Abnormalities in the distribution of serum immunoglobulin concentrations in juvenile rheumatoid arthritis

The Epidemiology and Clinical Manifestations of Autoimmunity in Selective IgA Deficiency

Selective immunoglobulin A deficiency (SIgAD) is the most common primary immunodeficiency, defined as an isolated deficiency of IgA (less than 0.07 g/L). Although the majority of people born with IgA deficiency lead normal lives without significant pathology, there is nonetheless a significant association of IgA deficiency with mucosal infection, increased risks of atopic disease, and a higher prevalence of autoimmune disease. To explain these phenomena, we have performed an extensive literature review to define the geoepidemiology of IgA deficiency and particularly the relative risks for developing systemic lupus erythematosus, hyperthyroidism, hypothyroidism, type 1 diabetes mellitus, Crohn's disease, ulcerative colitis, rheumatoid arthritis, juvenile idiopathic arthritis, ankylosing spondylitis, and vitiligo; these diseases have strong data to support an association. We also note weaker associations with scleroderma, celiac disease, autoimmune hepatitis, immune thrombocytopenic purpura, and autoimmune hemolytic anemia. Minimal if any associations are noted with myasthenia gravis, lichen planus, and multiple sclerosis. Finally, more recent data provide clues on the possible immunologic mechanisms that lead to the association of IgA deficiency and autoimmunity; these lessons are important for understanding the etiology of autoimmune disease.

Glu-C, an alternative digestive enzyme for the quantitative LC–MS/MS analysis of an IgG-based antibody biotherapeutic

Aim: LC–MS/MS bottom-up quantitation of proteins has become increasingly popular with trypsin as the most commonly used protease. However, trypsin does not always yield suitable surrogate peptides. An alternative enzyme, Glu-C, was used to generate surrogate peptides for quantifying a bispecific IgG1 biotherapeutic antibody in preclinical matrices.  Materials and methods: IgG1 was quantified by pellet digestion using an Acquity UPLC coupled  with a Xevo TQ-S mass spectrometer.  Results: Two generic LC–MS/MS methods (heavy and light chain) were developed which afforded acceptable precision and accuracy, and an lower limit of quantitation of 1 μg/ml in three preclinical matrices. A small nonsignificant bias was observed when cynomolgus serum LC–MS/MS results were compared with electrochemiluminescent immunoassay data. Conclusion: Glu-C was successfully used as an alternative digestion enzyme for bottom-up quantitation of an IgG1 in matrices from multiple preclinical species, with good agreement with electrochemiluminescent immunoassay data.

Phenotypic characterization of patients with rheumatologic manifestations of common variable immunodeficiency

Patients with common variable immunodeficiency (CVID) have a higher incidence of rheumatologic disorders. To delineate this clinical association, we investigated the phenotypic features of patients with CVID affected by these conditions.

METHODS

We conducted a retrospective analysis of 870 pediatric and adult patients with CVID included in the United States Immunodeficiency Network (USIDNET) registry. Outcomes included clinical characteristics (age, gender, ethnicity, rheumatologic diagnosis, and comorbidities), infectious history and basic immunophenotype (serum immunoglobulin levels, CD19+ B cells, and CD4/CD8 ratio) in patients with CVID and rheumatologic disorders compared to those with non-inflammatory CVID. Demographic and clinical data were compared using chi-square, Fisher's exact or Wilcoxon-Mann-Whitney tests. Non-parametric tests, single and multiple logistic regression models were used to evaluate the relationship between CVID-associated rheumatologic disorders and basic immunophenotypic parameters (IgA, IgM, CD19+ B-cell counts, and CD4/CD8 ratios).

RESULTS

Physician-reported rheumatic diseases were present in 5.9% of patients with CVID (n = 51) included in the registry. Although CVID affects both sexes equally, and patients are of predominantly White-Caucasian ethnicity, there were more females (3.3:1 female to male ratio) and increased proportion of non-white patients in the rheumatologic disease group (p < 0.05). Specific disorders included: inflammatory arthritis (n = 18), Sjogren's syndrome (n = 11), SLE (n = 8), Raynaud's syndrome (n = 8), vasculitis (n = 9), MCTD (n = 3), and other (n = 5). In about one-third of patients, a rheumatologic condition was associated with an additional inflammatory complication or malignancy. In regards to the immunophenotype parameters compared (CD19+ B-cell counts, CD4/CD8 ratio, IgA, and IgM), no significant differences were demonstrated between the two groups.

CONCLUSION

Our findings highlight the coexistence of primary antibody immunodeficiencies and systemic rheumatologic disorders, describe the spectrum of rheumatologic manifestations, and contrast differences in relevant demographic, clinical and immunophenotype parameters in the largest registry of CVID patients in the U.S. In spite of its limitations, our study details the intersection of systemic autoimmunity and CVID and provides valuable insights into these two groups of disorders. Further delineating the link between systemic autoimmunity and humoral immunodeficiencies can provide novel insights into the immune abnormalities underlying these related conditions.

IgA deficiency and autoimmunity

IgA is the most abundant immunoglobulin in the human body, and performs a very specialized role which involves mucosal immunity, development of tolerance and protection against infection. IgA is the key immunoglobulin in the respiratory and gastrointestinal tracts, which provide the most intimate interface between the environment and self. Normal levels of IgA are based on early studies consisting of only small numbers of patients. The international consensus definition of IgA deficiency is a level of 0.07g/l after the age of four years in the absence of IgG and IgM deficiencies. The epidemiology of IgA deficiency reveals interesting variances between geographical regions - the incidence in Caucasians being much higher than that in Asians. IgA deficiency has also been found to co-exist with autoimmune diseases, allergies and malignancies. The association with autoimmunity is particularly interesting because it suggests a common genetic linkage that could potentially also explain the diversity in geoepidemiology. Both MHC and non-MHC associations have been described and the 8.1 haplotype has been significantly associated with autoimmunity in IgA deficiency patients over controls. Non-MHC genetic associations include IFIH1 and CLEC16A. The mutations leading to IgA deficiency have not been defined, but in some cases of IgA deficiency it has been suggested that the pathogenesis involves a failure in switched memory B cells that can lead to this cohort experiencing an increased incidence of recurrent bacterial infections or autoimmune diseases. Attempts to investigate the role of cytokines that can induce IgA synthesis in cells of patients with IgA deficiency, such as IL21 or the combination of CD40L/anti-CD40, IL-4 and IL10, are underway.

Diagnosis and management of infectious complications of childhood rheumatic diseases

Progress in the diagnosis and management of pediatric rheumatic disease has improved complications from underlying disease and the survival of children. However, as a consequence, infection has now become one of the leading causes of morbidity and mortality. Differentiating between infections and disease flares in children with rheumatic conditions can often pose diagnostic quandaries. Children with rheumatic diseases are at risk of infection, not only because of the use of immune-modulating medications but also because of underlying immune dysfunction associated with their disease. Although bacterial infections are the most common, any organism can potentially be a causative agent and, at times, more invasive measures of diagnosis, for example bronchoscopy and tissue biopsies may be necessary. Maintaining a high index of suspicion of infection with prompt diagnosis and treatment are important to further improve patient outcomes.

Rates of hospitalized bacterial infection associated with juvenile idiopathic arthritis and its treatment

OBJECTIVE

To compare the incidence of hospitalized bacterial infections among children with and children without juvenile idiopathic arthritis (JIA) and to examine the effects of selected medications.

METHODS

Using national Medicaid data from 2000 through 2005, we identified a cohort of children with JIA and a comparator cohort of children with attention deficit hyperactivity disorder (ADHD). Exposures to methotrexate (MTX), TNF inhibitors, and oral glucocorticoids (GCs) were determined using pharmacy claims. Patients hospitalized with bacterial infections were identified using coded discharge diagnoses. We calculated adjusted hazard ratios (HR(adj) ) to compare infection incidence rates while adjusting for relevant covariates.

RESULTS

We identified 8,479 JIA patients with 13,003 person-years of followup; 36% took MTX and 16% took TNF inhibitors. Compared with ADHD patients, JIA patients who were not currently taking MTX or TNF inhibitors had an increased rate of infection (HR(adj) 2.0 [95% confidence interval (95% CI) 1.5, 2.5]). Among JIA patients not receiving TNF inhibitor therapy, MTX users had a similar rate of infection as those not currently taking MTX (HR(adj) 1.2 [95% CI 0.9, 1.7]). TNF inhibitor use (irrespective of MTX) resulted in a similar rate of infection as use of MTX without a TNF inhibitor (HR(adj) 1.2 [95% CI 0.8, 1.8]). Use of high-dose GCs (≥10 mg/day of prednisone or equivalent) increased the rate of infection as compared with no GC use, after adjustment for MTX and TNF inhibitor use (HR(adj) 3.1 [95% CI 2.0, 4.7]).

CONCLUSION

Children with JIA had an increased rate of infection compared to children with ADHD. Among children with JIA, the rate of infection was not increased with MTX or TNF inhibitor use, but was significantly increased with high-dose GC use.

Selective IgA deficiency in autoimmune diseases

Selective immunoglobulin A deficiency (IgAD) is the most common primary immunodeficiency in Caucasians. It has previously been suggested to be associated with a variety of concomitant autoimmune diseases. In this review, we present data on the prevalence of IgAD in patients with Graves disease (GD), systemic lupus erythematosus (SLE), type 1 diabetes (T1D), celiac disease (CD), myasthenia gravis (MG) and rheumatoid arthritis (RA) on the basis of both our own recent large-scale screening results and literature data. Genetic factors are important for the development of both IgAD and various autoimmune disorders, including GD, SLE, T1D, CD, MG and RA, and a strong association with the major histocompatibility complex (MHC) region has been reported. In addition, non-MHC genes, such as interferon-induced helicase 1 (IFIH1) and c-type lectin domain family 16, member A (CLEC16A), are also associated with the development of IgAD and some of the above diseases. This indicates a possible common genetic background. In this review, we present suggestive evidence for a shared genetic predisposition between these disorders.

Predictors of hip disease in the systemic arthritis subtype of juvenile idiopathic arthritis

OBJECTIVE

Hip involvement occurs in 20%-40% of all cases of juvenile idiopathic arthritis (JIA). Patients with systemic JIA (sJIA) are affected most frequently. The aim of our study was to investigate the predictors of clinical hip disease and radiographic hip damage in sJIA.

METHODS

The medical records (1997-2007) of all children (n = 98) with sJIA were reviewed. Potential clinical and laboratory predictors were examined at presentation and at 3 and 6 months. To account for censored observations, we used survival analysis.

RESULTS

During the study period, 59 children met our inclusion criteria. The mean age at diagnosis was 7.8 years. Thirty patients (51%) developed clinical hip disease, with 12 (20%) developing radiographic evidence of hip damage. The median time to develop clinical hip disease was 24 months. Using Kaplan-Meier estimates, 25% of patients develop radiographically evident hip damage within 43 months. At presentation, patients in whom clinical hip disease later developed had polyarthritis (hazard ratio 2.51, p = 0.01), elevated IgG (HR 1.12, p = 0.01) and IgM (HR 2.71, p = 0.02), and higher CHAQ scores (HR 1.65, p = 0.02). At 3 months after disease onset, patients in whom radiographic hip damage later developed had fever (HR 4.78, p = 0.02), polyarthritis (HR 4.63, p = 0.02), and higher CHAQ scores (HR 3.20, p = 0.005). At 6 months, polyarthritis was the strongest predictor of both clinical hip disease and radiographic hip damage.

CONCLUSION

Half of patients with sJIA develop clinical hip disease a median time of 24 months from diagnosis. Early identification of predictors of hip disease and damage in patients with sJIA may suggest earlier, more aggressive interventions to prevent joint destruction.

Juvenile idiopathic arthritis: Diagnosis and differential diagnosis

Juvenile idiopathic arthritis (JIA) is comprised of a heterogeneous group of several disease subtypes that are characterized by the onset of arthritis before the age of 16 years and has symptoms lasting at least 6 weeks. The previous classification of JIA included seven different categories, whereas its current classification was compiled by the International League of the Association for Rheumatology, and replaced the previous terms of "juvenile chronic arthritis" and "juvenile rheumatoid arthritis," which were used in Europe or North America, respectively, with the single nomenclature of JIA. As mentioned above, JIA is defined as arthritis of unknown etiology that manifests itself before the age of 16 years and persists for at least 6 weeks, while excluding other known conditions. The clinical symptoms of JIA can be quite variable. Several symptoms that are characteristic of arthritis are not necessarily diagnostic of JIA and may have multiple etiologies that can be differentiated with careful examination of patient history. The disease may develop over days or sometimes weeks, thereby making the diagnosis difficult at the time of presentation. To make a clinical diagnosis of JIA, the first step is to exclude arthritis with known etiologies. Of note, late treatment due to excessive delay of diagnosis can cause severe damage to joints and other organs and impair skeletal maturation. Therefore, early detection of JIA is critical to ensure prompt treatment and to prevent long-term complications including the likelihood of disability in childhood.

Selective IgA deficiency in children and adults with systemic lupus erythematosus

The objective of this study was to determine the frequency and clinical characteristics of selective IgA deficiency (SIgAD) in children and adults with systemic lupus erythematosus (SLE), and evaluate potential differences in presentation and course of the SLE. IgA deficiency was defined as a serum IgA concentration < or =0.01 mg/mL determined on two sera by radial diffusion. SLE was classified by the 1982 criteria of the American College of Rheumatology. Seventy-seven children with SLE followed prospectively for > or =20 years and 152 adults surveyed during a one-year period were assayed for serum IgA levels. Disease characteristics were compared among the deficient patients and the IgA-normal patients. Twelve patients with SIgAD were identified: 1) Juvenile(J)-SLE: four children with juvenile onset (< or =18 years) and four others encountered as adults; and 2) Adult(A)-SLE: four patients with adult onset. No significant differences were found in clinical presentation or course except for a possible increase in recurrent infections and the observation that there were only two African-Americans. Five patients had received blood transfusions with no reactions; three of these patients had serum anti-IgA antibodies. One pediatric patient developed low levels of IgA (<or =1 mg/mL) during a follow-up of three years. Two adult patients died (septicemia, carcinoma); one was on dialysis. SIgAD was identified in 5.2% of children and 2.6% of adults with SLE for an estimated 35-fold increase in frequency. This small number of patients did not appear to have an altered clinical presentation or course from that expected in patients with SLE who did not have SIgAD.

Juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA), a term referring to a group of disorders characterized by chronic arthritis, is the most common chronic rheumatic illness in children and is a significant cause of short- and long-term disability. This article discusses the classification, differential diagnosis, and treatment of JIA.

Juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA), a term referring to a group of disorders characterized by chronic arthritis, is the most common chronic rheumatic illness in children and is a significant cause of short- and long-term disability. This article discusses the classification, differential diagnosis, and treatment of JIA.

Functional and prognostic relevance of the -173 polymorphism of the macrophage migration inhibitory factor gene in systemic-onset juvenile idiopathic arthritis

OBJECTIVE

To address the functional and prognostic relevance of the -173 single-nucleotide G-to-C polymorphism of the macrophage migration inhibitory factor (MIF) gene in patients with systemic-onset juvenile idiopathic arthritis (systemic-onset JIA) by evaluating its association with serum and synovial fluid levels of MIF, with glucocorticoid requirement, and with the outcome of the disease.

METHODS

A total of 136 patients with systemic-onset JIA were studied, including 98 patients from the British Paediatric Rheumatology Study Group's National Repository for JIA and 38 patients who were followed up at the IRCCS Policlinico San Matteo (Pavia, Italy) and the IRCCS G. Gaslini (Genoa, Italy). The MIF-173 polymorphism was genotyped using SnaPshot ddNTP primer extension and capillary electrophoresis. MIF levels were measured by enzyme-linked immunosorbent assay. The evaluation of the association of the MIF-173 polymorphism with outcome was performed only in Italian patients who were followed up for >5 years, by analyzing retrospectively 1) the number of joints with active arthritis and the number of joints with limited range of motion; 2) the score, at the last visit, on the Italian version of the Childhood Health Assessment Questionnaire (C-HAQ); and 3) data concerning the treatment regimens during the disease course.

RESULTS

Systemic-onset JIA patients carrying a MIF-173*C allele had serum and synovial fluid levels of MIF significantly higher than those in patients with the GG genotype. The duration of glucocorticoid treatment on a daily regimen was significantly longer in patients carrying a MIF-173*C allele than in MIF-173 GG homozygous patients. Moreover, the duration of clinical response to intraarticular injection of triamcinolone hexacetonide was significantly shorter in patients carrying a MIF-173*C allele. At the last visit, the numbers of joints with active arthritis, the C-HAQ scores, and the numbers of joints with limited range of motion were significantly higher in patients carrying the MIF-173*C allele.

CONCLUSION

Our study shows the functional relevance of the MIF-173 polymorphism and suggests that the MIF-173*C allele is a predictor of poor outcome in systemic-onset JIA.

Immunologic features of chromosome 22q11.2 deletion syndrome (DiGeorge syndrome/velocardiofacial syndrome)

OBJECTIVES

To characterize immunologic function and clinical characteristics in patients with chromosome 22q11.2 deletion syndrome and determine whether there was significant change over time.

METHODS

This study characterized the laboratory and clinical features of the immunodeficiency in a cohort of 195 patients with chromosome 22q11.2 deletion syndrome and used cross-sectional and analysis of variance to compare the findings in different age groups with control patients. Changes over time were also characterized by a model effect method in a subset of patients who were studied serially.

RESULTS

Diminished T cell counts in the peripheral blood are common in patients with chromosome 22q11.2 deletion syndrome. The pattern of changes seen with aging in normal control patients was also seen in patients with chromosome 22q11.2 deletion syndrome, although the decline in T cells was blunted. Autoimmune disease was seen in most age groups, although the types of disorders varied according to age. Infections were also common in older patients, though they were seldom life threatening.

CONCLUSIONS

Slow declines in T cell populations are seen in chromosome 22q11.2 deletion syndrome. Clinical manifestations of immunodeficiency, such as recurrent infection and autoimmune disease, were common in this population but had little relationship to specific immunologic laboratory features.

Early predictors of poor functional outcome in systemic-onset juvenile rheumatoid arthritis: a multicenter cohort study

OBJECTIVE

To examine the ability of a previously described set of criteria to predict poor functional outcome in a large, multicenter cohort of children with systemic-onset juvenile rheumatoid arthritis (JRA).

METHODS

All children who were diagnosed with systemic-onset JRA since 1980 at the Hospital for Sick Children (Toronto), since 1983 at the Isaac Walton Killam Hospital for Children (Halifax), and since 1981 at the Children's Hospital of Eastern Ontario (Ottawa) were evaluated. Patients were included in the study if they had been evaluated clinically within 6 months of diagnosis and had been followed up for at least 2 years. Patients were divided into 4 cohorts according to their length of followup: 2-4 years, 4-7 years, 7-10 years, and >10 years. Using previously described criteria for destructive arthritis in children with systemic-onset JRA, the patients were classified as either high risk or low risk for poor functional outcome based on the data from their 6-month visit. High-risk patients had active systemic disease (persistent fever or corticosteroid requirement for control of systemic disease) and a platelet count > or =600 x 10(9)/liter. Poor outcome was defined as moderate or severe disability (defined as a score of > or =0.75 on the Childhood Health Assessment Questionnaire) or disease-associated death.

RESULTS

Among 122 eligible patients with systemic-onset JRA, we were able to contact 111 (91%) for outcome data. The mean followup period was 7.7 years (SD 3.7). The mean age at outcome assessment was 13.5 years (SD 5.3). There were 51 boys and 60 girls. Twenty-four patients (22%) had moderate-to-severe disability and 2 patients died; these 26 patients were considered to have had a poor outcome. We could determine risk classification for 104 patients. Twenty-four patients (23%) met the criteria for high risk at the 6-month visit. Overall, the risk of a poor functional outcome was significantly higher in the high-risk group (relative risk 3.3, 95% confidence interval [95% CI] 1.73-6.43, P = 0.0004). This risk was most marked in the cohort with > 10 years of followup (relative risk 4.3, 95% CI 1.82-10.29, P = 0.006).

CONCLUSION

The presence of active systemic disease at 6 months, as characterized by fever or the need for corticosteroids, and thrombocytosis strongly predicted the development of a poor functional outcome in these patients. This was especially apparent with longterm followup. Our study validates the previously developed prognostic criteria for systemic-onset JRA.

Viruses and childhood arthritis

The role of viral infections in the aetiology of acute and chronic arthritides of childhood is incompletely understood. The fact that some viruses cause acute arthritis is certain, although in most instances of presumed viral arthritis no agent is identified. The associations of viruses with diseases such as juvenile chronic arthritis (JCA) are limited, and have been difficult to prove with certainty. Rubella, parvovirus B19 and influenza AH2N2 have been shown by culture, serology or epidemiology to be related to at least some cases of JCA in some studies, but not in others. A rationale for pursuing investigations of viral aetiology of chronic arthritis is discussed, and a strategy involving early disease detection and close collaboration between clinicians and scientists is proposed.

Juvenile rheumatoid arthritis-like polyarthritis in chromosome 22q11.2 deletion syndrome (DiGeorge anomalad/velocardiofacial syndrome/conotruncal anomaly face syndrome)

OBJECTIVE

To investigate the association of polyarthritis and chromosome 22q11.2 deletions.

METHODS

Eighty patients with chromosome 22q11.2 deletion syndrome followed up at The Children's Hospital of Philadelphia were examined for evidence of arthropathy or arthritis. Patients with chromosome 22q11.2 deletion syndrome and polyarthritis underwent laboratory evaluations of immunologic function to determine the relationship of their immunodeficiency to the polyarthritis.

RESULTS

The prevalence of polyarthritis in patients with chromosome 22q11.2 deletion syndrome was markedly increased over the prevalence of polyarticular juvenile rheumatoid arthritis (JRA) in the general population. All 3 patients with polyarthritis had evidence of impaired T cell function. Two of the patients with polyarthritis also had IgA deficiency.

CONCLUSION

The chromosome 22q11.2 deletion syndrome represents a primary T cell disorder which can be associated with a JRA-like polyarthritis. All 3 patients with polyarthritis had evidence of more extensive immunoregulatory derangements than those typically seen in patients with chromosome 22q11.2 deletion, and these derangements may have predisposed to the development of polyarthritis.

A case of protein-losing enteropathy in idiopathic thrombocytopenic purpura with decreased IgA

A young woman presented with high fever and edema in January, 1984, and was diagnosed as having systemic lupus erythematosus. Prednisolone administration failed to improve her symptoms. In May she was admitted to hospital because of elevated erythrocyte sedimentation rate (ESR), hypoproteinemia, hypogammaglobulinemia, hypocomplementemia, positive antinuclear antibody, elevated immune complex level, and diarrhea. Edema disappeared following administration of diuretics and albumin, although the pathogenesis was still undetermined. In September, she was referred to our institution because of severe watery diarrhea and hypoproteinemia. Endoscopic examination showed a diffuse inflammatory lesion in the duodenum and the colon. Radioisotopic 51Cr-albumin study results were compatible with protein-losing enteropathy. Hypoproteinemia and inflammatory changes of the intestine were improved by antibiotics, suggesting that the inflammatory lesion was caused by bacterial infection. Despite the improvements in clinical symptoms and laboratory findings, the serum IgA level was still low and the thrombocytopenia remained. The morphological characteristics of the megakaryocytes were consistent with idiopathic thrombocytopenic purpura. In May, 1986, the thrombocytopenia deteriorated, causing purpura. Prednisolone was administered again, and this resulted in normalization of the platelet count, although the IgA level remained low. Finally the prednisolone was stopped, and the IgA level gradually recovered, with the improvement of the enterocolitis. The exact pathogenesis of the whole picture in this case is unclear, but an 8-year-long clinical course suggests that the protein-losing was caused by an infectious enterocolitis superimposed on IgA deficiency.

Intravenous gamma globulin therapy in systemic juvenile rheumatoid arthritis

Intravenous (IV) gamma globulin has been successfully used as replacement therapy for antibody-deficient patients and, more recently, in the treatment of autoimmune diseases such as idiopathic thrombocytopenic purpura, myasthenia gravis, and Kawasaki disease. In view of the successful treatment of these diseases, we initiated a pilot study of the effect of IV gamma globulin in systemic juvenile rheumatoid arthritis (JRA). Eight patients with active systemic JRA that was unresponsive to first-line agents, second-line agents, and/or corticosteroids received this therapy monthly for 6 months. Outcome measures included changes in articular and extraarticular features, steroid dosage, and laboratory parameters. Following IV gamma globulin therapy, there was significant improvement in arthritis and/or morning stiffness in 5 of 8 patients, while extraarticular features significantly improved in 7 of 8 patients. At study entry, 6 of 8 patients were receiving prednisone; at study end, prednisone was discontinued in 3 patients and decreased by more than 50% in the other 3. Overall, there was an 80% reduction in the prednisone dosage. Initially, all patients had anemia, low levels of serum albumin, and an elevated erythrocyte sedimentation rate, while a thrombocytosis was seen in 7 of 8 patients. Serum IgG was initially elevated in 6 patients. IV gamma globulin therapy resulted in a significant increase in hemoglobin and albumin levels and a significant decrease in the mean serum IgG level, platelet count, and erythrocyte sedimentation rate. In only 1 patient did IV gamma globulin fail to significantly improve the clinical or laboratory features of the disease. We suggest that this therapy may be beneficial in the treatment of systemic JRA.

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.

IgG subclass serum levels in juvenile chronic arthritis

IgG subclass levels of sera from 26 patients with juvenile chronic arthritis (JCA) were determined by means of mouse monoclonal antibodies. Patients were divided into three groups according to clinical activity of the disease: active disease, partial remission, and remission. One hundred and sixty four age matched, healthy children served as controls. IgG subclass concentrations were log transformed, and a robust regression method was applied to obtain expected values for the different ages. We found a significant increase of IgG3 (p less than 0.0001), IgG1 (p less than 0.002), and IgG2 (p less than 0.035) in JCA sera, while IgG4 values did not differ significantly from those of controls. When patients were divided according to clinical activity significant increases of IgG2 and IgG4 were observed in the patients in partial remission. Our data suggest that differential increase of IgG subclasses during the courses of JCA may be of relevance to the pathogenesis of the disease.

Pokeweed mitogen and Staphylococcus aureus Cowan I induced immunoglobulin A synthesis by lymphocytes of IgA deficient blood donors

In vitro IgA synthesis induced by pokeweed mitogen (PWM), Staphylococcus aureus Cowan I (STA), and combinations of STA and PWM (STA/PWM) was studied in lymphocytes of IgA deficient (sIgAd) blood donors. Cultures of T-depleted (non-T) cells with autologous or allogeneic control T, irradiated T (T), or T4 cells suggested abnormalities in non-T cell fractions in most (12/22) sIgAd donors. T cell abnormalities in themselves, detectable in six donors, did not appear to account for the failure of IgA synthesis. Repeat studies in 10 donors indicated fluctuations in in vitro IgA synthesis in four. IgA synthesis induced by STA/PWM combinations was observed in only one of eight sIgAd donors. Our findings suggest that in some donors defects leading to failure to produce IgA may not be constant and support the hypothesis of a maturation arrest in IgA+ B cells in sIgAd donors.

Immunoglobulin allotypes in families with pauciarticular-onset juvenile chronic arthritis

Immunoglobulin allotypes have been studied in the families of 17 pauciarticular-onset juvenile chronic arthritis patients included in the 9th Histocompatibility Workshop. There is no evidence of an association of these genetic factors with the disease, nor with the HLA and complement C4 disease markers.

Immunoglobulin A deficiency: genetic studies

Immunoglobulin A (IgA) deficiency (less than 0.01 mg/ml) was demonstrated in 155 of 72,296 blood donors. Studies of families of 60 donors revealed IgA deficiency in other members of 12 families. No consistent pattern of inheritance of IgA deficiency was found. HLA typing of 62 unrelated IgA deficient blood donors showed a significant increase in the prevalence of HLA-B8 (p less than 0.005).

Juvenile chronic arthritis

A review of the clinical and immunological features of 72 children with chronic arthritis revealed a similar pattern of disease in Australian children when compared with overseas studies. Most of the children had pauciarticular disease, but polyarthritis and systemic forms were seen. Although HLA=B27 was identified in some patients, no florid example of ankylosing spondylitis in childhood was seen. A small, but significant, number of children had evidence of potentially blinding iritis which developed insidiously, and one child had acute uveitis. Although elevated antistreptolysin-O titres and raised total IgM levels were seen in a significant number of children, they were not confined to any particular clinical pattern and were not of any major prognostic value. Half the children were severely incapacitated at the height of their disease, but follow-up for periods of up to five years revealed that fewer than 5% had a significant permanent disability.

Serological abnormalities in juvenile chronic arthritis: a review of 46 cases

Data of 46 patients with juvenile chronic arthritis were evaluated. All of them were under the age of 16 at the time of study. Patients with juvenile ankylosing spondylitis, psoriatic arthritis, and arthritis associated with inflammatory bowel disease were excluded from this series. Twenty-six patients had pauciarticular, 9 had systemic, 8 had polyarticular, and 3 patients had seropositive 'adult type' JCA. In all patient groups IgG, IgM, IgA, and C3 levels were significantly higher than in the control group. None of the controls but 13 of 46 patients had high IgE levels. IgA and IgG values were significantly higher in the seropositive subgroup than in the pauciarticular subgroup. There was no other positive correlation between levels of immunoglobulins, C3, and clinical features of disease. Platelet counts were significantly higher in patients with active disease. In the control group 4 out of 10 children had 'hidden' rheumatoid factor. All these children with positive findings were young.

The association of autoimmune diseases and anti-IgA antibodies in patients with selective IgA deficiency

The prevalence of antibodies to immunoglobulin A (IgA) was studied in eighty-three subjects with selective IgA deficiency (SIgAD), thirty-three normal individuals, thirty-two children with juvenile rheumatoid arthritis (JRA) and normal or elevated IgA, seventeen children with systemic lupus erythematosus (SLE) and normal or elevated IgA, and thirteen patients with hypogammaglobulinaemia. Anti-IgA antibodies were detected by haemagglutination of human erythrocytes coated with one of two IgA myelomas by the chromic chloride technique. Antibodies to IgA were not found in significant titre in individuals with normal or elevated IgA or in those with hypogammaglobulinaemia. In IgA deficient patients, elevated titres were found in 25--30% of those who were healthy or who had non-rheumatic diseases, 50% of those with rheumatoid arthritis, 77% of those with JRA and 100% of those with SLE. Patients with rheumatic diseases and SIgAD may therefore be particularly at risk of developing anti-IgA-mediated reactions to blood products.

Antigen-antibody complexes in the serum of patients with juvenile chronic arthritis

IgG-containing antigen-antibody complexes were detected in the sera of all of 7 patients with the systemic form of juvenile chronic arthritis, usually at high levels. Only 9 of 25 patients with the polyarticular form had such complexes, usually at low levels. Three patients had low levels of serum IgA which were probably drug induced; the one patient with low C2 and the 3 with low yeast opsonisation were probably not more than to be expected in a random population.

Immunological abnormalities in the sera of IgA-deficient blood donors

Immunological abnormalities of 163 IgA-deficient blood donors were studied. Anti-IgA antibodies were found in 15, anti-IgG antibodies (measured by the Ripley test) in 34, latex test positivity in 21, anti-IgM antibodies in 9 and antibodies against bovine milk in 41 sera. These numbers differed significantly from the control groups of normal blood donors. In the studies of thyroglobulin antibodies, antinuclear antibodies and blood group A and B isoagglutinins there was no difference from the controls. Interrelationships of all findings were studies by statistical analysis. Correlations were found between latex and Ripley tests and rheumatic disorders as well as between high age and anti-IgA antibodies. Male subjects had antibodies against bovine milk more often than females. Otherwise no striking findings were brought up by the statistical analysis.