PREVALENCE OF RH (C,c,D,E,e) AND KELL (K,k) BLOOD GROUP ANTIGENS AMONG UNIVERSITY OF BENIN MEDICAL STUDENTS, BENIN CITY, EDO STATE

Abstract

BACKGROUND:
Blood group antigens are carbohydrate, protein or lipid molecules carried on red cell surfaces
and or plasma. Though they serve different biologic functions, its clinical significance is related
to their immunogenicity and consequent in vivo destruction of foreign red cells. Asides the ABO
blood group system, antigens belonging to the Rh and Kell blood group systems are also of
major clinical significance. Blood group antigens exhibit significant polymorphism in human
populations. However, sparse data exist on Rh and Kell antigen phenotypes in Nigeria.
Knowledge of its distribution provides a local antigenic profile, supports anthropology (human
origins), creates a donor pool for uncommon phenotypes and is useful in preparation of
indigenous cell panels for allo-antibody screening and identification.
OBJECTIVE:
The objective of this study was to determine the prevalence of 5 major Rh (D, C, c, E, e) and
Kell (K, k) blood group antigen, its phenotypic distributions, the distribution of non D Rh
antigens among Rh D positive and Rh D negative subjects, as well as ethnic differences, if any,
in Benin City, Nigeria.
METHODOLOGY:
A cross-sectional study of 302 medical undergraduates of the University of Benin was conducted
between January 2015 and April 2015. Participants were recruited using a stratified random
sampling technique. Relevant bio-data (age, sex, ethnicity) were collected using a semi
structured, interviewer administered questionnaire. Rh antigens (D, C, c, E, e) and Kell (K, k)

blood group antigens were tested using commercially prepared antisera procured from Lorne
laboratories, UK. Tube agglutination technique was used. Descriptive and inferential statistics
were performed using Statistical Package for Social Sciences (SPSS), version 16, Chicago, USA.
Results are presented in frequencies and tables.
RESULT:
The mean ± SD age of the study participants was 22.75 ± 3.34 years. Male to female ratio was
1.72:1. The frequencies of the major Rh antigens were observed to be D (92.7%), C (20.5%), c
(97.7%), E (19.5%) and e (97.4%). The commonest Rh phenotype is Dccee (53.3%). None of the
participants tested positive for the Kell 1 (K) antigen. The prevalence of the Kell (k) antigen was
82.1%. The predominant Kell phenotype (82.1%) was K-k+. Rh C and E showed statistically
significant association with Rh D (p = 0.037 and 0.047 respectively). The distribution of the Rh
and Kell antigens were not statistically significant (p value > 0.05) among the various ethnic
groups. The probabilities of Rh and Kell mismatch transfusions in the study population were
highest for Rh C (16.3%), Rh E (15.7%) and Kell2, k (14.8%) antigens.
CONCLUSION/RECOMMENDATION:
This study has shown that Rh and Kell blood group antigens are highly prevalent in Benin City,
Nigeria, with variable frequencies and are a potential source of clinically significant mismatch
transfusions if extended matching is not performed. Further large scale studies in other parts of
Nigeria are needed for better understanding. The probabilities of mismatch transfusion and
potential allo-immunisation in the studied population is high for Rh (C, E) and Kell 2 (k)
antigens. Thus, local/regional blood banking systems in Nigeria should be improved to provide
routine extended erythrocyte phenotyping of clinically significant Rh and Kell antigens for at
risk blood recipients, particularly Rh (C, E) and Kell2 (k) antigens.

PREVALENCE OF RH (C,c,D,E,e) AND KELL (K,k) BLOOD GROUP ANTIGENS AMONG UNIVERSITY OF BENIN MEDICAL STUDENTS, BENIN CITY, EDO STATE