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

Helen K. Buteme, Rebecca Axelsson-Robertson, Lina Benson, Moses L. Joloba, W. Henry Boom, Gunilla Kallenius, Markus Maeurer

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. 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. 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). 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.