Abstract: Objective To analyze the distribution of irregular antibodies against blood types and the influencing factors of gender,age,blood transfusion or pregnancy history in hospitalized patients.Methods The blood samples of 3078 inpatients were collected,the manual polybrene tests were used for irregular antibody screening,the panel cells were used for irregular antibody identification to analyze the results and influencing factors. Results Thirty-two cases of 3078 inpatients were found to carry irregular antibodiesaccouted for with the positive rate of 10.396‰. Among them,the alloantibodies accounted for 84.38% whereas the autoantibodies,15.625%,after identification.The antibodies to Rh,MNSs and Lewis blood groups accounted for 43.75%,15.63% and 12.50%,respectively. The frequencies of IgG,IgM and IgM-IgG classes were 62.50%,31.25% and 6.25%,respectively. Univariate analyses showed that the positive rates of irregular antibodies in female,patients aged over 60 years,blood transfusion or pregnancy history were significantly increased when compared with the other patients investigated （P<0.05）. Multivariate logistic regression analysis showed that age （over 60）,blood transfusion and pregnancy were the main influencing factors of irregular antibody production （P<0.05）. Conclusion The level of serum irregular antibodies in hospitalized patients of Huainan district was positively related to age,history of blood transfusion and pregnancy.

Key words: Irregular antibody, History of Blood transfusion, History of pregnancy, Panel cells