Well-known causes include ABO-mismatched bone marrow transplant Autoimmune disorders / collagen vascular diseases (systemic lupus erythematosus, rheumatoid arthritis) Medications (eg, tranquilizers, antiseizure medications, recombinant erythropoietin, immune checkpoint inhibitors) HIV infection Lymphoproliferative diseases (chronic lymphocytic leukemia, large granular lymphocyte leukemia, chronic myeloid leukemia, Hodgkin lymphoma, non-Hodgkin lymphoma, multiple myeloma / plasma cell disorders) Parvovirus B19, particularly in immunocompromised patients such as those with HIV infection or chronic hemolytic anemias (the parvovirus binds to the blood group P antigen on erythroid precursors and is directly cytotoxic to the cells) Pregnancy Riboflavindeficiency Solid tumors Thymomas Toxins (organic phosphates) Symptoms of Pure Red Blood Cell Aplasia Symptoms of pure RBC aplasia are generally mild and relate to the degree of the anemia or to the underlying disorder.