Poor specific antibody response is a well-known primary immunodeficiency that is related to hypogammaglobulinemia or common variable immunodeficiency (CVID). The co-existence of CVID or hypogammaglobulinemia and systemic lupus erythematosus (SLE) has been rarely described. In all reported cases, the diagnosis of SLE antedates CVID. We report a 15-year-old Saudi girl who was diagnosed with poor specific antibody response at age 6 years in the form of poor or no antibody response and dysgammaglobulinemia. She developed SLE with musculoskeletal and hematological manifestations, positive antinuclear antibody and high anti-dsDNA nine years later. She was treated with rituximab with good response.
Keywords: Systemic lupus erythematosus; T cells and B cells; autoimmunity; common variable immune deficiency; poor specific antibody response; rituximab.