Person:

Lo, Mindy

Background: The significance of hypergammaglobulinemia as a marker of immune activation is unknown, as a differential diagnosis for hypergammaglobulinemia in children has not been adequately established. The goal of this study was to identify conditions associated with hypergammaglobulinemia in children, with the hypothesis that elevated immunoglobulin levels may precede or predict the development of autoimmune conditions. Methods: We reviewed the medical records for all children with IgG level ≥2000 mg/dL treated at a tertiary care children’s hospital from January 1, 2000 through December 31, 2009. We compared clinical and laboratory features of these patients, and developed an algorithm to predict the likelihood of underlying autoimmunity based on these characteristics. Results: After excluding children who had received IVIG, a total of 442 patients with hypergammaglobulinemia were identified. Of these, nearly half had autoimmune conditions, most frequently systemic lupus erythematosus and lupus-related disorders. Autoimmune gastrointestinal disorders such as inflammatory bowel disease were also common. Infectious diseases were the next largest category of diseases, followed with much less frequency by malignant, drug-related, and other conditions. In comparison with non-autoimmune conditions, patients with autoimmune disease had higher IgG levels, lower white blood cell counts, lower hemoglobin values, and lower C-reactive protein (CRP) levels. Multivariable logistic regression confirmed that CRP (P = 0.002), white blood cell count (P < 0.001), hemoglobin (P = 0.015), and female gender (P < 0.001) are independent risk factors for autoimmune disease in patients with high IgG levels. Conclusions: In a cohort of pediatric patients at a tertiary care children’s hospital, hypergammaglobulinemia was most commonly associated with autoimmune diseases. In female patients with hypergammaglobulinemia, the presence of leukopenia, anemia, and normal CRP was 95% predictive of underlying autoimmune disease.

Background: There is not yet a commonly accepted, standardized approach in the treatment of juvenile idiopathic uveitis when initial steroid therapy is insufficient. We sought to assess current practice patterns within a large cohort of children with juvenile uveitis. Methods: This is a cross-sectional cohort study of patients with uveitis enrolled in the Childhood Arthritis and Rheumatology Research Alliance (CARRAnet) registry. Clinical information including, demographic information, presenting features, disease complications, and medications were collected. Chi-square and Fisher’s exact tests were used to assess for associations between medications and clinical characteristics. Results: Ninety-two children with idiopathic and 656 with juvenile idiopathic arthritis (JIA)-associated uveitis were identified. Indication (arthritis or uveitis) for medication use was not available for JIA patients; therefore, detailed analysis was limited to children with idiopathic uveitis. In this group, 94 % had received systemic steroids. Methotrexate (MTX) was used in 76 % of patients, with oral and subcutaneous forms given at similar rates. In multivariable analysis, non-Caucasians were more likely to be treated initially with subcutaneous MTX (P = 0.003). Of the 53 % of patients treated with a biologic DMARD, all received a tumor necrosis factor (TNF) inhibitor. TNF inhibitor use was associated with a higher frequency of cataracts (52 % vs 21 %; P = 0.001) and antinuclear antibody positivity (49 % vs 29 %; P = 0.04), although overall complication rates were not higher in these patients. Conclusion: Among idiopathic uveitis patients enrolled in the CARRAnet registry, MTX was the most commonly used DMARD, with subcutaneous and oral forms equally favored. Patients who received a TNF inhibitor were more likely to be ANA positive and have cataracts. Electronic supplementary material The online version of this article (doi:10.1186/s12969-016-0069-5) contains supplementary material, which is available to authorized users.

Background: Accurate risk prediction of coronary artery aneurysms (CAAs) in North American children with Kawasaki disease remains a clinical challenge. We sought to determine the predictive utility of baseline coronary dimensions adjusted for body surface area (z scores) for future CAAs in Kawasaki disease and explored the extent to which addition of established Japanese risk scores to baseline coronary artery z scores improved discrimination for CAA development. Methods and Results: We explored the relationships of CAA with baseline z scores; with Kobayashi, Sano, Egami, and Harada risk scores; and with the combination of baseline z scores and risk scores. We defined CAA as a maximum z score (zMax) ≥2.5 of the left anterior descending or right coronary artery at 4 to 8 weeks of illness. Of 261 patients, 77 patients (29%) had a baseline zMax ≥2.0. CAAs occurred in 15 patients (6%). CAAs were strongly associated with baseline zMax ≥2.0 versus <2.0 (12 [16%] versus 3 [2%], respectively, P<0.001). Baseline zMax ≥2.0 had a C statistic of 0.77, good sensitivity (80%), and excellent negative predictive value (98%). None of the risk scores alone had adequate discrimination. When high‐risk status per the Japanese risk scores was added to models containing baseline zMax ≥2.0, none were significantly better than baseline zMax ≥2.0 alone. Conclusions: In a North American center, baseline zMax ≥2.0 in children with Kawasaki disease demonstrated high predictive utility for later development of CAA. Future studies should validate the utility of our findings.

The pathophysiology of systemic lupus erythematosus (SLE) has been intensely studied but remains incompletely defined. Currently, multiple mechanisms are known to contribute to the development of SLE. These include inadequate clearance of apoptotic debris, aberrant presentation of self nucleic antigens, loss of tolerance, and inappropriate activation of T and B cells. Genetic, hormonal, and environmental influences are also known to play a role. The study of lupus in children, in whom there is presumed to be greater genetic influence, has led to new understandings that are applicable to SLE pathophysiology as a whole. In particular, characterization of inherited disorders associated with excessive type I interferon production has elucidated specific mechanisms by which interferon is induced in SLE. In this review, we discuss several monogenic forms of lupus presenting in childhood and also review recent insights gained from cytokine and autoantibody profiling of pediatric SLE.