European Journal of Biomedical and Pharmaceutical Sciences

FREQUENCY OF HUMAN LEUCOCYTES ANTIGEN (HLA) B LOCUS IN UMBILICAL CORD BLOOD OF DIFFERENT ETHNIC SUBJECTS IN PORT HARCOURT

Nwagu Chinyere*, Jeremiah Zaccheaus Awortu, Adias Teddy Charles and Eze Evelyn Mgbeoma

ABSTRACT

The HLA system is known to be the most polymorphic genetic loci in humans. Distribution and frequencies of HLA alleles are highly variable among different human ethnic groups. The aim of the study was to determine the HLA B locus alleles and frequencies in umbilical cord blood in Port Harcourt, Rivers State, Nigeria. Frequencies of the HLA B locus alleles was determined in 90 unrelated umbilical cord blood samples using Sequence Specific Primer-Polymerase Chain Reaction(SSP-PCR) method. The results showed that a total of 25 HLA-B were found in the studied population. Out of which HLA B*53 (32.2%) was the most prevalent followed by B*15(28.8%), B*07(24.4%), B*35 (18.8 %) and B*76(13.3 %). The frequency of HLA B locus alleles among the participating ethnic groups in the study population like the Igbo, Hausa, Yoruba, Ikwerre, Ogoni, Ijaw, Efik and Fulani were also described. The most frequent alleles among the Igbos are HLA B*07(17.6%), HLA B*15(30.4%), HLA B*35(15.2%), HLA B*53(30.4%) and HLA B*76(13.0%). Among the Hausa are HLA B*07(28.6%), HLA B*15(14.3%), HLA B*27(28.6%), HLA B*35(28.6%), HLA B*46(14.3%), HLA B*52(14.3%), HLA B*53(28.8%) and HLA B*57(28.6%). Among the Yorubas are HLA B*07(23.5%), HLA B*15(29.4%), HLA B*35(23.5%), HLA B*53(29.4%) and HLA B*73(11.8%). Among the Ikwerre are HLA B*14, HLA B*15, HLA B*21, HLA B*35, HLA B*41, HLA B*42, HLA B*44, HLA B*53, HLA B*58 and HLA B*78 with allele frequencies of 12.5%, each. The common alleles for Ogoni are HLA B*15, HLA B*53(50.0%), HLA B*76(50.0%), HLA B* 18(25.0%) and HLA B* 58(25.0%). Among the Ijaw are HLA B*07(100%) and HLA A*35(100.0%). HLA B*07(80.0%), HLA B*15(20.0%) and HLA B*18(20.0%), HLA B*35(20.0%) and HLA B*76(40.0%) were found to be common among the Efik. Chi Square test was performed on data set to determine strength of association amongst the ethnic groups in HLA B locus allele frequency. The 2 value was 1579.2, p value 0.0001. The HLA B locus alleles are statistically significantly different across ethnic groups in Nigeria. In conclusion, the result of the study suggests a high variability in HLA B locus in the studied Nigerian population.

Keywords: Human leucocyte antigen, stem cell, umbilical cord blood, PCR.