Prolonged Severe CD4+ Lymphocytopenia and Hypogammaglobulinemia in Patients With Evans' Syndrome: A Case Report.

Primary immunodeficiency (PID) is one of the causes of secondary autoimmune hemolytic anemia (AIHA) and Evans' syndrome (ES). Serum immunoglobulins should be tested in patients with AIHA/ES, as common variable immunodeficiency is the most common PID of secondary AIHA/ES. However, it is not fully understood how immunodeficiency is assessed, in addition to serum immunoglobulins. Here, we present the case of a 34-year-old man with prolonged severe CD4+ lymphocytopenia and hypogammaglobulinemia in patients with ES despite repeated negative tests for human immunodeficiency virus antibodies. His CD4+ cell count remained below 60/µL for 56 months after treatment completion, including steroid and rituximab therapy. A gene panel test for immunodeficiency using next-generation sequencing did not reveal any pathogenic gene variants. He has been using continuously trimethoprim-sulfamethoxazole to prevent pneumocystis pneumonia due to severe CD4+ deficiency. This case highlights the need for a CD4+ cell count in some patients with AIHA/ES, such as those with hypogammaglobulinemia or recurrent infections.