Acute autoimmune hemolytic anemia with transient aplastic crisis likely triggered by Parvovirus B19 infection in an adolescent: a case report

Autoimmune hemolytic anemia (AIHA) is an uncommon but potentially life-threatening disorder characterized by immune-mediated destruction of red blood cells. Parvovirus B19 infection is a well-recognized cause of transient aplastic crisis due to suppression of erythroid precursors, and the simultaneous occurrence of immune hemolysis with marrow suppression presents a diagnostic challenge. We report the case of a 13-year-old boy who presented with fever, jaundice, and dark-colored urine. Laboratory evaluation revealed severe anemia (hemoglobin 5.5 g/dl), indirect hyperbilirubinemia, and a positive direct antiglobulin test confirming AIHA. Notably, the reticulocyte count was inappropriately low for the degree of hemolysis, suggesting transient marrow suppression. Extensive autoimmune and infectious investigations were largely negative except for equivocal parvovirus B19 IgM serology. The patient showed significant clinical and hematological improvement following packed red blood cell transfusion and corticosteroid therapy. This case highlights the importance of considering Parvovirus B19 infection in AIHA patients presenting with reticulocytopenia, as early recognition and appropriate supportive management are essential to prevent serious complications.