Fatal outcome in a patient with autoimmune hemolytic anemia associated with an IgM bithermic anti-ITP.
BACKGROUND
Several cold autoantibodies (usually IgG) with IT specificity have been reported previously, as have autoantibodies with joint I and P blood group specificities (IP1, ITP1, iP1, IP). A fatal outcome associated with an IgM cold autoantibody of ITP specificity is reported.


METHODS
A 54-year-old man suffered from progressively severe cold autoimmune hemolytic anemia for 9 months. Hemoglobin concentration ranged from 6 to 7 g per dL (60-70 g/L) and reticulocytes from 3 to 5 percent (0.030-0.050). The direct antiglobulin test was weakly positive for IgM and strongly positive for C3d. The serum contained a cold agglutinin that reacted strongest with cord i red cells (RBCs) > adult I RBCs > adult i RBCs, which is consistent with IT specificity. The Donath-Landsteiner test was positive; the reaction was neutralized by globoside. The serum reacted weakly or was negative with RBCs from five group p blood donors, which suggests anti-ITP specificity. Dithiothreitol treatment of the serum abolished the cold agglutinin reactivity, which suggests that the anti-IT was IgM. The patient received > 40 RBC transfusions and failed to respond to oral steroids, oral cytoxan, high-dose pulse intravenous steroids, and plasma exchange at room temperature and at 35 degrees C. He died of sepsis following an unsuccessful trial of chlorambucil. Autopsy revealed unsuspected disseminated non-Hodgkin's lymphoma.


CONCLUSIONS
Serologic studies are consistent with our patient's having a single IgM cold autoantibody with IT and P specificities (anti-ITP) and requiring both specificities on the same RBC to permit maximal antibody expression.
Ramos
R R
RR
Department of Pathology, Washington University School of Medicine, St. Louis, Missouri.
Curtis
B R
BR
Eby
C S
CS
Ratkin
G A
GA
Chaplin
H
H
D000327:Adsorption; D000373:Agglutinins; D000744:Anemia, Hemolytic, Autoimmune; D000918:Antibody Specificity; D001323:Autoantibodies / Q000276:immunology / Q000378:metabolism; D001797:Blood Protein Electrophoresis; D003080:Cold Temperature; D003450:Cryoglobulins; D017809:Fatal Outcome; D006801:Humans; D007048:I Blood-Group System / Q000276:immunology*; D007075:Immunoglobulin M / Q000097:blood*; D007145:Immunoglobulin kappa-Chains / Q000032:analysis; D008297:Male; D008875:Middle Aged; D009500:Neutralization Tests; D010127:P Blood-Group System / Q000235:genetics / Q000276:immunology*; D010266:Paraproteins / Q000032:analysis; D010641:Phenotype
D000373:Agglutinins; D001323:Autoantibodies; D003450:Cryoglobulins; D007048:I Blood-Group System; D007075:Immunoglobulin M; D007145:Immunoglobulin kappa-Chains; D010127:P Blood-Group System; D010266:Paraproteins; C029443:cold agglutinins