Marchina E. van der Ende

Low Nevirapine Plasma Concentrations Predict Virological Failure in an Unselected HIV-1-Infected Population

ObjectiveTo assess the relationship between plasma nevirapine concentrations and plasma HIV-1 RNA response in HIV-1-infected patients.DesignAn observational cohort analysis.MethodsPlasma samples were obtained on a routine basis from 189 patients receiving nevirapine 200mg twice daily, and plasma nevirapine concentrations were measured with reversed phase high performance liquid chromatography. Patients were divided into two groups based on plasma nevirapine concentrations below (and equal to) or above 3 mg/L. The association between steady-state nevirapine concentrations and plasma HIV-1 RNA was determined by multi-variate analysis.ResultsOut of 189 patients, 13 (7%) had low nevirapine plasma concentrations and 176 patients had concentrations above 3 mg/L. In total, 22 (12%) patients showed virological failure and 8 patients (4%) discontinued nevirapine because of adverse effects. The risk of failure in patients with nevirapine plasma concentrations ≤3mg/L was increased (relative risk 5.0, 95% CI 1.8–13.7). Rashes and liver enzyme elevations each occurred in 8% of patients.ConclusionLow nevirapine drug concentrations are predictive of virological failure.

Current and future applications of dried blood spots in viral disease management.

Almost five decades after their first application in diagnostics, dried blood spot (DBS) cards remain to be of key interest in many research areas and clinical applications. The advantages of sample stability during transport and storage, can now be combined with the high sensitivity of novel diagnostic techniques for the measurement and analysis of nucleic acids, proteins and small molecules which may overcome the limitations of the small samples sizes in DBS cards. Here we present a survey of the literature on the use of DBS cards for diagnosis, monitoring and epidemiological studies of virus infections other than HIV, including CMV, HBV, HCV, HAV, HEV, HTLV, EBV, HSV, measles-, rubella- and dengue-virus. The minimal invasiveness of sampling and the relative ease of handling and storing DBS cards is expected to offer additional opportunities to measure and analyze biomarkers of viral disease in resource poor settings or when limited amount of blood can be obtained. Large retrospective studies of virus infections in newborns using stored DBS cards have already been undertaken for screening of congenital infections. In addition, DBS cards have been used prospectively for prevalence studies, outbreak surveillance, mass screening for viral infections, follow-up of chronic infection and its treatment in resource-limited areas. We do not expect that current wet sampling techniques of plasma or serum will be replaced by DBS sampling but it allows extension of sampling in persons and settings that are currently difficult to access or that lack suitable storage facilities. In conclusion, DBS card sampling and storage will aid adequate outbreak management of existing and emerging viral diseases.

Long-Term Therapy With Tenofovir Is Effective for Patients Co-Infected With Human Immunodeficiency Virus and Hepatitis B Virus

BACKGROUND & AIMS We investigated the long-term efficacy and renal safety of tenofovir disoproxil fumarate (TDF), administered to patients co-infected with human immunodeficiency virus and hepatitis B virus (HBV) as part of an antiretroviral therapy. METHODS We performed a multicenter, prospective cohort study of 102 patients co-infected with human immunodeficiency virus and HBV who were treated with TDF. RESULTS At baseline, 80% of patients had a detectable viral load (HBV DNA >20 IU/mL). Among patients positive for hepatitis B e antigen (HBeAg) (n = 67), 92% had a virologic response (HBV DNA <20 IU/mL) after 5 years of treatment. There was no difference between patients with or without lamivudine resistance at baseline (P = .39). Loss rates of HBeAg and hepatitis B s antigen (HBsAg) were 46% and 12%, respectively. Among HBeAg-negative patients (n = 15), 100% had a virologic response after 4 years of treatment and 2 (13%) lost HBsAg. Twenty subjects (20%, all HBeAg-negative) had undetectable HBV DNA at baseline; during a median follow-up period of 52 months (interquartile range, 41-63 mo), 19 (95%) maintained a virologic response and 2 (10%) lost HBsAg. Overall, one patient acquired a combination of resistance mutations for anti-HBV drugs and experienced a virologic breakthrough. Three (3%) patients discontinued TDF because of increased serum creatinine levels. The estimated decrease in renal function after 5 years of TDF therapy was 9.8 mL/min/1.73 m(2), which was most pronounced shortly after TDF therapy was initiated. CONCLUSIONS TDF, administered as part of antiretroviral therapy, is a potent anti-HBV agent with a good resistance profile throughout 5 years of therapy. Only small nonprogressive decreases in renal function were observed.

Development of a real-time quantitative RT-PCR for the detection of HIV-2 RNA in plasma

An assay is described for the quantification of human immunodeficiency virus type 2 (HIV-2) RNA in EDTA plasma based on RT-PCR using the Taqman real-time PCR detection method. As standard, an electron microscopically counted virus stock of HIV-2 strain NIHZ was used. The lower detection limit is 5 # 102 HIV-2 RNA copies per ml of EDTA plasma. The assay is linear within the range required (5 # 102-106 HIV-2 RNA copies/ml of EDTA plasma) with an intra assay variability of 2.5% and an inter-assay variability ranging from 2% at 106 copies to 7.5% at the lower detection limit. Three primer/probe combinations were developed to circumvent false negative samples due to nucleotide variation in the target sequence. Using these primer/probe sets enabled the detection of HIV-2 DNA sequences from all HIV-2 seropositive individuals and two out of five dual human immunodeficiency virus type 1 (HIV-1) and HIV-2 seropositive individuals visiting the University Hospital Rotterdam.

No treatment versus 24 or 60 weeks of antiretroviral treatment during primary HIV infection: the randomized Primo-SHM trial.

In a three-arm randomized trial conducted among adult patients in HIV treatment centers in The Netherlands, Marlous Grijsen and colleagues examine the effects of temporary combination antiretroviral therapy during primary HIV infection.

Treatment failure of nelfinavir-containing triple therapy can largely be explained by low nelfinavir plasma concentrations

The relationship between plasma concentrations of nelfinavir and virologic treatment failure was investigated to determine the minimum effective concentration of nelfinavir. Plasma samples were prospectively collected from treatment-naive patients who began taking nelfinavir, 1250 mg BID + two nucleoside reverse transcription inhibitors (NRTIs). Nelfinavir concentration ratios were calculated by dividing each individual nelfinavir level by the time-adjusted population value. Virologic failure was defined as either no response (a detectable viral load after 6 months) or a relapse (detectable viral load after being undetectable, or an increase in viral load >1 log above nadir). Forty-eight patients were included with a median follow-up period of 8 months. The median concentration ratio of nelfinavir was 0.98 (interquartile range, 0.76–1.47). Virologic failure was observed in 29% of the patients. In a univariate analysis, the nelfinavir concentration ratio appeared to be the single determinant that was related to virologic failure (P = 0.039). Patients with a median ratio <0.90 had a relative risk of 3.0 (95% CI, 1.2–7.6) for virologic failure. Using this threshold, virologic failures were detected with 64% sensitivity and 74% specificity (P = 0.014). Virologic failure of nelfinavir-containing triple therapy can be explained, to a large extent, by low plasma levels of nelfinavir.

Nelfinavir and nevirapine side effects during pregnancy

Background:The risk of vertical transmission of HIV has been substantially reduced since the introduction of highly active antiretroviral therapy (HAART); however, the impact of taking HAART during pregnancy on the woman, the fetus and the infant is not yet understood. Objective:To assess and compare tolerability, safety and efficacy of nelfinavir- or nevirapine-containing HAART in a cohort of pregnant and non-pregnant HIV-infected women in the Netherlands. Design:Retrospective comparative study. Methods:In 15 centres specializing in HIV in the Netherlands, data on patient characteristics, HAART, adverse events, viral load response, mode of delivery and HIV status of the neonate were obtained from medical records of HIV-infected pregnant women who received HAART during pregnancy between January 1997 and June 2003. These data were compared with a control group of HIV-infected non-pregnant women that was obtained from the Dutch HIV-monitoring foundation database. Results:Data from 186 pregnant and 186 non-pregnant HIV-infected women using a nelfinavir- or nevirapine-containing regimen were analysed. The pregnant women were younger, used a nelfinavir containing regimen more often, had higher CD4 cell counts and lower HIV RNA levels. Nelfinavir-related gastrointestinal symptoms (P < 0.001), hyperglycaemia (P < 0.001) and nevirapine-related hepatotoxicity (P = 0.003) occurred more often during pregnancy. The risk of nevirapine-induced rash was not increased. No major adverse events occurred. Conclusion:Nelfinavir- or nevirapine-containing HAART regimens during pregnancy are well tolerated. Side effects of antiretroviral therapy are more frequent in pregnant than in non-pregnant women.

A phase I/IIa immunotherapy trial of HIV-1-infected patients with Tat, Rev and Nef expressing dendritic cells followed by treatment interruption

In a phase I/IIa clinical trial, 17 HIV-1 infected patients, stable on cART, received 4 vaccinations with autologous dendritic cells electroporated with mRNA encoding Tat, Rev and Nef, after which cART was interrupted. Vaccination was safe and feasible. During the analytical treatment interruption (ATI), no serious adverse events were observed. Ninety-six weeks following ATI, 6/17 patients remained off therapy. Although induced and/or enhanced CD4(+) and CD8(+) T-cell responses specific for the immunogens were observed in most of the patients, we found no correlation with the number of weeks off cART. Moreover, CD4(+) T-cell counts, plasma viral load and the time remaining off cART following ATI did not differ from historical control data. To conclude, the vaccine was safe, well tolerated and resulted in vaccine-specific immune responses. Since no correlation with clinical parameters could be found, these results warrant further research in order to optimize the efficacy of vaccine-induced T-cell responses.

A Prospective Open Study of the Efficacy of High-Dose Recombinant Hepatitis B Rechallenge Vaccination in HIV-Infected Patients

Double-dose hepatitis B virus revaccination of human immunodeficiency virus (HIV)-infected patients proved to be effective in 50.7% of 144 patients who had previously failed to respond to standard doses. In the multivariate analysis, female patients were found to have a significantly better response (P= .03). The effect of age on the response depended on the viral load at the time of revaccination. For patients with a detectable HIV RNA load, the effect of age was stronger (odds ratio [OR], 0.34 per 10 years older [95% confidence interval {CI}, 0.16-0.72]; P= .005) than for patients with an undetectable HIV RNA load (OR, 0.74 per 10 years older [95% CI, 0.50-1.09]; P= .12).

Discontinuation of Nevirapine Because of Hypersensitivity Reactions in Patients with Prior Treatment Experience, Compared with Treatment-Naive Patients: The ATHENA Cohort Study

BACKGROUND Recommendations that nevirapine (NVP) should be avoided in female individuals with CD4 cell counts >250 cells/microL and in male individuals with CD4 cell counts >400 cells/microL are based on findings in treatment-naive patients. It is unclear whether these guidelines also apply to treatment-experienced patients switching to NVP-based combination therapy. METHODS Patients in the ATHENA cohort study who had used NVP-based combination therapy were included. We identified patients who discontinued NVP-based combination therapy because of hypersensitivity reactions (HSRs; rash and/or hepatotoxicity) within 18 weeks after starting such therapy. We grouped patients according to their CD4 cell count at the start of NVP-based combination therapy (current CD4 cell count) as having a high CD4 cell count (for female patients, >250 cells/microL; for male patients, >400 cells/microL) or a low CD4 cell count. Treatment-experienced patients were further subdivided according to the last available CD4 cell count before first receipt of antiretroviral therapy (ART; pre-ART CD4 cell count) using the same criteria. Risk factors for HSR were assessed using multivariate logistic regression. RESULTS Of 3752 patients receiving NVP-based combination therapy, 231 patients (6.2%) discontinued NVP therapy because of HSRs. Independent risk factors included female sex and Asian ethnicity. Having an undetectable viral load (VL) at the start of NVP therapy was associated with reduced risk of developing an HSR (adjusted odds ratio [OR], 0.52; 95% confidence interval [CI], 0.38-0.71). Pretreated patients with low pre-ART and high current CD4 cell counts and a detectable VL when switching to NVP-based combination therapy had a significantly higher risk of developing an HSR, compared with treatment-naive patients who started NVP therapy with low CD4 cell counts (adjusted OR, 1.87; 95% CI, 1.11-3.12); pretreated patients with low pre-ART CD4 cell counts who switched to NVP therapy with a high current CD4 cell count and an undetectable VL did not have an increased risk of developing an HSR (adjusted OR, 1.03; 95% CI, 0.66-1.61). CONCLUSIONS Treatment-experienced patients who start NVP-based combination therapy with low pre-ART and high current CD4 cell counts and an undetectable VL have a similar likelihood for discontinuing NVP therapy because of HSRs, compared with treatment-naive patients with low CD4 cell counts. This suggests that NVP-based combination therapy may be safely initiated in such patients. However, in similar patients with a detectable VL, it is prudent to continue to adhere to current CD4 cell count thresholds.