Selective IgA deficiency with unusual features: Development of common variable immunodeficiency, Sjögren's syndrome, autoimmune hemolytic anemia and immune thrombocytopenic purpura

Abstract We report on a girl with selective IgA deficiency and persistently low complement component 4 (C4) levels compatible with heterozygous C4 deficiency. Deterioration of her serum immunoglobulin levels and transition to common variable immunodeficiency were observed within a 5 year follow‐up. She also developed Sjögren's syndrome, autoimmune hemolytic anemia and immune thrombocytopenic purpura While these abnormalities have been described before in various combinations, to our knowledge, they have not been reported in a single individual.