Convenience, efficacy, safety, and durability of INSTI-based antiretroviral therapies: evidence from the Italian MaSTER cohort

BACKGROUND

Integrase strand transferase inhibitors (INSTI), including raltegravir (RAL), elvitegravir (ELV), and dolutegravir (DTG), have demonstrated better efficacy and tolerability than other combination antiretroviral therapy (cART) classes in clinical trials; however, studies of sustainability of INSTI-containing therapy in the long-term are sparse. The purpose of this study was to provide an epidemiological overview comparing the outcome performance of different INSTI-based regimens longitudinally, including the metrics of efficacy, safety, convenience, and durability among a large, nationally representative cohort of persons living with HIV in Italy.

METHODS

We selected subjects in the MaSTER cohort (an Italian multicenter, hospital-based cohort established in the mid-1990s that currently has enrolled over 24,000 PLWH) who initiated an INSTI-based regimen either when naïve or following a regimen switch. Cox proportional hazards regression models were fitted to evaluate associations between therapy interruptions and age, sex, nationality, transmission risk group, viral suppression status, CD4 + T-cell count, diagnosis year, cART status (naïve or experienced), and hepatitis coinfection. Results were stratified by cART INSTI type.

RESULTS

There were 8173 participants who initiated an INSTI-based cART regimen in the MaSTER cohort between 2009 and 2017. The population was majority male (72.6%), of Italian nationality (88.6%), and cART-experienced (83.0%). Mean age was 49.7 (standard deviation: 13.9) years. In total, interruptions of the 1st INSTI-based treatment were recorded in 34% of cases. The most frequently cited reason for interruption among all three drug types was safety problems. In the survival analysis, past history of cART use was associated with higher hazards of interruption due to poor efficacy for all three drug types when compared to persons who were cART naïve. Non-viral suppression and CD4 + T-cell count < 200/mm3 at baseline were associated with higher hazards of interruption due to efficacy, safety, and durability reasons. Non-Italian nationality was linked to higher hazards of efficacy interruption for RAL and EVG. Age was negatively associated with interruption due to convenience and positively associated with interruption due to safety reasons. People who injects drugs (PWID) were associated with higher hazards of interruption due to convenience problems. Hepatitis coinfection was linked to higher hazards of interruption due to safety concerns for people receiving RAL.

CONCLUSION

One-third of the population experienced an interruption of any drugs included in INSTI therapy in this study. The most frequent reason for interruption was safety concerns which accounted for one-fifth of interruptions among the full study population, mainly switched to DTG. The hazard for interruption was higher for low baseline CD4 + T-cell counts, higher baseline HIV-RNA, non-Italian nationality, older age, PWID and possible co-infections with hepatitis viruses. The risk ratio was higher for past history of cART use compared to persons who were cART naive, use of regimens containing 3 drugs compared to regimens containing 2 drugs. Durability worked in favor of DTG which appeared to perform better in this cohort compared to RAL and EVG, though length of follow-up was significantly shorter for DTG. These observational results need to be confirmed in further perspective studies with longer follow-up.

UK guideline for the use of HIV post-exposure prophylaxis 2021

We present the updated British Association for Sexual Health and HIV (BASHH) guidelines for post-exposure prophylaxis (PEP) to HIV following sexual exposures, occupational exposures and other nonoccupational exposures in the community. This serves as an update to the 2015 BASHH guideline on PEP following sexual exposures and the 2008 Expert Advisory Group on AIDS guidelines on HIV PEP. We aim to provide evidence-based guidance on best clinical practice in the provision, monitoring and support of PEP for the prevention of HIV acquisition following sexual, occupational and other nonoccupational exposures in the community. The guideline covers when to prescribe PEP, what antiretroviral agents to use and how to manage PEP. This includes (i) evidence of PEP efficacy; (ii) evidence relating to individual-level efficacy of antiretroviral therapy to prevent the sexual transmission of HIV; (iii) data on the detectable (transmissible) prevalence of HIV in specific populations; (iv) risk of HIV transmission following different types of sexual and occupational exposure; (v) baseline risk assessment; (vi) drug regimens and dosing schedules; (vii) monitoring PEP; (viii) baseline and follow-up blood-borne virus testing; (ix) the role of PEP within broader HIV prevention strategies, for example, HIV pre-exposure prophylaxis (PrEP). The guideline also covers special scenarios such as PEP in pregnancy, breastfeeding and chronic hepatitis B virus infection, and when PEP should be considered in people using HIV PrEP. The guidelines are aimed at clinical professionals directly involved in PEP provision and other stakeholders in the field. A proforma to assist PEP consultations is included. A public consultation process was undertaken prior to finalizing the recommendations.

Antiretroviral therapy and liver disorders in the OPERA® cohort

Introduction:

A comprehensive assessment of liver disorders was conducted among people living with HIV (PLWH) on a new antiretroviral regimen based on common core agents.

Methods:

Treatment-naïve and experienced PLWH first initiating dolutegravir (DTG), elvitegravir (EVG), raltegravir (RAL), or darunavir (DRV) in the OPERA^® cohort were included if they had ⩾1 liver chemistry test performed both within 12 months before regimen start and over follow-up. Liver disorders were defined as a diagnosis of drug-induced liver injury (DILI) or moderate/severe liver chemistry elevations (LCE). History of liver disorders experienced within 12 months of initiation was summarized. Liver disorders occurring during follow-up were described as prevalent (all disorders) or incident (disorders occurring among PLWH without a history of liver disorders or advanced liver fibrosis).

Results:

Out of 16,024 PLWH, 38% initiated DTG, 43% EVG, 5% RAL, and 14% DRV. EVG users were younger and had a lower likelihood of comorbidities or lipid-lowering agent use than DTG users. EVG users were significantly less likely to have a history of moderate/severe LCE or to have prevalent moderate LCE. RAL users were older and had a higher likelihood of comorbidities or lipid-lowering agent use than DTG users. RAL users were significantly more likely to have a history of advanced liver fibrosis and prevalent moderate/severe LCE during follow-up. DRV users were older and had a lower likelihood of lipid-lowering agent use than DTG users. There was no difference in history of LCE, nor in prevalent or incident LCE between DRV and DTG users. No DILI diagnoses were recorded. Discontinuation following a liver disorder was rare (<1%) across all groups.

Conclusion:

While PLWH with comorbidities may have been channeled away from EVG and toward DTG and RAL, the incidence of moderate/severe LCE did not differ between DTG and EVG, RAL, and DRV.

Plain language summary

Liver disorders and HIV treatment

A comprehensive assessment of liver disorders was conducted using data from the OPERA^® cohort, which provides anonymous patient-level clinical data from electronic health records. People living with HIV (PLWH) who were starting a new HIV treatment regimen that included one of four common HIV drugs were included in this study. Liver disorders included drug-induced liver injury (DILI) and moderate or severe liver chemistry elevations. History of a disorder was defined as liver disorders that occurred before starting the new treatment. Prevalent disorders were those that occurred after starting the new treatment in the whole population. Incident disorders were those that occurred after starting the new treatment, but only among PLWH without any history of liver disorders.

Out of 16,024 PLWH, 38% initiated dolutegravir (DTG), 43% elvitegravir (EVG), 5% raltegravir (RAL), and 14% darunavir (DRV). EVG users were younger and less likely to have other diseases or use cholesterol lowering drugs compared to DTG users. They were also less likely to have a history of moderate/severe liver chemistry elevations or to have prevalent moderate liver chemistry elevations. RAL users were older and more likely to have other diseases or use cholesterol lowering drugs compared to DTG users. They were also more likely to have prevalent moderate/severe liver chemistry elevations than DTG users. DRV users were older and less likely to use cholesterol lowering agents compared to DTG users. There was no difference in history of liver chemistry elevations, or in prevalent, or incident liver chemistry elevations between DRV and DTG users. There were no DILI diagnoses and discontinuation of treatment following liver disorders was rare across all groups. Overall, the incidence of liver disorders after starting a new HIV treatment regimen did not differ between four common antiretroviral drugs.

Incidence and risk factors for liver enzyme elevation among naive HIV-1-infected patients receiving ART in the ICONA cohort

OBJECTIVES

To evaluate the incidence and risk factors for liver enzyme elevations (LEE) in patients initiating first-line ART in the ICONA prospective observational cohort, between June 2009 and December 2017.

PATIENTS AND METHODS

In total, 6575 ART-naive patients were selected, initiating two NRTIs with the third drug being a boosted PI (n=2436; 37.0%), an NNRTI (n=2384; 36.3%) or an integrase strand transfer inhibitor (INSTI) (n=1755; 26.7%). HBV surface antigen and HCV RNA were detected in 3.9% and 5.8% of the study population. Inverse probability weighted Cox regression analysis was used to calculate the HRs, according to first-line regimen, for LEE, defined as ALT or AST increases of ≥2.5× upper limit of normal (ULN) for patients with normal baseline values or ≥2.5× baseline for patients with higher baseline values.

RESULTS

One hundred and eighty-three LEE occurred over 20722 patient-years of follow-up. After adjusting for the main confounders, the risk of LEE halved with INSTIs compared with NNRTIs (HR 0.46, 95% CI 0.25-0.86), with a significant reduction in the raltegravir group (HR 0.11, 95% CI 0.02-0.84 using the NNRTI class as reference). HRs for LEE were significantly higher in subjects with HBV or HCV coinfection, in patients with poorly controlled HIV infection and in those who acquired HIV through homosexual transmission.

CONCLUSIONS

In our study, INSTI use almost halved the risk of LEE compared with other regimens. This finding could be particularly important for choosing ART in patients with risk factors for liver toxicity such as HCV and HBV coinfections.

The Influence of Antiretroviral Therapy on Hepatitis C Virus Viral Load and Liver Fibrosis in Human Immunodeficiency Virus-Coinfected Patients: An Observational Study

BACKGROUND

The role of antiretroviral therapy (ART) for Hepatitis C viral load (HCV-VL) and liver fibrosis is poorly understood. This study aimed at evaluating the influence of ART on HCV-VL and liver fibrosis in human immunodeficiency virus (HIV)/HCV-coinfected patients.

METHODS

We conducted a retrospective cohort study of HIV/HCV-coinfected patients followed at a tertiary university hospital.

RESULTS

In total, 143 patients were included. In 61 patients, ART initiation was accompanied by an increase in HCV-VL and a decrease in HIV viral load (HIV-VL), whereas ART suspension led to a decrease in HCV-VL and an increase in HIV-VL. Among the 55 HIV-suppressed patients who switched to a raltegravir (RAL)-containing regimen, median HCV-VL levels decreased significantly, while switching to a rilpivirine-containing regimen did not yield a significant reduction.

DISCUSSION

If the -treatment of chronic hepatitis starts before ART, ART initiation should be delayed as much as possible. If ART has been started, it is advisable to wait 1 year before initiating chronic hepatitis treatment. RAL as the third agent in an ART regimen could be beneficial in HIV/HCV-coinfected patients, in comparison to other antiretroviral drugs.

CONCLUSION

The start and the suspension of ART significantly interferes with HCV-VL in HIV/HCV-coinfected patients.

Metabolic, mitochondrial, renal and hepatic safety of enfuvirtide and raltegravir antiretroviral administration: Randomized crossover clinical trial in healthy volunteers

CONTEXT

Classical antiretroviral agents may acutely impact on metabolic, mitochondrial, renal and hepatic function in HIV-infected and uninfected persons. Fusion and integrase inhibitors are supposed to be safer, but have been scarcely investigated. To avoid any interference with HIV or other antiretrovirals, we assessed markers of these toxicities in healthy adult volunteers treated with Enfuvirtide (T20) or Raltegravir (RAL).

METHODS

Twenty-six healthy participants were randomized to T20/90mg vs. placebo (n = 12) or RAL/400mg vs. placebo (n = 14) every 12h in two 7-day periods separated by a 4-week washout period. Major end-points were changes in lipid profile (total cholesterol, high-density-lipoprotein (HDL)-cholesterol, low-density-lipoprotein (LDL)-cholesterol, triglycerides), insulin resistance (glucose) and mitochondrial toxicity (mitochondrial DNA content-mtDNA-in peripheral blood mononuclear cells). Renal and hepatic toxicity (creatinine, alanine transaminase (AST), alanine aminotransferase (ALT), bilirubin and total plasma proteins) and overall safety were also analysed. Effect of period, treatment, and basal measures were evaluated for each end-point.

RESULTS

Neither T20-administration nor RAL-administration yielded to any statistic significant change in the markers of metabolic, mitochondrial, renal or hepatic toxicity assessed. No symptoms indicative of drug toxicity were neither found in any subject.

CONCLUSIONS

In absence of HIV infection, or concomitant treatment, short-term exposure to T20 or RAL in healthy adult volunteers did not lead to any indicative changes in toxicity markers thus presuming the safe profile of both drugs.

A safety evaluation of raltegravir for the treatment of HIV

INTRODUCTION

Raltegravir (RAL) was the first commercialized agent from a new drug class with an innovative target, the integrase. Since its introduction in clinical practice RAL has become widely used for the treatment of HIV-1 infected patients. A decade after its approval, this article reviews key evidence from RAL with a special interest on safety outcomes. Areas covered: Pharmacologic, safety and efficacy data of RAL from clinical trials and post-commercialization published reports are hereby summarized after a literature review including PubMed search, relating proceedings and abstracts from relevant international HIV conferences, assessment reports from European and United States regulatory agencies and treatment guidelines (World Health Organization, United States Department of Health and Human Services and European AIDS Clinical Society), up to October 2017. Most frequent search terms were 'raltegravir', 'safety', 'adverse events', 'efficacy' and 'integrase-inhibitors'. Expert opinion: Despite the arrival of new integrase strand transfer inhibitors (INSTIs) with advantages in terms of dosing convenience (elvitegravir, ELV) and higher genetic barrier (dolutegravir, DTG), RAL has stood the test of time and its overall favourable safety profile, without significant appearance of unexpected adverse events, vouch for its relevance in the antiretroviral armamentarium.

Drug Hepatotoxicity: Newer Agents

Idiosyncratic hepatotoxicity is one of the most common reasons for an approved drug being restricted. This article focuses on hepatotoxicity of selected and recently introduced agents, such as, tyrosine kinase inhibitors, monoclonal antibodies, novel oral anticoagulants, newer antiplatelets, antibiotics, anti-diabetics, anti-epileptics, anti-depressants, anti-psychotics and anti-retrovirals. Overall, the incidence of clinically relevant hepatotoxicity from newer agents seems to be lower than that of the older agents. Nevertheless, cases of severe hepatotoxicity have been reported due to some of these newer agents, including, trastuzumab, ipilimumab, infliximab, imatinib, bosutinib, dasatinib, gefitinib, erlotinib, sunitinib, ponatinib, lapatinib, vemurafenib, dabigatran, rivaroxaban, felbamate, lamotrigine, levetiracetam, venlafaxine, duloxetine, darunavir, and maraviroc.

UK guideline for the use of HIV Post-Exposure Prophylaxis Following Sexual Exposure, 2015

We present the updated British Association for Sexual Health and HIV guidelines for HIV post-exposure prophylaxis following sexual exposure (PEPSE). This document includes a review of the current data to support the use of PEPSE, considers how to calculate the risks of infection after a potential exposure, and provides recommendations on when PEPSE should and should not be considered. We also review which medications to use for PEPSE, provide a checklist for initial assessment, and make recommendations for monitoring individuals receiving PEPSE. Special scenarios, cost-effectiveness of PEPSE, and issues relating to service provision are also discussed. Throughout the document, the place of PEPSE within the broader context of other HIV prevention strategies is considered.

Liver toxicity and risk of discontinuation in HIV/hepatitis C virus-coinfected patients receiving an etravirine-containing antiretroviral regimen: influence of liver fibrosis

OBJECTIVES

The aim of the study was to establish the risk of liver toxicity in HIV/hepatitis C virus (HCV)-coinfected patients receiving etravirine, according to the degree of liver fibrosis.

METHODS

A prospective cohort study of 211 HIV-infected patients initiating an etravirine-containing regimen was carried out. HCV coinfection was defined as a positive HCV RNA test, and baseline liver fibrosis was assessed by transient elastography. Hepatotoxicity was defined as clinical symptoms, or an aspartate aminotransferase (AST) or alanine aminotransferase (ALT) value > 5-fold higher than the upper limit of normal if baseline values were normal, or 3.5-fold higher if values were altered at baseline.

RESULTS

Overall, 145 patients (69%) were HCV coinfected, with a lower nadir (165 versus 220 cells/μL, respectively; p = 0.03) and baseline (374 versus 498 cells/μL, respectively; p = 0.04) CD4 count than monoinfected patients. Etravirine was mainly used with two nucleoside reverse transcriptase inhibitors (129; 61%) or with a boosted protease inhibitor (PI) (28%), with no significant differences according to HCV serostatus. Transient elastography in 117 patients (81%) showed a median (range) stiffness value of 8.25 (3.5-69) kPa, with fibrosis stage 1 in 43 patients (37%) and fibrosis stage 4 in 28 patients (24%). During an accumulated follow-up time of 449.3 patient-years (median 548 days), only one patient with advanced fibrosis (50.8 kPa) had grade 3-4 liver toxicity (0.7%). Transaminases changed slightly, with no significant differences compared with baseline fibrosis, and nine and six patients had grade 1 and 2 transaminase increases, respectively. Also, HCV coinfection was not associated with a higher risk of discontinuation (25% discontinued versus 21% of monoinfected patients; p = 0.39, log-rank test) or virological failure (8% versus 12%, respectively; p = 0.4).

CONCLUSIONS

Our data suggest that etravirine is a safe option for HIV/HCV-coinfected patients, including those with significant liver fibrosis.

Raltegravir-based therapy in a cohort of HIV/HCV co-infected individuals

The relationship between hepatic tolerance and hepatitis C virus (HCV) co-infection has not been extensively studied in clinical practice. We assessed the efficacy and safety of raltegravir-based therapy in an Italian cohort of HIV/HCV co-infected patients. One hundred and forty patients with HIV/HCV co-infection initiating raltegravir from SCOLTA project (Surveillance Cohort Long-Term Toxicity Antiretrovirals) were examined. Of them, 43 were women, with mean age of 45.4±6.4years; 65 (46%) had undetectable HIV-RNA<50copies/mL and 75 (54%) HIV-RNA≥50copies/mL. According to CDC classification, 49 (35%) were in stage C. Based on Fib4 score at the time of starting raltegravir, patients were classified in class I in 41 cases, class II in 68 and in class III in 31 cases. Globally, the Fib4 score slightly decreased during 24months follow-up, from 2.2 to a value of 1.8. Hepatic adverse events of any grade were observed in 67 patients, of which only 2 cases (3%) had severe liver toxicity (grade 3-4). Only one patient had to discontinue the therapy because of adverse events. According to univariate analysis, being in CDC stage C represented a risk for the development of liver toxicity, with a hazard ratio (HR) of 2.27 (95% CI 1.06-4.84, P=0.033). None of the other variables considered (age, sex, years since detection of HIV and HCV-RNA detectable, years of previous HIV therapy, concomitant therapy with PI or NRTI, CD4+ cell count, Fib4, and transaminases level at baseline) resulted statistically correlated to the outcome. In conclusion, raltegravir-based regimens can be safely used in HCV infected patients; in this study, the hepatic toxicity has been found to be more frequent in patients with an advanced HIV disease (CDC stage C), independently of HIV-RNA suppression at raltegravir initiation.

Dolutegravir, abacavir and lamivudine as HIV therapy

INTRODUCTION

Antiretroviral therapy has evolved dramatically and more potent, safer and convenient drugs have replaced former compounds. Dolutegravir (DTG) is the most recently approved integrase inhibitor. It displays attractive properties such as one pill once daily (QD) dosing, high barrier to resistance and clean safety profile. Moreover, it is planned to be marketed, co-formulated with abacavir (ABC) and lamivudine (3TC) as a single-tablet regimen (STR). The availability of this QD single pill represents a significant step further for a large number of HIV-infected persons.

AREAS COVERED

Updated summary of evidence-based information on efficacy and safety of DTG along with ABC and 3TC. All information available on antiretrovirals in the most advanced stages of clinical development reported in peer-reviewed journals or at international meetings has been reviewed.

EXPERT OPINION

The combination of DTG, ABC and 3TC displays a high efficacy, superior to many other antiretroviral combinations, including other convenient STR. The good safety profile, low potential for drug interactions and high resistance barrier of DTG- ABC-3TC are unique features than make this co-formulation the preferred choice as HIV therapy in multiple clinical scenarios, including most treatment-naïve and treatment-experienced patients, as part of switch strategies, and in patients with underlying serious medical conditions such as kidney abnormalities, liver disease, metabolic disturbances or neuropsychiatric conditions.

A switch to Raltegravir improves antiretroviral associated hepatotoxicity in individuals co-infected with HIV and hepatitis C

INTRODUCTION

Raltegravir is a switch option for HIV/HCV co-infected individuals due to its hepatic neutral profile. We evaluated the effect of a switch to Raltegravir from other antiretroviral agents in HIV and HCV-co-infected individuals naïve to HCV therapy.

METHODS

Observational, single-centre study. Data on alanine aminotransferase levels, HCV-VL, CD4 cell count, HIV viral load levels and hepatic fibrosis score were collated six months pre-switch, at the time of switch and six months post switch to Raltegravir therapy. Results were compared utilizing the Kruskal-Wallis test.

RESULTS

Twenty-seven individuals were identified. Median age was 43 years, median duration of HIV infection was 7 years and median documented period of HCV infection at the time of switch was 26 months. A sustained improvement in ALT levels was observed. Median ALT levels were 254 IU/L at the time of switch, decreasing significantly to 176 IU/L, (p = 0.0226) and 90 IU/L (p = 0.0138) 1 month post switch and 6 months post switch respectively. The median Hepatitis C viral load level at the time of the switch was 341,783 copies/mL, which decreased to 224,066 copies/mL 6 months after switch (p = 0.04).

DISCUSSION

A switch to Raltegravir in individuals with HIV/HCV co-infection was effective in maintaining HIV virological suppression with improvement in drug-associated hepatotoxicity as measured by ALT.

Hepatic safety and tolerability of raltegravir among HIV patients coinfected with hepatitis B and/or C

BACKGROUND

Potential liver toxicity is an important consideration for antiretroviral selection among patients coinfected with HIV and viral hepatitis (B and/or C). We sought to describe the hepatic safety profile of raltegravir in this population.

METHODS

Using data from HIV clinical cohorts at Johns Hopkins University and the University of North Carolina at Chapel Hill, we evaluated factors associated with liver enzyme elevations (LEEs) and calculated adverse event incidence rates for patients initiated on raltegravir-containing regimens prior to 1 January 2010. LEEs were graded according to Division of AIDS definitions.

RESULTS

During the study period, 456 patients received raltegravir - of whom 36% were hepatitis-coinfected (138 HCV, 17 HBV, 11 HBV+HCV). Coinfected patients were more likely to have baseline abnormal LEEs and developed severe (grade 3-4) LEEs at a rate 3.4× that of HIV-monoinfected patients (95% CI 1.28, 9.61). Among all participants, the incidence rate for first occurrence of severe LEEs was 5 per 100 person-years (95% CI 3, 7). In adjusted analyses, coinfected patients had a 2.7-fold increased hazard of severe LEEs (95% CI 1.03, 7.04). 60% of severe abnormalities occurred within 6 months after starting raltegravir; the drug was discontinued in 3 (1.3%) coinfected patients and 18 (6.2%) monoinfected patients.

CONCLUSIONS

Compared with HIV-monoinfected patients, those with HIV-hepatitis coinfection are at increased hazard of developing LEEs on raltegravir, at a level similar to other antiretrovirals. Severe events were uncommon, rarely leading to raltegravir discontinuation. With appropriate monitoring, raltegravir-based therapy is safe in hepatitis-coinfected patients.

Human immunodeficiency virus and liver disease forum 2012

In the United States, more than 1.1 million individuals are infected with the human immunodeficiency virus (HIV). These patients exhibit a high frequency of coinfections with other hepatotropic viruses and ongoing fibrosis, leading to cirrhosis and liver-related mortality. Etiologies of liver disease include viral hepatitis coinfections, drug-related hepatotoxicity, fatty liver disease, and direct and indirect effects from HIV infection, including increased bacterial translocation, immune activation, and presence of soluble proteins, that modulate the hepatic cytokine environment. New treatments for hepatitis C virus (HCV) using direct-acting agents appear viable, though issues related to intrinsic toxicities and drug-drug interactions remain. Recent research suggests that acute HCV infection, unrecognized hepatitis D infection, and hepatitis E may all represent emergent areas of concern. Antiretroviral agents, including those used in recent years, may represent risk factors for hepatic injury and portal hypertension. Key issues in the future include systematic implementation of liver disease management and new treatment in HIV-infected populations with concomitant injection drug use, alcohol use, and low socioeconomic status.

Liver fibrosis progression in HIV-HCV-coinfected patients treated with distinct antiretroviral drugs and impact of pegylated interferon/ribavirin therapy

BACKGROUND

Advanced liver fibrosis frequently develops in patients with chronic hepatitis C coinfected with HIV. Non-invasive techniques for staging liver fibrosis, such as transient elastometry, may allow both periodic monitoring and examination of large patient populations.

METHODS

A programme of liver fibrosis assessment using transient elastometry has been ongoing at our institution since 2004. All HIV-HCV-coinfected patients having ≥2 examinations separated by >18 months were included. Liver fibrosis progression (LFP) was defined as an increase in liver stiffness from <9.5 kPa (Metavir F0-F2) to >9.5 kPa (Metavir F3-F4), or an increase >30% in patients with baseline Metavir F3-F4.

RESULTS

A total of 545 HIV-HCV-coinfected patients were analysed (mean age 41 years, 71% male, 81% intravenous drug users, mean body mass index 23.3 kg/m(2), 4.2% hepatitis B surface antigen-positive, 8.4% alcohol abuse, mean CD4(+) T-cell count 519 cells/μl). At baseline, 527 patients were on antiretroviral therapy, with the most frequent third drug being atazanavir (19.7%), efavirenz (15.9%), lopinavir (13.1%) or nevirapine (7.2%). A total of 99 (18%) patients experienced LFP during a mean (sd) follow-up of 70.9 (15.7) months. Use of protease inhibitors (OR 4.93, 95% CI 1.73, 14.0; P=0.03) and male gender (OR 5.12, 95% CI 1.37, 19.1; P=0.01) were associated with LFP. By contrast, the achievement of HCV clearance following pegylated interferon/ribavirin (PEG-IFN/RBV) therapy (OR 0.27, 95% CI 0.1, 0.79; P=0.02) was protective. Lopinavir exposure was significantly associated with LFP (OR 1.02, 95% CI 1.0, 1.04; P=0.03), whereas nevirapine was protective (OR 0.94, 95% CI 0.9, 0.99; P=0.02).

CONCLUSIONS

The use of protease inhibitors, mainly lopinavir, is associated with increased LFP in HIV-HCV-coinfected patients. By contrast, nevirapine therapy and, particularly, HCV clearance with PEG-IFN/RBV significantly reduce LFP.

Hepatotoxicity and drug interactions in liver transplant candidates and recipients

In this article the medications that have been shown to increase rates of drug-induced liver injury in patients with cirrhosis and the important drug-drug interactions in recipients of liver transplantation are reviewed. In general, the risk of drug-induced liver injury in patients with cirrhosis does not seem to be higher when compared with the noncirrhotic population. There are, however, 2 classes of agents that have been implicated-medications used to treat tuberculosis and medications used to treat human immunodeficiency virus infection. However, with careful monitoring, even significant interactions can be effectively managed.

Antiretroviral and anti-hepatitis C virus direct-acting antiviral-related hepatotoxicity

Antiretroviral-related hepatotoxicity occurs commonly in patients with human immunodeficiency virus (HIV). Liver injury ranges from unconjugated hyperbilirubinemia and nodular regenerative hyperplasia to lactic acidosis and toxic hepatitis. Effective antiretroviral therapy has changed coinfected patients' primary morbidities and mortality to chronic liver disease rather than complications from HIV. Treatment for hepatitis C virus (HCV) is strongly encouraged early in all coinfected patients. However, drug-drug interactions must be considered to ensure safe and tolerable use alone or in combination with antiretroviral therapies. The first-generation and newer HCV direct-acting antivirals are promising in coinfected patients, with minimal side effects and hepatotoxicity.

Update on HIV/HCV coinfection

Liver disease is currently one of the leading causes of hospitalization and death in HIV-positive individuals. Coinfection with the hepatitis C virus (HCV) is a major contributor to this trend. Besides hepatic damage, which is enhanced in the presence of HIV-associated immunosuppression, HCV may contribute to disease in coinfected individuals by potentiating immune activation and chronic inflammation, which ultimately account for an increased risk of cardiovascular events, kidney disease, and cancers in this population. Fortunately, hepatitis C therapeutics has entered a revolutionary era in which we hope that most patients treated with the new oral direct-acting antivirals (DAA) will be cured. However, many challenges preclude envisioning a prompt elimination of HCV from the coinfected population. Issues that should be addressed include the following: (1) rising incidence of acute hepatitis C in men who have sex with men, and expansion/recrudescence of injection drug use in some settings/regions; (2) adverse drug interactions between antiretrovirals and DAA; and (3) high cost of DAA, which may lead many to defer or fail to access appropriate therapy.

[Consensus Statement by GeSIDA/National AIDS Plan Secretariat on antiretroviral treatment in adults infected by the human immunodeficiency virus (Updated January 2013)]

OBJECTIVE

This consensus document is an update of combined antiretroviral therapy (cART) guidelines for HIV-1 infected adult patients.

METHODS

To formulate these recommendations a panel composed of members of the GeSIDA/National AIDS Plan Secretariat (Grupo de Estudio de Sida and the Secretaría del Plan Nacional sobre el Sida) reviewed the efficacy and safety advances in clinical trials, cohort and pharmacokinetic studies published in medical journals (PubMed and Embase) or presented in medical scientific meetings. The strength of the recommendations and the evidence which support them are based on a modification of the criteria of Infectious Diseases Society of America.

RESULTS

cART is recommended in patients with symptoms of HIV infection, in pregnant women, in serodiscordant couples with high risk of transmission, in hepatitisB co-infection requiring treatment, and in HIV nephropathy. cART is recommended in asymptomatic patients if CD4 is <500cells/μl. If CD4 are >500cells/μl cART should be considered in the case of chronic hepatitisC, cirrhosis, high cardiovascular risk, plasma viral load >100.000 copies/ml, proportion of CD4 cells <14%, neurocognitive deficits, and in people aged >55years. The objective of cART is to achieve an undetectable viral load. The first cART should include 2 reverse transcriptase inhibitors (RTI) nucleoside analogs and a third drug (a non-analog RTI, a ritonavir boosted protease inhibitor, or an integrase inhibitor). The panel has consensually selected some drug combinations, for the first cART and specific criteria for cART in acute HIV infection, in tuberculosis and other HIV related opportunistic infections, for the women and in pregnancy, in hepatitisB or C co-infection, in HIV-2 infection, and in post-exposure prophylaxis.

CONCLUSIONS

These new guidelines update previous recommendations related to first cART (when to begin and what drugs should be used), how to monitor, and what to do in case of viral failure or adverse drug reactions. cART specific criteria in comorbid patients and special situations are similarly updated.

Hepatoxicity of new antiretrovirals: a systematic review

There has been a major paradigm shift in the management of HIV infected patients, with earlier initiation of antiretroviral treatment and lifelong exposure to drugs for which long-term safety issues must be faced by clinicians. Within the past 5 years, new drugs from both previously established and novel therapeutic classes have been released that tend to be safer and more efficient than their former combinations. Although hepatotoxicity was one of the most common side effects from initial antiretrovirals, phase II/III safety data regarding liver tolerance from more recent drugs are reassuring. However, data on the long-term exposure to these therapeutic options are needed, and a handful of case reports are emerging, reporting rare but potentially life-threatening adverse hepatic events in patients with hepatitis co-infection or taking other hepatotoxic drugs.

Response to raltegravir-based salvage therapy in HIV-infected patients with hepatitis C virus or hepatitis B virus coinfection

OBJECTIVES

To define the impact of coinfection with hepatitis B virus (HBV) or hepatitis C virus (HCV) on viroimmunological response to raltegravir-based salvage regimens that also include new HIV inhibitors such as maraviroc, darunavir and etravirine.

METHODS

We used data from a national observational study of patients starting raltegravir-based regimens to compare virological suppression and CD4 cell change from baseline in patients with and without concomitant HBV or HCV infection.

RESULTS

Overall, 275 patients (107 coinfected and 168 non-coinfected) were evaluated. Coinfected patients were more commonly former intravenous drug users and had a longer history of HIV infection and higher baseline aminotransferase levels. Both HIV-RNA and CD4 response were similar in the two groups. Mean time to first HIV-RNA copy number <50 copies/mL was 4.1 months (95% CI 3.5-4.6) in non-coinfected patients and 3.9 months (95% CI 3.3-4.5) in coinfected patients (hazard ratio 1.039, 95% CI 0.761-1.418, P = 0.766, log-rank test). The risk of developing new grade 3-4 hepatic adverse events was significantly higher in coinfected patients (hazard ratio 1.779, 95% CI 1.123-2.817, P = 0.009). The two groups of coinfected and non-coinfected patients had similar rates of interruption of any baseline drug (hazard ratio 1.075, 95% CI 0.649-1.781, P = 0.776) and of raltegravir (hazard ratio 1.520, 95% CI 0.671-3.447, P = 0.311). Few AIDS-defining events and deaths occurred.

CONCLUSIONS

Viroimmunological response to regimens based on raltegravir and other recent anti-HIV inhibitors is not negatively affected by coinfection with HBV or HCV. Liver toxicity, either pre-existing or new, is more common in coinfected patients, but with no increased risk of treatment interruption.

Anti-retroviral drugs do not facilitate hepatitis C virus (HCV) infection in vitro

An estimated 4 to 5 million people are co-infected with HIV/HCV worldwide. Recently observed outbreaks of acute HCV infection among HIV-positive men who have sex with men (MSM) have been linked to behavioral factors such as high risk sexual practices and recreational drug use. However, at the molecular level, many drugs such as glucocorticoids or cyclosporine A have been found to modulate viral replication. Thus, it is conceivable that drugs used in highly active antiretroviral therapy (HAART) may heighten susceptibility to HCV infection and contribute to the recent outbreaks. We therefore performed a comprehensive screen of antiretroviral drugs covering all available drug classes both individually and in typical combinations used during HAART to probe for direct effects on HCV cell entry, replication, new particle assembly and release. Importantly, no significant enhancement or inhibition of HCV cell entry, replication or new particle production was detected. While raltegravir and ritonavir boosted atazanavir reduce HCV replication, a tenfold reduction of HCVcc entry by the CCR5 antagonist maraviroc was observed. In conclusion, commonly used HAART agents do not specifically enhance HCV replication. Thus recent epidemic outbreaks of acute HCV in HIV-infected MSM are unlikely to be related to enhancing effects of HAART drugs.

96 Week follow-up of HIV-infected patients in rescue with raltegravir plus optimized backbone regimens: a multicentre Italian experience

BACKGROUND

Long term efficacy of raltegravir (RAL)-including regimens in highly pre-treated HIV-1-infected patients has been demonstrated in registration trials. However, few studies have assessed durability in routine clinical settings.

METHODS

Antiretroviral treatment-experienced patients initiating a RAL-containing salvage regimen were enrolled. Routine clinical and laboratory follow-up was performed at baseline, week 4, 12, and every 12 weeks thereafter. Data were censored at week 96.

RESULTS

Out of 320 patients enrolled, 292 (91.25%) subjects maintained their initial regimen for 96 weeks; 28 discontinued prematurely for various reasons: death (11), viral failure (8), adverse events (5), loss to follow-up (3), consent withdrawal (1). Eight among these 28 subjects maintained RAL but changed the accompanying drugs. The mean CD4+ T-cell increase at week 96 was 227/mm(3); 273 out of 300 patients (91%), who were still receiving RAL at week 96, achieved viral suppression (HIV-1 RNA <50 copies/mL). When analyzing the immuno-virologic outcome according to the number of drugs used in the regimen, 2 (n = 45), 3 (n = 111), 4 (n = 124), or >4 (n = 40), CD4+ T-cell gain was similar across strata: +270, +214, +216, and +240 cells/mm(3), respectively, as was the proportion of subjects with undetectable viral load. Laboratory abnormalities (elevation of liver enzymes, total cholesterol and triglycerides) were rare, ranging from 0.9 to 3.1%. The mean 96-week total cholesterol increase was 23.6 mg/dL.

CONCLUSIONS

In a routine clinical setting, a RAL-based regimen allowed most patients in salvage therapy to achieve optimal viral suppression for at least 96 weeks, with relevant immunologic gain and very few adverse events.

[Consensus document of Gesida and Spanish Secretariat for the National Plan on AIDS (SPNS) regarding combined antiretroviral treatment in adults infected by the human immunodeficiency virus (January 2012)]

This consensus document has been prepared by a panel consisting of members of the AIDS Study Group (Gesida) and the Spanish Secretariat for the National Plan on AIDS (SPNS) after reviewing the efficacy and safety results of clinical trials, cohort and pharmacokinetic studies published in medical journals, or presented in medical scientific meetings. Gesida has prepared an objective and structured method to prioritise combined antiretroviral treatment (cART) in naïve patients. Recommendations strength (A, B, C) and the evidence which supports them (I, II, III) are based on a modification of the Infectious Diseases Society of America criteria. The current antiretroviral treatment (ART) of choice for chronic HIV infection is the combination of three drugs. ART is recommended in patients with symptomatic HIV infection, in pregnancy, in serodiscordant couples with high transmission risk, hepatitis B fulfilling treatment criteria, and HIV nephropathy. Guidelines on ART treatment in patients with concurrent diagnosis of HIV infection and an opportunistic type C infection are included. In asymptomatic patients ART is recommended on the basis of CD4 lymphocyte counts, plasma viral load and patient co-morbidities, as follows: 1) therapy should be started in patients with CD4 counts <350 cells/μL; 2) when CD4 counts are between 350 and 500 cells/μL, therapy will be recommended and only delayed if patient is reluctant to take it, the CD4 are stabilised, and the plasma viral load is low; 3) therapy could be deferred when CD4 counts are above 500 cells/μL, but should be considered in cases of cirrhosis, chronic hepatitis C, high cardiovascular risk, plasma viral load >10(5) copies/mL, proportion of CD4 cells <14%, and in people aged >55 years. ART should include 2 reverse transcriptase inhibitors nucleoside analogues and a third drug (non-analogue reverse transcriptase inhibitor, ritonavir boosted protease inhibitor or integrase inhibitor). The panel has consensually selected and given priority to using the Gesida score for some drug combinations, some of them co-formulated. The objective of ART is to achieve an undetectable viral load. Adherence to therapy plays an essential role in maintaining antiviral response. Therapeutic options are limited after ART failures, but an undetectable viral load may be possible nowadays. Adverse events are a fading problem of ART. Guidelines in acute HIV infection, in women, in pregnancy, and to prevent mother-to-child transmission and pre- and post-exposition prophylaxis are commented upon. Management of hepatitis B or C co-infection, other co-morbidities, and the characteristics of ART in HIV-2 infection are included.

Plasma raltegravir exposure influences the antiviral activity and selection of resistance mutations

Raltegravir (RAL) resistance is associated with the selection of integrase mutations at positions 92, 143, 148, and/or 155. A substantial proportion of RAL failures, however, occurs in the absence of these changes. An examination of RAL plasma concentrations may help in interpreting this observation. All early RAL virological failures seen at 22 clinics in Spain during 2009 were identified. HIV integrase sequences and RAL plasma trough concentrations (C(t)) were examined. A total of 106 patients experiencing virological failure on RAL were identified. Only the earliest sample on failure was examined. Integrase sequences could be obtained for 89 (84%), of whom 30 (33.7%) depicted primary RAL resistance mutations (15 N155H, eight Q148H/R, three Y143R, one E92Q, and three more than one of them). Another nine (10.1%) patients showed only secondary changes. The remaining 50 RAL early failures (56.2%) did not select any integrase change. RAL C(t) could be measured in 66 patients at failure and in 21 of them before failure. In a control group of 37 patients with viral suppression on RAL, detectable plasma levels were seen in all cases, with greater median RAL C(t) than in failures, either at the time of viral rebound (p<0.001) or before it (p=0.055). Moreover, median C(t) at the time of failure was greater in patients selecting primary RAL resistance mutations than in the rest of the failures (p<0.001). Undetectable RAL C(t) was seen only in patients failing RAL without integrase resistance mutations (64.1% of them). RAL failures in the absence of integrase resistance mutations mainly reflect poor drug compliance.

Impaired maraviroc and raltegravir clearance in a human immunodeficiency virus-infected patient with end-stage liver disease and renal impairment: a management dilemma

Current product labels for maraviroc and raltegravir provide no dosing guidance for patients with end-stage liver disease and worsening renal function. We describe a 41-year-old man with human immunodeficiency virus (HIV) infection and rapidly progressive liver failure and vanishing bile duct syndrome at presentation. Despite discontinuation of all potential offending drugs, the patient's liver function continued to deteriorate. To achieve and maintain HIV suppression while awaiting liver transplantation, a regimen consisting of maraviroc, raltegravir, and enfuvirtide was started. These agents were chosen because the patient was not exposed to them before the onset of liver failure. While receiving product label-recommended twice-daily dosing of these drugs, he achieved and maintained HIV suppression. During a complicated and prolonged hospitalization, the patient also developed renal dysfunction. As hepatic metabolism is the primary route of clearance of maraviroc and raltegravir, we predicted that using approved doses of these drugs could result in significant drug accumulation. Since the safety profiles of supratherapeutic concentrations of these agents are not well defined, we chose to use therapeutic drug monitoring to guide further dosing. The reported concentrations showed severely impaired metabolic clearance of both drugs, with markedly prolonged elimination half-lives of 189 hours for maraviroc and 61 hours for raltegravir. Previously reported half-lives for maraviroc and raltegravir in HIV-infected patients with normal hepatic and renal function are 14-18 hours and 9-12 hours, respectively. Based on these results, the dosing intervals were extended from twice/day to twice/week for maraviroc and every 48 hours for raltegravir. Unfortunately, the patient's clinical condition continued to deteriorate, and he eventually died of complications related to end-stage liver disease. This case illustrates the difficulties in managing antiretroviral therapy in an HIV-infected patient with combined severe liver and renal failure. Prolonged excessively high exposure to maraviroc and raltegravir is likely to result in some level of concentration-dependent toxicity. Until more data are available, therapeutic drug monitoring remains the only evidence-based approach to optimize dosage selection of these drugs in this patient population.

[Human immunodeficiency virus infection and viral hepatitis]

Hepatic complications currently represent one of the leading reasons for medical consultations, hospitalisation, and death in the HIV-infected population. This is due to a large extent to viral hepatitis, given its disproportionate frequency in this population. Chronic hepatitis B affects 5-10% of the HIV-infected population. Vaccination has reduced the incidence of liver disease related to hepatitis-B virus (HBV), and the availability of tenofovir has dramatically improved the prognosis of HIV/HBV carriers. Delta hepatitis affects around 15% of HIV-infected individuals in Europe harbouring positive HBsAg. It has the worst prognosis, given its accelerated course to cirrhosis and the absence of successful therapy. Lastly, chronic hepatitis C is the major cause of liver disease in the HIV population. Although classically linked to persons infected parenterally (i.e., intravenous drug users), outbreaks of acute hepatitis C among homosexual men have been reported over the last decade. Treatment with pegylated interferon plus ribavirin provides a cure in less than 40% of patients. However, the introduction of new direct acting antivirals against hepatitis- C virus (HCV) (telaprevir, boceprevir) has revolutionised the field, as HAART did in 1996 in the HIV field, improving the prognosis of co-infected patients. However, interactions between these drugs and antiretroviral agents and the risk of selective resistance pose huge threats in this population.

Influence of antiretroviral therapy on liver disease

PURPOSE OF REVIEW

Liver disease is a major cause of morbidity and mortality in HIV-infected persons. The long-term beneficial versus potentially harmful influence of antiretroviral therapy (ART) on the liver is debated. We review current data on factors contributing to liver disease in HIV-monoinfected as well as in HIV/viral hepatitis-coinfected patients, highlighting the role of ART, HIV itself, immunodeficiency, patient characteristics, and lifestyle risk factors.

RECENT FINDINGS

New ART-related clinical syndromes, including noncirrhotic portal hypertension and nonalcoholic fatty liver disease, have emerged, and observational data suggest long-term ART-associated liver injury. Recently, there is increasing evidence that HIV itself and immunosuppression are contributing to liver injury in both HIV-coinfected and HIV-monoinfected patients. In HIV-positive persons, ART attenuates progression of chronic viral hepatitis.

SUMMARY

Current expert guidelines recommend earlier treatment of HIV infection in persons coinfected with hepatitis B virus and possibly hepatitis C virus. It is unknown whether an earlier start of ART is beneficial for the liver in HIV-monoinfected patients. Future research should focus on long-term ART-related hepatotoxicity.

Efficacy and safety of raltegravir in treatment-experienced HIV-1-infected patients switching from enfuvirtide-based regimens: 48 week results of the randomized EASIER ANRS 138 trial

OBJECTIVES

To assess the sustainable efficacy and safety of a switch from enfuvirtide to raltegravir in patients with multidrug-resistant HIV infection.

METHODS

One hundred and seventy patients with multidrug-resistant HIV infection and suppressed plasma HIV RNA levels < 400 copies/mL under an enfuvirtide-based regimen were randomized to maintain their regimen or to switch to a raltegravir-based regimen (immediate group) in a 48 week prospective, randomized, open-label trial. At week 24, patients in the maintenance arm also switched to raltegravir (deferred group). Baseline genotypic susceptibility scores (GSSs) were calculated using available historical resistance tests. Efficacy was assessed by the cumulative proportion of patients with virological failure, defined as a confirmed plasma HIV RNA ≥ 400 copies/mL up to week 48. The EASIER ANRS 138 trial is registered at ClinicalTrials.gov (NCT00454337).

RESULTS

At baseline, 86% of patients had plasma HIV RNA levels <50 copies/mL and 86% had a GSS ≥ 1. Through to week 48, in the on-treatment analysis, only one patient in the immediate group, with a GSS of 0, developed virological failure. At week 48, 90% of patients in both the immediate and deferred groups had plasma HIV-1 RNA levels <50 copies/mL. Median CD4 cell counts remained stable during follow-up. Of note, 12 of 66 (18.2%) patients receiving a regimen combining raltegravir and ritonavir-boosted tipranavir experienced alanine aminotransferase elevations, which led to a switch from tipranavir to darunavir in 8 cases, without discontinuation of raltegravir.

CONCLUSIONS

In well-suppressed patients with multidrug-resistant HIV infection, a switch from enfuvirtide to raltegravir is generally well tolerated and has sustained antiviral efficacy when combined with a potent background regimen.

Antiretroviral treatment interruption leads to progression of liver fibrosis in HIV-hepatitis C virus co-infection

OBJECTIVE

Despite potential negative consequences, HIV/hepatitis C virus (HCV) co-infected patients may discontinue antiretroviral treatment (ART) for several reasons. We examined the impact of ART interruption on liver fibrosis progression in co-infected adults, using the aspartate aminotransferase-to-platelet ratio index (APRI) as a surrogate marker of liver fibrosis.

METHOD

Data were analyzed from a multisite prospective cohort of 541 HIV-HCV co-infected adults. ART interruption was included as a time-updated variable and defined as the cessation of all antiretrovirals for at least 14 days. The primary endpoint was the development of an APRI score at least 1.5. Time-dependent Cox proportional hazards regression and inverse probability-of-treatment weighting (IPTW) in a marginal structural model were used to evaluate the association of baseline and time-varying covariates with developing significant fibrosis.

RESULTS

Patients were followed for a median of 1.02 years; 10% (n = 53) interrupted ART and 10% (n = 53) developed significant fibrosis. After accounting for potential confounders, including CD4 T-cell count, HIV viral load, baseline APRI score, age and gender, the hazard ratio for ART interruption was 2.52 (95% confidence interval 1.20-5.28). Use of IPTW resulted in a similar effect estimate, suggesting that mediation by time-varying confounders was negligible.

CONCLUSION

ART interruption was associated with an increased risk of fibrosis progression in HIV-HCV co-infection that was only partially accounted for by HIV viral load and CD4 T-cell counts. Our findings suggest that liver disease progression observed in ART-treated co-infected patients is partly due to the consequences of treatment interruptions.

Liver tolerance of raltegravir-containing antiretroviral therapy in HIV-infected patients with chronic hepatitis C

OBJECTIVES

To evaluate the liver safety of raltegravir-including combinations in HIV/hepatitis C virus (HCV) co-infected patients.

METHODS

Grade 3-4 transaminase elevations (TEs) and grade 4 total bilirubin elevations (TBEs) were assessed during 12 months in 108 HIV/HCV co-infected patients starting antiretroviral therapy including raltegravir in a retrospective cohort study. Furthermore, the relationship between baseline fibrosis and hepatotoxic events was determined.

RESULTS

Eight patients (7.4%) developed grade 3 TEs and two (1.9%) patients showed grade 4 TEs. TBE grade 4 was detected in two (1.9%) patients. No patient permanently discontinued raltegravir because of hepatotoxic events. Of the patients with and without significant fibrosis, six (9.4%) and two (11.8%), respectively, showed grade 3-4 TEs (P = 0.769). Grade 3-4 TEs was observed in four (9.8%) patients in whom cirrhosis was ruled out, while none of the patients diagnosed with cirrhosis developed grade 3-4 TEs (P = 0.303). During the follow-up, the median (Q1-Q3) CD4 cell count increased from 257 (145-421) cells/mm(3) to 407 (213-587) cells/mm(3) (P < 0.0001) and the number of patients with an undetectable HIV viral load augmented from 33 (30.6%) to 73 (81.1%) (P = 0.002).

CONCLUSIONS

Raltegravir-containing regimens are safe in HIV/HCV co-infected patients. The incidence of severe liver toxicity of raltegravir in these individuals is in the range of boosted protease inhibitors in clinical trials. The frequencies of grade 3-4 TEs and grade 4 TBEs were similar in patients receiving raltegravir with or without significant fibrosis or cirrhosis.

Predicting and preventing acute drug-induced liver injury: what's new in 2010?

IMPORTANCE OF THE FIELD

The field of drug-induced liver injury (DILI) continues to expand in terms of global registries and with new agents added every year. Given the need to improve on our current methods of preclinical testing and monitoring for DILI during both clinical trials and in the post-approval setting, there is increasing research aimed at better understanding why injury occurs and who is most susceptible. To this end, the active pursuit of biomarkers that will predict injury prior to its occurrence and genetic testing that can identify individuals at risk of DILI continue to be at the forefront.

AREAS COVERED IN THIS REVIEW

While alanine aminotransferase (ALT) testing remains the workhorse of biochemical monitoring, it only detects hepatic injury after it has occurred and, therefore, is not a true predictor. The utility and shortcomings of ALT and other liver tests are reviewed along with a synopsis of several other candidate biomarkers that are being studied. In addition, we review the recent data supporting testing for genetic predisposition to DILI and how identifying clinical risk factors may translate into better means for preventing DILI.

WHAT THE READER WILL GAIN

We update the basis on which age and gender are considered risk factors for DILI, and review the latest reports detailing the association of several candidate genes and the development of DILI in a susceptible patient. Human leukocyte antigen-B*5701 is closely linked to the hypersensitivity reaction seen with abacavir, and such screening has been successfully incorporated into HIV treatment around the globe and offers the promise that testing for other genetic markers will soon become a routine part of clinical practice. At present, candidate genes conferring specific susceptibility to DILI have been identified for a relatively few agents (e.g., flucloxacillin, amoxicillin-clavulanate, ximelagatran and isoniazid), but many more are under study. Preventing DILI often comes down to avoiding the use of potentially hepatotoxic drugs in certain situations, and we review the clinical scenarios in which this is most relevant.

TAKE HOME MESSAGE

Given the number and range of studies aimed at identifying predictors of DILI, the focus of this review is to summarize what we consider to be the most relevant new information published on the topics of clinical and genetic factors that predispose to DILI, the use of biomarkers as predictors of acute DILI, along with advances in prevention strategies.

Clinical syndromes and consequences of antiretroviral-related hepatotoxicity

Highly active antiretroviral therapy (HAART)-related hepatotoxicity complicates the management of patients infected with human immunodeficiency virus (HIV), increases medical costs, alters the prescription patterns, and affects the guideline recommendations. Among the clinical consequences derived from HAART-related liver toxicity, hypersensitivity reactions and lactic acidosis are recognized as acute events with potential to evolve into fatal cases, whereas there seems to be other syndromes not as well characterized but of equal concern as possible long-term liver complications. Belonging to the latter category of syndrome, HAART-related nonalcoholic steatohepatitis, liver fibrosis, portal hypertension, and nodular regenerative hyperplasia are discussed in this review. Updated information on liver toxicity of current antiretroviral drugs, including the most recently licensed, is provided. Management and prevention of liver toxicity among HIV-infected patients treated with HAART are reviewed as well.

Development of fatal acute liver failure in HIV-HBV coinfected patients

Coinfection with hepatitis B virus (HBV) is not uncommon in human immunodeficiency virus (HIV)-infected individuals and patients with HIV-HBV coinfection are at high risk for progression of liver disease. Current guidelines regarding the treatment of HIV infection recommend that patients who are coinfected with HIV and HBV receive highly active antiretroviral therapy (HAART) with activity against hepatitis B. While HIV-HBV coinfected patients often experience liver enzyme elevations after starting antiretroviral therapy, acute liver failure (ALF) is rare and typically occurs with older antiretroviral agents with known potential for hepatotoxicity. We describe two cases of fatal ALF in the setting of HIV-HBV coinfection after initiation of HAART. These cases occurred despite treatment with antiretrovirals that have activity against HBV and highlight the challenges in distinguishing drug hepatotoxicity and HBV immune reconstitution inflammatory syndrome. HIV-HBV coinfected patients should be monitored closely when initiating HAART, even when treatment includes agents that have activity against HBV.