Inflammatory cytokines and cell activation markers in HIV and HIV/TB co-infected patients attending AMPATH clinic at MTRH-Eldoret, Kenya

Abstract

Background: Infection with HIV and TB leads to inflammation. Markers of inflammation include TNF-α, IFN-γ, CD38 and HLA-DR. In HIV infection these markers create an environment which favours reactivation of latent TB to TB disease in patients on HAART. The markers TNF-α, IFN-γ, CD38, HLA-DR and CD4 cell count can be used to predict possible reactivation of latent TB to disease in HIV patients on HAART. The level of these inflammatory markers in HIV and HIV/TB co-infection is unknown. The purpose of this study was to investigate inflammatory markers TNF-α, IFN-γ, CD38, and HLA-DR levels in HIV and HIV/TB coinfected patients attending AMPATH clinic at MTRH-Eldoret. Objective: To determine inflammatory cytokines and cell activation markers in HIV and HIV/TB co-infected patients attending AMPATH clinic at MTRH-Eldoret. Methods: This was a cross sectional comparative study of 168 patients comprising of 84 HIV/TB co-infected and 84 HIV only patients who had been on HAART for more than 1 year. Clinical and demographic information was obtained from the patients hospital files and interview guide. Blood samples from each patient were collected into EDTA tubes and plasma separated within 2 hours of collection at 3,000 r.p.m for 3 minutes then kept at -800 C until analysis. Activation markers CD38, HLA DR and CD4 count were analysed by flow Cytometry (BD FAC’S calibur® ) on whole blood samples. Analysis of the inflammatory cytokines (TNF-α and IFN-γ) were done on the plasma samples by ELISA (Genway’s® ). The levels of inflammatory markers in the two groups were compared. Data was analysed using STATA version 13. P-value ≤ 0.05 was considered significant. Findings: The mean age for both HIV/TB and HIV patients was 42 years. The median (IQR) levels for TNF-α (pg/ml) was 7.26 (6.76- 8.12), IFN-γ (pg/ml) 26.3 (25.18- 27.22), CD38(%) 4.36 (2.06-6.31), HLA-DR (%) 92.44 (90.52-95.51) and CD4 (cells/mm3 ) 231 (117-350) in HIV/TB co-infected patients, while in HIV patients the levels were TNF-α 10.72 (8.12-12.13), IFN-γ 25.40 (23.59-27.67), CD38 5.94 (4.44-7.41), HLA-DR 93.33 (90.24-96.56) and CD4 383 (318-543). HIV only patients had higher levels of TNF-α (p=<0.001), CD38% (p=0.0002) and CD4 (p=<0.001) compared to those of TB/HIV co-infected patients. No significant difference was observed in the levels of IFN-γ and HLA-DR (p=0.1559) and (p=0.1754) respectively. Conclusion: Higher levels of inflammatory markers were found in HIV only patients compared to HIV/TB co-infected patients. This high level of inflammation leads to TB-reactivation. Keywords: inflammatory cytokines; cell activation marker; HIV and HIV/TB co-infected.