Антирезусные антитела, титр (Антитела к Rh)

Red blood cell phenotyping for Rh (C, E, c, e) and Kell (K) antigens supports selection of antigen-compatible blood and helps prevent hemolytic transfusion reactions. This antigen typing (also referred to as RhCE and Kell phenotyping) is also used in obstetric care to define maternal antigen status when assessing risk for maternal–fetal incompatibility. By documenting the presence or absence of clinically significant Rh and Kell antigens, the test informs transfusion planning and guides evaluation for hemolytic disease of the fetus and newborn.

Erythrocytes carry more than 250 defined antigens grouped into multiple genetic systems. Antigen–antibody binding on the red cell surface can produce hemagglutination, which underlies both routine serologic typing and the pathophysiology of transfusion reactions and maternal–fetal incompatibility. The Rh system is second in clinical relevance only to ABO. Although the D antigen defines Rh positive or negative status, additional Rh specificities—C, c, E, and e—are encoded by RHCE, while RHD encodes D. The C antigen appears in approximately 68% of White populations, whereas c is found in about 80%; C is more prevalent in East Asia and less frequent in populations of African ancestry. E and e are codominant; e is common across populations (about 98% in White cohorts) and E is less frequent (about 30% in White cohorts). E tends to be more immunogenic than e. Rarely, RHCE alleles may be inactivated or partially inactive, resulting in absent or altered expression of E/e and/or C/c antigens. The Kell blood group is also highly relevant in transfusion medicine and obstetrics because Kell antibodies are notably immunogenic. The Kell system comprises 35 antigens; among these, K/k (KEL1/KEL2), Kpa/Kpb (KEL3/KEL4), and Jsa/Jsb (KEL5/KEL6) are the most clinically significant. Laboratory determination of Rh (C, E, c, e) and Kell phenotypes is performed by hemagglutination using monoclonal antisera and by gel-based column agglutination methods. In gel methods, antisera are dispersed within the gel matrix; antigen-positive erythrocytes form agglutinates that are retained in the column during centrifugation, while nonagglutinated cells pass through. These approaches provide reliable identification of clinically important erythrocyte antigens to support transfusion compatibility and perinatal risk assessment.