Exposure to TDF is associated with an increased risk over time of kidney tubular abnormalities in the absence of significant impaired glomerular function. Although long-term consequences of this tubulopathy are unknown, close monitoring of accelerated bone mineral loss and renal insufficiency are warranted. Periodic screening of tubular function parameters should be recommended to patients receiving TDF.

Background Given that peginterferon–ribavirin treatment is poorly tolerated, there is interest in the identification of predictors of response, particularly in HIV/hepatitis C virus (HCV)-coinfected patients that respond less than HCV-monoinfected individuals. A single nucleotide polymorphism (SNP) near the IL28B gene (rs12979860) has been shown to predict treatment response in HCV-monoinfected patients carrying genotype 1. Information is lacking for HIV/HCV-coinfected individuals and/or other HCV genotypes. Methods From 650 HIV/HCV-coinfected patients, we identified those who had completed a course of peginterferon–ribavirin therapy with a validated outcome and available repository DNA. The rs12979860 SNP was examined in a blinded fashion. Results A total of 164 patients were included in the final IL28B genotyping analysis, 90 (55%) of whom achieved sustained virological response (SVR). HCV genotype distribution was as follows: HCV-1 58%, HCV-3 31% and HCV-4 11%. Overall, the SVR rate was higher in patients with CC than in those CT/TT genotypes: 56 of 75 (75%) versus 34 of 89 (38%) (P <0.0001). The effect of the SNP was seen in HCV genotypes 1 and 4 but not in HCV genotype 3 carriers. In the multivariable analysis (odds ratio; 95% confidence interval; P value), the rs12979860 CC genotype was a strong predictor of SVR (3.7; 1.6–8.5; 0.002), independent of HCV genotype 3 (8.0; 3.1–21.0; <0.001), serum HCV-RNA less than 600 000 IU/ml (11.9; 3.8–37.4; <0.001) and lack of advanced liver fibrosis (3.5; 1.4–8.9; 0.009). Conclusion The rs12979860 SNP located near the IL28B gene is associated with HCV treatment response in HIV-infected patients with chronic hepatitis C due to genotypes 1 or 4. Thus, IL28B genotyping should be considered as part of the treatment decision algorithm in this difficult-to-treat population.

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Liver damage may result from multiple factors in HIV-infected patients. The availability of reliable noninvasive tools to measure liver fibrosis has permitted the screening of large patient populations. Cross-sectional study of all consecutive HIV outpatients who underwent examination by transient elastometry (FibroScan) at one HIV reference clinic during 2007. Advanced liver fibrosis (ALF) was defined as hepatic stiffness >9.5 kilopascals, which corresponds to Metavir stages F3-F4 in the liver biopsy. A total of 681 consecutive HIV-infected patients (64% injecting drug users; mean age 43; 78% male; 98% on antiretroviral therapy) had at least one valid FibroScan evaluation. ALF was diagnosed in 215 (32%) of them. In the univariate analysis, ALF was significantly associated with older age, low CD4 counts, chronic hepatitis C, past alcohol abuse, elevated ALT, high triglycerides, low cholesterol, high homeostasis model assessment (HOMA) index and exposure to didanosine and/or stavudine. In a multivariate model (OR, 95% CI), chronic hepatitis C (2.83, 1.57-5.08), past alcohol abuse (2.26, 1.37-3.74), exposure to didanosine and/or stavudine (1.85, 1.14-3.01), high HOMA index (1.25, 1.04-1.51), older age (1.09, 1.05-1.14) and elevated ALT (1.04, 1.03-1.06) remained as independently associated with ALF. Therefore, in addition to chronic hepatitis C and alcohol abuse, insulin resistance and/or exposure to dideoxy-nucleosides may contribute to ALF in HIV-infected patients.

The IL28B rs12979860 CC genotype is associated with a higher prevalence of cirrhosis in HIV-HCV-coinfected patients than CT/TT genotypes, suggesting that IL28B CC carriers may experience a more rapid progression of HCV-related liver fibrosis, perhaps as result of increased liver inflammation. Thus, access to HCV treatment is of utmost importance in IL28B CC carriers, in whom treatment response is better and in whom progression to cirrhosis might occur more rapidly.

The probability of achieving sustained virological response with pegIFN-RBV therapy in HIV-HCV-coinfected patients can be reliably estimated prior to initiation of therapy using an index that includes 4 noninvasive parameters.

The equilibrative nucleoside transporter 1 (ENT1) is the main protein involved in ribavirin cellular uptake. Polymorphisms at the ENT1 gene may influence ribavirin activity as part of hepatitis C virus (HCV) therapy. A retrospective study was conducted in 109 human immunodeficiency virus (HIV)-infected patients who were infected with HCV genotypes 1 or 4 who had received pegylated interferon (pegIFN)-ribavirin. Single nucleotide polymorphisms (SNPs) at the ENT1 gene were examined using TaqMan 5'-nuclease assays. In the study population, allelic frequencies at rs760370 were as follows: A3 (43 [39%] of 109 patients), AG (50 [46%] of 109 patients), and GG (16 [15%] of 109 patients). Achievement of rapid virological response was more frequent in GG carriers than in AA/AG carriers (50% vs 17%, respectively; P = .007). In multivariate analysis, the GG genotype (odds ratio [OR], 15.9; 95% confidence interval [CI], 2.8-92.2; P < .002), a baseline serum HCV-RNA level <600,000 IU/mL (OR, 45.7; 95% CI, 8.7-240.5; P <.001) and a serum ribavirin trough concentration >2.5 μg/mL (OR, 4.8; 95% CI, 1.3-17.1; P < .016) were associated with rapid virological response. When 2 or more of these factors were present, positive and negative predictive values of rapid virological response were 65% and 91%, respectively. In summary, a SNP rs760370A→G at the ENT1 gene influences the chance of rapid virological response to pegIFN-ribavirin therapy in HIV-infected patients with chronic HCV infection due to HCV genotypes 1 or 4, most likely modulating intracellular ribavirin exposure within hepatocytes.

Background: Limited data are available on the use of unboosted atazanavir in combination with nucleoside reverse transcriptase inhibitors (NRTIs) in treatment-experienced HIV-infected patients. Methods: We conducted a multicentre, retrospective study among patients with plasma HIV-1 RNA levels ,50 copies/mL under antiretroviral therapy who switched to unboosted atazanavir+ NRTIs between January 2002 and December 2008. Virological failure during follow-up was defined as a confirmed plasma HIV-1 RNA level .50 copies/mL. Baseline risk factors for virological failure were identified using Cox proportional hazards models. Results: A total of 886 patients were analysed. At baseline, median age was 44 years, 71.5% were males and median CD4 cell count was 490 cells/mm 3. NRTIs used in combination with atazanavir were tenofovir, abacavir and emtricitabine/lamivudine in 36.9%, 44.1% and 94.4% of patients, respectively. Median follow-up was 21 months. The 3 year probability of virological failure was 20.1%. Only a history of virological failure under NRTIs [hazard ratio (HR) 1.63, P ¼0.049] and under protease inhibitors (HR 2.04, P ¼ 0.006) were significantly associated with the risk of virological failure. Among the 431 patients without a prior history of virological failure, the 3 year probability of virological failure was 11.3%, and only hepatitis C virus co-infection (HR 2.25, P ¼ 0.026) and abacavir use (HR 0.43, P ¼ 0.04) were associated with the risk of virological failure. Safety of the switch was satisfactory, with improvement of the lipid profile. Conclusions: In patients with virological suppression and no prior history of virological failure, a switch to unboosted atazanavir in combination with NRTIs is associated with a low probability of virological failure and a good safety profile.