APDS patients with immune-complex vasculitis and resolution with leniolisib

Activated phosphoinositide 3-kinase delta syndrome (APDS) is an inborn error of immunity with heterogeneity in the clinical manifestations of immune dysregulation, including recurrent sinopulmonary infections, bronchiectasis, chronic herpesvirus infections, autoimmunity, lymphoproliferation, and malignancy. Immune complexmediated vasculitides have not yet been described in APDS patients. Here we offer a case series of three patients with APDS who have refractory IgA vasculitis (also called Henoch-Schönlein purpura), a form of immune complex-mediated vasculitis that activates complement and attracts neutrophils, macrophages and eosinophils to cause local tissue injury. Leniolisib is an inhibitor of PI3K p110δ and an FDA-approved treatment for APDS. IgA vasculitis resolved upon treatment with the inhibitor leniolisib. Patients with immune dysregulation including IgA vasculitis should be screened for APDS.