The interaction between antiretroviral agents and tacrolimus in liver and kidney transplant patients

Overcoming barriers and stigma: new frontiers in solid organ transplantation for people with HIV

There is a growing need for solid organ transplantation (SOT) for people living with human immunodeficiency virus (HIV). With the advent of antiretroviral therapy, people living with HIV are experiencing increased life expectancies and are, therefore, developing more comorbidities, including end-stage organ disease. In cases of advanced organ failure, SOT is often the best therapeutic option to improve quality of life and overall survival. As organ shortages persist, transplantation of organs from donors with HIV to recipients with HIV has become a potential therapeutic option. This article first reviews the current state of organ transplantation from donors without HIV to recipients with HIV (HIV D-/R+) by organ and discusses key lessons learned from these transplant trials, including those about drug-drug interactions, rejection, and opportunistic infections. It then explores transplantation from donors with HIV to recipients with HIV (HIV D+/R+), a new frontier. Finally, it investigates challenges of implementation, including public awareness and regulatory requirements, and explores future directions for SOT in people living with HIV.

Bictegravir/emtricitabine/tenofovir alafenamide combination in the management of kidney transplant patients with HIV receiving immunosuppressants

We report here a drug-drug interaction with tacrolimus in a HIV-positive patient with renal transplant, after switch from highly active antiretroviral therapy with boosted protease inhibitors to the combination bictegravir/emtricitabine/tenofovir alafenamide. Although the tacrolimus doses were adapted to take account of the pharmacokinetic interactions with protease inhibitors, a tacrolimus overdosage occurred in the patient nonetheless. Through this case report, we highlight the need to consider a sufficient timeframe of withdrawal of protease inhibitors, which induce a prolonged drug-drug interaction with tacrolimus. To conclude, we purport that the combination bictegravir/emtricitabine/tenofovir alafenamide could be an attractive alternative in the context of transplantation provided a discontinuation of boosted protease inhibitors for more than 48 hours before introducing tacrolimus.

Improved ability to achieve target trough levels with liquid versus capsule tacrolimus in kidney transplant patients with HIV on protease inhibitor- or cobicistat-based regimens

HIV + patients are commonly accepted for kidney transplantation. However, patients on protease inhibitor (PI)- or cobicistat (cobi)-based regimens have trouble achieving optimal tacrolimus (Tac) levels. Our study compared the ability to achieve target levels using liquid versus immediate-release capsule Tac in kidney transplant patients with HIV on PI- or cobi-based regimens. The study included four kidney transplant patients who were converted to liquid Tac due to inability to achieve acceptable drug levels on the capsule formulation. Tac trough levels were analyzed retrospectively to compare target levels before and after conversion. The individual patient time in the therapeutic range (TTR) was calculated using Rosendaal's linear interpolation method, and the difference between before and after conversion TTR was determined. In combined data, 44.63% of all Tac trough levels were within the target range after conversion to liquid Tac compared to 22.07% prior to conversion (P < .001). Furthermore, 3.31% and 7.44% of Tac trough levels were lower than 3 ng/mL or higher than 12 ng/mL, respectively, after conversion compared to 11.72% (P = .0564) and 24.14% (P < .0001) prior to conversion. The overall mean TTR was 45.1% after conversion to liquid Tac compared to 16.2% prior to conversion (P = .097). Finally, the coefficient of variation for Tac trough levels was 42.6 after conversion compared to 56.4 prior to conversion. A significantly improved ability to achieve target trough Tac levels was achieved with liquid Tac extemporaneous versus capsule formulation in kidney transplant patients with HIV taking a PI- or cobi-based regimen.

Clinical outcomes in HIV+/HCV+ coinfected kidney transplant recipients in the pre- and post-direct-acting antiviral therapy eras: 10-Year single center experience

BACKGROUND

Previous studies have demonstrated inferior patient and graft survival following kidney transplant (KT) in HIV+/HCV+ coinfected patients compared to HIV+/HCV- recipients. However, these studies were conducted prior to the availability of direct-acting antiviral (DAA) agents and data in the modern era are lacking.

METHODS

Single center retrospective study of HIV+/HCV+ coinfected KT recipients (2007-2017). Outcomes were assessed for the pre-DAA and post-DAA (ie, after December 2013) eras including 1-year patient survival, death-censored graft survival, and acute rejection; and serious infections (defined as infections requiring admission to the intensive care unit during initial transplant hospitalization or re-admission to the hospital after discharge) within the first 6 months post-transplant.

RESULTS

A total of 13 consecutive HIV+/HCV+ recipients were identified. Median time of post-transplant follow-up was 722 days. Seven patients were transplanted in the DAA era; five of them had anti-HCV Ab+ donors, with two donors being HCV NAT positive; all received DAA therapy, six of them post-transplant (median time from KT to DAA: 83 days; IQR, 54-300). All the patients in the pre-DAA era were on a protease inhibitor-containing ART regimen. One-year patient and death-censored graft survivals were 83% and 67%, respectively, for the patients transplanted in the pre-DAA era, and 100% for both outcomes in the subgroup of patients transplanted in the post-DAA era (P > 0.05). Compared to patients in the post-DAA era, those in the pre-DAA era had higher incidence of serious infections (0 vs 67%; P = 0.02). Acute rejection exclusively occurred in the pre-DAA group (n = 1; 17%).

CONCLUSIONS

Outcomes of HIV+/HCV+ KT recipients, including HIV-/HCV+ to HIV+/HCV+ transplants, in the DAA era were excellent in this small cohort. Larger studies are needed.

Challenges of kidney transplantation in HIV positive recipients

Human immunodeficiency virus (HIV) infection has long been a contraindication to kidney transplantation due to transplant immunosuppression, HIV-associated renal dysfunction, and nephrotoxicity associated with antiretroviral therapy (ART). However, advances in antiretroviral therapies and transplant immunosuppression regimens have allowed patients to successfully undergo kidney transplantation. Emerging data has shown that kidney transplantation may be a viable option for appropriately selected HIV patients with end-stage renal disease (ESRD). In this review, we discuss the indications, immunosuppression protocols, and outcomes of kidney transplantation in HIV patients.

Successful lung transplantation in an HIV seropositive patient with desquamative interstitial pneumonia: a case report

BACKGROUND

Until recently, lung transplantation was not considered in patients with human immunodeficiency virus (HIV). HIV seropositive patients with suppressed viral loads can now expect long-term survival with the advent of highly active antiretroviral therapies (HAART); however, HIV remains a relative contraindication to lung transplantation. We describe, to our knowledge, the first HIV seropositive lung transplant recipient in Canada. We also review the literature of previously reported cases of solid-organ transplantation in patients with HIV with a focus on immunosuppression considerations.

CASE PRESENTATION

A 48-year old man received a bilateral lung transplant for a diagnosis of desquamative interstitial pneumonia (DIP) attributed to cigarette and cannabis smoking. His control of HIV infection pre-transplant was excellent on HAART, and he had no other contraindications to lung transplantation. The patient underwent bilateral lung transplantation using basiliximab, methylprednisolone, and mycophenolate mofetil (MMF) as induction immunosuppression. He was maintained on MMF, prednisone, and tacrolimus thereafter, and restarted his HAART regimen immediately post-operatively. His post-transplant course was complicated by Grade A1 minimal acute cellular rejection, as well as an enterovirus/rhinovirus graft infection. Despite these complications, his functional status and control of HIV infection remain excellent 24 months post-transplant.

CONCLUSIONS

Our patient is one of only several HIV seropositive lung transplant recipients reported globally. With growing acceptance of transplantation in this population, there is a need for clarification of prognosis post-transplantation, as well as optimal immunosuppression regimens for these patients. This case report adds to the recent literature that suggests HIV seropositivity should not be considered a contraindication to lung transplantation, and that post-transplant patients with HIV can be managed safely with basiliximab, tacrolimus, MMF and prednisone.

[Nephrotoxicity of antiretrovirals other than tenofovir]

The remarkable improvement of the outcome of HIV infection came with the price of substantial toxicity of some antiretrovirals. The first molecules used to treat HIV included an important nephrotoxicity. Zalcitabine, stavudine and didanosine can induce severe lactic acidosis. Lactate production is enhanced and the renal capacity to regulate pH is overwhelmed. However, this side effect is not due to a direct dysfunction of the kidneys. Zalcitabine was withdrawn from the market because of this risk. Indinavir, a protease inhibitor, is soluble only in very acidic solutions. Consequently, the small fraction that is excreted in the urine precipitates and can be responsible for uro-nephrolithiasis, leukocyturia, cristalluria, obstructive acute kidney failure, and acute or chronic interstitial nephritis. This is the reason why indinavir is almost not prescribed nowadays, even if it is still marketed. In addition to the direct nephrotoxicity of some antiretrovirals, anti-HIV treatment also includes a toxicity which pathophysiology is not completely elucidated. This nephrotoxicity is the consequence of organ accelerated ageing and of an increased vascular risk. Kidney vascularization (from renal arteries to capillaries) is essential to kidney function and all cardiovascular risks are also renal risks. It is now clearly established that combined antiretroviral treatment increases the vascular risk. A better comprehension of the links between HIV infection, its treatment and very long-term kidney risk is needed to improve the complex management of patients who have now cumulated several decades of HIV infection and treatment with various toxicities.

Kidney Transplantation in HIV-Positive Patients: A Single-Center, 16-Year Experience

Hahnemann University Hospital has performed 120 kidney transplantations in human immunodeficiency virus (HIV)-positive individuals during the last 16 years. Our patient population represents ∼10% of the entire US population of HIV-positive kidney recipients. In our earlier years of HIV transplantation, we noted increased rejection rates, often leading to graft failure. We have established a multidisciplinary team and over the years have made substantial protocol modifications based on lessons learned. These modifications affected our approach to candidate evaluation, donor selection, perioperative immunosuppression, and posttransplantation monitoring and resulted in excellent posttransplantation outcomes, including 100% patient and graft survival at 1 year and patient and graft survival at 3 years of 100% and 96%, respectively. We present key clinical data, including a granular patient-level analysis of the associations of antiretroviral therapy regimens with long-term survival, cellular and antibody-mediated rejection rates, and the causes of allograft failures. In summary, we provide details on the evolution of our approach to HIV transplantation during the last 16 years, including strategies that may improve outcomes among HIV-positive kidney transplantation candidates throughout the United States.

The Times, They are a-Changing: HOPE for HIV-to-HIV Organ Transplantation

HIV-infected persons who achieve undetectable viral loads on antiretroviral therapy currently have near-normal lifespans. Liver disease is a major cause of non-AIDS-related deaths, and as a result of longer survival, the prevalence of end-stage renal disease in HIV is increasing. HIV-infected persons undergoing organ transplantation generally achieve comparable patient and graft survival rates compared to their HIV-uninfected counterparts, despite a nearly threefold increased risk of acute rejection. However, the ongoing shortage of suitable organs can limit transplantation as an option, and patients with HIV have higher waitlist mortality than others. One way to solve this problem would be to expand the donor pool to include HIV-infected individuals. The results of a South Africa study involving 27 HIV-to-HIV kidney transplants showed promise, with 3- and 5-year patient and graft survival rates similar to those of their HIV-uninfected counterparts. Similarly, individual cases of HIV-to-HIV liver transplantation from the United Kingdom and Switzerland have also shown good results. In the United States, HIV-to-HIV kidney and liver transplants are currently permitted only under a research protocol. Nevertheless, areas of ambiguity exist, including streamlining organ allocation practices, optimizing HIV-infected donor and recipient selection, managing donor-derived transmission of a resistant HIV strain, determining optimal immunosuppressive and antiretroviral regimens, and elucidating the incidence of rejection in HIV-to-HIV solid organ transplant recipients.

Successful Treatment of Mitochondrial Toxicity in an HIV-Positive Patient After Liver Transplantation

Liver transplantation in patients infected with the human immunodeficiency virus (HIV) has been increasingly performed with reasonable outcomes; however, medical management of both immunosuppression and antiretroviral therapy can be challenging owing to drug toxicities and interactions. Nucleoside reverse transcriptase inhibitors (NRTIs), a common backbone of highly active antiretroviral therapy (HAART), were the first class of effective antiretroviral drugs developed. NRTIs are commonly used for posttransplant HAART therapy and have a rare but fatal complication of mitochondrial toxicity, manifesting as severe lactic acidosis, hepatic steatosis, and lipoatrophy. Herein, we have reported on the first known successful treatment of severe mitochondrial toxicity secondary to NRTIs in an HIV-infected transplant recipient.

Integrase strand transferase inhibitors: the preferred antiretroviral regimen in HIV-positive renal transplantation

In the era of antiretroviral therapy, people living with HIV/AIDS live longer and are subject to co-morbidities that affect the general population, such as chronic kidney disease. An increasing number of people living with HIV/AIDS with end-stage renal disease are candidates for renal transplantation. Prior experience demonstrated that HIV-positive renal transplant recipients had acceptable survival but graft survival was decreased and rejection rates were increased, possibly due to suboptimal management of immunosuppressive medications in the face of drug interactions with antiretroviral therapy, particularly protease inhibitors and non-nucleoside reverse transcriptase inhibitors. Integrase strand transferase inhibitors are advantageous since they avoid drug-drug interactions with immunosuppressive drugs such as calcineurin inhibitors. We report clinical outcomes of 12 HIV-positive patients who underwent 13 kidney transplantations at our institution between 2000 and 2015. Cumulative survival was 75%, one-year and three-year survival were 100% and 63%. Integrase strand transferase inhibitor-based regimens were used in nine patients, of which eight survived. In patients on integrase strand transferase inhibitor, there was 100% graft survival and two had allograft rejection. In contrast, graft failure occurred in three patients on non-integrase strand transferase inhibitor-based regimens. Based on our study findings and on previously published data, we conclude that integrase strand transferase inhibitor-based therapy, preferably instituted prior to transplantation, is the preferred antiretroviral regimen in HIV-positive renal transplantation.

Update on kidney transplantation in human immunodeficiency virus infected recipients

Improved survival of human immunodeficiency virus (HIV) infected patients with chronic kidney disease following the introduction of antiretroviral therapy resulted in the need to revisit the topic of kidney transplantation in these patients. Large cohort studies have demonstrated favorable outcomes and proved that transplantation is a viable therapeutic option. However, HIV-infected recipients had higher rates of rejection. Immunosuppressive therapy did not negatively impact the course of HIV infection. Some of the immunosuppressive drugs used following transplantation exhibit antiretroviral effects. A close collaboration between infectious disease specialists and transplant professionals is mandatory in order to optimize transplantation outcomes in these patients. Transplantation from HIV⁺ donors to HIV⁺ recipients has been a subject of intense debate. The HIV Organ Policy Equity act provided a platform to research this area further and to develop guidelines. The first HIV⁺ to HIV⁺ kidney transplant in the United States and the first HIV⁺ to HIV⁺ liver transplant in the world were recently performed at the Johns Hopkins University Medical Center.

Treatment of severe non-infectious uveitis in high-risk conditions (Part 2): systemic infections; management and safety issues

INTRODUCTION

Management of patients with severe immune-mediated uveitis requires the use of immunosuppressive (IS) drugs in selected cases. This may be particularly challenging in certain patients with associated conditions, which may increase the risk of side effects or modify guidelines for the use of such drugs. Chronic viral and mycobacterial infections in the setting of non-infectious uveitis create a number of diagnostic but also therapeutic dilemmas to clinicians because they can be exacerbated by IS therapies with detrimental effects.

AREAS COVERED

In this review, we will focus on very specific chronic infections that can be affected by IS therapies: human immunodeficiency virus infection, chronic hepatitis virus infection and tuberculosis. The main aim of this review is to provide an updated and comprehensive practical guide for practitioners regarding the therapeutic decision-making and management of patients with non-infectious uveitis affected by the aforementioned infectious conditions.

EXPERT OPINION

Clinicians should be aware of the risk of viral and mycobacterial reactivation of an underlying infection during IS therapy. However, most of these conditions do not represent an absolute contraindication if one were able to apply an appropriate prior screening and close monitoring of such therapy.

New Hopes for HIV and HCV Coinfection in 2004

An increase in liver-related causes of death in HIV-positive patients who are coinfected with the hepatitis C virus (HCV) has been acknowledged over the last few years, particularly since the mid 1990s, when the natural history of HIV infection started to improve with the use of highly active antiretroviral therapy (HAART). Chronic hepatitis C is very common among HIV-infected patients who were infected through intravenous drugs use or contaminated blood products (e.g., hemophiliacs). The bidirectional interferences between HIV and HCV modify the natural history of both infections. Moreover, interactions between anti-HIV and anti-HCV drugs are of concern, and a lower response to anti-HCV therapy limits its benefit in HIV-coinfected patients. Although a slower HCV RNA decay is seen in coinfected patients after standard therapy is initiated with pegylated interferon plus ribavirin, the stopping rule at week 12 that is recommended for HCV-monoinfected individuals seems to be equally valid in HIV-positive patients. This finding is of great value, because it allows treatment to be offered in the absence of contraindication (e.g., low CD4 count, alcohol abuse, etc.) but discontinued as early as 12 weeks when no chances of cure are predicted, which saves costs and deleterious side effects. HAART therapy seems to temper somehow the negative impact exerted by HIV infection over HCV-related liver fibrosis. Liver transplantation is currently the best option for HIV-infected patients with end-stage liver disease. However, the management of patients on the waiting list and after transplantation carries significant new challenges. New anti-HCV drugs are urgently needed and new strategies with the currently available drugs need to be assessed to reduce the negative impact of hepatitis C in HIV-coinfected individuals.

Changes in clearance, volume and bioavailability of immunosuppressants when given with HAART in HIV-1 infected liver and kidney transplant recipients

Solid organ transplantation in human immunodeficiency virus 1 (HIV)-infected individuals requiring the concomitant use of immunosuppressants (IS) [e.g. cyclosporine (CsA) or tacrolimus (TAC)] and antiretrovirals (ARVs) [e.g. protease inhibitors (PIs) and/or non-nucleoside reverse transcriptase inhibitors (NNRTIs)] is complicated by significant drug interactions. This paper describes the pharmacokinetics of CsA and TAC in 52 patients on both IS and NNRTIs, PIs or combined NNRTIs + PIs, in studies conducted at 2 weeks, 3, 6, 12 and 24 months after transplantation. Cyclosporine and TAC blood concentrations were measured by LC/MS/MS. This multisubject, varied ARV-IS drug combination, longitudinal observational patient study provided a unique opportunity to examine the effect of different ARV drugs on IS pharmacokinetics (PK) by comparing the ratios of parameters over time and between PK parameters. Subjects taking concomitant PIs exhibited increases in CsA and TAC exposure (AUC/dose) due to the increased apparent oral bioavailability and decreased apparent oral clearance. Those subjects taking CsA and concomitant efavirenz (EFV) showed time dependent increases in exposure due to ~30% increases in the apparent oral bioavailability over time as well as a decreased apparent oral clearance, while subjects on TAC and EFV showed time-dependent changes in all PK parameters. The increased bioavailability was not observed in patients on CsA and nevirapine (NVP). These differences between IS drugs and the changes in PK parameters are not easily predicted, illustrating the importance of continued therapeutic drug monitoring in patients on these complex medication regimens. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

Kidney disease in children and adolescents with perinatal HIV-1 infection

Introduction

Involvement of the kidney in children and adolescents with perinatal (HIV-1) infection can occur at any stage during the child's life with diverse diagnoses, ranging from acute kidney injury, childhood urinary tract infections (UTIs), electrolyte imbalances and drug-induced nephrotoxicity, to diseases of the glomerulus. The latter include various immune-mediated chronic kidney diseases (CKD) and HIV-associated nephropathy (HIVAN).

Discussion

The introduction of highly active anti-retroviral therapy (HAART) has dramatically reduced the incidence of HIVAN, once the commonest form of CKD in children of African descent living with HIV, and also altered its prognosis from eventual progression to end-stage kidney disease to one that is compatible with long-term survival. The impact of HAART on the outcome of other forms of kidney diseases seen in this population has not been as impressive. Increasingly important is nephrotoxicity secondary to the prolonged use of anti-retroviral agents, and the occurrence of co-morbid kidney disease unrelated to HIV infection or its treatment. Improved understanding of the molecular pathogenesis and genetics of kidney diseases associated with HIV will result in better screening, prevention and treatment efforts, as HIV specialists and nephrologists coordinate clinical care of these patients. Both haemodialysis (HD) and peritoneal dialysis (PD) are effective as renal replacement therapy in HIV-infected patients with end-stage kidney disease, with PD being preferred in resource-limited settings. Kidney transplantation, once contraindicated in this population, has now become the most effective renal replacement therapy, provided rigorous criteria are met. Given the attendant morbidity and mortality in HIV-infected children and adolescents with kidney disease, routine screening for kidney disease is recommended where resources permit.

Conclusions

This review focuses on the pathogenesis and genetics, clinical presentation and management of kidney disease in children and adolescents with perinatal HIV-1 infection.

Treatment of acute tacrolimus toxicity with phenytoin in solid organ transplant recipients

The pharmacokinetics of tacrolimus are influenced by many factors, including genetic variability, acute infections, liver dysfunction, and interacting medications, which can result in elevated concentrations. The most appropriate management of acute tacrolimus toxicity has not been defined though case reports exist describing the therapeutic use of enzyme inducers to increase tacrolimus metabolism and decrease concentrations. We are reporting on the utilization of phenytoin to assist in decreasing tacrolimus concentrations in a case series of four solid organ transplant recipients with acute, symptomatic tacrolimus toxicity presenting with elevated serum creatinine, potassium, and tacrolimus trough concentrations greater than 30 ng/mL. All four patients had the potential causative agents stopped or temporarily held and were given 300 to 400 mg/day of phenytoin for two to three days. Within three days of beginning phenytoin, all four patients had a decrease in tacrolimus concentration to less than 15 ng/mL, a return to or near baseline creatinine concentration, and lack of phenytoin-related side effects. Therefore, phenytoin appears to be a safe and potentially beneficial treatment option in patients with symptomatic tacrolimus toxicity.

Pharmacokinetic interaction between the hepatitis C virus protease inhibitor boceprevir and cyclosporine and tacrolimus in healthy volunteers

The hepatitis C virus protease inhibitor boceprevir is a strong inhibitor of cytochrome P450 3A4 and 3A5 (CYP3A4/5). Cyclosporine and tacrolimus are calcineurin inhibitor immunosuppressants used to prevent organ rejection after liver transplantation; both are substrates of CYP3A4. This two-part pharmacokinetic interaction study evaluated boceprevir with cyclosporine (part 1) and tacrolimus (part 2). In part 1, 10 subjects received single-dose cyclosporine (100 mg) on day 1, single-dose boceprevir (800 mg) on day 3, and concomitant cyclosporine/boceprevir on day 4. After washout, subjects received boceprevir (800 mg three times a day) for 7 days plus single-dose cyclosporine (100 mg) on day 6. In part 2A, 12 subjects received single-dose tacrolimus (0.5 mg). After washout, they received boceprevir (800 mg three times a day) for 11 days plus single-dose tacrolimus (0.5 mg) on day 6. In part 2B, 10 subjects received single-dose boceprevir (800 mg) and 24 hours later received boceprevir (800 mg) plus tacrolimus (0.5 mg). Coadministration of boceprevir with cyclosporine/tacrolimus was well tolerated. Concomitant boceprevir increased the area under the concentration-time curve from time 0 to infinity after single dosing (AUC(inf) ) and maximum observed plasma (or blood) concentration (C(max) ) of cyclosporine with geometric mean ratios (GMRs) (90% confidence interval [CI]) of 2.7 (2.4-3.1) and 2.0 (1.7-2.4), respectively. Concomitant boceprevir increased the AUC(inf) and C(max) of tacrolimus with GMRs (90% CI) of 17 (14-21) and 9.9 (8.0-12), respectively. Neither cyclosporine nor tacrolimus coadministration had a meaningful effect on boceprevir pharmacokinetics.

CONCLUSION

Dose adjustments of cyclosporine should be anticipated when administered with boceprevir, guided by close monitoring of cyclosporine blood concentrations and frequent assessments of renal function and cyclosporine-related side effects. Administration of boceprevir plus tacrolimus requires significant dose reduction and prolongation of the dosing interval for tacrolimus, with close monitoring of tacrolimus blood concentrations and frequent assessments of renal function and tacrolimus-related side effects.

Outcomes of liver transplant recipients with hepatitis C and human immunodeficiency virus coinfection

Hepatitis C virus (HCV) is a controversial indication for liver transplantation (LT) in human immunodeficiency virus (HIV)-infected patients because of reportedly poor outcomes. This prospective, multicenter US cohort study compared patient and graft survival for 89 HCV/HIV-coinfected patients and 2 control groups: 235 HCV-monoinfected LT controls and all US transplant recipients who were 65 years old or older. The 3-year patient and graft survival rates were 60% [95% confidence interval (CI) = 47%-71%] and 53% (95% CI = 40%-64%) for the HCV/HIV patients and 79% (95% CI = 72%-84%) and 74% (95% CI = 66%-79%) for the HCV-infected recipients (P < 0.001 for both), and HIV infection was the only factor significantly associated with reduced patient and graft survival. Among the HCV/HIV patients, older donor age [hazard ratio (HR) = 1.3 per decade], combined kidney-liver transplantation (HR = 3.8), an anti-HCV-positive donor (HR = 2.5), and a body mass index < 21 kg/m(2) (HR = 3.2) were independent predictors of graft loss. For the patients without the last 3 factors, the patient and graft survival rates were similar to those for US LT recipients. The 3-year incidence of treated acute rejection was 1.6-fold higher for the HCV/HIV patients versus the HCV patients (39% versus 24%, log rank P = 0.02), but the cumulative rates of severe HCV disease at 3 years were not significantly different (29% versus 23%, P = 0.21). In conclusion, patient and graft survival rates are lower for HCV/HIV-coinfected LT patients versus HCV-monoinfected LT patients. Importantly, the rates of treated acute rejection (but not the rates of HCV disease severity) are significantly higher for HCV/HIV-coinfected recipients versus HCV-infected recipients. Our results indicate that HCV per se is not a contraindication to LT in HIV patients, but recipient and donor selection and the management of acute rejection strongly influence outcomes.

Nephrotoxicity of HAART

Highly active antiretroviral therapy (HAART) and other medical therapies for HIV-related infections have been associated with toxicities. Antiretroviral therapy can contribute to renal dysfunction directly by inducing acute tubular necrosis, acute interstitial nephritis, crystal nephropathy, and renal tubular disorders or indirectly via drug interactions. With the increase in HAART use, clinicians must screen patients for the development of kidney disease especially if the regimen employed increases risk of kidney injury. It is also important that patients with chronic kidney disease (CKD) are not denied the best combinations, especially since most drugs can be adjusted based on the estimated GFR. Early detection of risk factors, systematic screening for chronic causes of CKD, and appropriate referrals for kidney disease management should be advocated for improved patient care. The interaction between immunosuppressive therapy and HAART in patients with kidney transplants and the recent endorsement of tenofovir/emtricitabine by the Centers for Disease Control (CDC) for preexposure prophylaxis bring a new dimension for nephrotoxicity vigilance. This paper summarizes the common antiretroviral drugs associated with nephrotoxicity with particular emphasis on tenofovir and protease inhibitors, their risk factors, and management as well as prevention strategies.

Liver transplant outcomes in HIV-infected patients: a systematic review and meta-analysis with synthetic cohort

OBJECTIVES

The relative success of liver transplantation in those with HIV compared to HIV-uninfected individuals remains a point of intense debate. We aimed to evaluate the effectiveness of liver transplantation in HIV-hepatitis co-infected patients using a meta-analysis and individual patient data meta-analysis as a synthetic cohort.

METHODS

We searched MEDLINE via PubMed, EMBASE, Cochrane CENTRAL, AIDSLINE (inception to 2010), AMED, CINAHL, TOXNET, Development and Reproductive Toxicology, Hazardous Substances Databank, Psych-info and relevant conferences. We included cohort studies and individual case-reports evaluating survival of co-infected transplant patients. We abstracted data on cohort and case demographics and outcomes. We pooled cohorts using a random-effects analysis and created a synthetic cohort of cases using individual patient data. We confirmed this with the pooled cohort analysis.

RESULTS

We included 15 cohort studies and 49 case series with individual patient data. At 12 months, 84.4% [95% confidence interval (CI) 81.1-87.8%] of patients had survived. Within the HIV-infected population evaluated, HIV-hepatitis B virus (HBV) co-infection was associated with optimal survival. In an adjusted model, individuals positive for HBV were 8.28 (95% CI 2.26-30.33) times more likely to survive when compared to those without HBV. Further, individuals with an undetectable HIV viral load at the time of transplantation were 2.89 (95% CI 1.41-5.91) times more likely to survive when compared to those with detectable HIV viremia. Hepatitis C virus was not a predictor of patient survival when adjusted for by other key predictors [0.54 (95% CI 0.17-1.80)].

Renal transplantation in HIV-infected patients: 2010 update

The prognosis of human immunodeficiency virus (HIV) infection has improved in recent years with the introduction of antiretroviral treatment. While the frequency of AIDS-defining events has decreased as a cause of death, mortality from non-AIDS-related events including end-stage renal diseases has increased. The etiology of chronic kidney disease is multifactorial: immune-mediated glomerulonephritis, HIV-associated nephropathy, thrombotic microangiopathies, and so on. HIV infection is no longer a contraindication to transplantation and is becoming standard therapy in most developed countries. The HIV criteria used to select patients for renal transplantation are similar in Europe and North America. Current criteria state that prior opportunistic infections are not a strict exclusion criterion, but patients must have a CD4+ count above 200 cells/mm(3) and a HIV-1 RNA viral load suppressible with treatment. In recent years, more than 200 renal transplants have been performed in HIV-infected patients worldwide, and mid-term patient and graft survival rates have been similar to that of HIV-negative patients. The main issues in post-transplant period are pharmacokinetic interactions between antiretrovirals and immunosuppressants, a high rate of acute rejection, the management of hepatitis C virus coinfection, and the high cardiovascular risk after transplantation. More studies are needed to determine the most appropriate antiretroviral and immunosuppressive regimens and the long-term outcome of HIV infection and kidney graft.

Outcome of liver transplantation for haemophilia

BACKGROUND

Prior to routine screening of blood products many patients with haemophilia were infected with hepatitis C virus (HCV) and have subsequently gone on to develop end-stage liver disease (ESLD).

PATIENTS AND METHODS

We report our experience of liver transplantation (LT) in patients with haemophilia that developed ESLD secondary to HCV. Patients transplanted from 1994 to 2008 were identified retrospectively. Patient demographics pre-, intra- and post-operative details and outcome were documented.

RESULTS

A total of 3800 LT were performed of which 13 had haemophilia A, 4 haemophilia B and one factor (F)X deficiency. All patients were male with a median age of 52 years (range 26-59), all were HCV antibody positive, 5 (28%) were human immunodeficiency virus (HIV) positive and 4 (22%) had hepatocellular carcinoma. Median intra-operative blood loss was 4.2 l (range 0.8-12) and all received coagulation factor support peri-operatively. Coagulation was unsupported by 72 h post-operatively in all recipients. Two patients developed complications as a result of post-operative bleeding. At a median follow-up of 90 months, 8 patients have died, including 4 of the 5 patients that were HIV positive. The median survival of patients with and without HIV co-infection was 26 and 118 months, respectively.

CONCLUSION

LT in patients with haemophilia cures the coagulation disorder and in the absence of HIV/HCV co-infection is associated with long-term patient survival.

HIV/HCV-coinfection: which role can new antiretrovirals such as integrase inhibitors play?

End-stage liver disease has become one of the most frequent causes of death in HIV/HCV-coinfected patients. The role of new antiretrovirals in the progression of liver fibrosis has yet to be defined. However with significant toxicities and drug-to-drug interactions of nucleoside reverse transcriptase inhibitors in combination with ribavirin, with drug to drug interaction of HIV protease inhibitors with HCV protease inhibitors and calcineurin-inhibitors, new antiretrovirals lacking these interactions represent attractive alternatives in the setting of anti-HCV therapy or post liver transplantation. In the following review we want to focus on the new class of HIV integrase inhibitors and discuss present data with regard to special issues of HIV and HCV co-infection.

Liver transplantation in HIV-positive patients

Death from end-stage liver disease (ESLD) because of chronic hepatitis B and C has become an increasing problem in human immunodeficiency virus (HIV)-infected patients in the last years. This is mainly because of the dramatic decrease of HIV-related morbidity and mortality since the introduction of highly active antiretroviral therapy (HAART). Although the data on the outcome of liver transplantation in HIV-infected recipients with ESLD is limited, overall results seem comparable to non-HIV-infected recipients. Therefore, liver transplant centres around the world are increasingly accepting HIV-infected individuals as organ recipients. Post-transplantation control of HIV replication is achieved by continuing HAART. As in non-HIV-infected patients, hepatitis B virus recurrence is efficiently prevented by hepatitis B immunoglobulin and antiviral therapy. Re-infection of the allograft with hepatitis C virus, however, remains an important problem, and progress to allograft cirrhosis may even be more rapid than in HIV-negative patients. Interactions in drug metabolism between the HAART components and the immunosuppressive drugs are difficult to predict and require close monitoring of drug levels and dose adjustments. The complexity in this setting makes close cooperation between transplant surgeons, hepatologists, HIV-clinicians and pharmacologists mandatory. As experience on liver transplantation in HIV-infected individuals is still limited, to date results from large prospective trials addressing key issues are needed.

Kidney transplantation in HIV-positive patients: report of our first 7 cases

INTRODUCTION

Infection with human immunodeficiency virus (HIV) is associated with end-stage renal disease (ESRD). Although many teams initially were reluctant to offer kidney transplantation as a therapeutic option in HIV-positive patients with ESRD, new drug regimens introduced in the late 1990s have dramatically improved the life expectancy in these patients.

OBJECTIVE

To report the results of the first 7 kidney transplantation procedures in HIV-positive patients at our institution.

PATIENTS AND METHODS

Patients were selected to minimize the risks of HIV disease progression, opportunistic infections, and tumors. Protease-inhibitor therapies were suspended because of possible interaction with immunosuppression drugs. The induction regimen did not include lymphocyte-depleting drugs. After undergoing transplantation, patients were monitored by the transplantation and infectious disease teams.

RESULTS

To date, all patients are alive with functioning grafts. We did not observe any episodes of acute rejection, and there were few adverse events. Drug tolerance was good for both immunosuppression and antiretroviral therapies.

CONCLUSION

Kidney transplantation in HIV-positive patients with ESRD is warranted. Provided that patients are carefully selected, good results can be achieved with few adverse events, episodes of acute rejection, and drug interactions. Posttransplantation, these patients must be closely monitored by both the transplantation and infectious diseases teams to ensure optimal management.

Renal transplantation in patients with HIV

HIV infection has been a major global health problem for almost three decades. With the introduction of highly active antiretroviral therapy in 1996, and the advent of effective prophylaxis and management of opportunistic infections, AIDS mortality has decreased markedly. In developed countries, this once fatal infection is now being treated as a chronic condition. As a result, rates of morbidity and mortality from other medical conditions leading to end-stage liver, kidney and heart disease are steadily increasing in individuals with HIV. Presence of HIV infection used to be viewed as a contraindication to transplantation for multiple reasons: concerns for exacerbation of an already immunocompromised state by administration of additional immunosuppressants; the use of a limited supply of donor organs with unknown long-term outcomes; and, the risk of viral transmission to the surgical and medical staff. This Review examines open questions on kidney transplantation in patients infected with HIV-1 and clinical strategies that have resulted in good outcomes. It also describes the clinical concerns associated with the treatment of renal transplant recipients with HIV.

Drug interactions in transplant patients: what everyone should know

PURPOSE OF REVIEW

Adverse events due to drug-drug interactions remain a challenge in the postsurgical care of transplant recipients. A combination of potent and selective immunosuppressive drugs, which have a narrow therapeutic index, with medications for the treatment of comorbidities such as dyslipidemia, infection, psychiatric conditions, and hypertension, can lead to life-threatening drug-drug interactions.

RECENT FINDINGS

There are a number of important drug-drug interactions which are important for physicians to consider. It is critical to understand the pharmacodynamics and pharmacokinetics of drug-drug interactions, their potential impact on patient care, and the management strategies.

SUMMARY

Close therapeutic drug monitoring and evaluation of drug-specific side effects continue to be an important key to minimize adverse events due to drug-drug interactions.

Safety and efficacy of raltegravir in HIV-infected transplant patients cotreated with immunosuppressive drugs

Solid organ transplantations (SOT) are performed successfully in selected HIV-infected patients. However, multiple and reciprocal drug-drug interactions are observed between antiretroviral (ARV) drugs and calcineurin inhibitors (CNIs) through CYP450 metabolization. Raltegravir (RAL), a novel HIV-1 integrase inhibitor, is not a substrate of CYP450 enzymes. We retrospectively reviewed the outcomes of 13 HIV-infected transplant patients treated by an RAL + two nucleosidic reverse transcriptase inhibitor (NRTI) regimen, in terms of tolerability, ARV efficacy (plasma viral load, CD4 cell count), drug interactions, RAL pharmacokinetics and transplant outcome. Thirteen patients with liver (n = 8) or kidney (n = 5) transplantation were included. RAL was initiated (400 mg BID) either at time of transplantation (n = 6), or after transplantation (n = 7). Median RAL trough concentration was 507 ng/mL (176-890), which is above the in vitro IC95 for wild type HIV-1 strains (15 ng/mL). Target trough levels of CNIs were promptly obtained with standard dosages of tacrolimus or cyclosporine. RAL tolerability was excellent. There was no episode of acute rejection. HIV infection remained controlled. After a median follow-up of 9 months (range: 6-14), all patients were alive with satisfactory graft function. The use of an RAL + two NRTI-based regimen is a good alternative in HIV-infected patients undergoing SOT.

Hot topics in HIV and hepatitis coinfection: noninvasive diagnosis of liver disease, liver transplantation, and new drugs for treatment of hepatitis coinfection

Although liver biopsy still remains the globally accepted gold standard for assessing liver disease, the more recent introduction of noninvasive markers in form of blood tests as well as transient elastography have led to the development of new algorithms for assessing liver disease in HIV and hepatitis coinfected individuals. Other hot topics in coinfection include need and outcome for liver organ transplantation in the increasing number of HIV-infected patients with end-stage liver disease as well as development of new agents and strategies for treatment of hepatitis B or C coinfection.

Human immunodeficiency virus and liver transplantation: our point of view

INTRODUCTION

Highly active antiretroviral therapy (HAART) has been able to improve the immune system function and survival of HIV patients with a consequent increase in the number of HIV patients affected by end-stage liver disease (ESLD). Between June 2003 and October 2006, 10 HIV-positive patients underwent liver transplantations in our center.

METHODS

All patients were treated with HAART before transplantation; treatment was interrupted on transplantation day and was restarted once the patients' conditions stabilized. Five patients were hepatitis C virus (HCV)-positive, 3 were hepatitis B virus (HBV)-positive, and 2 were HBV-HCV coinfected. HIV viral load before transplantation was <50 copies/mL in all cases. CD4+ cell count before transplantation ranged between 144 and 530 c/microL. Immunosuppression was based on Cyclosporine (CyA) and steroid weaning for 8 patients, and on Tacrolimus and steroid weaning for 2 patients.

RESULTS

Five patients were cytomegalovirus (CMV)-positive pp65 antigenemia posttransplantation, and 1 patient was EBV-positive; 2 patients had a coinfection with HHV6. Four patients suffered from a cholestatic HCV recurrent hepatitis treated with antiviral therapy (peginterferon and Ribavirin). Three patients died after transplantation.

DISCUSSION

The outcome of liver transplantation in HIV patients was influenced by infections (HCV, CMV, and EBV) and Kaposi's Sarcoma. HCV recurrence was more aggressive, showing a faster progression in this patient population. Drug interaction between HAART and immunosuppressants occurs; longer follow-up and better experience may improve the management of these drug interactions.

Drop in trough blood concentrations of tacrolimus after switching from nelfinavir to fosamprenavir in four HIV-infected liver transplant patients

Solid organ transplantation in HIV-infected individuals requires concomitant use of immunosuppressants and antiretrovirals that may cause significant drug interactions. Here we report on a peculiar pharmacokinetic interaction between tacrolimus and protease inhibitors (PIs) which occurred in four HIV-infected liver transplant patients who had to shift PI therapy from nelfnavir to fosamprenavir as a consequence of regulatory restrictions. After the switch, tacrolimus trough blood concentrations significantly dropped in all patients (mean ±sd 6.9 ±2.6 versus 3.2 ±2.0 ng/ml before and after the switch, respectively; P=0.01), so that a marked dosage increase was needed (0.29 ±0.14 versus 0.88 ±0.48 mg/day, 1–3 days before and 3 weeks after the switch, respectively; P=0.046) to attain the desired target (8.7 ±2.3 ng/ ml). Consistently, marked changes of the concentration/dose ratio of tacrolimus were observed in all cases (27.2 ±9.7 ng/ml per mg/kg/day versus 9.7 ±4.0 ng/ml per mg/kg/day before and after the switch, respectively; P<0.001). Our findings suggest that fosamprenavir may be less potent than nelfinavir in inhibiting tacrolimus clearance and support the need for higher tacrolimus dosage to avoid insufficient immunosuppression in HIV-infected liver transplant patients when switching from nelfinavir to fosamprenavir or even when directly starting antiretroviral therapy with fosamprenavir.

Effect of highly active antiretroviral therapy on tacrolimus pharmacokinetics in hepatitis C virus and HIV co-infected liver transplant recipients in the ANRS HC-08 study

OBJECTIVE

To characterise the interactions between tacrolimus and antiretroviral drug combinations in hepatitis C virus-HIV co-infected patients who had received a liver transplant.

DESIGN

An observational, open-label, multiple-dose, two-period, one-sequence design clinical trial in which patients received tacrolimus as an immunosuppressive therapy during the postoperative period and then had an antiretroviral drug regimen added. Tacrolimus pharmacokinetics were evaluated at steady state during these two periods.

METHODS

Fourteen patients participated in the study and seven participated in the intensified pharmacokinetic protocol. Patients were included if they had undergone liver transplantation for end-stage chronic hepatitis C, absence of opportunistic infection, a CD4 cell count of >150 cells/microL and an undetectable HIV plasma viral load (<50 copies/mL) under highly active antiretroviral therapy. During the posttransplantation period, the tacrolimus dose was adjusted according to blood concentrations. When liver function and the tacrolimus dose were stable, antiretroviral therapy was reintroduced.

RESULTS

When lopinavir/ritonavir were added to the tacrolimus regimen (seven patients), the tacrolimus dose was reduced by 99% to maintain the tacrolimus concentration within the therapeutic range. Only two patients were treated with nelfinavir, which led to a wide variation in inhibition of tacrolimus metabolism. When efavirenz (four patients) or a nucleoside analogue combination (one patient) was added, very little change in tacrolimus dosing was required.

CONCLUSION

The lopinavir/ritonavir combination markedly inhibited tacrolimus metabolism, whereas the effect of efavirenz was small. Tacrolimus dosing must be optimised according to therapeutic drug monitoring and the antiretroviral drug combination.

Liver transplantation in HIV-positive patients

This article reviews the worldwide evolution of liver transplantation as a therapeutic intervention in HIV-infected patients. Since the introduction of highly active antiretroviral therapy (HAART), liver disease secondary to viral hepatitis has become a leading cause of morbidity and mortality among HIV-positive individuals. The authors contrast survival data from pilot studies in the pre-HAART era to those data emerging from more recent trials. Particular emphasis is placed on current selection criteria for HIV-positive transplant candidates. Additional consideration is given to the effect of prolonged transplant waiting time on survival outcome. The complexity of the post-transplant medication regime, including drug interactions, optimal immunosuppression and most appropriate HAART regimes, are discussed in detail. Postoperative challenges including optimal management of hepatitis B virus and recurrent hepatitis C virus post-transplant are reviewed separately. The ethical and practical arguments relating to the use of a scarce and valuable resource in this population are debated. The authors conclude with several recommendations to assist pretransplant assessment and postoperative management of such complex patients and speculate on the direction and evolution of this field in the coming years.

Immunosuppressant pharmacokinetics and dosing modifications in HIV-1 infected liver and kidney transplant recipients

Solid organ transplantation in human immunodeficiency virus (HIV)-infected individuals requiring concomitant use of immunosuppressants (IS) (e.g. cyclosporine [CsA], sirolimus [SrL], tacrolimus [FK]) and antiretrovirals (ARVs) (e.g. protease inhibitors [PIs] and/or nonnucleoside reverse transcriptase inhibitors [NNRTIs]) is complicated by significant drug interactions. To assist in appropriate clinical management, we describe the pharmacokinetics and dosing modifications in 35 patients (20 kidney, 13 liver and two kidney-liver HIV-infected subjects with end-stage kidney or liver disease), on both IS and NNRTIs, PIs, and combined NNRTIs + PIs, in studies done at weeks 2-4 and/or 12 weeks after transplantation or after a change in IS or ARV drug regimen (n = 97 studies). CsA, SrL and FK concentrations were measured in whole blood by LC/MS. HIV-infected transplant recipients using PIs with IS had marked increases in CsA, FK or SrL trough levels compared to those on NNRTIs alone or to patients not on ARVs, necessitating either a reduction in dose or an increase in dosing interval. Subjects on efavirenz (EFV) and CsA required much higher doses of CsA than those using any other ARV. Changes in antiretroviral therapy should be carefully managed to avoid insufficient immunosuppression or toxicity due to drug interactions.

Review article: drug hepatotoxicity

BACKGROUND

Drug toxicity is the leading cause of acute liver failure in the United States. Further understanding of hepatotoxicity is becoming increasingly important as more drugs come to market.

AIMS

(i) To provide an update on recent advances in our understanding of hepatotoxicity of select commonly used drug classes. (ii) To assess the safety of these medications in patients with pre-existing liver disease and in the post-liver transplant setting. (iii) To review relevant advances in toxicogenomics which contribute to the current understanding of hepatotoxic drugs.

METHODS

A Medline search was performed to identify relevant literature using search terms including 'drug toxicity, hepatotoxicity, statins, thiazolidinediones, antibiotics, antiretroviral drugs and toxicogenomics'.

RESULTS

Amoxicillin-clavulanic acid is one of the most frequently implicated causes of drug-induced liver injury worldwide. Statins rarely cause clinically significant liver injury, even in patients with underlying liver disease. Newer thiazolidinediones are not associated with the degree of liver toxicity observed with troglitazone. Careful monitoring for liver toxicity is warranted in patients who are taking antiretrovirals, especially patients who are co-infected with hepatitis B and C. Genetic polymorphisms among enzymes involved in drug metabolism and HLA types may account for some of the differences in individual susceptibility to drug hepatotoxicity.

CONCLUSIONS

Drug-induced hepatotoxicity will remain a problem that carries both clinical and regulatory significance as long as new drugs continue to enter the market. Future results from ongoing multicentre collaborative efforts may help contribute to our current understanding of hepatotoxicity associated with drugs.