Characterization of Free Phenytoin Concentrations in End-Stage Renal Disease Using the Winter-Tozer Equation.

BACKGROUND: The Winter-Tozer (WT) equation has been shown to reliably predict free phenytoin levels in healthy patients. In patients with end-stage renal disease (ESRD), phenytoin-albumin binding is altered and, thus, affects interpretation of total serum levels. Although an ESRD WT equation was historically proposed for this population, there is a lack of data evaluating its accuracy. OBJECTIVE: The objective of this study was to determine the accuracy of the ESRD WT equation in predicting free serum phenytoin concentration in patients with ESRD on hemodialysis (HD). METHODS: A retrospective analysis of adult patients with ESRD on HD and concurrent free and total phenytoin concentrations was conducted. Each patient's true free phenytoin concentration was compared with a calculated value using the ESRD WT equation and a revised version of the ESRD WT equation. RESULTS: A total of 21 patients were included for analysis. The ESRD WT equation produced a percentage error of 75% and a root mean square error of 1.76 µg/mL. Additionally, 67% of the samples had an error >50% when using the ESRD WT equation. A revised equation was found to have high predictive accuracy, with only 5% of the samples demonstrating >50% error. CONCLUSION: The ESRD WT equation was not accurate in predicting free phenytoin concentration in patients with ESRD on HD. A revised ESRD WT equation was found to be significantly more accurate. Given the small study sample, further studies are required to fully evaluate the clinical utility of the revised ESRD WT equation.

Faldaprevir and deleobuvir for HCV genotype 1 infection.

BACKGROUND: Interferon-free regimens would be a major advance in the treatment of patients with chronic hepatitis C virus (HCV) infection. METHODS: In this phase 2b, randomized, open-label trial of faldaprevir (a protease inhibitor) and deleobuvir (a nonnucleoside polymerase inhibitor), we randomly assigned 362 previously untreated patients with HCV genotype 1 infection to one of five groups: faldaprevir at a dose of 120 mg once daily and deleobuvir at a dose of 600 mg three times daily, plus ribavirin, for 16, 28, or 40 weeks (TID16W, TID28W, or TID40W, respectively); faldaprevir at a dose of 120 mg once daily and deleobuvir at a dose of 600 mg twice daily, plus ribavirin, for 28 weeks (BID28W); or faldaprevir at a dose of 120 mg once daily and deleobuvir at a dose of 600 mg three times daily, without ribavirin, for 28 weeks (TID28W-NR). The primary end point was a sustained virologic response 12 weeks after the completion of therapy. RESULTS: The primary end point was met in 59% of patients in the TID16W group, 59% of patients in the TID28W group, 52% of patients in the TID40W group, 69% of patients in the BID28W group, and 39% of patients in the TID28W-NR group. The sustained virologic response 12 weeks after the completion of therapy did not differ significantly according to treatment duration or dosage among ribavirin-containing regimens. This response was significantly higher with TID28W than with TID28W-NR (P=0.03). Rates of a sustained virologic response 12 weeks after the completion of therapy were 56 to 85% among patients with genotype 1b infection versus 11 to 47% among patients with genotype 1a infection and 58 to 84% among patients with IL28B CC versus 33 to 64% with non-CC genotypes. Rash, photosensitivity, nausea, vomiting, and diarrhea were the most common adverse events. CONCLUSIONS: The rate of a sustained virologic response 12 weeks after the completion of therapy was 52 to 69% among patients who received interferon-free treatment with faldaprevir in combination with deleobuvir plus ribavirin. (Funded by Boehringer Ingelheim; SOUND-C2 ClinicalTrials.gov number, NCT01132313.).

Differential regulation of cytotoxicity pathway discriminating between HIV, HCV mono- and co-infection identified by transcriptome profiling of PBMCs.

BACKGROUND: Despite the easy accessibility and diagnostic utility of PBMCs and their potential to show distinct expression patterns associated with the accelerated disease progression in HIV/HCV co-infection, there has not been a systematic study focusing on the global dysregulations of the biological pathways in PBMCs from HIV, HCV mono- and co-infected individuals. This study aimed at identifying the transcriptome distinctions of PBMCs between these patient groups. METHODS: Genome-wide transcriptomes of PBMCs from 10 HIV/HCV co-infected patients, 7 HIV+ patients, 5 HCV+ patients, and 5 HIV/HCV sero-negative healthy controls were analyzed using Illumina microarray. Pairwise comparisons were performed to identify differentially expressed genes (DEGs), followed by gene set enrichment analysis (GSEA) to detect the global dysregulations of the biological pathways between HIV, HCV mono- and co-infection. RESULTS: Forty-one, 262, and 44 DEGs with fold change > 1.5 and FDR (false discovery rate) <0.05 for the comparisons of HCV versus co-infection, HIV versus co-infection, and HIV versus HCV were identified, respectively. Significantly altered pathways (FDR < 0.05), featured by those involved in immune system, signaling transduction, and cell cycle, were detected. Notably, the differential regulation of cytotoxicity pathway discriminated between HIV, HCV mono- and co-infection (up-regulated in the former versus the latter group: co-infection versus HIV or HCV, HIV versus HCV; FDR <0.001 ~ 0.019). Conversely, the cytokine-cytokine receptor interaction pathway was down-regulated in co-infection versus either HCV (FDR = 0.003) or HIV (FDR = 0.028). For the comparison of HIV versus HCV, the cell cycle (FDR = 0.016) and WNT signaling (FDR = 0.006) pathways were up- and down-regulated in HIV, respectively. CONCLUSIONS: Our study is the first to identify the differential regulation of cytotoxicity pathway discriminating between HIV, HCV mono- and co-infection, which may reflect the distinct patterns of virus-host cell interactions underlying disease progression. Further inspection of cytotoxicity pathway has pinned down to the expression of the KIR genes to be associated with specific patterns of particular virus-host interactions. Between HIV and HCV, the altered cell cycle and WNT signaling pathways may suggest the different impact of HIV and HCV on cell proliferation and differentiation.

Hepatitis C seroconversions in HIV infection across Europe: which regions and patient groups are affected?

BACKGROUND & AIMS: In the last decade, several outbreaks of sexually acquired acute hepatitis C (HCV) infection have been described in HIV-positive men who have sex with men (MSM). The aims of this study were to determine whether there has been an increase in the number of acute HCV infections in different parts of Europe. METHODS: HCV seroconversion was defined as an HCV-antibody test change from negative to positive within the observation period in EuroSIDA. Binomial regression was performed to determine factors associated with being tested for HCV and HCV seroconversion. RESULTS: A total of 223 HCV seroconversions were observed from 16,188 tests [1.38% (95%CI 1.20-1.56)] among 5736 patients between 2002 and 2013. Overall the odds of acquiring HCV infection increased by 4% per year (OR 1.04 [95%CI 0.99-1.09]; P = 0.10). Overall 63.2% (141/223) of all seroconversions were seen among MSM. Similar patterns were observed across all European regions (P = 0.69, test for interaction) and HIV transmission risks groups (P = 0.69, test for interaction). In multivariate analysis, North, South and East Europe had higher odds of HCV seroconversion compared with Western Europe [OR 1.90 (1.28-2.81), 1.55 (0.99-2.45) and 1.86 (1.21-2.84); P = 0.0014, P = 0.058 and P = 0.0044 respectively]. CONCLUSIONS: Within EuroSIDA a significant increase in HCV seroconversions can be observed after accounting for increased levels of testing for HCV in recent years. This highlights the need for increased HCV prevention efforts among HIV-positive persons in Europe.

Emerging challenges in managing hepatitis B in HIV patients.

Roughly 10 % of HIV-positive individuals worldwide have concomitant chronic hepatitis B virus (HBV) infection, with large differences between geographical regions and/or risk groups. Hepatitis B is a preventable infection with vaccines. However, it cannot be eradicated once acquired, resembling HIV and in contrast with HCV. In developed countries, hepatitis B exhibits particular features in the HIV population. First, HBV infection is less frequently misdiagnosed than in the general population. Second, nucleos(t)ide analogs active against HBV are widely used as part of antiretroviral combinations and are taken by most HIV patients. Lastly, as the HIV population ages given the success of antiretroviral therapy, non-AIDS co-morbidities are becoming a major cause of disease, for which specific drugs are required, increasing the risk of interactions and hepatotoxicity. Furthermore, concern on HBV reactivation is rising as immunosuppressive drug therapies are increasingly been used for cancers and other non-malignant conditions. In this scenario, new challenges are emerging in the management of hepatitis B in HIV-positive individuals. Among them, major interest is focused on failures to suppress HBV replication, HBV breakthroughs and reactivations, the meaning of isolated anti-HBc, screening for liver cancer, and the complexity arising when hepatitis viruses C and/or D are additionally present. This review will focus on these challenges and the major advances in HBV coinfection in HIV.

Hepatitis delta is a major determinant of liver decompensation events and death in HIV-infected patients.

BACKGROUND: Coinfection with hepatitis viruses is common in individuals infected with human immunodeficiency virus (HIV) and has become a leading cause of complications and death in those receiving antiretroviral therapy (ART). METHODS: We retrospectively examined the effect of coinfection with hepatitis B, C, and/or D viruses (HBV, HCV, HDV, respectively) on liver decompensation events (ascites, variceal bleeding, encephalopathy, and/or hepatocellular carcinoma) and liver-related mortality in HIV-positive patients on regular follow-up since the year 2004 at a reference HIV clinic in Madrid, Spain. RESULTS: A total of 1147 HIV-infected patients (mean age, 42 years; 81% males; 46% intravenous drug users, 85.4% on ART) were analyzed. Mean follow-up was 81.2 ± 17.8 months. At baseline, 521 patients (45.4%) were HCV-antibody positive, 85 (7.4%) were hepatitis B surface antigen positive, and 17 (1.5%) were anti-HDV positive. A total of 233 HIV/HCV-coinfected patients received antiviral therapy for HCV, of whom 106 (45%) achieved sustained virologic response (SVR). Overall, 15 patients died of liver-related complications and 26 developed hepatic decompensation events. Taking as controls the 524 HIV-monoinfected patients, HDV coinfection (adjusted hazard ratio [AHR], 7.5; 95% confidence interval [CI], 1.84-30.8; P = .005) and baseline liver stiffness (AHR, 1.1; 95% CI, 1.07-1.13; P < .0001) were associated with a higher rate of liver-related morbidity and mortality. In contrast, SVR following hepatitis C therapy in HIV/HCV-coinfected patients was protective (AHR, 0.11; 95% CI, .01-.86; P = .03). CONCLUSIONS: Hepatitis delta is associated with a high rate of death and liver decompensation events in HIV-infected patients on ART.

Identification of a new epitope for HIV-neutralizing antibodies in the gp41 membrane proximal external region by an Env-tailored phage display library.

HIV controllers are a valuable source for the identification of HIV-neutralizing antibodies, as chronic infection over decades allows extensive affinity maturation of antibodies for improved Ag recognition. We analyzed a small cohort of elite controllers (ECs) for HIV-neutralizing antibodies using a panel of standardized HIV-1 pseudovirions on TZM-bl cells. An HIV-1 Env-tailored phage display library was generated to select epitopes targeted by neutralizing antibodies in the EC26 plasma sample showing the broadest neutralizing activity. Selected Env fragments were mostly allocated to the membrane proximal external region of gp41. After preabsorbing the EC26 plasma with the selected phage EC26-2A4, we achieved 50% depletion of its neutralizing activity. Furthermore, antibodies affinity-purified with the EC26-2A4 epitope from EC26 plasma showed neutralizing activity, proving that the selected phage indeed contains an epitope targeted by neutralizing plasma antibodies. Epitope fine mapping of the purified plasma antibodies on peptide arrays identified a new epitope overlapping, but clearly distinct, from the prominent 2F5 epitope. Of note, the purified antibodies did not show autoreactivity with cardiolipin, whereas low reactivity with phosphatidylserine comparable to mAb 2F5 was observed. Thus, this new epitope represents a promising candidate for further analysis in view of HIV vaccine development.

Combination therapy with telaprevir for chronic hepatitis C virus genotype 1 infection in patients with HIV: a randomized trial.

BACKGROUND: Telaprevir (TVR) plus peginterferon-α2a (PEG-IFN-α2a) and ribavirin substantially increases treatment efficacy for genotype 1 chronic hepatitis C virus (HCV) infection versus PEG-IFN-α2a-ribavirin alone. Its safety and efficacy in patients with HCV and HIV-1 are unknown. OBJECTIVE: To assess the safety and efficacy of TVR plus PEG-IFN-α2a-ribavirin in patients with genotype 1 HCV and HIV-1 and to evaluate pharmacokinetics of TVR and antiretrovirals during coadministration. DESIGN: Phase 2a, randomized, double-blind, placebo-controlled study. (ClinicalTrials.gov: NCT00983853). SETTING: 16 international multicenter sites. PATIENTS: 62 patients with HCV genotype 1 and HIV-1 who were HCV treatment-naive and receiving 0 or 1 of 2 antiretroviral regimens were randomly assigned to TVR plus PEG-IFN-α2a-ribavirin or placebo plus PEG-IFN-α2a-ribavirin for 12 weeks, plus 36 weeks of PEG-IFN-α2a-ribavirin. MEASUREMENTS: HCV RNA concentrations. RESULTS: Pruritus, headache, nausea, rash, and dizziness were higher with TVR plus PEG-IFN-α2a-ribavirin during the first 12 weeks. During this period, serious adverse events occurred in 5% (2 in 38) of those receiving TVR plus PEG-IFN-α2a-ribavirin and 0% (0 in 22) of those receiving placebo plus PEG-IFN-α2a-ribavirin; the same number in both groups discontinued treatment due to adverse events. Sustained virologic response occurred in 74% (28 in 38) of patients receiving TVR plus PEG-IFN-α2a-ribavirin and 45% (10 in 22) of patients receiving placebo plus PEG-IFN-α2a-ribavirin. Rapid HCV suppression was seen with TVR plus PEG-IFN-α2a-ribavirin (68% [26 in 38 patients] vs. 0% [0 in 22 patients] undetectable HCV RNA levels by week 4). Two patients had on-treatment HCV breakthrough with TVR-resistant variants. Patients treated with antiretroviral drugs had no HIV breakthroughs; antiretroviral exposure was not substantially modified by TVR. LIMITATION: Small sample size and appreciable dropout rate. CONCLUSION: In patients with HCV and HIV-1, more adverse events occurred with TVR versus placebo plus PEG-IFN-α2a-ribavirin; these were similar in nature and severity to those in patients with HCV treated with TVR. With or without concomitant antiretrovirals, sustained virologic response rates were higher in patients treated with TVR versus placebo plus PEG-IFN-α2a-ribavirin.

Safety and efficacy of dolutegravir in treatment-experienced subjects with raltegravir-resistant HIV type 1 infection: 24-week results of the VIKING Study.

BACKGROUND: Dolutegravir (DTG; S/GSK1349572), a human immunodeficiency virus type 1 (HIV-1) integrase inhibitor, has limited cross-resistance to raltegravir (RAL) and elvitegravir in vitro. This phase IIb study assessed the activity of DTG in HIV-1-infected subjects with genotypic evidence of RAL resistance. METHODS: Subjects received DTG 50 mg once daily (cohort I) or 50 mg twice daily (cohort II) while continuing a failing regimen (without RAL) through day 10, after which the background regimen was optimized, when feasible, for cohort I, and at least 1 fully active drug was mandated for cohort II. The primary efficacy end point was the proportion of subjects on day 11 in whom the plasma HIV-1 RNA load decreased by ≥0.7 log(10) copies/mL from baseline or was <400 copies/mL. RESULTS: A rapid antiviral response was observed. More subjects achieved the primary end point in cohort II (23 of 24 [96%]), compared with cohort I (21 of 27 [78%]) at day 11. At week 24, 41% and 75% of subjects had an HIV-1 RNA load of <50 copies/mL in cohorts I and II, respectively. Further integrase genotypic evolution was uncommon. Dolutegravir had a good, similar safety profile with each dosing regimen. CONCLUSION: Dolutegravir 50 mg twice daily with an optimized background provided greater and more durable benefit than the once-daily regimen. These data are the first clinical demonstration of the activity of any integrase inhibitor in subjects with HIV-1 resistant to RAL.

Hepatitis C therapy: highlights from the 2012 annual meeting of the European Association for the Study of the Liver.

The results from clinical trials testing new direct-acting antivirals (DAAs) for chronic hepatitis C were the major focus of interest at the 2012 annual meeting of the European Association for the Study of the Liver. Besides triple combinations, in which any one of the new DAAs is given along with peginterferon-α/ribavirin, clinical trials exploring interferon-free oral regimens combining several DAAs attracted major attention. The good tolerance, broad hepatitis C virus (HCV) genotype activity, and high resistance barrier of sofosbuvir make this nucleotide analogue one of the most promising DAAs. Among HCV protease inhibitors, the safety, potency, and convenient dosing of simeprevir, asunaprevir, faldaprevir, and ABT-450/r were particularly highlighted. Among NS5A inhibitors, the good performance of daclatasvir encourages further clinical development. Finally, intriguing results were released about the role of interleukin 28B (IL-28B) polymorphisms using interferon-free regimens, indirectly supporting the role of innate immunity for clearing HCV definitively.

Genetic determinants of idiopathic noncirrhotic portal hypertension in HIV-infected patients.

BACKGROUND: Noncirrhotic portal hypertension (NCPH) is a rare but potentially life-threatening complication in patients with human immunodeficiency virus (HIV). Cases of NCPH have been reported in HIV-negative individuals as result of treatment with thiopurines for leukemia or inflammatory bowel disease. Exposure to didanosine, which is also a purine analogue, predisposes to NCPH in the HIV setting. However, it is unclear why NCPH only develops in a small subset of didanosine-treated patients. METHODS: A multicenter, case-control study was conducted to investigate the role of pharmacogenomics in NCPH in HIV patients with prior didanosine exposure. Three controls were chosen for each case, adjusted for sex, age, CD4 counts, plasma HIV-RNA, and site. Tagging 36 single-nucleotide polymorphisms (SNPs) at enzymes involved in the purine metabolism (inosine triphosphatase, 5'-nucleotidase cytosolic-II, purine nucleoside phosphorylase and xanthine oxidase) was performed using SNPlex microarray technology. RESULTS: Eighty individuals were examined; 22 with NCPH and 58 matched controls. Two SNPs at the 5'-nucleotidase gene were associated with NCPH: rs11191561 (48% CG/GG vs 17% CC; P=.003) and rs11598702 (40% CC/CT vs 9% TT; P=.003). SNPs at another 2 loci at the xanthine oxidase gene were also associated with NCPH: rs1429376 (71% AA vs 23% CC/AC; P=.015) and rs1594160 (71% AA vs 23% CC/AC; P=.015). There was a cumulative risk of NCPH for these 4 SNPs: 7%, 26%, 42%, 50%, and 100%, respectively, for 0, 1, 2, 3, or all SNPs (P=.001). CONCLUSIONS: SNPs at the 5'-nucleotidase and xanthine oxidase genes influence the risk of NCPH in HIV patients treated with didanosine.

Does hepatitis C viremia or genotype predict the risk of mortality in individuals co-infected with HIV?

BACKGROUND & AIMS: The influence of HCV-RNA levels and genotype on HCV disease progression is not well studied. The prognostic value of these markers was investigated in HIV/HCV co-infected individuals from the EuroSIDA cohort. METHODS: EuroSIDA is a prospective cohort of 18,295 HIV-1 infected patients in 105 centres across Europe, Israel, and Argentina. All subjects with known HCV antibody (HCVAb) status (n=13,025) were enrolled in the present study. RESULTS: 4044 (31.0%) patients had detectable HCVAb. After adjustment, HCVAb+ patients had an increased incidence of liver-related death (LRD) compared to HCVAb- individuals (IRR 8.90; 95% CI 5.60-14.14, p<0.0001). Information on HCV-RNA was available for 2709 (67.0%) HCVAb+ patients and 2010 (74.2%) were HCV-RNA+. Of 1907 patients with measured HCV genotype, 1008 (52.9%), 62 (3.3%), 567 (29.7%), and 270 (14.2%) were infected with genotype 1, 2, 3 and 4, respectively. Patients with detectable HCV-RNA had similar incidence of non-LRD, but higher incidence of LRD compared to HCVAb+ aviremic patients (adjusted IRR 1.18; 95% CI 0.93-1.50, p=0.17) and (adjusted IRR 2.11; 95% CI 1.30-3.42, p=0.0025), respectively. In patients with HCV viremia, HCV-RNA levels and HCV genotype did not influence the risk of non-LRD or LRD. CONCLUSIONS: HCV seropositive HIV patients had a 9-fold increased risk of LRD compared to patients who were HCV seronegative. Risk of death from any cause or LRD was not influenced by level of HCV viremia or HCV genotype.

Central memory CD4 T cells are associated with incomplete restoration of the CD4 T cell pool after treatment-induced long-term undetectable HIV viraemia.

OBJECTIVES: It is unclear to what extent T cell reconstitution may be possible in HIV-1-infected individuals on continuous successful highly active antiretroviral therapy (HAART). Herein, we analysed distinct phenotypic markers of immune recovery in patients with undetectable viraemia for 8 years, taking as reference untreated patients and healthy controls. METHODS: Seventy-two subjects were examined: 28 HIV-1+ patients on successful long-term HAART, 24 HIV-1+ untreated viraemic patients and 20 age-matched healthy controls. Analysis of naive and memory CD4 and CD8 T cells was combined with measurements of activation status (expression of CD38) and with thymic function (expression of CD31). Statistical significance was determined by non-parametric tests. RESULTS: After long-term HAART, the majority of parameters were normalized compared with age-matched control values, including T cell activation and thymic function. However, absolute counts of naive and central memory CD4 T cells remained below normal levels. The only parameters significantly associated with CD4 counts at the end of follow-up were the pre-HAART CD4 count ( ß ±â€ŠSD = 0.54 ± 0.16, P = 0.003) and the level of CD4 central memory cells at the end of follow-up (ß ± SD = 1.18 ± 0.23, P < 0.0001). Only patients starting HAART with CD4 counts >350 cells/mm(3) reached a complete normalization of CD4 counts. CONCLUSIONS: Even after long-term successful HAART, complete CD4 restoration may be attainable only in patients starting therapy with moderately high CD4 counts, prompting early initiation of antiretroviral therapy. Incomplete CD4 restoration may be associated with a defective restoration of central memory CD4 T cells, a cell subset with a pivotal role in T cell homeostasis.

HIV Gag-specific immune response mediated by double negative (CD3(+)CD4(-)CD8(-)) T cells in HIV-exposed seronegative individuals.

Double negative (DN) T cells are CD3(+), CD4(-), CD8(-) cells with either T-cell receptors (TCR) αß or TCR γδ whose importance on protection against HIV infection is unknown. Since HIV-exposed seronegative individuals correspond to an ideal group in whom correlates of protection are expected, the role of these cells was studied in 13 HIV-serodiscordant couples in a stable relationship and reporting unprotected sexual intercourses. HIV-specific immune responses mediated by DN T-cells were evaluated by measuring intracellular IFNγ and MIP1ß (CCL4) production in response to HIV-Gag peptides. Thirty-five healthy controls not exposed to HIV were tested similarly and used to define a threshold for positive responses. Interestingly, Gag-specific DN T-cell responses were found in 3/13 (23%) HIV-exposed seronegative individuals (Group A), involving both DN/αß(+) and DN/γδ(+) T-cells through MIP1ß and IFNγ production. 4/13 (30%) of partners infected with HIV (Group B) also showed Gag-specific responses but were mediated exclusively by DN/γδ(+) T-cells, mainly through IFNγ production. DN T-cells in Group A individuals can display differential HIV-specific immune responses, which might contribute to the low susceptibility to infection with HIV shown by individuals in Group A.

Scaling up epidemics of acute hepatitis C and syphilis in HIV-infected men who have sex with men in Spain.

BACKGROUND: Outbreaks of acute hepatitis C in HIV-positive men who have sex with men (MSM) are being reported in large cities in western countries along with increasing rates of sexually transmitted diseases. METHODS: All HIV individuals attended at a large outclinic in Madrid within the last 5 years were examined. Incident syphilis was diagnosed based on rapid plasma reagin (RPR) reactivity, being negative previously or showing >4-fold increase. Acute hepatitis C was diagnosed based on HCV antibody seroconversion and/or positive serum HCV-RNA after being negative within the last year. RESULTS: A total of 859 episodes of syphilis and 19 of acute hepatitis C were diagnosed during the study period. Syphilis was recognized in 65/2,094 (3.1%) individuals attended in 2008 and rose up to 261/2,512 (10.4%) in 2012 (P < 0.001). Acute hepatitis C was diagnosed in only one subject in 2008 but rose up to 7 in 2012 (P = 0.12). All 19 HIV patients with acute hepatitis C were MSM. Syphilis was diagnosed concomitantly in seven. All eight individuals who were treated with peginterferon/ribavirin were cured, whereas only one untreated experienced spontaneous clearance (P = 0.004). Two clusters of infections by HCV genotypes 4 and 1a were identified by phylogenetic analyses. CONCLUSIONS: The incidence of acute hepatitis C is low but steadily increasing in HIV-positive MSM in Madrid (<1% yearly), despite the very high rates of syphilis (currently 20% yearly in HIV-positive MSM). Preventive measures for sexually transmitted infections and periodic HCV screening are warranted in this population as treatment of acute hepatitis C is very effective.

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.

Variants in the ITPA gene protect against ribavirin-induced hemolytic anemia in HIV/HCV-coinfected patients with all HCV genotypes.

BACKGROUND: A recent genome-wide association study reported a strong association with a single-nucleotide polymorphism (SNP) in the inosine triphosphate (ITPA) gene and hemolytic anemia in patients infected with hepatitis C virus (HCV) receiving pegylated interferon and ribavirin. We investigate these polymorphisms in a cohort of human immunodeficiency virus (HIV)/HCV-coinfected patients. METHODS: DNA was available for 161 patients with validated outcomes. We analyzed the association between the variants and week 4 hemoglobin reduction. Anemia over the course of therapy, ribavirin (RBV) dose reduction, serum RBV level, and rapid virological response (RVR) and sustained virological response (SVR) were also investigated. Using a candidate gene approach, ITPA variants rs1127354 and rs7270101 were tested using the ABI TaqMan kit. Multivariable models were used to identify predictors of anemia. RESULTS: A significant minority (33%) of patients were predicted to have reduced ITPase activity. The minor allele of each variant was associated with protection against week 4 anemia. In multivariable models only the genetic variants, creatinine, and zidovudine exposure remained significant. ITPase deficiency was not associated with RBV-dose reduction, RVR, or SVR. CONCLUSIONS: This study confirms that polymorphisms in the ITPA gene are associated with protection from RBV-induced anemia in HIV/HCV-coinfected patients but not improved clinical outcomes.

Comparison of high ribavirin induction versus standard ribavirin dosing, plus peginterferon-α for the treatment of chronic hepatitis C in HIV-infected patients: the PERICO trial.

BACKGROUND: Ribavirin (RBV) exposure seems to be critical to maximize treatment response in human immunodeficiency virus (HIV)-positive patients with chronic hepatitis C virus (HCV) infection. METHODS: HIV/HCV-coinfected individuals naive to interferon were prospectively randomized to receive peginterferon-α-2a (180 µg/d) plus either RBV standard dosing (1000 or 1200 mg/d if <75 or ≥ 75 kg, respectively) or RBV induction (2000 mg/d) along with subcutaneous erythropoietin ß (450 IU/kg/wk), both during the first 4 weeks, followed by standard RBV dosing until completion of therapy. Early stopping rules at weeks 12 and 24 were applied in patients with suboptimal virological response. RESULTS: A total of 357 patients received ≥ 1 dose of the study medication. No differences in main baseline characteristics were found when comparing treatment arms. Sustained virological response (SVR) was attained by 160 (45%) patients, with no significant differences between RBV induction and standard treatment arms (SVR in 72 of 169 patients [43%] vs 88 of 188 [47%], respectively). At week 4, undetectable HCV RNA (29% vs 25%) and mean RBV trough concentration (2.48 vs 2.14 µg/mL) were comparable in both arms, whereas mean hemoglobin decay was less pronounced in the RBV induction plus erythropoietin arm than in the RBV standard dosing arm (-1.7 vs -2.3 mg/dL; P < .005). Treatment discontinuation occurred in 91 (25%) patients owing to nonresponse and in 29 (8%) owing to adverse events. HCV relapse occurred in 34 patients (10%). Univariate and multivariate analyses identified HCV genotype 2 or 3 (odds ratio [OR], 10.3; 95% confidence interval [CI], 2.08-50.2; P = .004), IL28B CC variants (OR, 2.92; 95% CI, 1.33-6.41; P = .007), nonadvanced liver fibrosis (OR, 2.27; 95% CI, 1.06-5.01; P = .03), and rapid virological response (OR, 40.3; 95% CI, 5.1-314.1; P < .001) as predictors of SVR. CONCLUSIONS: A 4-week course of induction therapy with high RBV dosing along with erythropoietin does not improve SVR rates in HIV/HCV-coinfected patients. Preemptive erythropoietin might blunt the benefit of RBV overdosing by enhancing erythrocyte uptake of plasma RBV.

Management and treatment of chronic hepatitis C in HIV patients.

Progression to cirrhosis occurs faster whereas response to peginterferon/ribavirin therapy is lower in patients with chronic hepatitis C coinfected with human immunodeficiency virus (HIV), as compared with hepatitis C virus (HCV) monoinfected individuals. The use of antiretroviral therapy may ameliorate poor outcomes in HIV/HCV coinfected patients. However, in the best scenario peginterferon/ribavirin therapy provides cure to 30% of patients harboring HCV genotypes 1 or 4 and to 70% of HCV genotypes 2 or 3 carriers, a rate lower than that seen in HCV monoinfection. Moreover, a substantial proportion of HIV/HCV coinfected patients are not treated due to contraindications, or do not complete therapy due to serious adverse events, or just do not wish to receive such a poorly tolerated medication. For these reasons, the advent of direct acting antivirals (DAA) has been eagerly awaited for treating HIV/HCV coinfected patients. However, new challenges have arisen, including the potential for harmful drug interactions with antiretroviral agents, poor drug adherence due to polymedication, increased risk for selection of drug-resistant HCV mutants, and unaffordable coverage in an environment of economic constraints. The use of noninvasive tools to measure liver fibrosis (i.e., elastometry) and pharmacogenomics (testing for IL28B and perhaps ITPA polymorphisms), along with consideration of early viral kinetics to guide length and drugs needed could help to individualize and improve the cost effectiveness of therapeutic decisions using DAA in HIV-infected patients with chronic hepatitis C.