Overlapping autoimmunity and immunodeficiency: a case of selective IgA deficiency with autoimmune hemolytic anemia

The most prevalent primary immunodeficiency is selective immunoglobulin A deficiency (SIgAD), which is characterized by serum IgA levels equal to or less than 7 mg/dL with normal levels of IgG and IgM in a patient who is at least 4 years old. Most patients are asymptomatic; however, SIgAD increases the risk of respiratory and gastrointestinal infections, autoimmune disorders, transfusion reactions, and atopy. Our 4-year-old female patient had a history of recurrent severe infections requiring multiple hospital admissions, raising our suspicion of an immunodeficiency, especially with a family history of SIgAD. She had several episodes of pallor and jaundice that were caused by autoimmune hemolytic anemia, with the last episode being associated with a severe respiratory infection. This case highlights the importance of early diagnosis and ongoing follow-up of children with SIgAD to ensure prompt treatment of infections and autoimmune complications even before the age of four years. It also recommends regular monitoring and early supportive intervention to reduce disease flare-ups and monitor for progression to common variable immunodeficiency.