Background: The success of longitudinal trials depends greatly on using effective strategies to retain participants and ensure internal validity, maintain sufficient statistical power, and provide for the generalizability of study results. Objective: This paper describes the challenges and specific strategies used to retain participants in a Phase 2B safety and effectiveness study of daily oral and vaginal tenofovir formulations for the prevention of HIV-1 infection in the MTN-003 (VOICE) trial in Kampala, Uganda. Methods: Once enrolled, participants were seen every 28 days at the research site and their study product was re-filled. Challenges to retention included a mobile population, non-disclosure of study participation to spouse/family, and economic constraints. Strategies used to maintain high participation rates included the use of detailed locator information, a participant tracking database, regular HIV/STI testing, and the formation of close bonds between staff and subjects. Results: We enrolled 322 women out of the 637 screened. The overall retention rate was 95% over a 3 year follow up period. Only 179 (3%) out of the 6124 expected visits were missed throughout study implementation. Reasons for missed visits included: participants thinking that they did not need frequent visits due to their HIV negative status, time constraints due to commercial sex work, and migration for better employment. Conclusions: With the implementation of multi-faceted comprehensive follow-up and retention strategies, we achieved very high retention rates in the MTN-003 study. This paper provides a blueprint for effective participant retention strategies for other longitudinal HIV prevention studies in resource-limited settings in Sub-Saharan Africa.
Background Viral load measurement is commonly applicable to monitor HIV infection in patients to determine the number of HIV-RNA in serum samples of individuals. The aim of the present study was to set up a highly specific, sensitive, and reproducible home-brewed Real-time PCR assay based on TaqMan chemistry to quantify HIV-1 RNA genome. Methods In this study, three sets of primer pairs and a TaqMan probe were designed for HIV subtypes conserved sequences. An internal control was included in this assay to evaluate the presence of inhibition. Standard curve and threshold cycle values were determined using in vitro transcribed RNA from int region of HIV-1. A serial dilution of RNA standards was generated by in vitro transcription, from 10 to 109 copies/ml to find the sensitivity and the limit of detection (LOD) of the assay and to evaluate its performance in a quantitative RT-PCR assay. Results The assay has a low LOD equivalent to 33.13 copies/ml of HIV-1 RNA and a linear range of detection from 10 to 109 copies/ml. The coefficient of variation (CV) for Inter and Intra-assay precision of this in-house HIV Real-time RT-PCR ranged from 0.28 to 2.49% and 0.72 to 4.47%, respectively. The analytical and clinical specificity was 100%. Conclusions The results indicate that the developed method has a suitable specificity and sensitivity and is highly reproducible and cost-benefit. Therefore, it will be useful to monitor HIV infection in plasma samples of individuals.
Background: Direct-acting antivirals (DAAs) lead to high cure rates of Hepatitis C Virus (HCV) infections in HIV/HCV coinfected patients. Recent data suggest that treatment failures occur more often in HIV/HCV coinfected persons. Objective: We aimed to identify risk factors for treatment failure in coinfected patients. Methods: We analyzed data collected from the German Hepatitis C-Registry (DHC-R, Trials Registration number DRKS00009717). 437 HIV/HCV coinfected patients were included. Sustained virological response (SVR) rates and the impact of CD4+ count, HIV viral load, liver cirrhosis and splenomegaly were evaluated. Results: 83.5% (365/437) of the patients were male (average age: 46.6 +/- 9.2 y). Most patients received antiretroviral therapy (ART) (88.1%; 385/437), had a HIV RNA <= 40 copies/ml (88.5%; 285/322) and were infected with HCV genotype (GT) 1 (77.6%; 339/437). Overall SVR12 rate was 92% (402/437). In patients with HIV RNA <= 40 copies/ml and >40 copies/ml SVR12 rates were 93.2% (272/292) and 85.3%, respectively (29/34; p = .11). SVR12 rates were 91.8% (45/49) and 92.7% (253/273; p = .84) in patients with a CD4+ <350/mu l and >= 350/mu l. We observed no difference in either of the subgroups in patients with cirrhosis or splenomegaly. In the univariate logistic regression analysis none of the analyzed HIV or HCV specific parameters, liver cirrhosis or splenomegaly were associated with treatment outcome. Conclusion: We found high SVR12 rates in HIV/HCV coinfected patients and no significant difference was observed due to the patients CD4+ cell count, HIV viral load, portal hypertension or liver cirrhosis.
Objective Lipid management is one of the cornerstones of cardiovascular risk reduction. Treatment of HIV infection with protease inhibitors (PIs) may cause dyslipidaemia, whilst the integrase inhibitor raltegravir (RAL) has a relatively favorable effect on plasma lipids. We examined the effect of switching from PIs to RAL on endothelial function, and its effect on immunological and inflammatory parameters. Methods We performed a 16-week open-label prospective crossover study: 8 weeks intervention (switch PIs to RAL) and 8 weeks control (unchanged cART regimen). Flow-mediated dilatation (FMD), inflammatory plasma, and cellular markers of immune activation were measured at weeks 0, 8, and 16. Results Study participants (n = 22) with a median age of 50 years (IQR 42–60) and known HIV infection of 6.5 years (IQR 5.0–17.3) were on stable cART with undetectable HIV viral loads. After 8 weeks of RAL therapy, a reduction in FMD of −0.81% was seen, compared to +0.54% control (pairwise, p = 0.051), while fasting total cholesterol (−17% versus +10%; p < 0.001), LDL cholesterol (−21% versus −3%; p = 0.026), and triglycerides (−41% versus +18%; p = 0.001) significantly decreased during RAL therapy compared to the control. Furthermore, a relation between the change in percentage of B-1 cells and the change in FMD was found (β 0.40, 95%CI 0.16; 0.64, p = 0.005) during treatment with RAL. Finally, during RAL therapy, 27% of the patients experienced an increased ALT rise. Conclusions We present an overall negative study, where switching from PIs to RAL slightly reduced the endothelial function while decreasing plasma lipids, thus possibly decreasing the CVD risk in the long term. A transient elevation of ALT was seen upon switch to RAL.
Objective: To evaluate whether treatment with 100,000 IU/month (equivalent to 3200 IU/day) of cholecalciferol and 1 g/day of dietary calcium supplementation in HIV patients following different cART regimens yields normal levels of vitamin D3 and PTH as well as whether changes in bone mineral density are clinically significant. Methods: Consecutive HIV patients following different cART regimens received 100,000 IU/month (equivalent to 3200 IU/day) of cholecalciferol and 1 g/day of dietary calcium supplementation. The participants underwent BMD assessment via dual energy X-ray absorptiometry of the spine and hip at baseline (T0) and after 24 months (T1). Levels of 25(OH) vitamin D3 and parathyroid hormone (PTH) were assessed at T0 and T1. Quantitative variables were assessed with a paired t-test, independent t-test or analysis of variance, as appropriate. A chi-squared analysis was used to assess the association between qualitative variables. A p-value <0.05 was considered significant. Patients were divided into three groups depending on the cART regimen. Results: A total of 79 patients were included (40 males, 51% and 39 females, 49%), with a mean age of 46.6 (SD ±11.2) years, a baseline CD4 count of 649 cells/µl and a mean 25 hydroxycholecalciferol (25(OH) D3) value of 25 + 10 ng/ml. After 24 months, the 25(OH) D3 increased to 40 + 11 ng/ml. The initial BMDs at T0 were estimated as 0.919 (±0.27) and 0.867 (±0.14) g/cm2 at the spine and hip, respectively. After 24 months, the BMD was 0.933 (±0.15) g/cm2 at the spine and 0.857 (±0.14) g/cm2 at the hip. Based on a BMD change exceeding 3%, a worsening was observed in 23% of patients at the spine and 27% at the hip, whereas stability or improvement was demonstrated in 77% of patients at the spine and 73% at the hip. Subgrouping patients based on antiretroviral therapy indicated that, at T1, there was a statistically significant increase in vitamin D3 concentration in all patients, while PTH concentration was not significantly reduced in patients taking tenofovir or efavirenz. BMD stability or improvement was demonstrated in 77% of patients at the spine and 73% at the hip after 24 months. The multivariate analysis confirms a decrease in vitamin D3 and an increase in PTH levels in smokers, as well higher vitamin D3 concentrations in males and lower spine BMDs in menopausal females. Conclusion: The proposed protocol of cholecalciferol and dietary calcium supplementation is safe and valid for correcting vitamin D abnormalities in almost all patients as well as reducing PTH levels in a high percentage of patients; however, it is not sufficient for normalization, particularly in patients exposed to tenofovir or efavirenz. At the spine, no significant BMD change was found in any of the therapy groups. At the hip, our data confirm a modest negative effect on bone mass caused by tenofovir and efavirenz.
