IntroductionIn many settings, several factors including adverse drug reactions and clinical failure can limit treatment choices for combined antiretroviral therapy (cART). The aim of the study was to describe the incidence of first-line cART changes and associated factors in a cohort of Kenyan sex workers.MethodsThis was a retrospective review of medical records collected from 2009 to 2013. The review included records of HIV-infected patients aged ≥ 18 years, who received either stavudine or zidovudine or tenofovir disoproxil fumarate-based regimens. Using systematic random sampling, the study selected 1 500 records and censoring targeted the first incident of a drug change from the first-line cART.ResultsThe overall incidence rate of cART changes was 11.1 per 100 person-years within a total follow-up period of 3 427.9 person-years. Out of 380 patients who changed cART, 370 (97%) had a drug substitution and 10 (3%) switched regimens. The most commonly cited reasons for changing cART were adverse drug reactions (76%). Tenofovir disoproxil fumarate had a lower drug change rate (1.9 per 100 person years) compared to stavudine (27 per 100 person years). Using zidovudine as the reference group, stavudine-based regimens were significantly associated with an increased hazard of drug changes (adjusted hazards ratio 10.2; 95% CI: 6.02-17.2).ConclusionThese findings suggest a moderate incidence of cART changes among sex workers in Nairobi, Kenya. Individuals using stavudine were at a higher risk of experiencing a change in their cART, mostly presenting within 20 months, and primarily due to adverse drug reactions.

IntroductionSeveral risk factors including stavudine and age have been strongly associated with polyneuropathy. However, conflicting data exist on height as an independent risk factor in polyneuropathy. The objective of this study is to exclude height as an independent polyneuropathy risk factor in a cohort of human immunodeficiency virus (HIV)-infected Kenyan sex workers.MethodsThis was an analysis of prospectively collected data of treatment-naive subjects initiating either stavudine or tenofovir diphosphate fumarate or zidovudine-based antiretroviral therapy (ART) regimens from January 2008 to August 2012. Polyneuropathy was characterised as burning sensation, numbness, or dysesthesia. The study used arithmetic means of weight (kg) and height (cm) measured in duplicates using calibrated scales.ResultsAfter exclusion of duplicate data sets and un-confirmed cases of polyneuropathy, the study identified 212 patients without polyneuropathy, 14 pre-ART and 94 post-ART related polyneuropathy cases. Polyneuropathy cases were older but did not differ in demographic, clinical and laboratory parameters at baseline. There was a significant difference in first-line ART regimens with more patients on tenofovir disoproxil fumarate in the post-ART group (p=0.017).ConclusionPolyneuropathy is a common disorder among HIV-infected Kenyan sex workers. These data cannot support the postulated increased risk by height after matching for gender and ART duration. Though stavudine is associated with polyneuropathy, in this study many patients previously not exposed to stavudine developed polyneuropathy. This suggests the involvement of unknown risk factors such as genetic and metabolite differences in the development of polyneuropathy.

Human immunodeficiency virus-related polyneuropathy remains a painful condition resulting from damaged nerve endings. HIV infection strongly associates with a predominantly polyneuropathy that is attributed to HIV infection itself, or a toxic neuropathy associated with combination antiretroviral therapy (CART). In non-HIV-infected individuals, both deficiency and high intake of vitamins have been associated with polyneuropathy. For that reason, clinicians recommend vitamin supplements before and during CART. Although some, but not all, HIV-related vitamin deficiencies may replete during treatment with CART, it is predictable that high vitamin supplement intakes may contribute to nerve disorders. In resource-limited settings where the diagnosis of polyneuropathy heavily relies on symptoms, data on risk factors for polyneuropathy including vitamin status, alcohol consumption, and co-infections are limited. In addition, studies on genetic influence on the concentration of micronutrients in the blood of long-term users of CART are scarce. Possible sources of high intakes of vitamins could arise from the fact that a number of HIV-infected persons self-medicate. In addition, since HIV-infected individuals have an increased lifespan, relying on symptoms alone to specifically diagnose HIV-associated neuropathies could be a barrier to effective treatment in recourse-poor settings. This paper reviews evidence on single nucleotide polymorphisms (SNPs) with the potential to influence bioavailability of vitamins in HIV-infected patients. Genome-wide association studies have reported SNPs in alkaline phosphatase, fucosyltransferase 2, cubilin, transcobalamin 1, and tumor necrosis factor as potential determinants of various blood levels of vitamin B-6, B-12 and E. As long term CART increasingly become, personalized, future research should focus on SNPs, which influence vitamin blood levels, and with potential to augment long-term treatment with CART.