Absence of consistent association between human leukocyte antigen-I and -II alleles and human T-lymphotropic virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis risk in an HTLV-1 French Afro-Caribbean population

ObjectivesHuman T-cell lymphotropic virus type 1 (HTLV-1) infection leads to the risk of developing HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) in less than 5% of cases. The mechanism of disease progression in HAM/TSP remains unknown. A significant role of certain human leukocyte antigen (HLA) genotypes in determining the risk of HAM/TSP has been reported in Japan, where the HLA-A*02 gene has been found to be associated with a lower HTLV-1 provirus load and with protection from HAM/TSP, whereas HLA-DRB1*0101 has been found to be associated with an increased susceptibility to HAM/TSP. The aim of the present case–control study was to investigate the HLA class I and class II allele distribution in HTLV-seropositive French Afro-Caribbean individuals, originating from the French West Indies.MethodsAssociations with HLA class I (A and B) and class II (DRB1 and DQB1) alleles were tested in 123 HAM/TSP patients and 85 asymptomatic HTLV-1 carriers. HLA typing was undertaken on genomic DNA extracted from peripheral blood leukocytes.ResultsIn our cohort, no significant effect on either the risk of developing HAM/TSP or HTLV-1 provirus load was found for HLA class I or class II, including HLA-A*02 (p = 0.43).ConclusionsOur findings are in contrast to those in the Japanese population, however the literature on HLA associations in HTLV-1 infections across different populations over the past decade have reported conflicting results and this suggests strong ethnic disparities.