Chronic immune thrombocytopenia in a child with X-linked agammaglobulinemia-an uncommon phenotype.

Autoimmune disorders are common in patients with primary immunodeficiency diseases (PIDs). However, the prevalence of autoimmunity is low in patients with X-linked agammaglobulinemia (XLA), mostly due to the absence of antibodies. Chronic or persistent immune thrombocytopenia (ITP), which is usually considered an antibody-mediated disease, is uncommon in patients with XLA. In this study, we detailly described a surprising autoimmune phenomenon, chronic ITP, in a small boy diagnosed with XLA. This is an interesting phenotype found in XLA, and it is helpful to understand the immune pathogenesis of autoimmunity in patients with XLA.