HIV-1 RNA levels, resistance, and drug diffusion in semen versus blood in patients receiving a lopinavir-containing regimen

Penetration and antiviral efficacy of total and unbound maraviroc, raltegravir and rilpivirine in both female and male genital fluids from HIV-positive patients receiving regimens containing these antiretrovirals

Background

Sub-optimal penetration of antiretroviral drugs in genital compartments might promote local HIV persistence and increase the risk of HIV transmission.

Objectives

To describe the penetration of maraviroc, raltegravir, raltegravir glucuronide and rilpivirine in seminal plasma and cervico-vaginal secretions (CVS) and to assess local antiretroviral efficacy in HIV-1-positive patients.

Methods

This was a prospective, multicentre study. Inclusion criteria were HIV-1 positive, age >18 years, receiving regimens containing maraviroc and/or raltegravir and/or rilpivirine for >1 month, and good self-reported adherence. Paired blood and genital samples were collected 12 h (raltegravir and maraviroc) or 24 h (rilpivirine) post-dose. These concentrations were determined (UPLC-MS/MS) in blood and seminal plasma (total and unbound) and CVS (total, dried spots) and HIV-RNA was quantified in paired blood and genital samples.

Results

Among the 54 enrolled patients, 15 received maraviroc (6 men), 27 received raltegravir (14 men) and 20 received rilpivirine (10 men), corresponding to 54 total and 52 unbound plasma concentrations, 29 total CVS samples and 23 total and 18 unbound seminal plasma samples. Maraviroc and raltegravir displayed a ratio of genital fluids/plasma concentrations >0.5 in both male and female genital tracts. Conversely, rilpivirine displayed a low ratio. Antiretroviral free fractions were consistent with historical data. Nine patients had blood plasma HIV-RNA >50 copies/mL (2/9 had sub-optimal antiretroviral blood plasma exposure) and two other patients had detectable HIV-RNA in genital fluids.

Conclusions

Maraviroc and raltegravir demonstrated good penetration in genital compartments, yielding good local virological response in genital compartments, whereas rilpivirine presented a low penetration profile but good local response.

Transmission of HIV-1 drug resistance mutations within partner-pairs: A cross-sectional study of a primary HIV infection cohort

BACKGROUND

Transmission of human immunodeficiency virus type 1 (HIV-1) drug resistance mutations, particularly that of minority drug-resistant variants, remains poorly understood. Population-based studies suggest that drug-resistant HIV-1 is less transmissible than drug-susceptible viruses. We compared HIV-1 drug-resistant genotypes among partner-pairs in order to assess the likelihood of transmission of drug resistance mutations and investigate the role of minority variants in HIV transmission.

METHODS AND FINDINGS

From 1992-2010, 340 persons with primary HIV-1 infection and their partners were enrolled into observational research studies at the University of Washington Primary Infection Clinic (UWPIC). Out of 50 partner-pairs enrolled, 36 (72%) transmission relationships were confirmed by phylogenetic distance analysis of HIV-1 envelope (env) sequences, and 31 partner-pairs enrolled after 1995 met criteria for this study. Drug resistance mutations in the region of the HIV-1 polymerase gene (pol) that encodes protease and reverse transcriptase were assessed by 454-pyrosequencing. In 25 partner-pairs where the transmission direction could be determined, 12 (48%) transmitters had 1-4 drug resistance mutations (23 total) detected in their HIV-1 populations at a median frequency of 6.0% (IQR 1.5%-98.7%, range 1.0%-99.6%). Of 10 major mutations detected in five transmitters at a frequency >95%, 100% (95% CI 69.2%-100%) were detected in recipients. All of these transmitters were antiretroviral (ARV)-naïve at the time of specimen collection. Fourteen mutations (eight major mutations and six accessory mutations) were detected in nine transmitters at low frequencies (1.0%-11.8%); four of these transmitters had previously received ARV therapy. Two (14% [95% CI 1.8%-42.8%]) G73S accessory mutations were detected in both transmitter and recipient. This number is not significantly different from the number expected based on the observed frequencies of drug-resistant viruses in transmitting partners. Limitations of this study include the small sample size and uncertainties in determining the timing of virus transmission and mutation history.

CONCLUSIONS

Drug-resistant majority variants appeared to be commonly transmitted by ARV-naïve participants in our analysis and may contribute significantly to transmitted drug resistance on a population level. When present at low frequency, no major mutation was observed to be shared between partner-pairs; identification of accessory mutations shared within a pair could be due to transmission, laboratory artifact, or apolipoprotein B mRNA-editing enzyme, catalytic polypeptides (APOBECs), and warrants further study.

Pharmacokinetics of antiretrovirals in genital secretions and anatomic sites of HIV transmission: implications for HIV prevention

The incidence of HIV remains alarmingly high in many parts of the world. Prophylactic use of antiretrovirals, capable of concentrating in the anatomical sites of transmission, may reduce the risk of infection after an unprotected sexual exposure. To date, orally and topically administered antiretrovirals have exhibited variable success in preventing HIV transmission in large-scale clinical trials. Antiretroviral mucosal pharmacokinetics may help explain the outcomes of these investigations. Penetration and accumulation of antiretrovirals into sites of transmission can influence dosing strategies and pre-exposure prophylaxis clinical trial design. Antiretroviral tissue distribution varies widely within and between drug classes, attributed in part to their physicochemical properties and tissue-specific drug transporter expression. Nucleoside(-tide) reverse transcriptase inhibitors, the CCR5 antagonist maraviroc, and the integrase inhibitor raltegravir demonstrate the highest penetration into the male and female reproductive tracts and colorectal tissue relative to blood. This review describes antiretroviral exposure in anatomic sites of transmission, and places these findings in context with the prevention of HIV and the efficacy of pre-exposure prophylactic strategies.

Antiretroviral bioanalysis methods of tissues and body biofluids

Research in the many areas of HIV treatment, eradication and prevention has necessitated measurement of antiretroviral (ARV) concentrations in nontraditional specimen types. To determine the knowledgebase of critical details for accurate bioanalysis, a review of the literature was performed and summarized. Bioanalytical assays for 31 ARVs, including metabolites, were identified in 205 publications measuring various tissues and biofluids. 18 and 30% of tissue or biofluid methods, respectively, analyzed more than one specimen type; 35-37% of the tissue or biofluid methods quantitated more than one ARV. 20 and 76% of tissue or biofluid methods, respectively, were used for the analysis of human specimens. HPLC methods with UV detection predominated, but chronologically MS detection began to surpass. 40% of the assays provided complete intra- and inter-assay validation data, but only 9% of publications provided any stability data with even less for the prevalent ARV in treatments.

Pharmacokinetics of antiretroviral drugs in anatomical sanctuary sites: the male and female genital tract

HIV resides within anatomical 'sanctuary sites', where local drug exposure and viral dynamics may differ significantly from the systemic compartment. Suboptimal antiretroviral concentrations in the genital tract may result in compartmentalized viral replication, selection of resistant mutations and possible re-entry of wild-type/resistant virus into the systemic circulation. Therefore, achieving adequate antiretroviral exposure in the genital tract has implications for the prevention of sexual and vertical transmission of HIV. Penetration of antiretrovirals in the genital tract is expressed by accumulation ratios derived from the measurement of drug concentrations in time-matched seminal plasma/cervicovaginal fluid and plasma samples. Penetration varies by gender and may be drug (as opposed to class) specific with high interindividual variability. Concentrations in seminal plasma are highest for nucleoside analogues and lowest for protease inhibitors and efavirenz. Seminal accumulation of newer agents, raltegravir and maraviroc, is moderate (rank order of accumulation is nucleoside/nucleotide reverse transcriptase inhibitors [lamivudine/zidovudine/tenofovir/didanosine > stavudine/abacavir] > raltegravir > indinavir/maraviroc/nevirapine >> efavirenz/protease inhibitors [amprenavir/atazanavir/darunavir > lopinavir/ritonavir > saquinavir] > enfuvirtide). In the female genital tract, the nucleoside analogues exhibit high accumulation ratios, whereas protease inhibitors have limited penetration; however, substantial variability exists between individuals and study centres. Second generation non-nucleoside reverse transcriptase inhibitor etravirine, and maraviroc and raltegravir, demonstrate effective accumulation in cervicovaginal secretions (rank order of accumulation is nucleoside/nucleotide reverse transcriptase inhibitor [zidovudine/lamivudine/didanosine > emtricitabine/tenofovir] > indinavir > maraviroc/raltegravir/darunavir/etravirine > nevirapine/abacavir > protease inhibitors [amprenavir/atazanavir/ritonavir] > lopinavir/stavudine/efavirenz > saquinavir).

Antiretroviral drug concentrations in the male and female genital tract: implications for the sexual transmission of HIV

PURPOSE OF REVIEW

To summarize the recent literature (2008-2010) on antiretroviral (ARV) drug disposition into the male and female genital tract.

RECENT FINDINGS

Recent studies have confirmed that penetration of antiretroviral agents into the male and female genital tracts are both drug and sex specific. Concentrations achieved vary considerably depending on the class of drug studied, the sampling techniques used and the times samples are obtained.

SUMMARY

There appear to be several patterns of drug penetration into the male and female genital tract. In addition there appear to be different patterns of genital shedding under the influence of antiretroviral therapy. What effect these factors will have on the sexual transmission of HIV or the evolution and transmission of resistant HIV remains to be seen.

Discordance in HIV-1 viral loads and antiretroviral drug concentrations comparing semen and blood plasma

OBJECTIVES

For individuals not on antiretroviral therapy, the risk of heterosexual transmission of HIV appears negligible when blood plasma (BP) viral loads are <1500 HIV-1 RNA copies/mL. It is not clear whether this observation can be extrapolated to individuals on highly active antiretroviral therapy (HAART). Because of differential tissue penetration, antiretroviral drug concentrations may be sufficient to maintain an undetectable viral load in the BP yet not achieve adequate levels to suppress HIV in the genital tract. Therefore, we wanted to correlate HIV viral loads and drug concentrations in semen plasma (SP) and BP.

METHODS

Thirty-three men were included. All were on combination antiretroviral therapy with an undetectable BP viral load for at least 1 year. Blood and semen samples were collected within 2 h of each other and tested for HIV RNA by the NucliSens QT (bioMerieux, St Laurent, QC, Canada) method; drug concentrations were determined by liquid chromatography tandem mass spectrometry.

RESULTS

Two of the 33 patients (6.1%) with BP viral loads below detection had time-matched HIV viral loads in SP > or =700 copies/mL. Both patients were on efavirenz, the SP concentrations of which were < or =10% of the levels in BP and well below the minimal therapeutic drug monitoring target concentration required to suppress HIV.

CONCLUSIONS

Because, at least in part, of poor drug penetration into the genital tract, an undetectable HIV viral load in the BP does not guarantee an undetectable viral load in semen. In view of this, caution should be taken in concluding that patients on HAART with suppressed viraemia are sexually non-infectious.

ABCB1 polymorphisms and the concentrations of lopinavir and ritonavir in blood, semen and saliva of HIV-infected men under antiretroviral therapy

INTRODUCTION

Lopinavir and ritonavir are frequently included in highly active antiretroviral therapy (HAART) regimens for HIV infection. These drugs are substrates, and may also inhibit and/or induce the P-glycoprotein (ABCB1) transporter, encoded by the polymorphic ABCB1 gene. We investigated the impact of three common exonic ABCB1 polymorphisms on the concentrations of lopinavir and ritonavir in blood, semen and saliva of HIV-infected men under stable HAART containing ritonavir-boosted lopinavir.

MATERIALS & METHODS

Blood, semen and saliva samples were collected from 113 subjects, 30-35 minutes before the scheduled morning dose of lopinavir/ritonavir, and trough drug concentrations were measured using LC/MS/MS. The 1236C>T, 2677G>T/A and 3435C>T polymorphisms were genotyped using the single base extension-termination method and ABCB1 haplotypes were statistically inferred.

RESULTS

Median (25th-75th percentile) trough concentrations (ng/ml) of lopinavir in plasma, semen and saliva were 6326 (4070-8617), 286.0 (128.4-475.5) and 72.7 (38.0-119.6), respectively. The corresponding concentrations (ng/ml) for ritonavir were 261.8 (172.2-398.6), 17.7 (9.2-27.6) and 5.3 (3.2-9.0), respectively. Univariate and multivariate regression analysis revealed no influence of ABCB1 genotypes or haplotypes on the concentrations of lopinavir and ritonavir in plasma, semen and saliva of HIV-infected men under stable HAART treatment.

CONCLUSION

The ABCB1 1236C>T, 2667G>T/A and 3435C>T genotypes and haplotypes are not predictors of lopinavir and ritonavir concentrations in blood plasma, semen or saliva of HIV-infected men under stable HAART treatment. The concentrations of lopinavir and ritonavir in saliva are not reliable predictors of the concentration of these drugs in semen.

Quantification of antiretroviral drugs for HIV-1 in the male genital tract: current data, limitations and implications for laboratory analysis

Antiretroviral therapy has reduced the morbidity and mortality associated with HIV-1/AIDS in developed countries. Viral replication in blood plasma is suppressed by antiretroviral drugs, whereas virus in the male genital tract is genetically and phenotypically unique and may not be suppressed. This viral compartmentalization affects antiretroviral drug penetration of the male genital tract and capacity for antiretroviral therapy to reduce sexual transmission. The problem of having two distinct viral populations within any given individual is compounded by the fact that antiretroviral drugs penetrate semen to varying degrees. Incomplete suppression of genital tract virus may yield drug-resistant virus and increase the risk of sexual transmission. This review critically appraises current studies of antiretroviral drug quantification in semen and suggests recommendations to address observed limitations.

Factors of intermittent HIV-1 excretion in semen and efficiency of sperm processing in obtaining spermatozoa without HIV-1 genomes

OBJECTIVE

To study the risk factors for HIV-1 in semen according to the localization of HIV-1 in sperm cell fractions and to assess the efficiency of sperm processing in obtaining spermatozoa without HIV-1 genomes.

METHODS

Ninety-four HIV-infected patients provided 281 paired blood and semen samples. Sperm cell separation was performed using two successive methods. HIV-1 RNA was quantified in blood and seminal plasma. HIV-1 RNA and DNA were detected in cell fractions.

RESULTS

HIV-1 RNA was found in 14% of seminal plasma samples and up to 8.7% of native semen cells were positive for HIV-1 RNA and DNA. Ten seminal plasma samples had detectable RNA although blood viral load was undetectable. Antiretroviral treatment reduced the likelihood of RNA detection in seminal plasma. For semen with polynuclear cells and HIV-1 RNA in seminal plasma, the likelihood of detecting HIV-1 genomes in semen cells was increased fourfold and sixfold, respectively. In 25% of patients, HIV-1 excretion was intermittent. In the group of patients with systematic negative seminal plasma, HIV-1 genomes were detected in up to 10% of sperm cell samples. Our method of sperm processing always enabled us to obtain spermatozoa without detectable HIV-1 genomes.

CONCLUSIONS

Polynuclear cells in semen are a risk factor for seminal HIV-1 excretion. Blood viral load was the only predictive factor for the intermittence of HIV-1 excretion in semen over time. Sperm processing using two successive methods was effective in obtaining spermatozoa without detectable HIV-1 genomes regardless of the viral load level in native semen.

Evidence of genotypic resistance diversity of archived and circulating viral strains in blood and semen of pre-treated HIV-infected men

OBJECTIVE

To study the genetic diversity of drug-resistant HIV strains present in blood and in semen, especially those archived in peripheral blood mononuclear cells (PBMC) and non-sperm cells (NSC).

METHODS

Paired blood and semen samples were collected from twenty heavily pre-treated HIV-infected men. HIV RNA in blood plasma (BP) and seminal plasma (SP), as well as proviral DNA in PBMC and NSC were quantified and used for resistance genotyping. Phylogenetic analysis of protease gene clones was used to explore the diversity of the viral quasi-species.

RESULTS

Median BP HIV RNA, PBMC proviral DNA, SP HIV RNA and non-sperm cell proviral DNA loads were respectively: 4.77, 3.65, 3.16 and 1.77 log10 copies per ml or per 10 cells. Resistant HIV strains were found in the BP and PBMC of all the patients, in the SP of 14 patients, and in the NSC of five patients. Overall, the blood and genital compartments exhibited different genotypic resistance patterns in six patients (30%), with additional resistance mutations in the semen of four patients. Phylogenetic analysis of clones of HIV protease gene showed that viral strains in SP originated not only from passive diffusion from BP, but also from local production in semen. The storage of archived proviruses differed according to the anatomic reservoir.

CONCLUSION

HIV resistant strains are frequent (70%) in the semen of heavily pre-treated men, and the diversity of genotypic resistance pattern confirms HIV compartmentalization. Thus, the risk of sexual transmission of resistant strains can only be partly predicted by standard tests applied to BP.