title: A case report: IgG autoanti-N as a cause of severe autoimmune hemolytic anemia.
abstract: A 21-year-old white worn was referred for evaluation of hemolytic anemia after a 9-day history of marked hemoglobinuria, jaundice, and weakness. The patient's hematocrit was 18%, despite at least eight transfusions over the previous week, and the reticulocyte count was < 1%. Serologic evaluation revealed a weakly positive direct antiglobulin test with anti-C3 only The serum contained cold and warm-reacting anti-N Dithiothreitol had no effect on either the cold- or the warm-reacting anti-N activity, and radioimmunoassay with monoclonal anti-IgG was strongly positive, indicating that both the cold- and the warm-reacting anti-N reactivity resided in the IgG fraction. The patient was treated with N - 'N' + red cell transfusions, prednisone, and azathioprine and gradually became transfusion independent. Postrecovery typing revealed her red cells to be M+N+S+s+. This constitutes the third case of autoimmune hemolytic anemia associated with IgG autoanti-N. The marked hemoglobinuria and reticulocytopenia are unique features of this case.
authors.affiliation: Immunohematology Laboratory, Duke University Medical Center, Box 2928, Durham, NC 27710, USA.
authors.forename: M R
authors.initials: MR
authors.lastname: Combs
authors.forename: M J
authors.initials: MJ
authors.lastname: Telen
authors.forename: S E
authors.initials: SE
authors.lastname: Hall
authors.forename: W F
authors.initials: WF
authors.lastname: Rosse