Oxidative stress and mitochondrial dysfunction in human immunodeficiency virus patients on highly active antiretroviral therapy

Thesis Abstract

This study was aimed at evaluating oxidative stress and mitochondrial dysfunction in HIV patients on a combination of emtricitabine, tenofovir and efavirenz (ATRIPLA), commonly used for treating these patients attending the HIV clinic of Enugu State University Teaching (ESUT) Hospital, Parklane, Enugu, Nigeria following short and long-term therapy. Ninety six (96) subjects (divided into four groups) aged between 18 and 60 years were recruited for the study from the HIV clinic and the laboratory of the hospital. Ethical clearance was obtained from the Ethical Committee of the same hospital. Group 1 consisted of twenty four (24) apparently healthy HIV sero-negative age–matched individuals (No HIV or control group) who work in different laboratories of the hospital. Group 2 consisted of 24 sero-positive patients who had not started any form of treatment (treatment naive group), while group 3 was made up of twenty four (24) subjects on a short-term course of highly active antiretroviral therapy (HAART) (for less than one year). Group 4 was made up of twenty four (24) subjects who were on HAART for more than one year, representing those on long-term therapy. Ten mililiters (10 ml) of blood sample was collected from each patient from the antecubital-vein without venous stasis into EDTA and plain bottles. Serum was processed from the retracted whole blood and stored in duplicates in cryobottles at -200C for biochemical analyses while the anticoagulated blood samples were further processed for CD4+ cell count and DNA extraction for genomic studies. Total antioxidant capacity (TAC in nmol/l), malondialdehyde (MDA in mmol/l), lactate level (in mg/dl), creatine kinase activity (Ck-MB isoform in IU/L), triacylglycerols (TAG) concentrations in mg/dl, CD4+ count in cells/μl, alanine aminotransferase (ALT) activity in IU/L and genomic studies were all done using standard operative procedures. A comparison of the various groups showed a non-significant (p > 0.05) difference in lactate concentration across the study groups with groups 1, 2, 3 and 4 having lactate concentrations of 10.71±0.37, 12.84 ±0.59, 10.68±0.38 and 10.20±0.18 respectively. Group 2 subjects had significantly (p < 0.05) higher malondialdehyde (MDA) concentration (r25.33±0.38) compared to group 1 (1.63±0.35), group 3 (12.29±0.20) and group 4 (14.72±0.78) respectively. The ALT activity was significantly (p < 0.05) higher in group 2 (46.51±0.80) compared to group 1 (22.43±1.07), group 3 (31.05±1.10) and group 4 (39.93±0.92) respectively. HIV-infected patients on HAART for less than 1 year (group 3) had significantly (p < 0.05) higher total antioxidant status (TAS) at 1208.21±12.56 compared to group 1 (No HIV control group) at 1172.67±20.42, greater than 1year on HAART at 500.88±6.13 and Naïve HIV group at 402.17±5.53 respectively. The TAS of group 3 subjects (subjects less than 1 year on HAART) was significantly (p < 0.05) higher than that of group 1 subjects (No HIV subjects), group 2 subjects (Naïve HIV subjects) and group 4 (subjects greater than 1 year on HAART).   Creatine kinase (CK) activity was significantly (p < 0.05) higher in group 2 (285.36±33.18) compared to group 1 (104.62±16.55), group 3 (178.95±13.54) and group 4 (207.75±22.40) respectively. There was a non-significant (p > 0.05) difference in triacylglycerols (TAG) concentration across the study groups with groups 1, 2, 3 and 4 having TAG concentrations of 131.25±10.54, 128.17±12.41, 124.24±9.53 and 129.13±10.63 respectively. The CD4+ count of group 1 subject (748.04±25.26) was significantly (p < 0.05) higher than that in group 2 (258.54±54.11), group 3 (422.42±30.08) and group 4 (680.84±48.41). Subjects on long term treatment of HAART had significantly (p < 0.05) higher CD4+ count compared to the treatment naïve group and those on short term treatment. For the genomic studies, the average normalized copy number of the mitochondrial genes under review (mtDNA D-loop, ATPase 8, TRNALEUuur) were greater for the naïve and those on therapy for more than 1 year while mtDNA (ND4) showed no copy number variation across the groups. The treatment naïve group had the highest expression of the mt-141 gene (ATPase 8) with copy number (11.84±1.78). However, the group on HAART for more than a year had a significantly (p < 0.05) higher expression of the mt-141 gene (ATPase 8) with copy number (5.38±0.98) as well as the short-term treated group with copy number 2.45 ±0.43 compared to the No-HIV group (0.08±0.07). The present study showed that HIV infection and long-term use of HAART increase oxidative stress which may impact on the mitochondrial function.