Purpose: Type III interferon is well known to have diverse antiviral and immunomodulatory activities. Studies describing the association of interleukin (IL)-28 polymorphisms in treatment-experienced HIV participants are limited. This study was aimed to determine the association of IL-28B gene polymorphisms with immunological recovery in HIV patients on 6-9 months of antiretroviral therapy (ART).
Methods: Eighty treatment-naive HIV patients were recruited, of which 48 patients were followed up after 6-9 months of ART. Whole blood samples were collected before and after 6-9 months of ART. CD4, CD8 and CD3 counts were enumerated flow cytometry. IL-28B polymorphisms (rs12979860 and rs8099917) were profiled by polymerase chain reaction (PCR)-restriction fragment length polymorphism. The IL-28 mRNA and plasma HIV-1 viral load were estimated using real-time PCR and plasma IL-28 level by ELISA.
Results: The CD4, CD4/CD3%, IL-28 mRNA and reversal of CD4/CD8 ratio were significantly increased following 6-9 months of ART (P < 0.01). The rs12979860 CC genotype and rs12979860:rs8099917 (CC: TT) haplotype showed significant association with higher CD4+ T-cell count amongst treatment-naive HIV-infected individuals (P < 0.05). In addition, there was a significant association of rs12979860 CC genotype with increase in CD4/CD3% following 6-9 months of ART. IL-28 mRNA showed correlation with the HIV-1 viral load, and there was a significant increase in the IL-28 mRNA expression following 6-9 months of ART.
Conclusion: Our preliminary findings suggest that IL-28 polymorphisms could influence both immunological recovery and therapeutic response in HIV infection. Hence, functional studies are warranted to understand the mechanistic basis of IL-28-mediated host genetic influence on HIV therapeutic response.