Warm autoimmune hemolytic anemia associated with an IgM autoanti-Ge

A 28-year-old male with a prior history of Hodgkin's disease and a recent upper respiratory tract infection presented with autoimmune hemolytic anemia (AIHA). The patient's red blood cells (RBCs) were spontaneously agglutinated after room temperature and 37 degrees C washes. Dithiothreitol-treated RBCs reacted strongly with anti-C3 and were nonreactive with anti-IgG, -IgM, and -IgA; they reacted with anti-IgM (kappa light chains only) by flow cytometry. The patient's serum was nonreactive. An acid eluate was only weakly reactive, but a 56 degrees C heat eluate strongly agglutinated untreated RBCs (3+). Ficin-treated RBCs were nonreactive. En(a-) RBCs were strongly reactive, but Ge- RBCs were nonreactive. The anti-Ge in the eluate was IgM. The patient's untreated RBCs were shown, by flow cytometry, to be weakly Ge+. This is the first report of IgM-mediated warm AIHA associated with autoanti-Ge.