Kell Blood Group System: A Systematic Review and Meta-Analysis

Abstract Background Kell is highly immunogenic after ABO and Rh blood group system, and anti-Kell antibodies have been linked to hemolytic transfusion reaction and fetal hemolytic disease in newborns. The antithetic KEL1/KEL2, KEL3/KEL4, and KEL6/KEL7 antigens are expressed in the Kell blood group system. At least 36 antigens are carried on a single 93 kDa red-cell trans-membrane protein in the Kell blood system. This study aimed to review different literature on the kell blood group and associated phenotypes and to find out the epidemiology and frequency of different Kell antigens all over the world. Methods Epidemiological studies of Kell antigens (2000 to 2022) were extracted to capture all reported data of different kell genotypes/phenotypes from different populations. Different databases like Google Scholar, PubMed, JSTOR, Scopus, and Science Direct were accessed to download all the published data reporting different percentages of kell antigens. Results A total of 250 research papers and articles were downloaded; 60 studies met our inclusion criteria. Most of the research studies consisted of KEL1/KEL2, KEL3/ KEL4, and KEL6/KEL7. According to this meta-analysis, the prevalence of KEL1 and KEL3 are lower than KEL2 (100%) and KEL4 (100%). In all captured studies the prevalence of KEL1 ranged from 0 to 23.6%, KEL2 from 0 to 100%, KEL3 from 0 to 11.7%, KEL4 100%, KEL5 0%, KEL6 100%, and KEL7 was 97.31%. Discussion This is the first meta-analysis to check the occurrence of Kell blood antigens frequency and the spectrum of variants associated with it in populations of the world. This review will help to identify which is the common antigen of the Kell blood group system and how it can affect the person by disease associated with it.