Journal of Blood Medicine (Nov 2022)
Alloimmunization to Rh Antigen (D, C, E, C, E) Among Pregnant Women Attending Antenatal Care in South Western Uganda
Abstract
Yona Mbalibulha,1 Bernard Natukunda,1 Andrew Livex Okwi,2 Joan N Kalyango,3 Kajja Isaac,4 Sam Ononge5 1Department of Medical Laboratory Science, Faculty of Medicine, Mbarara University of Science and Technology, Mbarara, Uganda; 2Department of Pathology, College of Health Science, Makerere University, Kampala, Uganda; 3Director, Clinical and Epidemiology Unit, School of Medicine, College of Health Science, Makerere University, Kampala, Uganda; 4Deputy Principal, College of Health Sciences, Makerere University, Kampala, Uganda; 5Department of Obstetrics & Gynaecology, Makerere University College of Health Sciences, Kampala, UgandaCorrespondence: Yona Mbalibulha, Department of Medical Laboratory Sciences, Faculty of Medicine, Mbarara University of Science and Technology, PO Box 1410, Mbarara, Uganda, Tel +256 773018980, Email [email protected]: Maternal red cell alloimmunization to Rh antigen in pregnant women occurs when the immune system is sensitized by foreign red blood cell surface antigens, in this case fetal red blood cells, inducing an immune response. Various antigens of blood group systems may cause alloimmunization, especially the Rh, Kel, Fy, JK, and MNS systems. This study aimed to determine alloimmunization to the different frequencies of Rh antigen among pregnant women in South Western Uganda.Methods: A total of 1369 pregnant women consented and were recruited into a cross-sectional study during their regular antenatal visits during the period August 2020 to July 2021. Samples (4 mL) of anticoagulated and coagulated blood were obtained, and Rh blood grouping including Rh antigen and the indirect antiglobulin test (IAT) was carried out using the agglutination technology of the LISS ID-Card technique in the Ortho Biovue ID-Micro Typing System.Results: Out of 1369 participants recruited to the study, 78 (5.7%) were D−, 1291 were D+, and 134 (9.8%) had alloantibodies. Among those with alloantibodies, 115 (85.8%) were D+ and 19 (14.2%) D−. The percentage alloimmunization according to the Rh antigens was highest in e (9.72%), c (2.48%), C (2.34%) and E (0.94%) antigens. With the ABO system, alloimmunization was highest in blood group B (10.7%), followed by A (10.6%), O (9.2%) and then AB (7.1%). Alloimmunization was more prevalent in D− (24%) than in D+ participants (8.9%). Rhesus antigen e was the most prevalent antigen (99.8%), followed by c. The alloimmunization rate of 9.8% among these participants is high, and appears in both D+ and D− women. The other Rhesus antigens are seen to cause alloimmunization, with antigen e causing the highest prevalence. In conclusion, there is a need to identify antibodies and study the outcome for clinical significance, especially in D+ women, to facilitate proper pregnancy management.Keywords: Rh alloimmunization, Rh antigens, hemolytic disease of the fetus and newborn, pregnant women, Western Uganda
