Abstract
Biological ageing refers to the gradual decrease in physiological functions, resulting in immune senescence, cellular damage and apoptosis. Telomere length is a biomarker of biological ageing. Limited studies have associated shorter telomere length with HIV and parasite single infections, with no studies reporting the association of HIV and parasite co-infection with telomere length. The study aimed to investigate whether telomere length shortening is accelerated in a South African population co-infected with HIV and helminths compared to participants singly infected with either HIV or helminths. Additionally, telomere length data were compared with participants' biochemical and full blood count parameters. A total of 200 participants were in groups of uninfected control, HIV single infection, helminth single infection and HIV and helminth co-infection groups. Relative telomere length (RTL) was determined using Real-Time PCR and associated with biochemical and full blood count parameters using multivariate regression analysis models that were adjusted for confounders. The uninfected control group was used as a reference group. The uninfected control group had the highest mean RTL (1.21 +/- 0.53) while the HIV-infected (0.96 +/- 0.42) and co-infected (0.93 +/- 0.41) groups had similar RTLs, and lastly, the helminth-infected group (0.83 +/- 0.33) had the lowest RTL (p = 0.0002). When compared to the uninfected control group, a significant association between RTL and biochemical parameters, including blood iron (beta = -0.48), ferritin (beta = -0.48), transferrin saturation (beta = -0.57), transferrin (beta = -0.57), phosphate (beta = -0.47), vitamin A (beta = -0.49) and C-reactive protein (beta = -0.52) were noted in the co-infected group (p < 0.05). In addition, a significant association between RTL and full blood count, including (beta = -0.47), haematocrit (beta = -0.46), mean corpuscular volume (beta = -0.47), lymphocytes (beta = -0.45), mean corpuscular haemoglobin concentration (beta = -0.45), red cell distribution width (beta = -0.47), monocytes (beta = -0.45), eosinophils (beta = -0.45), basophils (beta = -0.44) and transferrin saturation (beta = -0.57) were also noted in the co-infected group (p < 0.05). Accelerated biological ageing, as indicated by telomere length shortening, is associated with HIV and helminth co-infections.