Human leukocyte antigen class 1 genotype distribution and analysis in persons with active tuberculosis and household contacts from Central Uganda.

ABSTRACT

BACKGROUND: To determine the distribution of Human leukocyte antigen (HLA) class I genotypes in a Ugandan population of persons with tuberculosis (TB) and establish the relationship between class I HLA types and Mycobacterium tuberculosis (MTB) disease. METHODS: Blood samples were drawn from HIV negative individuals with active TB and HIV negative household controls. DNA was extracted from blood samples and HLA typed by the polymerase chain reaction-sequence specific primer method. The allelic frequencies were determined by direct count. RESULTS: HLA-A*02, B*15, C*07, C*03, B*58, C*04, A*01, A*74, C*02 and A*30 were the dominant genotypes in this Ugandan cohort. There were differences in the distribution of HLA types between the individuals with active TB and the household controls with only HLA-A*03 allele showing a statistically significant difference (p = 0.017 crude; OR = 6.29 and p = 0.016; OR = 11.67 after adjustment for age). However, after applying the Benjamini and Hochberg adjustment for multiple comparisons the difference was no longer statistically significant (p = 0.374 and p = 0.176 respectively). CONCLUSIONS: We identified a number of HLA class I alleles in a population from Central Uganda which will enable us to carry out a functional characterization of CD8+ T-cell mediated immune responses to MTB. Our results do not show a positive association between the HLA class I alleles and TB in this Ugandan population however the study sample was too small to draw any firm conclusions about the role of HLA class I alleles and TB development in Uganda.