dc.description.abstract | Background: Adverse drug reactions (ADRs) associated with prolonged use of
antiretroviral therapy (ART) are a serious hindrance to achieving optimal treatment
outcomes. Evidence demonstrates that metabolites play an important role in the
advancement of ART-related ADRs. So far, there is a paucity of information on the
prevalence of long-term ART-related ADRs and the underlying molecular processes
in the Kenyan populations.
The development of ART-related ADRs varies substantially between individuals and
the role of important factors such as ethnicity that contribute to the heterogeneity
among Africans and Europeans populations has not been adequately investigated.
Objective: To describe long-term ART-related ADRs and corresponding variations
in plasma metabolites in HIV-infected Kenyan and German patients on long-term
ART.
Methods: The description of common ADRs and related determinants was
performed through a retrospective analysis of electronic medical records from the
Sex Workers Outreach Program (SWOP) (n = 1,450) in Kenya. The study identified
factors associated with polyneuropathy through a nested case-control study that
involved HIV-infected patients who developed polyneuropathy (cases, 94) and those
without polyneuropathy (controls, 212) after long-term ART. The description of the
corresponding variations in plasma metabolites was achieved through an
exploratory cohort (n = 65). The exploratory cohort comprised of HIV-infected
Kenyan (n = 36) and German (n = 29) patients on long-term ART. The metabolomic
profiling entailed the collection of blood samples from HIV-infected Kenyan
patients, while in the case of the German cohort the study utilized archived plasma
samples. Concentrations of plasma metabolites were determined using Liquid
Chromatography coupled with Mass Spectrometric techniques (HPLC-MS).
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To reveal common ADRs and associated factors, the statistical analyses involved
both descriptive and inferential statistics. Further, a bivariate analysis was
conducted to compare polyneuropathy related factors between cases and controls.
Metabolomic data analysis involved the application of the Analysis of Variance,
Partial Least Squares-Discriminant Analysis, Significance Analysis of Microarray
and metabolic pathway mapping using Metaboanalyst Programme.
Results: In SWOP clinics, long-term use of ART-regimens containing either
stavudine (d4T) or azidothymidine (AZT) or tenofovir disoproxil fumarate (TDF)
combined with lamivudine (3TC) and efavirenz (EFV) or nevirapine (NVP) for a
median duration of 4.3 years (1.7-5.3) related to the development of ADRs among
HIV-infected Kenyan patients. The common ADRs in SWOP facilities included
lipodystrophy 211 (41.7%), polyneuropathy 149 (29.4%), anaemia 78 (15.4%),
hepatotoxicity 47 (9.3%), skin rash 14 (2.8%) and renal toxicity 7 (1.4%). The
development of ADRs accounted for 287 (76%) of all ART regimen changes, mostly
due to stavudine-related lipodystrophy (n = 204, 76%) and polyneuropathy (n= 54,
20%).
The risk of patients developing an ADR during 24 months of ART was statistically
significant (Log-rank test, p = 0.044). While the use of tenofovir disoproxil fumarate
(TDF) was protective [hazards ratio 0.50; 95% CI: 0.3-0.8], older patients (≥ 40 years)
had an increased risk of developing an ADR [hazards ratio 1.0; 95% CI: 1.0-1.1].
Patients with polyneuropathy were significantly older (0 = 0.017) and had a higher
systolic blood pressure (p = 0.025). Apparently, TDF was significantly related to the
development of polyneuropathy (p = 0.017), suggesting an earlier exposure to
stavudine before changing to TDF.
The metabolomic analysis revealed raised levels of phosphatidylcholine diacyl C42:0
(PC aa C42:0) in HIV-infected Kenyan patients with polyneuropathy (0.8±0.3) and
without polyneuropathy (0.7±0.2) compared to HIV-infected German patients prior
to ART (0.5±0.2) and after initiation of ART (0.5±0.2). Correspondingly, levels of
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LysoPC a C17:0 were elevated in HIV-infected Kenyan patients with
polyneuropathy (2.3±0.9) and without polyneuropathy (2.1±0.9) compared to HIVinfected
German patients prior to ART (1.6±0.5) and after initiation of ART (1.5±0.5)
(variable importance in projection > 1, p = 0.05). There were elevated levels of shortchain
acylcarnitine (propionylcarnitine) in HIV-infected Kenyan patients with
stavudine-related polyneuropathy (0.3±0.1) compared to HIV-infected
polyneuropathy free, ART-naive German patients (0.28±0.1), polyneuropathy free
German patients on ART (0.2±0.1) and polyneuropathy free Kenyan patients on ART
(0.2±0.1) (p < 0.001).
Discussion and conclusion: Lipodystrophy and polyneuropathy were the most
commonly encountered ADRs in SWOP clinics, accounting for most of the ART drug
changes. Although the prevalence of ADRs vary from one study to another, factors
such as variations in ADR reporting procedures and concomitant medication may
have influenced these findings. Older age significantly related to an increased
hazard of developing ADRs and a significantly increased risk of developing
polyneuropathy. This suggests that the burden of ADRs such as polyneuropathy is
likely to be high in older HIV-infected populations compared to younger
populations on long-term ART.
Typical long-term ADRs were more likely to develop in older HIV-infected Kenyan
patients compared to HIV-infected German patients. Although patients in SWOP
clinics tolerated well the use of TDF-based regimens, a significant number of patients
on these regimens ended up with polyneuropathy. The development of
polyneuropathy in patients, who never used stavudine, suggests an ongoing burden
of polyneuropathy even after the ban on stavudine. The findings of this study
further demonstrate that many plasma metabolites undergo significant alterations in
HIV-infected patients before and after long-term exposure to ART. The observed upregulation
of glycerophospholipids namely PC aa C42:0 and LysoPC a C17:0 and
short-chain acylcarnitine namely propionylcarnitine (C3) suggests that
glycerophospholipids and fatty acid oxidation metabolism could be the most
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disturbed pathways in HIV-infected patients on long-term ART. The affected
pathways seemed to correlates well with clinical manifestations such as
polyneuropathy, lipoatrophy, pancreatitis, lactic acidosis and nephrotoxicity. The
current results may serve as a starting point for the search of new biomolecules that
could be potential biomarkers for early detection of adverse drug reactions. There is
a need for further studies to confirm causal pathway between HIV-infection,
metabolomic changes and clinical outcomes. | en_US |
dc.description.department | a
Department of Psychiatry, University of Nairobi, ; bDepartment of Mental Health, School of Medicine,
Moi University, Eldoret, Kenya | |