Th1 cytokine gene polymorphism and the corresponding plasma cytokine levels: A comparative study in HIV‐1 positive and exposed uninfected infants

The pro‐inflammatory (Th1) cytokines namely interleukin (IL)‐2, IL‐6, IL‐12, interferon (IFN)‐γ, tumor necrosis factor‐α (TNF‐α) are vital in the clearance of HIV infection. This prospective cohort study aimed to evaluate the polymorphisms of Th1 cytokine genes and their corresponding plasma cytokine levels in HIV‐1 positive and exposed uninfected (EU) infants born to HIV‐1 positive mothers. CD4 count, viral load of HIV‐1 positive mothers was done using commercially available reagents. Cytokine genotyping analysis and levels were done in 20 HIV‐1 positive and 54 EU infants. The polymorphisms of Th1 cytokines were done using the PCR‐SSP method. Plasma cytokine levels were estimated using Bio‐Plex‐Pro cytokine assay (BIO‐RAD; USA). Results revealed treatment status of the mothers and viral load were the two confounding factors having a significant effect on HIV status of the infant. TNF‐α GG genotype is significantly higher in EU infants as compared with HIV‐1 positive infants. GG genotype was associated with high TNF‐ α levels in HIV‐1 positive infants but the difference was not statistically significant. HIV‐1 positive infants with ‐IFN‐γ (+874) TT genotype was significantly associated with high IFN‐γ levels. To the best of our knowledge, this is the first study reporting the role of Th1 cytokine gene polymorphisms and their corresponding plasma cytokine levels in HIV‐1 positive and EU infants from India.