The immunologic features of patients with early-onset and polyautoimmunity.

Inflammatory conditions are increasingly described in patients with primary immunodeficiencies; however, little is known about the prevalence of immune defects in patients who present first with autoimmunity. We describe the immunologic features of children with early-onset/polyautoimmunity followed in the Multiple Autoimmunity and Immunodeficiency (MAID) Clinic, where patients are co-managed by rheumatologists and immunologists. The most common autoimmune manifestations were cytopenias, lymphoproliferation, and colitis. Recurrent infections were noted in 65% of patients. Abnormalities in lymphocyte subsets and immunoglobulins were common. A pathogenic variant was identified in 19% of patients, and 2 novel inherited disorders were discovered. Additionally, 42% of patients had treatment changes implemented in the MAID clinic. By evaluating this unique cohort of patients, we report on the immunologic underpinning of early-onset/polyautoimmunity. The high rate of genetic diagnoses and treatment interventions in this population highlights the value of collaboration between rheumatologists and immunologists in the care of these complex patients.