Identification and test methods of rare unexpected antibodies in grassroots medical institutions

Objective To explore how to identify rare unexpected antibodies using routine serology methods in blood transfusion department of grassroots hospitals. Methods A patient with gastrointestinal bleeding with inconsistent forward and reverse blood typing, positive antibody screening and incompatible blood matching in our hospital was selected as the research object. Mixed human O cell absorption method was used for blood type identification, and 10-panel reagent red blood cells, manual polybrene test, 2-mercaptoethanol(2-ME) test, blind match and pedigree study were used to explore the antibody characteristics. Results The serological test results of the patient′s serum were as follows: The blood group was type B and RhD positive, and negative for direct antiglobulin test; The antibody was IgM; The likelihood of this antibody being anti-s, anti-Fya or anti-k was low, and compound antibodies could not be excluded; The blood of the patient did not match with blood samples of 20 blood donors in the major side, while it matched with all the blood samples of her three sisters. Conclusion When the antibodies of high-prevalence antigen series in plasma cannot be identified, the matched blood may be found tthrough family survey for irradiation and transfusion.