High thermal amplitude auto-anti-"N" complicating pretransfusion compatibility tests on a patient with malaria and...

Antigen "N" is a high-frequency antigen of the MNS blood groups and carried on glycophorin B that is resistant to enzymatic cleavage by trypsin, and provides differential diagnosis of its antibody specificity to N being present of glycophorin A. Naturally occurring IgM antibodies to N are known to be clinically insignificant, as against the IgG counterpart with clinical relevance.

Auto-anti-"N" association with the bladder cancer was explored for its clinical significance as well as its interference in grouping anomaly.

A warm environment was created while blood sampling for the laboratory work up as the patient had a high-titer auto-cold agglutinin causing spontaneous hemagglutination. The antibody was tested by standard serological methods with the red cell, antisera, and enzymes prepared in house or obtained commercially.

The case was admitted to hospital with high fever and hematuria; he was diagnosed with malaria and bladder cancer. He required transfusions in the face of severe anemia. His blood sample posed problems in compatibility tests due to autoantibody present. Serological workup revealed its specificity as anti-"N."

Auto-anti-"N" as a cause of severe anemia could not be attributed to, for concurrent malarial infection. However, its presence may have some association with the underlying malignant condition.