic diseases. The HLA antigens which are serologically defined (A and B series) are being used most extensively for clinical work, but the role of other immunologic determinants in the HLA complex is being evaluated. These include D-locus (MLC) determinants, several complement components, and immune response genes which have been well characterized in the mouse, but not in man. The products of the major histocompatibility complex are inherited in a simple Mendelian fashion as a series of co-dominant alleles. Large population studies have characterized the frequencies of various alleles, and family studies have allowed tentative mapping of the various loci within the complex on the sixth chromosome in man. A number of diseases which are considered to be autoimmune in nature are now known to be associated with specific HLA antigens. Of these disease associations, the strongest and best studied are the seronegative spondyloarthropathies which are highly associated with the B27 antigen. Included in this group are ankylosing spondylitis, Reiter's syndrome, psoriatic arthropathy, colitic arthropathy, Yersinia arthritis and a small group of juvenile rheumatoid arthritis patients with features of ankylosing spondylitis. The clinical application of tissue typing or B27 testing is most helpful in regard to difficult diagnostic problems in patients with early or atypical seronegative spondyloarthropathy. Its value as an indicator of prognosis, and its value in counselling family members is not well established. There are many interesting hypotheses regarding pathogenetic mechanisms of these rheumatic diseases based on susceptibility factors related to the major histocompatibility complex. An abnormal immune response gene within the complex is probably a key feature of the mechanism, but the exact details are little more than speculative at this point.

Lyme arthritis: an epidemic of oligoarticular arthritis in children and adults in three connecticut communities

An epidemic form of arthritis has been occurring in eastern Connecticut at least since 1972, with the peak incidence of new cases in the summer and early fall. Its identification has been possible because of tight geographic clustering in some areas, and because of a characteristic preceding skin lesion in some patients. The authors studied 51 residents of three contiguous Connecticut communities -- 39 children and 12 adults -- who developed an illness characterized by recurrent attacks of asymmetric swelling and pain in a few large joints, especially the knee. Attacks were usually short (median: 1 week) with much longer intervening periods of complete remission (median: 2.5 months), but some attacks lasted for months. To date the typical patient has had three recurrences, but 16 patients have had none. A median of 4 weeks (range: 1-24) before the onset of arthritis, 13 patients (25%) noted an erythematous papule that developed into an expanding, red, annular lesion, as much as 50 cm in diameter. Only 2 of 159 family members of patients had such a lesion and did not develop arthritis (P less than 0.000001). The overalll prevalence of the arthritis was 4.3 cases per 1,000 residents, but the prevalence among children living on four roads was 1 in 10. Six families had more than 1 affected member. Nine of 20 symptomatic patients had low serum C3 levels, compared to none of 31 asymptomatic patients (P less than 0.005); no patient had iridocyclitis or a positive test for antinuclear antibodies. Neither cultures of synovium and synovial fluid nor serologic tests were positive for agents known to cause arthritis. "Lynne arthritis" is thought to be a previously unrecognized clinical entity, the epidemiology of which suggests transmission by an arthropod vector.