[Irregular antierythocytic antibodies outside of the ABO system in the perinatal period]

Included in this study are the results of the tests done with irregular anti-erythrocytic antibodies outside of the ABO system of women in reproductive stage. In 2,623 cases considered, 279 samples positive for the antibodies were found (10.6%). In 184 cases (65.9%), the antibodies were classified as "immune irregular". The most frequently found antibodies from this group were the anti-D (63.08%), followed by the anti-c (1.07%), the anti-Kell (0.72%), anti-C, anti-E and an anti-Rh system (0.36% for each one). In 52 cases (18.6%) there were irregular "natural" antibodies, predominantly the anti-Lewis (9.68%), followed by anti-P (5.02%), the anti-I (3.2%), an anti-M and an anti-N (0.36% each one). In 43 (15.4%) cases, we were not able to identify the specificity of the antibody found. We include a discussion and a comparison of the frequency of these antibodies in our population. Based on these data, we recommend the clinician to consider the existence and specificity of the irregular anti-erythrocytic antibodies in their obstetric patients, candidates to transfusional therapy, as well as those newborn with hemolytic diseases.