Multicenter study on season of birth and celiac disease: evidence for a new theoretical model of pathogenesis.

OBJECTIVE: To investigate whether season of birth is associated with celiac disease (CD). STUDY DESIGN: We performed a medical record review of 1964 patients with biopsy-proven CD at 3 teaching hospitals (2 pediatric centers and 1 adult center) between 2000 and 2010. The first positive small intestinal biopsy result defined age of diagnosis. The observed proportions of births in each season (spring [March-May], summer [June-August], fall [September-November], and winter [December-February]) were compared with the expected proportions using binomial probability tests. RESULTS: The mean age at diagnosis was 9.8 ± 5.0 years in the 2 pediatric centers and 43.6 ± 15.8 years in the adult center. The cohort was predominately female (69%). Overall, more patients were born in spring (27%) than in any other season: summer (25%), fall (25%), and winter (23%). In patients diagnosed before age 15 years, the spring birth excess was present in boys (33%; P = .0005), but not in girls (26%; P = .43). The sex difference in season of birth was less striking in patients with CD diagnosed at age ≥15 years. CONCLUSION: Season of birth is an environmental risk factor for CD, particularly in boys diagnosed before age 15 years. The results are consistent with a new theoretical model that integrates potential environmental factors (eg, gluten introduction, ultraviolet-B exposure, vitamin D status) and acute viral gastrointestinal infections in early childhood.

Clinical effects and safety of rituximab for treatment of refractory pediatric autoimmune diseases.

OBJECTIVE: To evaluate the safety, tolerability, and clinical effects of rituximab, an anti-CD20 monoclonal antibody, in the treatment of severe pediatric autoimmune diseases. STUDY DESIGN: We reviewed the records of 10 patients treated with rituximab for severe, refractory autoimmune diseases at a single tertiary care children's hospital. Adverse events as well as treatment effects were recorded. RESULTS: All patients received 4 weekly doses of rituximab at 375 mg/m2 per dose. One patient died as the result of complications of her underlying systemic lupus erythematosus 7 weeks after rituximab therapy. Three patients had serious infections, all of which resolved with standard therapy. Rituximab led to transient or sustained improvement in clinical and laboratory parameters in nine subjects. At a median follow-up of 9 months, the median prednisone dose was reduced in the responders by 0.75 mg/kg per day (mean decrease of 63%), and four patients were able to discontinue corticosteroids entirely. With longer follow-up (median, 22 months), we found that 5 of 9 patients remained clinically stable after rituximab therapy, whereas 4 patients had recurrent or new features of their underlying autoimmune disorders requiring additional corticosteroids or other immunosuppressive medications. CONCLUSIONS: Rituximab had an acceptable toxicity profile in this group of patients with severe, refractory autoimmune diseases, although there were three serious infections and one patient death. Rituximab appears to be beneficial for patients with refractory autoimmune diseases and may reduce corticosteroid exposure. Although rituximab therapy provided a durable clinical benefit for some patients in this population, other patients had reemergence of their underlying autoimmune disease.