A report on the clinical efficacy of rituximab administration in patients with inborn errors of immunity and autoimmune manifestations

Abstract

BackgroundRituximab (RTX), an anti-CD20 monoclonal antibody, is considered a novel therapeutic agent in a variable spectrum of immune disorders. Herein, we investigated the clinical efficacy of RTX in inborn errors of immunity (IEIs) with autoimmune manifestations. MethodsPatients with IEIs diagnosed clinically based on European Society for Immunodeficiencies (ESID) diagnostic criteria with at least one autoimmune manifestation referred to Mofid Children's Hospital, Tehran, Iran, between 2010 and 2021 were investigated. Medical records of patients were retrospectively investigated. All patients had received RTX as a course of at least four 375 mg/m2 infusions in weekly intervals. Complete and partial responses were defined as normalization or improvement of biological markers of hemolysis and the requirement for maintenance treatment. ResultsTwenty-three patients (65.2% females and 34.8% males) with common variable immunodeficiency (CVID) (5, 21.7%), unspecified primary immune regulatory disorder (PIRD) (5, 21.7%), LRBA deficiency (4, 17.4%), non-syndromic combined immunodeficiency (CID) (2, 8.7%), STAT3-GOF mutation (2, 8.7%), ataxia-telangiectasia (2, 8.7%), Epstein-Barr virus (EBV)-susceptible PIRD (1, 4.3%), Nijmegen breakage syndrome (1, 4.3%), and familial hemophagocytic lymphohistiocytosis (fHLH) (1, 4.3%) were enrolled.The median (IQR) age at the time of the study, the onset of symptoms, and diagnosis were 12 (6–14), 3 (1–5), and 5 (3–9) years, respectively. Fourteen (60.8%) patients had consanguineous parents. Autoimmune manifestations included cytopenia (17, 73.9%), Kawasaki disease (1, 4.3%), thyroiditis (1, 4.3%), juvenile idiopathic arthritis (JIA) (1, 4.3%), enteropathy (4, 17.4%), mixed connective tissue disease (MCTD) (2, 8.7%), systemic lupus erythematosus (SLE) (2, 8.7%), and Behcet's syndrome (1, 4.3%). The cumulative response rate was 86.8% (complete response: 14, 60.8%, partial response: 6, 26%). At the end of the survey, 8 (34.7%) patients were deceased. ConclusionsRituximab is a promising therapeutic option for autoimmune disorders in the context of IEI. Regular follow-up after the initial rituximab infusion is essential in IEI children.