Renal safety of a tenofovir-containing first line regimen: experience from an antiretroviral cohort in rural Lesotho

Proximal tubular renal dysfunction among HIV infected patients on Tenofovir versus Tenofovir sparing regimen in western Kenya

Introduction

Tenofovir Disoproxil Fumarate (TDF) is the most widely used Anti-Retroviral Therapy (ART) drug due to its potency, safety profile and World Health Organization (WHO) recommendation. TDF causes proximal tubular renal dysfunction (PTRD) leading to Fanconi syndrome, acute kidney injury and chronic kidney disease. Modest rates (2–4%) of TDF related toxicity based on estimated Glomerular Filtration Rate (GFR) have been described, while TDF-induced PTRD has been reported to be 22%. TDF toxicity is more likely among African patients, it is reversible and TDF may be renal dosed in patients with dysfunction. The objective of this study was to assess proximal tubular renal dysfunction, global renal function, and their determinants among patients on TDF versus TDF-sparing regimen.

Methods

This was a cross-sectional study among people living with HIV/AIDS (PLWHA) attending the Academic Model Providing Access to Healthcare (AMPATH) program. The primary outcome of interest in this study was PTRD while the secondary outcome of interest was estimated GFR. PTRD was defined as any two of beta-2 microglobulin in urine, metabolic acidosis, normoglycemic glucosuria and fractional excretion of phosphate. Student’s t-test, chi-square and their non-parametric equivalents were used to test for statistical significance. Univariate and multivariate logistic regression analysis was carried out.

Results

A total of 516 participants were included in the final analysis, 261 on TDF while 255 were on TDF-sparing regimens. The mean (SD) age of all participants was 41.5 (12.6) years with majority being female (60.3%). The proportion of PTRD was 10.0% versus 3.1% in the TDF compared to TDF-sparing group (P<0.001). Mean estimated GFR was 112.8 (21.5) vs 109.7 (21.9) ml/min/1.73mm³ (P = 0.20) for the TDF compared to TDF-sparing group. TDF users were more likely to have PTRD compared to non-TDF users, adjusted Odds Ratio (AOR) 3.0, 95% CI 1.12 to 7.75.

Conclusion

There was significant PTRD in the TDF compared to TDF-sparing group without significant difference in estimated GFR. The clinical significance of these findings may not be clear in the short term.

Factors Associated with Antiretroviral Therapy Toxicity Out-Comes in Patients with and without Hypertension

BACKGROUND

Negative effects of antiretroviral therapy (ART) drugs on HIV/AIDS patients are one of the major health issues in the therapeutic treatment of this communicable disease. This holds particularly for people living with HIV (PLHIV) who might have a non-communicable disease (like hypertension), which also requires a lifetime treatment. In this study, we investigated the association between hypertension and other possible factors on ART toxicity markers in patients with hypertension, compared to those without hypertension.

METHODS

This retrospective longitudinal study reviewed chronic patient files of 525 patients (of which 222 were hypertensive) who satisfied the inclusion criteria and were on ART at a hospital in central Eswatini. Specific levels of estimated glomerular filtration (eGFR), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were used as drug toxicity markers. To analyze the longitudinal data between the exposure of interest and outcome variables, a Generalized Estimated Equation method was employed.

RESULTS

Participants with hypertension had decreased eGFR compared to those without hypertension (β = -2.22; p-value = 0.03). There was no significant association between ALT, AST and hypertension (p-value = 0.34 and 0.20, respectively). Factors that were found to have a significant association with ART toxicity markers included age, sex, ART duration, hypertension treatment and time of study. The eGFR was found to be significantly increasing over the study period (p-value < 0.001) for all participants. The significance was consistent in both hypertensive and non-hypertensive participants independently (p-value = 0.002 and <0.001, respectively). The overall trends of ALT and AST over time were also significant (p-value = 0.003 and <0.001, respectively).

CONCLUSIONS

Patients with hypertension had decreased eGFR, and there was a significant association of eGFR with time of the study. Special attention, therefore, to monitor calamities which are indicated by a decrease of eGFR (like renal impairment) should be given in PLHIV on ART with hypertension, especially more so if they were on ART for longer time.

Determinants and Incidence of Chronic Kidney Disease with Tenofovir-Based Antiretroviral Therapy Regimens: A Cohort Study in HIV-Infected Adults in South China

Background:

The data of the impact of tenofovir (TDF) on kidney damage in Chinese HIV-1 infected patients are limited.

Objective:

To evaluate the incidence and risk factors of stage 3 chronic kidney disease (CKD) and rapid kidney function decline (RKFD) among Chinese HIV-1 infected patients starting with a TDF-based regimen.

Method:

We enrolled in 797 TDF-initiated HIV-1-infected patients in a Chinese cohort. Kidney dysfunctions were defined as stage 3 CKD (eGFR < 60 mL/min/1.73 m2 during follow-up) and RKFD (eGFR decline > 10 mL/min/1.73 m2/year). A linear mixed-effects model was used to quantify the average eGFR change per 48 weeks. A generalized estimating equation regression analysis was conducted to determine the risk factors associated with renal dysfunction. The method of multiple imputation was used to reduce the bias caused by missing data.

Results:

In this retrospective study, 14 (2%) patients experienced stage 3 CKD, and 272 (34%) individuals experienced RKFD during a median of 26 (IQR, 4-78; maximum 325) weeks follow-up period. The mean loss in eGFR per 48 weeks increased consistently over time, from -2.59 mL/min/1.73 m2 before 48 weeks to -17.61 mL/min/1.73 m2 after 288 weeks. For every 10 mL/min/1.73 m2 increase of eGFR, the risk of RKFD increased by 29% (95%CI: 18%, 40%). Each 10 years older and every 10 mL/min/1.73 m2 higher in baseline eGFR, the risk of stage 3 CKD increased to 1.56 (95% CI: 1.00, 2.43) and decreased by 65% (95% CI: 48%, 76%), respectively. Anemia and higher viral load were significantly associated with RKFD. The results were robust across a range of multiple imputation analyses.

Conclusions:

TDF-associated CKD is rare in HIV-1 infected Chinese adults. Longer TDF-exposed patients are more likely to have renal dysfunction, especially those with older age, anemia, lower baseline eGFR, and higher viral load.

Evaluation of safety and efficacy of tenofovir disoproxil in hemodialysis and renal transplant patients monoinfected with hepatitis B virus based on real life data

Introduction

There are limited data about the safety of tenofovir disoproxil fumarate (TDF) in chronic renal failure (CRF). In this study, we aimed to evaluate the safety and efficacy of TDF in renal transplant recipients and hemodialysis patients with chronic hepatitis B (CHB) during long-term follow-up.

Material and methods

CHB patients undergoing hemodialysis (group 1), renal transplant recipients (group 2) and patients with normal renal function were included in the study. All patients were treated with TDF for at least 6 months. The groups were compared with regards to safety and efficacy. HBV-DNA levels were studied using a Cobas-TaqMan 96 system.

Results

A total of 217 patients with CHB (group 1: 8 patients, group 2: 9 patients, group 3: 200 patients) were enrolled in this study. The frequency of clinical adverse effects was significantly higher in groups 1 and 2compared with group 3 (37.5% vs. 11.1% vs. 0.5%, respectively, p < 0.001). However, no patients discontinued the drug due to the adverse effects. Serum creatinine levels were similar at baseline and at the end of follow-up in groups 1 and 2 (6.5 ±1.8 mg/dl and 6.9 ±1.5 mg/dl; 1.3 ±0.2 and 1.4 ±0.4 mg/dl, respectively, p < 0.05). HBV-DNA negativity rates were comparable at the 12^th month and at the end of follow-up (50-83% for group 1, 60-67% for group 2 and 70-75% for group 3, respectively, p > 0.05).

Conclusions

Clinical adverse effects of TDF were more common in patients with CRF in comparison with patients without CRF. However, the occurrence of adverse effects did not necessitate discontinuation of the drug. TDF was safe and effective for this group of patients.

Prevalence of tubulopathy and association with renal function loss in HIV-infected patients

BACKGROUND

The incidence of chronic kidney disease (CKD) is 10 times higher in human immunodeficiency virus (HIV)-infected patients than in the general population. We explored the prevalence and determinants of proximal tubular dysfunction (PTD) in HIV-infected individuals, and assessed the impact of the tubulopathy on the estimated glomerular filtration rate (eGFR) outcome.

METHODS

A cohort study was performed on 694 outpatients followed in a French centre to analyse the prevalence of PTD, the diagnosis performance of screening tools and the associated factors. eGFR was prospectively evaluated to analyse the predictive value of the tubulopathy on eGFR decrease.

RESULTS

At inclusion, 14% of the patients presented with PTD and 5% with CKD. No individual tubular marker, including non-glomerular proteinuria, glycosuria dipstick or hypophosphataemia, registered sufficient performance to identify PTD. We found a significant interaction between tenofovir disoproxil fumarate exposure and ethnicity (P = 0.03) for tubulopathy risk. Tenofovir disoproxil fumarate exposure was associated with PTD in non-Africans [adjusted odds ratio (aOR) = 4.71, P < 10-3], but not in patients of sub-Saharan African origin (aOR = 1.17, P = 0.73). Among the 601 patients followed during a median of 4.3 years, 13% experienced an accelerated eGFR decline. Unlike microalbuminuria and glomerular proteinuria, tubulopathy was not associated with accelerated eGFR decline.

CONCLUSION

PTD is not rare in HIV-infected individuals but is less frequent in sub-Saharan African patients and is associated with tenofovir disoproxil fumarate exposure only in non-Africans. Its diagnosis requires multiple biochemical testing and it is not associated with an accelerated eGFR decline.

Chronic Kidney Disease and Associated Factors Among HIV/AIDS Patients on HAART in Ethiopia

Background

In developing countries, both opportunistic infections and chronic diseases account a high HIV-associated mortality and morbidity. Chronic kidney disease (CKD) associated with HIV infection has got increased attention in sub-Saharan Africa as a result of the high HIV prevalence and due to the late diagnosis and initiation of HAART. Thus, this study was conducted to assess CKD and associated factors among HIV patients on HAART in Ethiopia.

Methods

A hospital-based cross-sectional study with a secondary data review was conducted on 336 on HIV/AIDS patients on HAART from February to July 2017 at University of Gondar Referral Hospital. The study participants were selected using a systematic random sampling technique. Socio-demographic and clinical data were collected using a semi-structured questionnaire at their follow-up date with interview and chart review. Three to five milliliters of venous blood and five milliliters of urine specimen were collected for serum creatinine and urine albumin determination, respectively. Data were entered into SPSS version 20 for analysis. Glomerular filtration rate was estimated using the CKD-EPI estimator. Bivariate and multivariate logistic regression was employed and p-value <0.2 and < 0.05, respectively, was considered statistically significant.

Results

The prevalence of CKD on the study participants was 54 (16.1%) (95% CI, 12.2–20.4%). By stage, about 27 (8.0%) had stage 1 (persistent proteinuria with eGFR ≥ 90 mL/min/1.73 m²), 16 (4.8%) had stage 2 (persistent proteinuria with eGFR of 60–89.9 mL/min/1.73 m²), 6 (1.8%) had stage 3 (eGFR 30–59.9 mL/min/1.73 m² with or without proteinuria) and 5 (1.5%) had stage 5 ((kidney failure), eGFR<15mL/min/1.73 m² with or without proteinuria). With multivariate logistic regression analysis, being male (AOR=2.05 (1.03–4.09), p=0.04), being merchant (AOR=2.91 (1.00–8.48), p=0.049) and having viral load≥1000 copies/mm³ (AOR=3.1 (1.38–7.00), P<0.01) were significantly associated with CKD.

Conclusion

The prevalence of CKD among HIV patients on HARRT is high. Being male, merchant and having viral load ≥1000 copies/mm³ were associated factors of CKD. Patients should be regularly monitored and screened for early diagnosis and management of CKD. Those patients who have being merchant with high viral load and male patients should require close monitoring.

Tenofovir-associated renal toxicity in a cohort of HIV infected patients in Ghana

Objective

Tenofovir disoproxil fumarate (TDF) is a nucleotide analogue recommended in international HIV treatment guidelines. Purpose of this study was to estimate the long term effects of TDF on renal profile in a cohort of HIV patients in Ghana. Three hundred (300) consecutive HIV-positive patients who initiated TDF-based antiretroviral treatment in 2008 at the Korle-Bu Teaching Hospital were sampled. Creatinine clearance (CrCl) was calculated using the Cockcroft-Gault equation at baseline and renal impairment was defined as CrCl values of 30.0–49.9 mL/min (moderate renal impairment) and < 30 mL/min (severe renal impairment) as per institutional guidelines for renal function test.

Results

Median follow up time was 2.9 years (IQR 2.3–3.4 years). At study endpoint, 63 participants (21.0% [95% CI 6.5–26.1]) recorded CrCl rate below 50 mL/min indicating incident renal impairment, made up of 18.3% moderate renal impairment and 2.3% severe renal impairment. Factors associated with incidence of renal impairment were increasing age, decrease in creatinine clearance rate at baseline, WHO HIV stage III/IV and participants with BMI of < 18.5 kg/m². Patients with identified renal impairment risk factors at ART initiation should be targeted and monitored effectively to prevent renal injury.

Renal dysfunction by baseline CD4 cell count in a cohort of adults starting antiretroviral treatment regardless of CD4 count in the HIV Prevention Trials Network 071 [HPTN 071; Population Effect of Antiretroviral Therapy to Reduce HIV Transmission (PopART)] study in South Africa

OBJECTIVES

Renal dysfunction is a significant cause of morbidity and mortality among HIV-positive individuals. This study evaluated renal dysfunction in a cohort of adults who started antiretroviral treatment (ART) regardless of CD4 count at three Department of Health (DOH) clinics included in the HIV Prevention Trials Network 071 (HPTN 071) Population Effect of Antiretroviral Therapy to Reduce HIV Transmission (PopART) trial.

METHODS

A retrospective cohort analysis of routine data for HIV-positive individuals starting ART between January 2014 and November 2015 was completed. Incident renal dysfunction was defined as an estimated glomerular filtration rate (eEGFR) < 60 mL/min after ART initiation among individuals with a baseline (pre-ART) eGFR ≥ 60 mL/min.

RESULTS

Overall, 2423 individuals, with a median baseline CD4 count of 328 cells/μL [interquartile range (IQR) 195-468 cells/μL], were included in the analysis. Forty-seven individuals had a baseline eGFR < 60 mL/min. Among 1634 nonpregnant individuals started on a tenofovir-containing ART regimen and with a baseline eGFR ≥ 60 mL/min, 27 developed an eGFR < 60 mL/min on ART. Regression analysis showed lower odds of baseline eGFR < 60 mL/min at baseline CD4 counts of > 500 cells/μL [adjusted odds ratio (aOR) 0.29; 95% confidence interval (CI) 0.11-0.80], 351-500 cells/μL (aOR 0.22; 95% CI 0.08-0.59) and 201-350 (aOR 0.48; 95% CI: 0.24-0.97) compared with baseline CD4 counts < 200 cells/μL.

CONCLUSIONS

This study showed low rates of renal dysfunction at baseline and on ART, with lower rates of baseline renal dysfunction among individuals with baseline CD4 counts > 200 cells/μL. Strategies that use baseline characteristics, such as age, to identify individuals at high risk of renal dysfunction on ART for enhanced eGFR monitoring may be effective and should be the subject of future research.

Tenofovir-associated kidney disease in Africans: a systematic review

BACKGROUND

Data on chronic kidney disease development in HIV infection is important towards building a comprehensive knowledge of HIV, ageing and polypharmacy in Africa. Several previous studies on tenofovir-associated kidney disease in Africa have shown conflicting results. This review summarises what is known about the development of kidney disease in HIV-positive African patients on tenofovir disoproxil fumarate (TDF)-containing ART. We set out to document the occurrence of kidney disease in HIV-positive Africans on TDF-containing ART in population-based studies and to evaluate the renal safety of TDF in Africans.

METHODS

We conducted a systemic review using published studies which were identified through a computerized search of original research using the Medline/PubMed database, EMBASE, EBM Reviews, Proquest Google Scholar and Global Health reported from inception until 5 October 2017. Two reviewers independently abstracted the data and performed quality assessment of the included studies. We screened 595 articles and included 31 in the qualitative analysis performed.

RESULTS

A total of 106 406 patients (of whom 66,681 were on Tenofovir) were involved in these 31 studies with sample sizes ranging from 30 to 62,230. Duration on tenofovir-containing ART ranged from those initiating ART at baseline to those who received TDF for up to 9 years. All but one of the studies involved only patients 16 years and older. The studies had differing definitions of kidney dysfunction and were of variable study design quality. The documented outcomes had substantial discrepancies across the studies, most likely due to methodological differences, study size and disparate outcome definitions.

CONCLUSIONS

Our review identified studies in Africans reporting statistically significant renal function decline associated with TDF use but the clinical significance of this effect was not enough to contraindicate its continued use in ART regimens. Consistent with studies in other populations, patients are at greater risk if they have pre-existing renal disease and are more advanced in age. More research is needed on paediatric populations under 16 years of age. Trial registration This review was registered on Prospero (registration number CRD42018078717).

Renal outcomes in patients initiated on tenofovir disoproxil fumarate-based antiretroviral therapy at a community health centre in Malawi

Tenofovir-based antiretroviral therapy (TDF ART) is the first-line regimen for human immunodeficiency virus (HIV) in Africa. However, contemporary data on nephrotoxicity are lacking. We determined the renal outcomes of patients commenced on TDF ART in Malawi. ART-naïve patients initiated on TDF ART at a community health centre between 1 July 2013 and 31 December 2015 were included. The estimated glomerular filtration rate (eGFR, Cockcroft-Gault) was recorded at the initiation of therapy and over 18 months thereafter. The prevalence of renal impairment at ART initiation (eGFR < 60 ml/min) and the incidence of nephrotoxicity (eGFR < 50 ml/min) were determined. A total of 439 patients (median age: 32 years; 317 [72.2%] female) were included. Twenty-one (4.8%) patients had renal impairment at ART initiation; eGFR improved in all during follow-up. Nephrotoxicity occurred in 17 (4.0%) patients with eGFR > 50 ml/min at baseline, predominantly within the first six months of therapy. Increasing age and diastolic hypertension (>100 mmHg) were independent risk factors for nephrotoxicity development. The prevalence of kidney disease at ART initiation was 4.8% and nephrotoxicity occurred in 4.0%. Some eGFR decline may have been due to weight gain. Targeted monitoring of kidney function six months after TDF initiation should be considered in Malawi.

The incidence of first-line antiretroviral treatment changes and related factors among HIV-infected sex workers in Nairobi, Kenya

INTRODUCTION

In 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.

METHODS

This 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.

RESULTS

The 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).

CONCLUSION

These 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.

Changes in estimated glomerular filtration rate over time in South African HIV-1-infected patients receiving tenofovir: a retrospective cohort study

Introduction: Tenofovir has been associated with decline in kidney function, but in patients with low baseline kidney function, improvements over time have been reported. Additionally, the magnitude and trajectory of estimated glomerular filtration rate (eGFR) changes may differ according to how eGFR is calculated. We described changes in eGFR over time, and the incidence of, and risk factors for, kidney toxicity, in a South African cohort.

Methods: We included antiretroviral-naïve patients ≥16 years old who started tenofovir-containing antiretroviral therapy (ART) between 2002 and 2013. We calculated eGFR using the Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), and Cockcroft-Gault equations. We described changes in eGFR from ART initiation using linear mixed effects regression. We described the incidence of eGFR <30 mL/min on treatment, and identified associations with low eGFR using Cox regression.

Results: We included 15156 patients with median age of 35.4 years (IQR 29.9–42.0), median CD4 cell count of 168 cells/µL (IQR 83–243), and median eGFR (MDRD) of 98.6 mL/min (IQR 84.4–115.6). Median duration of follow up on tenofovir was 12.9 months (IQR 5.1–23.3).

Amongst those with a baseline and subsequent eGFR  available, mean eGFR change from baseline at 12 months was −4.4 mL/min (95% CI −4.9 to −4.0), −2.3 (−2.5 to −2.1), and 0.6 (0.04 to 1.2) in those with baseline eGFR ≥90 mL/min; and 11.9 mL/min (11.0 to 12.7), 14.6 (13.5 to 15.7), and 11.0 (10.3 to 11.7) in those with baseline eGFR <90 mL/min, according to the MDRD, CKD-EPI (n = 11 112), and Cockcroft-Gault (n = 9 283) equations, respectively.

Overall, 292 (1.9%) patients developed eGFR <30 mL/min. Significant associations with low eGFR included older age, baseline eGFR <60 mL/min, CD4 count <200 cells/µL, body weight <60 kg, and concomitant protease inhibitor use.

Conclusions: Patients on tenofovir with baseline eGFR ≥90 mL/min experienced small but significant declines in eGFR over time when eGFR was estimated using the MDRD or CKD-EPI equations. However, eGFR increased in patients with eGFR <90 mL/min, regardless of which estimating equation was used. Decreases to below 30 mL/min were uncommon. In settings with limited access to laboratory testing, monitoring guidelines should consider focusing on higher risk patients.

Key toxicity issues with the WHO-recommended first-line antiretroviral therapy regimen

INTRODUCTION

WHO recommends tenofovir, efavirenz, and lamivudine or emtricitabine for first-line antiretroviral therapy (ART) in adults, which replaced more toxic regimens using stavudine, zidovudine or nevirapine. Areas covered: We searched Pubmed to identify observational studies and randomized controlled trials reporting toxicity of these antiretrovirals published between 2011 and 2016, and hand-searched abstracts presented at major HIV conferences in 2015 and 2016, focusing on data from sub-Saharan Africa. Tenofovir's nephrotoxicity manifests as mild renal tubular dysfunction (common and of uncertain clinical significance), acute kidney injury (rare), and chronic declining glomerular filtration rate (common). African studies, which include high proportions of patients with renal dysfunction from opportunistic diseases, report population improvement in renal function after starting tenofovir-based ART. Tenofovir modestly decreases bone mineral density, and there is emerging data that this increases fracture risk. Efavirenz commonly causes early self-limiting neuropsychiatric toxicity and hypersensitivity rashes. Recent studies have highlighted its long-term neuropsychiatric effects, notably suicidality and neurocognitive impairment, and metabolic toxicities (dyslipidemia, dysglycemia, and lipoatrophy). We point out the challenges clinicians face in the recognition and attribution of adverse drug reactions. Expert commentary: Tenofovir and efavirenz are generally well tolerated, but both are associated with potentially serious toxicities. Pharmacovigilance systems in resource-limited settings with high HIV burden should be strengthened.

Renal Function Impairment and Associated Factors among HAART Naïve and Experienced Adult HIV Positive Individuals in Southwest Ethiopia: A Comparative Cross Sectional Study

BACKGROUND

Human immunodeficiency virus (HIV) infection and its treatment cause renal diseases. Renal disease is associated with an increasing cause of morbidity and mortality in HIV positive individuals than in the general population. It has been also associated with adverse outcomes, such as complications of decreased renal functions and progression to renal failure.

OBJECTIVE

To determine the prevalence and factors associated with renal function impairment among highly active antiretroviral therapy (HAART) naive and HAART experienced adult HIV positive individuals.

METHODS

A facility based comparative cross-sectional study was conducted in Jimma University Specialized Hospital (JUSH) from June to September 2014. HIV positive individuals who visited JUSH during the study period were included in the study. Sociodemographic and clinical data were collected using a structured questionnaire. Blood specimen was analyzed for renal function tests. Descriptive statistics, Mann-Whitney U test and logistic regression analysis were done using SPSS version 16 software.

RESULTS

A total of 446 HIV positive individuals, 223 HAART naïve and 223 HAART experienced, were recruited. The overall prevalence of renal function impairment was 18.2% [95%CI: 14.6-21.7]. The prevalence of renal impairment in HAART naive and HAART experienced persons was 28.7% [95%CI: 23.1-34.4] and 7.6% [95%CI: 4.6-11.6], respectively. Age ≥ 50 years (AOR = 3.6; 95% CI 1.4, 9.6), advanced WHO stage (AOR = 2.3; 95% CI 1.1, 4.7), and CD4 count <200 (AOR = 6.9; 95% CI 3.3, 14.2) were independent risk factors among HAART naive participants. Female gender (AOR = 6.6; 95 CI % 1.2, 34), age ≥ 50 years (AOR = 12.1; 95% CI 1.7, 84) and CD4 count <200 (AOR = 17; 95% CI 5.2, 58) were independent risk factors among HAART experienced participants.

CONCLUSION

The prevalence of renal function impairment was higher among HAART naïve than HAART experienced HIV positive individuals. Renal function impairment was associated with disease advancement and old age.

Associations between plasma tenofovir concentration and renal function markers in HIV-infected women

Background

Tenofovir disoproxil fumarate (TDF) has been associated with kidney tubular dysfunction and reduced renal function. Limited studies were performed in Europe and Asia that related plasma tenofovir (TFV) concentration with renal function; no such studies to date have been performed on Africans.

Objective

To investigate the correlation between plasma tenofovir (TFV) concentration and certain renal function markers in HIV-infected women on TDF antiretroviral therapy (ART). These markers were also compared to a HIV-uninfected control group.

Methods

HIV-infected women (n = 30) on TDF-based ART were matched with 30 controls for age and body mass index. Renal markers analysed were estimated glomerular filtration rate (eGFR), creatinine clearance (CrCl), serum creatinine, albuminuria, glucosuria, serum urea, serum uric acid, urine sodium and maximum tubular reabsorption of phosphate. Baseline eGFR and CrCl data were obtained retrospectively for the HIV-infected women. Plasma TFV was assayed using a validated HPLC-MS/MS method. Stepwise regression, Mann-Whitney test, unpaired and paired t-tests were applied in the statistical analyses.

Results

TFV concentration was independently associated with albuminuria (adjusted r² = 0.339; p = 0.001) in HIV-infected women. In the adjusted (weight) analysis, eGFR (p = 0.038), CrCl (p = 0.032) and albuminuria (p = 0.048) were significantly higher in HIV-infected compared to the uninfected women, but eGFR was abnormally high in HIV-infected women. Both eGFR (p < 0.001) and CrCl (p = 0.008) increased from baseline to follow-up in HIV-infected women.

Conclusion

Plasma TFV concentration was associated with increased albuminuria in HIV-infected women in this sub-study. Both eGFR and CrCl were increased in HIV-infected women from baseline. These findings should be confirmed in larger studies, and hyperfiltration in HIV-infected women warrants further investigation.

Effect of changing from first- to second-line antiretroviral therapy on renal function: a retrospective study based on data from a single health facility in Namibia

BACKGROUND

Tenofovir disoproxil fumarate (TDF) and lopinavir/ritonavir (LPV/r) can cause renal impairment with this combination co-administered during second-line combination antiretroviral therapy (cART) potentially associated with greater risk of nephrotoxicity. As a result, the aim of this study is to assess effects of second-line cART on renal function.

METHODS

Retrospective longitudinal study in patients receiving cART.

RESULTS

71 patients received TDF, zidovudine or stavudine, each combined with 3TC/NVP or 3TC/EFV. Before second-line cART, 46.5% had abnormal kidney function. First-line cART had no relationship with calculated creatinine clearance (CrCl). During second-line cART, more males than females had abnormal renal function and more females experienced increases in CrCl. Calculated CrCl during second-line cART related strongly with CrCl during first-line cART. Time spent on cART had a weak relationship with CrCl.

CONCLUSION

Patients on first-line cART for several years without renal impairment may experience new onset impairment during second line cART. Patients with pre-existing renal impairment just before switching to second-line cART may experience a further decline.

Incidence of stage 3 chronic kidney disease and progression on tenofovir-based regimens

OBJECTIVE

To describe the incidence of rapid kidney function decline (RKFD), and stage 3 chronic kidney disease (CKD) in HIV-1-infected adults initiated on tenofovir-containing antiretroviral therapy.

METHODS

A retrospective cohort study at the infectious diseases clinic of Tygerberg Academic Hospital in Cape Town, South Africa. Patients with more than 3 ml/min per year decline in estimated glomerular filtration were classified as having RKFD, and stage 3 CKD was defined as a value less than 60 ml/min per 1.73 m. We used logistic and Cox proportional hazards regression models to determine factors associated with RKFD and stage 3 CKD.

RESULTS

Of 650 patients, 361 (55%) experienced RKFD and 15 (2%) developed stage 3 CKD during a median interquartile range follow-up time of 54 (46.6-98) weeks. For every 10-year increase in age and 10 ml/min lower baseline estimated glomerular filtration, the odds of RKFD increased by 70% [adjusted odds ratio = 1.70, 95% confidence interval (CI) 1.36-2.13] and 57% (adjusted odds ratio = 1.57, 95% CI 1.38-1.80), respectively. Each 10-year older age was associated with a 1.90-fold increased risk of developing stage 3 CKD (adjusted hazard ratio = 1.90, 95% CI: 1.10-3.29). Women had about four-fold greater risk of stage 3 CKD compared with men (adjusted hazard ratio = 3.96, 95% CI: 1.06-14.74).

CONCLUSION

About half of our study population developed RKFD but only 2% progressed to stage 3 CKD. Approaches that provide balanced allocation of limited resources toward screening and monitoring for kidney dysfunction and HIV disease management are critically needed in this setting.

Adverse Drug Reactions Causing Admission to Medical Wards: A Cross-Sectional Survey at 4 Hospitals in South Africa

Limited data exist on the burden of serious adverse drug reactions (ADRs) in sub-Saharan Africa, which has high HIV and tuberculosis prevalence. We determined the proportion of adult admissions attributable to ADRs at 4 hospitals in South Africa. We characterized drugs implicated in, risk factors for, and the preventability of ADR-related admissions.We prospectively followed patients admitted to 4 hospitals' medical wards over sequential 30-day periods in 2013 and identified suspected ADRs with the aid of a trigger tool. A multidisciplinary team performed causality, preventability, and severity assessment using published criteria. We categorized an admission as ADR-related if the ADR was the primary reason for admission.There were 1951 admissions involving 1904 patients: median age was 50 years (interquartile range 34-65), 1057 of 1904 (56%) were female, 559 of 1904 (29%) were HIV-infected, and 183 of 1904 (10%) were on antituberculosis therapy (ATT). There were 164 of 1951 (8.4%) ADR-related admissions. After adjustment for age and ATT, ADR-related admission was independently associated (P ≤ 0.02) with female sex (adjusted odds ratio [aOR] 1.51, 95% confidence interval [95% CI] 1.06-2.14), increasing drug count (aOR 1.14 per additional drug, 95% CI 1.09-1.20), increasing comorbidity score (aOR 1.23 per additional point, 95% CI 1.07-1.41), and use of antiretroviral therapy (ART) if HIV-infected (aOR 1.92 compared with HIV-negative/unknown, 95% CI 1.17-3.14). The most common ADRs were renal impairment, hypoglycemia, liver injury, and hemorrhage. Tenofovir disoproxil fumarate, insulin, rifampicin, and warfarin were most commonly implicated, respectively, in these 4 ADRs. ART, ATT, and/or co-trimoxazole were implicated in 56 of 164 (34%) ADR-related admissions. Seventy-three of 164 (45%) ADRs were assessed as preventable.In our survey, approximately 1 in 12 admissions was because of an ADR. The range of ADRs and implicated drugs reflect South Africa's high HIV and tuberculosis burden. Identification and management of these ADRs should be considered in HIV and tuberculosis care and treatment programs and should be emphasized in health care worker training programmes.

Low Incidence of Renal Dysfunction among HIV-Infected Patients on a Tenofovir-Based First Line Antiretroviral Treatment Regimen in Myanmar

BACKGROUND

Since 2004, Médecins Sans Frontières-Switzerland has provided treatment and care for people living with HIV in Dawei, Myanmar. Renal function is routinely monitored in patients on tenofovir (TDF)-based antiretroviral treatment (ART), and this provides an opportunity to measure incidence and risk factors for renal dysfunction.

METHODS

We used routinely collected program data on all patients aged ≥15 years starting first-line TDF-based ART between January 2012 and December 2013. Creatinine clearance (CrCl) was assessed at base line and six-monthly, with renal dysfunction defined as CrCl < 50 ml/min/1.73 m2. We calculated incidence of renal dysfunction and used Cox regression analysis to identify associated risk factors.

RESULTS

There were 1391 patients, of whom 1372 had normal renal function at baseline. Of these, 86 (6.3%) developed renal dysfunction during a median time of follow-up 1.14 years with an incidence rate of 5.4 per 100 person-years: 78 had CrCl between 30-50 ml/min/1.73 m2 and were maintained on TDF-based ART, but 5 were changed to another regimen: 4 because of CrCl <30 ml/min/1.73 m2. Risk factors for renal dysfunction included age ≥45 years, diagnosed diabetes, underlying renal disease, underweight and CD4 count <200 cells/mm3. There were 19 patients with baseline renal dysfunction and all continued on TDF-based ART: CrCl stayed between 30-49 ml/min/1.73 m2 in five patients while the remainder regained normal renal function.

CONCLUSIONS

In a resource-poor country like Myanmar, the low incidence of renal toxicity in our patient cohort suggests that routine assessment of CrCl may not be needed and could be targeted to high risk groups if resources permit.

Evaluation of the Nova StatSensor® Xpress(TM) Creatinine point-of-care handheld analyzer

Creatinine is a parameter that is required to monitor renal function and is important to follow in patients under treatment with potentially toxic renal drugs, such as the anti-HIV drug Tenofovir. A point of care instrument to measure creatinine would be useful for patients monitoring in resource-limited settings, where more instruments that are sophisticated are not available. The StatSensor Xpress Creatinine (Nova Biomedical Cooperation, Waltham, MA, USA) point of care analyzer was evaluated for its diagnostic performance in indicating drug therapy change. Creatinine was measured in parallel using the Nova StatSensor Xpress Creatinine analyzer and the Vitros 5,1FS (Ortho Clinical Diagnostics, Inc, Rochester, USA), which served as reference standard. The precision (i.e., repeatability and reproducibility) and accuracy of the StatSensor Xpress Creatinine analyzer were calculated using a panel of specimens with normal, low pathological and high pathological values. Two different Nova StatSensor Xpress Creatinine analyzers were used for the assessment of accuracy using repeated measurements. The coefficient of variation of the StatSensor Xpress Creatinine analyzers ranged from 2.3 to 5.9% for repeatability and from 4.2 to 9.0% for between-run reproducibility. The concordance correlation agreement was good except for high values (>600 µmol/L). The Bland-Altman analysis in high pathological specimens suggests that the Nova StatSensor Xpress Creatinine test tends to underestimate high creatinine values (i.e., >600 µmol/L). The Nova StatSensor Xpress Creatinine analyzers showed acceptable to good results in terms of repeatability, inter-device reproducibility and between-run reproducibility over time using quality control reagents. The analyzer was found sufficiently accurate for detecting pathological values in patients (age >10 year) and can be used with a moderate risk of misclassification.

Renal impairment in HIV-infected patients initiating tenofovir-containing antiretroviral therapy regimens in a Primary Healthcare Setting in South Africa

OBJECTIVE

Long-term use of tenofovir disoproxil fumarate is associated with declines in glomerular function and chronic kidney disease in HIV-infected patients. We aimed to assess the prevalence and incidence of renal impairment in a primary care setting in sub-Saharan Africa.

METHODS

We analysed data from 1092 HIV-infected patients initiating tenofovir at a primary care clinic in Cape Town, South Africa. Renal function was assessed for the first 12 months on ART by estimating glomerular filtration rate (eGFR) calculated using the Cockroft-Gault equation categorised into normal, mild, moderate and severe reduction in renal function based on values >90, 60-89, 30-59 and <30 ml/min/1.73 m(2) , respectively. Associations were assessed using logistic regression, and average GFR trajectory over time was modelled using linear mixed-effects models.

RESULTS

The cohort consisted of 62% women; median age was 34 years (IQR 29; 41 years). The majority had normal renal function pre-ART (79%), 19% had mildly reduced GFR, and 2% had moderate renal impairment. Older age, more advanced WHO stage and anaemia were independently associated with prevalent renal impairment. On average, estimated glomerular function improved over the first year on tenofovir [1.10 ml/min/1.73 m(2) average increase over 12 months (95% CI: 0.80; 1.40)]. Male gender, anaemia and immunosuppression (WHO Stage III/IV and CD4 cell counts <100 cells/mm(3) ) were associated with lower average eGFR levels over time. Overall, 3% developed eGFR <50 ml/min/1.73 m(2) during this period. Serum creatinine tests conducted before 4 months on ART had low predictive value for predicting change in eGFR after a year on ART.

CONCLUSION

Generally, renal function improved in HIV-infected adults initiating ART in this primary healthcare setting during the first year on ART. While monitoring of renal function is recommended in the first 4 months on ART, renal impairment appears uncommon during the first 12 months of tenofovir-containing ART in primary care populations.

Clinical practice guideline for the management of chronic kidney disease in patients infected with HIV: 2014 update by the HIV Medicine Association of the Infectious Diseases Society of America

It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.

HIV-associated renal and genitourinary comorbidities in Africa

With the recent massive scale-up of access to antiretroviral therapy (ART) in resource-limited countries, HIV has become a chronic disease with new challenges. There is mounting evidence of an increased burden of renal and genitourinary diseases among HIV-infected persons caused by direct HIV viral effects and/or indirectly through the development of opportunistic infections, ART medication-related toxicities, and other noncommunicable diseases (NCDs). We review the epidemiology of HIV-associated renal and urogenital diseases, including interactions with kidney-related NCDs such as hypertension, diabetes mellitus, and cardiovascular disease. We also examine the current evidence regarding the impact of HIV infection on the development of urogenital diseases. Highly advisable in sub-Saharan Africa are the establishment of renal disease registries, reviews of existing clinical practice including cost-effectiveness studies, and the adoption and use of HIV-related NCD management, with training for different cadres of health providers. Epidemiological research priorities include prospective studies to evaluate the true prevalence and spectrum of HIV-related renal disease and their progression. Simple diagnostics tools should be evaluated, including urinary dipsticks and point-of-care urea and creatinine tests to screen for kidney injury in primary care settings. Study of urological manifestations of HIV can help determine the extent of disease and outcomes. As patients live longer on ART, the burden of renal and genitourological complications of HIV and of ART can be expected to increase with a commensurate urgency in both discovery and evidence-based improvements in clinical management.

Impact of antiretroviral therapy on renal function among HIV-infected Tanzanian adults: a retrospective cohort study

Background

Data regarding the outcomes of HIV-infected adults with baseline renal dysfunction who start antiretroviral therapy are conflicting.

Methods

We followed up a previously-published cohort of HIV-infected adult outpatients in northwest Tanzania who had high prevalence of renal dysfunction at the time of starting antiretroviral therapy (between November 2009 and February 2010). Patients had serum creatinine, proteinuria, microalbuminuria, and CD4⁺ T-cell count measured at the time of antiretroviral therapy initiation and at follow-up. We used the adjusted Cockroft-Gault equation to calculate estimated glomerular filtration rates (eGFRs).

Results

In this cohort of 171 adults who had taken antiretroviral therapy for a median of two years, the prevalence of renal dysfunction (eGFR <90 mL/min/1.73 m²) decreased from 131/171 (76.6%) at the time of ART initiation to 50/171 (29.2%) at the time of follow-up (p<0.001). Moderate dysfunction (eGFR<60 mL/min/1.73 m²) decreased from 21.1% at antiretroviral therapy initiation to 1.1% at follow-up (p<0.001), as did the prevalence of microalbuminuria (72% to 44%, p<0.001). Use of tenofovir was not associated with renal dysfunction at follow-up.

Conclusion

Mild and moderate renal dysfunction were common in this cohort of HIV-infected adults initiating antiretroviral therapy, and both significantly improved after a median follow-up time of 2 years. Our work supports the renal safety of antiretroviral therapy in African adults with mild-moderate renal dysfunction, suggesting that these regimens do not lead to renal damage in the majority of patients and that they may even improve renal function in patients with mild to moderate renal dysfunction.

Multi-Media Educational Tool Increases Knowledge of Clinical Trials in Uganda

BACKGROUND

Informed consent is premised on the participants' understanding the scope of the research and the associated risks and benefits. The objective was to evaluate the improvement in knowledge in a population unfamiliar with clinical trial concepts about "what it means to be part of a clinical trial" using an innovative educational tool called the 'Speaking Book'.

METHODS

This was a randomized controlled trial conducted at a research site in Uganda. 201 participants were randomized to: 1) clinical trials information session control arm, or 2) clinical trials information session followed by instruction in the use of the Speaking Book with a take-home copy (intervention arm). After the session, participants of both groups completed a 22-item multiple-choice test on the rights and responsibilities of participants. Participants returned after one week to complete the same test to assess knowledge retention. The mean pre- and post-test score difference was assessed according to trial arm using an unpaired t-test of proportions.

RESULTS

Ninety-one (90%) participants completed both the initial and follow-up tests in the control arm and 100 (100%) in the intervention arm. The average age of participants was 38 years, 53% were female and 67% were employed; 20% had previously been invited to participate in a clinical trial; of these, 19% had participated. The mean difference in proportion of correct responses from test 1 to test 2 was 2.7% (95%CI 0.3%-5.0%) for the control arm and 11.6% (95%CI 9.3%-13.7%) for the intervention arm (t-score= -5.3, p-value<0.0001).

CONCLUSION

Participants who had instruction in the use of the Speaking Book had a larger increase in knowledge than those who had no access to this tool. To better engage patients unfamiliar with clinical trial concepts, innovative educational techniques can assist to increase knowledge to make an informed decision about participation in a clinical trial.

Feasibility and benefits of scaling up antiretroviral treatment provision with the 2010 WHO antiretroviral therapy guidelines in rural Lesotho

The latest WHO guidelines (2010) for antiretroviral therapy (ART) in adults and adolescents recommend that countries should progressively reduce the use of stavudine in favour of tenofovir or zidovudine and that ART initiation commence at an earlier CD4 threshold of <350 cell/mm(3). In Lesotho, a high-burden, resource-limited setting, these two changes had been recommended since late 2007. A number of practical steps were taken to support implementation of Lesotho's national ART guidelines at the program level including: development of guidelines tailored to nurses working in primary care settings; training and clinical mentorship of different levels of health care workers; laboratory support; pharmacy support; and monitoring and evaluation. Clinical and programmatic benefits included decreased mortality, toxicity, and simplified patient management that was supportive of the decentralized, nurse-led model of care. This experience demonstrates that, despite limited resources, it was feasible to provide a standard of care similar to that of western guidelines and that these changes were supportive of simplified patient management.

Update on tenofovir toxicity in the kidney

Tenofovir (TFV) is a widely used and effective treatment for HIV infection. Numerous studies have shown that TFV exposure is associated with small but significant declines in estimated glomerular filtration rate (eGFR). However, TFV toxicity is targeted mainly at the proximal tubule (PT), and in severe cases can cause the renal Fanconi syndrome or acute kidney injury. Severe toxicity occurs in a minority of patients, but milder PT dysfunction is more common; the long-term significance of this on kidney and bone health is uncertain. Recent work suggests that changes in eGFR on TFV therapy might be explained by inhibition of PT creatinine secretion rather than actual alterations in glomerular function. Risk factors for nephrotoxicity include pre-existing kidney disease, increased age, and low body mass. Mitochondria in the PT are the targets of TFV toxicity, but the exact mechanisms remain unclear. Substantial improvement of renal function occurs in many patients with TFV toxicity upon stopping therapy, but function does not always return to baseline. In recent years, TFV usage has been extended to new clinical spheres, including pediatrics, resource-poor settings and treatment of hepatitis B infection; theoretical reasons exist as to why some of these patients might be at higher or lower risk of TFV toxicity. Finally, strategies have been proposed to prevent TFV toxicity or enhance recovery.

Rates of switching antiretroviral drugs in a primary care service in South Africa before and after introduction of tenofovir

Introduction

Antiretroviral changes (single drug substitutions and regimen switches) limit treatment options and introduce challenges such as increased cost, monitoring and adherence difficulties. Patterns of drug substitutions and regimen switches from stavudine (d4T) and zidovudine (AZT) regimens have been well described but data on tenofovir (TDF) are more limited. This study describes the patterns and risk factors for drug changes of these antiretroviral drugs in adults.

Method

This retrospective cohort study included HIV positive, antiretroviral treatment (ART) naïve adults aged ≥18 years who started ART with two nucleoside reverse transcriptase inhibitors (NRTIs) and a non-nucleoside reverse transcriptase inhibitor. Follow-up was censored at first drug change and analysis focused on NRTI changes only.

Results

Between September 2002 and April 2011, 5095 adults initiated ART in Gugulethu. This comprised 948 subjects on TDF, 3438 on d4T and 709 subjects on AZT. Virological suppression rates at 1 year, regimen switching due to virological failure and overall losses to the programme were similar across the three groups. TDF had the lowest incidence rate of drug substitutions (2.6 per 100 P/Ys) compared to 17.9 for d4T and 8.5 per 100 P/Ys for AZT. Adverse drug reactions (ADRs) accounted for the majority of drug substitutions of d4T. Multivariate analysis showed that increasing age, female sex and d4T exposure were associated with increased hazard of drug substitution due to ADRs. Conversely, TDF exposure was associated with a substantially lower risk of substitution (adjusted hazards ratio 0.38; 95% CI 0.20–0.72).

Conclusion

Regimen switches and virological suppression were similar for patients exposed to TDF, d4T and AZT, suggesting all regimens were equally effective. However, TDF was better tolerated with a substantially lower rate of drug substitutions due to ADRs.

Pharmacovigilance and global HIV/AIDS

PURPOSE OF REVIEW

This review focuses on current status, progress, challenges and opportunities in global pharmacovigilance for HIV/AIDS treatment.

RECENT FINDINGS

Over 6 million HIV-infected individuals worldwide are on treatment with more than 150 innovator and generic antiretroviral drug products. This achievement is made possible through sponsorship of HIV/AIDS programs [The Global Fund to Fight AIDS, Tuberculosis and Malaria; the President's Emergency Program for AIDS Relief (PEPFAR)] and the availability of generic fixed-dose combination products. The WHO prequalifies generic drug products used by Global Fund programs; the US Food and Drug Administration tentatively approves generic products used by PEPFAR programs through a fast-track review process. Adequate national or regional quality and safety monitoring systems after drug distribution are lacking. The pharmaceutical sector, a significant player in pharmacovigilance in the developed world, has not been engaged. Innovative approaches based on collaboration and partnerships will be needed. Clinic-based or program-based cohort studies, randomized clinical trials and electronic medical records may contribute pharmacovigilance-relevant information.

SUMMARY

Attention to drug quality and safety is obligatory for long-term program sustainability. Systematic approaches to regional pharmacovigilance that make use of diverse data sources, and collaborative partnerships between industry, clinical and/or research programs and national health authorities can potentially contribute to overall health system strengthening.

HIV treatment and care in resource-constrained environments: challenges for the next decade

Many successes have been achieved in HIV care in low- and middle-income countries (LMIC): increased number of HIV-infected individuals receiving antiretroviral treatment (ART), wide decentralization, reduction in morbidity and mortality and accessibility to cheapest drugs. However, these successes should not hide existing failures and difficulties. In this paper, we underline several key challenges. First, ensure long-term financing, increase available resources, in order to meet the increasing needs, and redistribute the overall budget in a concerted way amongst donors. Second, increase ART coverage and treat the many eligible patients who have not yet started ART. Competition amongst countries is expected to become a strong driving force in encouraging the least efficient to join better performing countries. Third, decrease early mortality on ART, by improving access to prevention, case-finding and treatment of tuberculosis and invasive bacterial diseases and by getting people to start ART much earlier. Fourth, move on from WHO 2006 to WHO 2010 guidelines. Raising the cut-off point for starting ART to 350 CD4/mm³ needs changing paradigm, adopting opt-out approach, facilitating pro-active testing, facilitating task shifting and increasing staff recruitments. Phasing out stavudine needs acting for a drastic reduction in the costs of other drugs. Scaling up routine viral load needs a mobilization for lower prices of reagents and equipments, as well as efforts in relation to point-of-care automation and to maintenance. The latter is a key step to boost the utilization of second-line regimens, which are currently dramatically under prescribed. Finally, other challenges are to reduce lost-to-follow-up rates; manage lifelong treatment and care for long-term morbidity, including drug toxicity, residual AIDS and HIV-non-AIDS morbidity and aging-related morbidity; and be able to face unforeseen events such as socio-political and military crisis. An old African proverb states that the growth of a deep-rooted tree cannot be stopped. Our tree is well rooted in existing field experience and is, therefore, expected to grow. In order for us to let it grow, long-term cost-effectiveness approach and life-saving evidence-based programming should replace short-term budgeting approach.

Cost-effectiveness of tenofovir instead of zidovudine for use in first-line antiretroviral therapy in settings without virological monitoring

Background

The most recent World Health Organization (WHO) antiretroviral treatment guidelines recommend the inclusion of zidovudine (ZDV) or tenofovir (TDF) in first-line therapy. We conducted a cost-effectiveness analysis with emphasis on emerging patterns of drug resistance upon treatment failure and their impact on second-line therapy.

Methods

We used a stochastic simulation of a generalized HIV-1 epidemic in sub-Saharan Africa to compare two strategies for first-line combination antiretroviral treatment including lamivudine, nevirapine and either ZDV or TDF. Model input parameters were derived from literature and, for the simulation of resistance pathways, estimated from drug resistance data obtained after first-line treatment failure in settings without virological monitoring. Treatment failure and cost effectiveness were determined based on WHO definitions. Two scenarios with optimistic (no emergence; base) and pessimistic (extensive emergence) assumptions regarding occurrence of multidrug resistance patterns were tested.

Results

In the base scenario, cumulative proportions of treatment failure according to WHO criteria were higher among first-line ZDV users (median after six years 36% [95% simulation interval 32%; 39%]) compared with first-line TDF users (31% [29%; 33%]). Consequently, a higher proportion initiated second-line therapy (including lamivudine, boosted protease inhibitors and either ZDV or TDF) in the first-line ZDV user group 34% [31%; 37%] relative to first-line TDF users (30% [27%; 32%]). At the time of second-line initiation, a higher proportion (16%) of first-line ZDV users harboured TDF-resistant HIV compared with ZDV-resistant viruses among first-line TDF users (0% and 6% in base and pessimistic scenarios, respectively). In the base scenario, the incremental cost effectiveness ratio with respect to quality adjusted life years (QALY) was US$83 when TDF instead of ZDV was used in first-line therapy (pessimistic scenario: US$ 315), which was below the WHO threshold for high cost effectiveness (US$ 2154).

Conclusions

Using TDF instead of ZDV in first-line treatment in resource-limited settings is very cost-effective and likely to better preserve future treatment options in absence of virological monitoring.

Renal safety of tenofovir containing antiretroviral regimen in a Singapore cohort

BACKGROUND

Tenofovirdisoproxilfumarate (TDF) is a nucleotide analogue widely recommended in international HIV treatment guidelines. The association of TDF and renal dysfunction has remained an area of interest.

FINDINGS

We conducted a retrospective review of all patients on TDF from July 2007 to December 2009 in our institution and evaluated their renal function. Absolute change of creatinine clearance (CLCr) using Cockroft-Gault equation from baseline was calculated at 6, 12, 18 and 24 months. Overall, 226 patients were included in the study. Ninety percent were male. The median age was 46 yrs old (23-82), median weight was 60 kg (IQR 53.75-68), median CD4 count was 127 cells/mm3 (IQR 38-258) and median CLCr 82.7 mL/min (IQR 71.4-101.7) on initiation of TDF. The median decline of CLCr from baseline was -3.9 ml/min (IQR -12.3 to 7.6), and -3.6 ml/min (IQR -12.4 to 6.7) at 12 (n = 102), 24 months (n = 75) respectively. Eighteen of 226 patients had a decline in renal function to </=50 ml/min. Majority of which had an improvement of CLCr on follow up. Only 80% of patients ever received monitoring of renal function.

CONCLUSION

While we noted renal toxicity to be rare and transient among our cohort receiving TDF as part of their ARV regimen, these results reflect the short term renal effects of TDF given that ARV treatment is lifelong. Given that laboratory monitoring may be difficult to implement in many situations, future prospective studies looking into an evidence based algorithm for less frequent renal function monitoring than current guideline recommendations may be helpful.

The cost-effectiveness of pre-exposure prophylaxis for HIV infection in South African women

BACKGROUND

Recent trials report the short-term efficacy of tenofovir-based pre-exposure prophylaxis (PrEP) for prevention of human immunodeficiency virus (HIV) infection. PrEP's long-term impact on patient outcomes, population-level transmission, and cost-effectiveness remains unknown.

METHODS

We linked data from recent trials to a computer model of HIV acquisition, screening, and care to project lifetime HIV risk, life expectancy (LE), costs, and cost-effectiveness, using 2 PrEP-related strategies among heterosexual South African women: (1) women receiving no PrEP and (2) women not receiving PrEP (a tenofovir-based vaginal microbicide). We used a South African clinical cohort and published data to estimate population demographic characteristics, age-adjusted incidence of HIV infection, and HIV natural history and treatment parameters. Baseline PrEP efficacy (percentage reduction in HIV transmission) was 39% at a monthly cost of $5 per woman. Alternative parameter values were examined in sensitivity analyses.

RESULTS

Among South African women, PrEP reduced mean lifetime HIV risk from 40% to 27% and increased population discounted (undiscounted) LE from 22.51 (41.66) to 23.48 (44.48) years. Lifetime costs of care increased from $7280 to $9890 per woman, resulting in an incremental cost-effectiveness ratio of $2700/year of life saved, and may, under optimistic assumptions, achieve cost savings. Under baseline HIV infection incidence assumptions, PrEP was not cost saving, even assuming an efficacy >60% and a cost <$1. At an HIV infection incidence of 9.1%/year, PrEP achieved cost savings at efficacies ≥50%.

CONCLUSIONS

PrEP in South African women is very cost-effective by South African standards, conferring excellent value under virtually all plausible data scenarios. Although optimistic assumptions would be required to achieve cost savings, these represent important benchmarks for future PrEP study design.

Adverse drug reactions to antiretroviral therapy (ARVs): incidence, type and risk factors in Nigeria

Background

Data on adverse drug reactions (ADRs) related to antiretroviral (ARV) use in public health practice are few indicating the need for ART safety surveillance in clinical care.

Objectives

To evaluate the incidence, type and risk factors associated with adverse drug reactions (ADRs) among patients on antiretroviral drugs (ARV).

Methods

Patients initiated on ARVs between May 2006 and May 2009 were evaluated in a retrospective cohort analysis in three health facilities in Nigeria. Regimens prescribed include nucleoside backbone of zidovudine (AZT)/lamivudine (3TC), stavudine (d4T)/3TC, or tenofovir (TDF)/3TC in combination with either nevirapine (NVP) or efavirenz (EFV). Generalized Estimating Equation (GEE) model was used to identify risk factors associated with occurrence of ADR.

Results

2650 patients were followed-up for 2456 person-years and reported 114 ADRs (incidence rate = 4.6/100 person-years).There were more females 1706(64%) and 73(64%) of the ADRs were reported by women. Overall, 61(54%) of ADRs were reported by patients on AZT with 54(47%) of these occurring in patients on AZT/NVP. The commonest ADRs reported were pain 25(30%) and skinrash 10(18%). Most ADRs were grade 1(39%) with only 1% being life threatening (grade 4). Adjusted GEE analysis showed that ADR was less likely to occur in patients on longer duration of ART compared to the first six months on treatment; 6-12 months AOR 0.38(95% CI:0.16-0.91) and 12-24 months AOR 0.34(95% CI:0.16-0.73) respectively. Compared to patients on TDF, ADR was less likely to occur in patients on d4T and AZT AOR 0.18(95% CI 0.05-0.64) and AOR 0.24(95% CI:0.7-0.9) respectively. Age, gender and CD4 count were not significantly associated with ADRs.

Conclusion

ADRs are more likely to occur within the first six months on treatment. Close monitoring within this period is required to prevent occurrence of severe ADR and improve ART adherence. Further research on the tolerability of tenofovir in this environment is recommended.

Renal function declines more in tenofovir- than abacavir-based antiretroviral therapy in low-body weight treatment-naïve patients with HIV infection

Objective

To compare the rate of decline of renal function in tenofovir- and abacavir-based antiretroviral therapy (ART) in low-body weight treatment-naïve patients with HIV infection.

Design

We conducted a single-center retrospective cohort study of 503 Japanese patients who commenced on either tenofovir- or abacavir-based initial ART.

Methods

The incidence of renal dysfunction, defined as more than 25% fall in estimated glomerular filtration rate (eGFR) from the baseline, was determined in each group. The effect of tenofovir on renal dysfunction was estimated by univariate and multivariate Cox hazards models as the primary exposure. Changes in eGFR until 96 weeks were estimated in both groups with a repeated measures mixed model.

Results

The median body weight of the cohort was 64 kg. The estimated incidence of renal dysfunction in the tenofovir and the abacavir arm was 9.84 per 100 and 4.55 per 100 person-years, respectively. Tenofovir was significantly associated with renal dysfunction by univariate and multivariate analysis (HR = 1.747; 95% CI, 1.152–2.648; p = 0.009) (adjusted HR = 2.080; 95% CI, 1.339–3.232; p<0.001). In subgroup analysis of the patients stratified by intertertile baseline body weight, the effect of tenofovir on renal dysfunction was more evident in patients with lower baseline body weight by multivariate analysis (≤60 kg: adjusted HR = 2.771; 95%CI, 1.494–5.139; p = 0.001) (61–68 kg: adjusted HR = 1.908; 95%CI, 0.764–4.768; p = 0.167) (>68 kg: adjusted HR = 0.997; 95%CI, 0.318–3.121; p = 0.995). The fall in eGFR was significantly greater in the tenofovir arm than the abacavir arm after starting ART (p = 0.003).

Conclusion

The incidence of renal dysfunction in low body weight patients treated with tenofovir was twice as high as those treated with abacavir. Close monitoring of renal function is recommended for patients with small body weight especially those with baseline body weight <60 kg treated with tenofovir.