EPHA 2 sequence variants are associated with susceptibility to Kaposi ’ s sarcoma-associated herpesvirus infection and Kaposi ’ s sarcoma prevalence in HIV-infected patients

Background: To determine if variations exist in the KSHV host receptor EPHA2′s coding region that affect KSHV infectivity and/or KS prevalence among South African HIV-infected patients. Methods: A retrospective candidate gene association study was performed on 150 patients which were randomly selected from a total of 756 HIV-infected patients and grouped according to their KS status and KSHV serodiagnosis; namely group 1: KS/KSHV; group 2: KS/KSHV; group 3: KS/KSHV. Peripheral blood DNA was used to extract DNA and PCR amplify and sequence the entire EPHA2 coding region, which was compared to the NCBI reference through multiple alignment. Results: 100% (95% CI 92.9–100%) of the KS positive patients, and 31.6% (95% CI 28.3–35.1%) of the KS negative patients were found to be KSHV seropositive. Aggregate variation across the entire EPHA2 coding region identified an association with KS (OR=6.6 (95% CI 2.8, 15.9), p=2.2× 10). This was primarily driven by variation in the functionally important protein tyrosine kinase domain (Pkinase-Tyr; OR=4.9 (95% CI 1.9, 12.4), p= 0.001) and the sterile-α-motif (SAM; OR=13.8 (95% CI 1.7, 111.6), p= 0.014). Mutation analysis revealed two novel, non-synonymous heterozygous variants (c.2254 T > C: OR undefined, adj. p= 0.02; and c.2990 G > T: OR undefined, adj. p= 0.04) in Pkinase-Tyr and SAM, respectively, to be statistically associated with KS; and a novel heterozygous transition (c.2727C > T: OR=6.4 (95% CI 1.4, 28.4), adj. p= 0.03) in Pkinase-Tyr to be statistically associated with KSHV. Conclusions: Variations in the KSHV entry receptor gene EPHA2 affected susceptibility to KSHV infection and KS development in a South African HIV-infected patient cohort.