HIV-associated gut dysbiosis is independent of sexual practice and correlates with noncommunicable diseases.

Loss of gut mucosal integrity and an aberrant gut microbiota are proposed mechanisms contributing to chronic inflammation and increased morbidity and mortality during antiretroviral-treated HIV disease. Sexual practice has recently been uncovered as a major source of microbiota variation, potentially confounding prior observations of gut microbiota alterations among persons with HIV (PWH). To overcome this and other confounding factors, we examine a well-powered subset of AGEhIV Cohort participants comprising antiretroviral-treated PWH and seronegative controls matched for age, body-mass index, sex, and sexual practice. We report significant gut microbiota differences in PWH regardless of sex and sexual practice including Gammaproteobacteria enrichment, Lachnospiraceae and Ruminococcaceae depletion, and decreased alpha diversity. Men who have sex with men (MSM) exhibit a distinct microbiota signature characterized by Prevotella enrichment and increased alpha diversity, which is linked with receptive anal intercourse in both males and females. Finally, the HIV-associated microbiota signature correlates with inflammatory markers including suPAR, nadir CD4 count, and prevalence of age-associated noncommunicable comorbidities.

Lower IQ and poorer cognitive profiles in treated perinatally HIV-infected children is irrespective of having a background of international adoption.

BACKGROUND: HIV-associated cognitive deficiency in perinatally HIV-infected (PHIV) children has been studied in Western countries in a population of which an increasing proportion has been internationally adopted. Studies often lack an appropriate internationally adopted HIV-uninfected control group, potentially confounding the relationship between HIV and cognitive functioning. This study aims to further elucidate the association between treated HIV infection and cognitive development by addressing the background of international adoption. METHODS: We cross-sectionally studied the impact of HIV on cognition by comparing PHIV children and HIV- uninfected controls, matched for age-, sex-, ethnicity-, socioeconomic status (SES)- and adoption status. We used a standardized neuropsychological test battery to measure intelligence (IQ), and the cognitive domains of processing speed, working memory, executive function, learning ability and visual-motor function and compared outcomes using lineair regression models, adjusted for IQ. We determined cognitive profiles and cognitive impairment by using multivariate normative comparison (MNC) and explored associations with HIV disease- and treatment-related factors. RESULTS: We enrolled fourteen PHIV children (mean age 10.45 years [1.73 SD], 93% adopted from sub-Saharan Africa at a median age of 3.3 years [IQR 2.1-4.2]) and fifteen HIV- uninfected controls. Groups did not clinically nor statistically differ in age, sex, ethnicity, SES, region of birth, adoption status and age at adoption. PHIV scored consistently lower on all cognitive domains and MNC outcomes. Compared to controls, PHIV children had a significant lower IQ (mean 81 [SD 11] versus mean 97 [SD 15], p = 0.005), and a poorer cognitive profile by MNC (Hotelling's T2 mean -4.36 [SD 5.6] versus mean 0.16 [SD 4.5], p = 0.021), not associated with HIV disease- and treatment-related factors. Two PHIV (14%) and one control (7%) were classified as cognitively impaired (p = 0.598). CONCLUSIONS: Findings indicate treated HIV-infection to be independently associated with lower IQ and poorer cognitive profiles in PHIV children, irrespective of a background of international adoption.

Efficacy and safety of long-term maraviroc use in a heterogeneous group of HIV-infected patients: A retrospective cohort study.

Since the registration of maraviroc (MVC) as an antiretroviral agent in 2008, only studies with a follow-up time of <5 years have been published. Therefore, little is known about its long-term safety and efficacy in clinical practice. In this cohort study, data on long-term follow-up of MVC treatment in routine practice were analysed. A retrospective cohort study was conducted at University Medical Centre Utrecht with a follow-up period up to almost 10 years. The efficacy and tolerability of MVC-containing antiretroviral therapy (ART) was analysed in human immunodeficiency virus type 1 (HIV-1)-infected patients. The cohort consisted of 111 HIV patients who were treated for a median of 11.0 years (IQR 4.0-15.0 years) and with a median of 4 (IQR 2-6) previous ART regimens. The median time of MVC use was 49 months (IQR 21-82 months). Mean CD4+ T-cell counts continued to increase up to 9 years following initiation of MVC. Patients with a detectable viral load (≥50 copies/mL HIV-RNA) at the start of MVC-containing ART reached high proportions of viral suppression. Only three patients (2.7%) experienced treatment failure despite optimal therapy. Nine patients (8.1%) discontinued MVC owing to intolerance of their ART regimen. Severe laboratory abnormalities were deemed to be unrelated to MVC use. During the 487 person-years of follow-up, 18 patients (16.2%) died. MVC use in this heavily pre-treated cohort was generally well tolerated during long-term follow-up. Furthermore, use of MVC resulted in a good immunological and virological response in clinical practice.

Virological and Social Outcomes of HIV-Infected Adolescents and Young Adults in The Netherlands Before and After Transition to Adult Care.

BACKGROUND: As a result of effective combination antiretroviral therapy (cART) and advanced supportive healthcare, a growing number of human immunodeficiency virus (HIV)-infected children survive into adulthood. The period of transition to adult care is often associated with impaired adherence to treatment and discontinuity of care. We aimed to evaluate virological and social outcomes of HIV-infected adolescents and young adults (AYAs) before and after transition, and explore which factors are associated with virological failure. METHODS: We included 59 HIV-infected AYAs from the Netherlands who had entered into pediatric care and transitioned from pediatric to adult healthcare. We used HIV RNA load and cART data from the Dutch Stichting HIV Monitoring database (1996-2014), and collected social and treatment data from patients' medical records from all Dutch pediatric HIV treatment centers and 14 Dutch adult treatment centers involved. We evaluated risk factors for virological failure (VF) in a logistic regression model adjusted for repeated measurements. RESULTS: HIV VF occurred frequently during the study period (14%-36%). During the transition period (from 18 to 19 years of age) there was a significant increase in VF compared with the reference group of children aged 12-13 years (odds ratio, 4.26 [95% confidence interval, 1.12-16.28]; P = .03). Characteristics significantly associated with VF were low educational attainment and lack of autonomy regarding medication adherence at transition. CONCLUSIONS: HIV-infected AYAs are vulnerable to VF, especially during the transition period. Identification of HIV-infected adolescents at high risk for VF might help to improve treatment success in this group.

Longer prior exposure to zidovudine/lamivudine-containing combination antiretroviral therapy, age, and male gender are each associated with reduced subcutaneous adipose tissue.

OBJECTIVES: Whether zidovudine (AZT)-associated lipoatrophy occurrence differs by concomitant exposure to protease (PIs) or non-nucleoside reverse transcriptase inhibitors (NNRTIs) remains unclear. Baseline body composition data from a randomized trial in subjects stable on first-line AZT-based therapy were used to explore this issue. METHODS: In this substudy of the PREPARE trial, centrally read baseline whole-body dual energy x-ray aborptiometry (DXA) and single-slice abdominal CT scans were analyzed with respect to duration and type of prior AZT/lamivudine (3TC) combination antiretroviral therapy (cART), including by multivariate linear regression adjusted for age, gender, ethnicity, body mass index (BMI), and nadir CD4. RESULTS: DXA and CT, from 134 and 136 patients, respectively [87% male; 82% Caucasian; mean (SD) age, 45.6 years (10); BMI, 24.3 kg/m² (3.2)], were analyzed. Prior AZT/3TC cART exposure was 5.5 (2.2) years. Seventy-eight and 27 patients had concomitantly and exclusively used NNRTIs and PIs, respectively. AZT/3TC cART, AZT/3TC/NNRTI, and AZT/3TC/PI, respectively, were associated with the presence of a mean (95% CI) of 247 g (-438 to -56; P = .012), 267 g (-467 to -66; P = .010), and 216 g (-430 to -1.7; P = .048) less baseline limb fat per additional year of prior exposure. Although abdominal subcutaneous (SAT) adipose tissue was likewise less with longer AZT/3TC cART, this was only significant for AZT/3TC/ NNRTI but not AZT/3TC/PI. Visceral adipose tissue (VAT) amount was not clearly associated to prior treatment. Increased age and male gender were independently associated with lower limb fat and SAT, but more VAT. CONCLUSIONS: Longer exposure to AZT/3TC, regardless of whether in combination with PI or NNRTI, as well as increased age and male gender are independently associated with lower limb fat mass.

Randomized comparison of metabolic and renal effects of saquinavir/r or atazanavir/r plus tenofovir/emtricitabine in treatment-naïve HIV-1-infected patients.

OBJECTIVES: The aim of the study was to compare the effects on lipids, body composition and renal function of once-daily ritonavir-boosted saquinavir (SQV/r) or atazanavir (ATV/r) in combination with tenofovir/emtricitabine (TDF/FTC) over 48 weeks. METHODS: An investigator-initiated, randomized, open-label, multinational trial comparing SQV/r 2000/100 mg and ATV/r 300/100 mg once daily, both in combination with TDF/FTC, in 123 treatment-naïve HIV-1-infected adults was carried out. The primary endpoint was to demonstrate noninferiority of SQV/r compared with ATV/r with respect to the change in fasting cholesterol after 24 weeks. Secondary outcome measures were changes in metabolic abnormalities, body composition, renal function, and virological and immunological efficacy over 48 weeks. Patients who had used at least one dose of trial drug were included in the analysis. RESULTS: Data for 118 patients were analysed (57 patients on SQV/r and 61 on ATV/r). At week 24, changes in lipids were modest, without increases in triglycerides, including a significant rise in high-density lipoprotein (HDL) cholesterol and a nonsignificant decrease in the total:HDL cholesterol ratio in both arms with no significant difference between arms. Lipid changes at week 48 were similar to the changes observed up to week 24, with no significant change in the homeostasis model assessment (HOMA) index. Adipose tissue increased regardless of the regimen, particularly in the peripheral compartment and to a lesser extent in the central abdominal compartment, with an increase in adipose tissue reaching statistical significance in the ATV/r arm. A slight decline in the estimated glomerular filtration rate (eGFR) was observed in both arms during the first 24 weeks, with no progression thereafter. The immunological and virological responses were similar over the 48 weeks. CONCLUSIONS: Combined with TDF/FTC, both SQV/r 2000/100 mg and ATV/r 300/100 mg had comparable modest effects on lipids, had little effect on glucose metabolism, conserved adipose tissue, and similarly reduced eGFR. The virological efficacy was similar.

Steady-state nevirapine plasma concentrations are influenced by pregnancy.

OBJECTIVES: Optimal plasma concentrations of antiretroviral drugs are required during pregnancy to treat maternal HIV infection and prevent mother-to-child transmission. We investigated the effect of pregnancy on nevirapine (NVP) plasma concentrations. METHODS: We included all HIV-1-infected women for whom NVP plasma concentrations were available as part of routine patient care at two university hospitals. Plasma NVP concentrations were compared for pregnant (n=45) and non-pregnant (n=152) women. Univariate and multivariate linear regression analyses were used to identify and adjust for other confounding factors associated with NVP plasma concentrations. For pregnant women who had a plasma NVP concentration available both during and outside pregnancy, a paired analysis was performed. RESULTS: Steady-state NVP plasma concentrations were lower in pregnant women: 5.2 mg/L (interquartile range 3.9-6.8) vs. 5.8 mg/L (4.3-7.7) (P=0.08). After adjusting for confounders, both pregnancy (regression coefficient=-0.90 mg/L, P=0.046) and African descent (regression coefficient=+1.13 mg/L, P=0.005) influenced NVP concentrations significantly. The paired analysis showed mean concentrations of 4.8 mg/L during pregnancy and 5.8 mg/L outside pregnancy (paired t-test, P=0.073). CONCLUSIONS: Pregnancy has a moderate but significant lowering effect on NVP plasma concentrations. Being of African descent compensates for the lowering effect of pregnancy on NVP concentrations.

Mitochondrial DNA assessment in adipocytes and peripheral blood mononuclear cells of HIV-infected patients with lipodystrophy according to a validated case definition.

BACKGROUND: Several studies have compared mitochondrial DNA (mtDNA) content in tissue from HIV-1-infected patients on highly active antiretroviral therapy with and without evidence of lipodystrophy, the diagnosis of which was based on subjective clinical assessment. OBJECTIVES: The aim of this study was to assess the utility of mtDNA quantification as a marker of HIV-associated lipodystrophy as diagnosed using a published validated case definition. METHODS: We assessed mtDNA content in adipocytes from both thigh and lumbar subcutaneous adipose tissue (n=19), and in peripheral blood mononuclear cells (PBMC) (n=26), obtained from 26 HIV-1-infected patients classified as having lipodystrophy (n=17) or not having lipodystrophy (n=9) according to the validated definition derived from the Lipodystrophy Case Definition Study. RESULTS: The adipocyte and PBMC mtDNA contents did not significantly differ between patients with and without lipodystrophy. Lipodystrophy patients had been treated for significantly longer times, especially with dideoxynucleoside analogues. In both groups, the thigh adipocyte mtDNA content was significantly greater than that of the lumbar region. When all patients were considered together, a statistically significant negative correlation was found between thigh adipocyte mtDNA content and stavudine treatment duration. CONCLUSIONS: Longer exposure to dideoxynucleoside analogues was associated with lipodystrophy, and longer exposure to stavudine was correlated with lower mtDNA content in thigh adipocytes. However, a single measurement of adipocyte mtDNA content in this limited sample of patients could not distinguish between patients with and without clinical lipodystrophy. The observed variation in mtDNA content between different subcutaneous adipose tissue depots argues for harmonization of future studies regarding which depot to biopsy.

Pharmacokinetic parameters of nevirapine and efavirenz in relation to antiretroviral efficacy.

Optimal adherence is essential for successful antiretroviral therapy. We analyzed the relation between minimum plasma drug concentration (Cmin) and total drug exposure over 24 hr (AUC24) with virologic failure for therapy-adherent patients in the nevirapine (NVP) and efavirenz (EFV) groups of the double nonnucleoside study (2NN), which compared the efficacy of NVP and/or EFV together with stavudine and lamivudine. The objective was to find cutoff values of the Cmin and AUC24 below which the risk of virologic failure increased. The relation between Cmin and AUC24 with virologic failure (never a plasma viral load [pVL] < 50 copies/ml or a rebound to two consecutive pVL > 50 copies/ml) was analyzed with proportional hazard analyses. Data were censored at end of study or change of allocated treatment. The risk of virologic failure with NVP (n = 511) started to increase at a Cmin < 3.1 mg/L (hazard ratio [HR], 1.33; 95% confidence interval [CI], 0.89-1.97), but there was no cutoff value below which a statistically significant increased risk occurred. Neither was such a cutoff point identified for the AUC24. The risk of virologic failure with EFV (n = 312) was significantly increased at a Cmin < 1.1 mg/L (HR, 1.95; 95% CI, 1.08-3.54) and an AUC24 < 40 mg x hr x L1 (HR, 1.95; 95% CI, 1.07-3.54). Both cutoff values represent the median values for adherent patients. These associations were driven by patients from Thailand. Adjusting for geographical region made the association between Cmin and AUC24 with virologic failure statistically nonsignificant. The sensitivity of the Cmin values was too low (29% for NVP, 64% for EFV) to be an adequate predictor for virologic failure. We conclude that identifying the Cmin value for the sole purpose of predicting virologic failure in patients who report to be adherent to NVP or EFV is questionable because of the absence of a concentration-response relation (NVP) or the low sensitivity for such a cutoff value (NVP and EFV).

Occult hepatitis B virus infection before and 1 year after start of HAART in HIV type 1-positive patients.

Occult hepatitis B virus (HBV) infection is diagnosed when HBc antibodies and HBV-DNA are detectable in serum while hepatitis B surface antigen (HBsAg) is not. The clinical relevance of this phenomenon in HIV-1 patients starting highly active antiretroviral therapy (HAART) is unknown. We followed 93 therapy naive HIV-1-infected adults who were anti-HBc positive, HBsAg and HBeAg negative, during first year of HAART. At baseline, HBV-DNA was quantified, and HBV genotype was determined in the HBV-DNA-positive patients by sequencing a part of the HBV genome. Four of 93 patients (4%) were HBV DNA positive at baseline. All four patients tested negative for HBV-DNA after 1 year. They all received lamivudine as part of their HAART. They had no clinically significant liver enzyme elevations (LEE) during the first year of HAART. Two of the patients had a genotype A, one genotype E, and in the fourth patient sequencing was not possible. In one patient we found significant mutations in the a determinant region of HBsAg, at positions 142 and 144. In our population of therapy-naive HIV-1-infected adults who were anti-HBc positive, we found occult HBV infection in 4% of the patients. We did not find an increased risk for LEE in our population of patients after the start of HAART. Our results illustrate that occult HBV infection is more a diagnostic than a clinical problem. It may be caused by very low levels of HBV replication, concurrent presence of HBsAg and anti-HBs, or mutations in the HBsAg a determinant.

Comparison of first-line antiretroviral therapy with regimens including nevirapine, efavirenz, or both drugs, plus stavudine and lamivudine: a randomised open-label trial, the 2NN Study.

BACKGROUND: The 2NN Study was a randomised comparison of the non-nucleoside reverse-transcriptase inhibitors (NNRTI) nevirapine and efavirenz. METHODS: In this multicentre, open-label, randomised trial, 1216 antiretroviral-therapy-naive patients were assigned nevirapine 400 mg once daily, nevirapine 200 mg twice daily, efavirenz 600 mg once daily, or nevirapine (400 mg) and efavirenz (800 mg) once daily, plus stavudine and lamivudine, for 48 weeks. The primary endpoint was the proportion of patients with treatment failure (less than 1 log(10) decline in plasma HIV-1 RNA in the first 12 weeks or two consecutive measurements of more than 50 copies per mL from week 24 onwards, disease progression [new Centers for Disease Control and Prevention grade C event or death], or change of allocated treatment). Analyses were by intention to treat. FINDINGS: Treatment failure occurred in 96 (43.6%) of 220 patients assigned nevirapine once daily, 169 (43.7%) of 387 assigned nevirapine twice daily, 151 (37.8%) of 400 assigned efavirenz, and 111 (53.1%) of 209 assigned nevirapine plus efavirenz. The difference between nevirapine twice daily and efavirenz was 5.9% (95% CI -0.9 to 12.8). There were no significant differences among the study groups in the proportions with plasma HIV-1 RNA concentrations below 50 copies per mL at week 48 (p=0.193) or the increases in CD4-positive cells (p=0.800). Nevirapine plus efavirenz was associated with the highest frequency of clinical adverse events, and nevirapine once daily with significantly more hepatobiliary laboratory toxicities than efavirenz. Of 25 observed deaths, two were attributed to nevirapine. INTERPRETATION: Antiretroviral therapy with nevirapine or efavirenz showed similar efficacy, so triple-drug regimens with either NNRTI are valid for first-line treatment. There are, however, differences in safety profiles. Combination of nevirapine and efavirenz did not improve efficacy but caused more adverse events.

Differential CD4 T-cell response in HIV-1-infected patients using protease inhibitor-based or nevirapine-based highly active antiretroviral therapy.

OBJECTIVES: To study the dynamics of CD4 T-lymphocyte counts (CD4 counts) after the initiation of either protease inhibitor (PI)-based or nevirapine (NVP)-based first-line highly active antiretroviral therapy (HAART). DESIGN AND METHODS: A retrospective cohort study of 1029 HIV-infected antiretroviral therapy-naive patients initiating either PI-based or NVP-based HAART was carried out. Patients were censored as soon as they experienced virological failure, or changed their original antiretroviral regimen for any reason. RESULTS: In total, 920 and 109 patients initiated PI- and NVP-based HAART, respectively. The patients in the PI group more often had AIDS (15 vs. 6% in the NVP group), had a lower median baseline CD4 count (234 vs. 250 cells/microL in the NVP group) and had higher median baseline plasma HIV-1 RNA levels (pVL) (5.0 vs. 4.7 log10 HIV-1 RNA copies/mL in the NVP group). After 96 weeks of follow-up, the mean increase from baseline in CD4 count, adjusted for baseline CD4 count, age, gender and baseline pVL, was 310 cells/microL in the PI group and 212 cells/microL in the NVP group (P=0.003). This difference was mainly attributable to the patients in the NVP group initiating HAART with a baseline CD4 count below 200 cells/microL. There were no differences between the PI and NVP groups with respect to the change in the number of CD4 cells as a proportion of the total number of lymphocytes. CONCLUSION: Patients successfully treated with NVP-based HAART have a smaller increase in absolute CD4 cells compared with those treated with PI-based HAART.

Prednisolone does not prevent hypersensitivity reactions in antiretroviral drug regimens containing abacavir with or without nevirapine.

OBJECTIVES: To determine the effect of adjuvant prednisolone use on the development of abacavir (ABC)- and nevirapine (NVP)-associated hypersensitivity reactions (HSR). METHODS: Randomized open-label study in antiretroviral-naive adult HIV-1 infected patients using a factorial design in which NVP and/or hydroxyurea (HU) and/or prednisolone are added to a regimen of ABC, zidovudine and lamivudine. Prednisolone (40 mg once daily) was added for the first 2 weeks of treatment. As it was difficult to distinguish ABC-associated HSR from NVP-associated HSR, these events were treated as a composite endpoint. The odds ratio (OR) of developing HSR for prednisolone-use was calculated with and without stratification by NVP and/or HU. Logistic regression was performed to identify risk factors for developing HSR. RESULTS: Of the 229 patients 115 were randomized to prednisolone and 114 to no-prednisolone; 19 (17%) and 11 (10%) patients, respectively, developed HSR. The expected prevention of HSR by prednisolone use was not observed. In fact use of prednisolone showed an increased risk for HSR although this did not reach statistical significance [OR, 1.82; 95% confidence interval (CI), 0.82-4.03]. There was a higher incidence of HSR in the NVP group than in the non-NVP group (20% versus 6%; P = 0.002). An additional risk factor identified in a multivariate logistic model was a high baseline CD4 cell count (OR, 1.26 per 100 x 10(6) cells/l increase; 95% CI, 1.06-1.51). CONCLUSIONS: The simultaneous start of ABC and NVP in first-line antiretroviral regimens should be avoided because of a high (20%) incidence of HSR. Short-term therapy with prednisolone did not prevent HSR in patients using ABC with or without NVP.

Increased risk of lipodystrophy when nucleoside analogue reverse transcriptase inhibitors are included with protease inhibitors in the treatment of HIV-1 infection.

BACKGROUND: Changes in body fat distribution are an adverse effect of therapy with HIV protease inhibitors (PI). It has been suggested that nucleoside analogue reverse transcriptase inhibitors (NRTI) may also contribute to this so-called lipodystrophy syndrome, but the relative contribution of the two drug classes is unclear as they are usually administered concomitantly. METHOD: The occurrence of lipodystrophy, as reported by physicians using no standardized criteria, was followed in patients randomly assigned to treatment with either a PI alone or a PI combined with an NRTI. The patients were part of a multicenter, open-label, randomized comparison of ritonavir (RTV)/saquinavir (SQV) with or without the addition of stavudine (d4T) in HIV-1-infected patients without prior PI and d4T experience (the Prometheus study). RESULTS: Lipodystrophy was reported in 29 of 175 (17%) patients during 96 weeks of follow up. Overall, it was reported significantly more frequently in patients who were randomized to RTV/SQV/d4T (22/88; 25%), than in patients randomized to RTV/SQV alone (7/87; 8%) (P = 0.003). When the analysis was limited to patients without any prior antiretroviral experience, lipodystrophy likewise was significantly more frequent in patients randomized to RTV/SQV/d4T (12/50; 24%) than in those randomized to RTV/SQV (2/44; 5%) (P = 0.008). CONCLUSION: This randomized clinical trial, in spite of not having been blinded, supports a contributory role of NRTI in the development of antiretroviral therapy-associated lipodystrophy. The low incidence of lipodystrophy in patients with no or limited NRTI exposure supports further evaluation of NRTI-sparing regimens as alternatives to current antiretroviral regimens.

T-cell progenitor function during progressive human immunodeficiency virus-1 infection and after antiretroviral therapy.

Impairment of T-cell renewal has been proposed as contributing to CD4(+) T-cell depletion in persons infected with human immunodeficiency virus-1. We analyzed the T-cell development capacity of progenitors using fetal thymus organ culture. Those who progressed to AIDS had a dramatic loss in T-cell development capacity shortly after seroconversion. In contrast, long-term nonprogressors retained progenitor capacity 8 years after seroconversion. Approximately 70% of patients experienced an improvement in T-cell development capacity after receiving 6 months of potent antiretroviral therapy. Improvement in T-cell development in fetal thymus organ culture correlated with an increase in the number of naive CD4(+) T cells in peripheral blood. Numbers of progenitors in blood and bone marrow after seroconversion or during therapy did not correlate with the change observed in T-cell development capacity. These data provide evidence that HIV-1 infection can interfere with T-cell renewal at the level of the progenitor cell. Interference with T-cell renewal may contribute to CD4(+) T-cell depletion.

The steady-state pharmacokinetics of nevirapine during once daily and twice daily dosing in HIV-1-infected individuals.

OBJECTIVE: To investigate and to compare the steady-state plasma pharmacokinetics of nevirapine in a dosing regimen of 400 mg once daily versus 200 mg twice daily in HIV-1-infected individuals. DESIGN: Open-label, randomized, cross-over study. METHODS: Twenty HIV-1-infected individuals who already used nevirapine as part of their antiretroviral regimen were randomized to continue their current regimen (200 mg twice daily) or to switch to the alternate regimen (400 mg once daily). The steady-state plasma pharmacokinetics of nevirapine were assessed after 2 weeks during a 24-h period. Subsequently, patients were switched to the alternate regimen and the pharmacokinetics of nevirapine were assessed again after 2 weeks. Non-compartmental methods were used to calculate the area under the plasma concentration versus time curve (AUC[24h]), and the maximal (Cmax) and minimal plasma concentration (Cmin), the time to Cmax (t(max)), the plasma elimination half-life (t1/2), the apparent oral clearance (Cl/F) and the apparent volume of distribution (V/F). Differences in these pharmacokinetic parameters for the two dosing regimens were tested using ANOVA. RESULTS: The exposure to nevirapine, as measured by the AUC[24h], was not significantly different between the 400 mg once daily and 200 mg twice daily dosing regimen (P = 0.60). Furthermore, the values for t(max), t1/2 Cl/F and V/F were not significantly different between the two dosing regimens (P > or = 0.08). However, Cmax and Cmin were higher and lower, respectively, when nevirapine was used in the once daily regimen as compared with the twice daily regimen. The median values for Cmax and Cmin as measured for the once daily and twice daily regimens were 6.69 and 5.74 microg/ml, respectively (P = 0.03), and 2.88 and 3.73 microg/ml, respectively (P < 0.01). CONCLUSION: These data show that the daily exposure to nevirapine, as measured by the plasma AUC[24h], is not different between a 400 mg once daily and a 200 mg twice daily dosing regimen. However, Cmax and Cmin are higher and lower, respectively, for the once daily regimen as compared with the twice daily regimen. The clinical implications of these differences remain to be established.

Hepatitis B and C virus co-infection and the risk for hepatotoxicity of highly active antiretroviral therapy in HIV-1 infection.

OBJECTIVE: To investigate the risk of hepatotoxicity after initiation of protease inhibitor-containing highly active antiretroviral therapy (HAART) for HIV-1 infected patients with chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) co-infection. DESIGN: Retrospective study with 394 HIV-1-infected patients initiating HAART at a single university clinic. METHODS: Liver enzyme elevation (LEE) was defined as alanine aminotransferase or aspartate aminotransferase at least five times the upper limit of normal and an absolute increase of > 100 U/l. Relative risks for time to LEE were estimated using Cox proportional hazards models. RESULTS: Of 394 patients 7% were hepatitis B surface antigen (HBsAg)-positive and 14% were anti-HCV-positive. Patients with chronic hepatitis had a higher risk for LEE compared with patients without co-infection: 37% versus 12% respectively. After adjustment for higher baseline transaminases, the presence of HBsAg or anti-HCV remained associated with an increased risk of LEE - relative risk 2.78 (95% confidence interval, 1.50-5.16) and 2.46 (95% confidence interval, 1.43-4.24) respectively. In patients with LEE, transaminases declined whether HAART was continued or modified. Of patients with chronic HBV infection 38% lost HBeAg or developed anti-HBe after initiation of HAART, and one seroconverted from HBsAg-positive to anti-HBs-positive. However, there was no clear relationship with LEE. CONCLUSIONS: HIV-1-infected patients co-infected with HBV or HCV were at considerably higher risk of developing LEE when HAART was initiated compared with patients without co-infection, but it is usually not necessary to modify antiretroviral therapy.

Experience with nevirapine in previously treated HIV-1-infected individuals.

OBJECTIVE: To assess the tolerability, virological, immunological and clinical effects of nevirapine in the setting of a compassionate use programme in pretreated HIV-infected individuals. DESIGN: Retrospective observational cohort-study in 13 HIV-outpatient clinics in The Netherlands. MAIN OUTCOME MEASURES: plasma HIV-1 RNA levels; CD4 cell counts; incidence of new AIDS-defining diseases; multivariate analysis of predictors for virological success; incidence of skin rashes. RESULTS: 187 HIV-infected individuals treated with nevirapine in the Nevirapine Named Patient Programme in The Netherlands were included. After 48 weeks, 38% of patients had an HIV-1 RNA level below 1,000 copies/ml. In multivariate regression analysis, prior treatment with three or less nucleoside analogue reverse transcriptase inhibitors, and a higher baseline CD4 cell count was predictive of virological success. The median CD4 cell count remained stable over the 48 weeks. Eleven patients experienced a new AIDS-defining event. The total incidence of rash (including rash not leading to discontinuation of nevirapine) was 13.9 and 6.4% of the patients discontinued nevirapine because of rash. None of the 28 patients with undetectable HIV-1 RNA levels at baseline developed a rash. CONCLUSIONS: We conclude that nevirapine when used as part of salvage therapy, is safe and most likely to give sustained suppression of HIV-1 in patients that have been less extensively pretreated. CD4 cell counts remained stable despite the low rate of virological success, this also occurred in patients not concurrently using protease inhibitors (PIs). The incidence of nevirapine-related rash in PI-pretreated patients and especially in patients with undetectable HIV-1 RNA levels at the start of nevirapine treatment, is considerably lower than previously reported for antiretroviral-naive patients.