급성골수백혈병 환자에서 발견된 자가 항-M 항체 증례 보고

The anti-M antibody is a naturally occurring antibody and generally active below 37˚C, with optimum activity at 4˚C. Since auto-anti-M antibody was first reported in 1970, twenty cases have been described. The auto-anti-M antibody could be presented with a negative direct antiglobulin test result and not be associated with anemia or adverse symptoms. Therefore, it is likely to be missed during the routine serologic procedure. Here, we report the first case of auto-anti-M antibody in Korea. A 73-year-old male with relapsed acute myeloid leukemia was admitted with general weakness and atypical pneumonia. The underlying disease created a need for frequent transfusions due to anemia and thrombocytopenia. In the pre-transfusion test, unexpected and not previously seen antibodies were identified as anti-M antibodies and confirmed. The auto-control result was positive. Antigen tests were performed for the antibody’s accurate specification. Finally, it was confirmed that the patient’s red blood cell phenotype had an M antigen and was reported as an auto-anti-M antibody. To our knowledge, this is the first auto-anti-M antibody case in Korea and the Asian region.