Genetic polymorphism at Interleukin-7 receptor gene at +510 position and its impact on pain and other symptoms among HIV and AIDS patients
Genetic polymorphism of cytokine genes has been shown to be associated with susceptibility to diseases. We investigated the frequency of the IL-7 receptor-α +510 CT SNP in relation to pain and other symptoms among HIV and AIDS patients attended at various South African hospitals for treatment. Demographic as well as clinical data was obtained through structured interviews and patient files were consulted. A total of 107 mouth wash samples were obtained from volunteers, and DNA was extracted from these samples using the Qiagen protocol. Genotyping of the IL-7 receptor +510 CT SNP was conducted using sequence specific PCR. The CC and TC genotypes were the most common, while the TT genotype was rare (47.7, 45.8 and 6.5% respectively). The CC genotype was more common among patients who had body pain at the time they went for testing (χ2 = 4.75; P = 0.029) while the TC genotype was more common among those that did not have pain (χ2 = 6.86; P = 0.009). The TC genotype was also more common among patients who did not have genital sores (χ2 = 4.663; P = 0.031). The TT genotype was more common among patients whose infection state had improved as well as among those who had tuberculosis, although the differences were not significant. We concluded that the CC genotype is associated with pain while the TC genotype is protective of pain and genital sores. Further studies will be needed to confirm these hypotheses in larger populations.