Transmission of HIV Drug Resistance and the Predicted Effect on Current First-line Regimens in Europe

Transmitted human immunodeficiency virus drug resistance in Europe is stable at around 8%. The impact of baseline mutation patterns on susceptibility to antiretroviral drugs should be addressed using clinical guidelines. The impact on baseline susceptibility is largest for nonnucleoside reverse transcriptase inhibitors.

Background. Numerous studies have shown that baseline drug resistance patterns may influence the outcome of antiretroviral therapy. Therefore, guidelines recommend drug resistance testing to guide the choice of initial regimen. In addition to optimizing individual patient management, these baseline resistance data enable transmitted drug resistance (TDR) to be surveyed for public health purposes. The SPREAD program systematically collects data to gain insight into TDR occurring in Europe since 2001.

Methods. Demographic, clinical, and virological data from 4140 antiretroviral-naive human immunodeficiency virus (HIV)–infected individuals from 26 countries who were newly diagnosed between 2008 and 2010 were analyzed. Evidence of TDR was defined using the WHO list for surveillance of drug resistance mutations. Prevalence of TDR was assessed over time by comparing the results to SPREAD data from 2002 to 2007. Baseline susceptibility to antiretroviral drugs was predicted using the Stanford HIVdb program version 7.0.

Results. The overall prevalence of TDR did not change significantly over time and was 8.3% (95% confidence interval, 7.2%–9.5%) in 2008–2010. The most frequent indicators of TDR were nucleoside reverse transcriptase inhibitor (NRTI) mutations (4.5%), followed by nonnucleoside reverse transcriptase inhibitor (NNRTI) mutations (2.9%) and protease inhibitor mutations (2.0%). Baseline mutations were most predictive of reduced susceptibility to initial NNRTI-based regimens: 4.5% and 6.5% of patient isolates were predicted to have resistance to regimens containing efavirenz or rilpivirine, respectively, independent of current NRTI backbones.

Conclusions. Although TDR was highest for NRTIs, the impact of baseline drug resistance patterns on susceptibility was largest for NNRTIs. The prevalence of TDR assessed by epidemiological surveys does not clearly indicate to what degree susceptibility to different drug classes is affected.

Impact of hyperglycaemia and cholesterol levels on the outcome of hepatitis C virus (HCV) treatment in HIV/HCV-coinfected patients

OBJECTIVES

High serum total cholesterol and low-density lipoprotein (LDL) levels have been demonstrated to increase the probability of a sustained viral response (SVR) in chronic hepatitis C. Conversely, insulin resistance reduces SVR rates. We investigated the influence of baseline glucose and lipid values on the outcome of hepatitis C virus (HCV) treatment in HIV-1 infected subjects.

METHODS

We retrospectively reviewed the charts of HIV/HCV-coinfected patients treated with an interferon-based regimen from 2002 to 2008. Fasting glucose levels and total cholesterol, LDL and triglyceride levels were recorded prior to the initiation of treatment.

RESULTS

Of the 96 patients enrolled in the study, 36 (37.5%) had genotype 1, 48 (50%) genotype 2 or 3 and 12 (12.5%) genotype 4. SVR was obtained in 25% (nine of 36) and 70% (42 of 60) of patients with genotype 1 and other genotypes, respectively. In the multivariate analysis, the independent predictors of SVR were: genotype other than genotype 1 [adjusted odds ratio 9.64, confidence interval (CI) 2.7-34.3; P<0.0001], HCV viraemia [adjusted odds ratio 0.36, CI 0.15-0.9; P=0.028], fasting glucose > or =100 mg/dL [adjusted odds ratio 0.13, CI 0.034-0.51; P=0.003], and cholesterol level > or =190 mg/dL [adjusted odds ratio 5.96, CI 1.6-22.3; P=0.008].

CONCLUSIONS

Higher baseline serum glucose and cholesterol levels may be significant prognostic indicators for anti-HCV treatment outcome in HIV/HCV-coinfected patients.

Changing patterns in HIV-1 non-B clade prevalence and diversity in Italy over three decades

BACKGROUND

HIV-1 non-B subtypes have recently entered Western Europe following immigration from other regions. The distribution of non-B clades and their association with demographic factors, over the entire course of the HIV-1 epidemic, have not been fully investigated in Italy.

METHODS

We carried out a phylogenetic analysis of HIV-1 pol sequences derived from 3670 patients followed at 50 Italian clinical centres over nearly three decades.

RESULTS

Overall, 417 patients (11.4%) carried non-B subtypes. The prevalence of non-B strains increased from 2.6% in 1980-1992 to 18.9% in 1993-2008 (P<0.0001) in a subset of 2479 subjects with a known year of diagnosis. A multivariate analysis on a subset of 1364 patients for whom relevant demographic data were available indicated that African ethnicity, heterosexual route of infection and year of diagnosis were independently associated with non-B HIV-1 infection (P ≤ 0.0001). All pure subtypes, except for clade K, and seven circulating recombinant forms were detected, accounting for 56.6 and 34.1% of the non-B infections, respectively. The F1 subtype was the most prevalent non-B clade among Europeans and was acquired heterosexually in half of this patient population. Unique recombinant forms accounted for 9.4% of the non-B sequences and showed a B/F1 recombination pattern in one-third of cases.

CONCLUSIONS

The circulation of non-B clades has significantly increased in Italy in association with demographic changes. Spread of the F1 subtype and B/F recombinants appears to predominate, which may result in a redistribution of the relative proportions of the different strains, and this could lead to overlapping epidemics. Thus, the HIV-1 landscape in Italy may in future be distinct from that of the rest of Europe.

Does fluvastatin favour HCV replication in vivo? A pilot study on HIV-HCV coinfected patients

Fluvastatin showed anti-hepatitis C virus (HCV) activity in vitro, through the inhibition of geranylgeranylation of cellular proteins, and a synergistic effect with interferon (IFN)-alpha. Nevertheless statins up-regulate low-density lipoprotein (LDL) receptor, required for HCV cell entry, and the closely related scavenger receptors SRBI and CD36; moreover they reduce class II major histocompatibility complex expression on antigen presenting cell, modulating T-cell activation. In vivo LDL levels have been identified as prognostic indicator of sustained viral response to IFN in patients with HCV infection, suggesting that lipid-lowering agents might conversely favour HCV entry into the hepatocytes and translate into higher viral replication. We evaluated the effect of fluvastatin on HCV-RNA levels, CD36 expression and T-cell homeostasis in HCV-RNA positive patients. HCV-RNA was measured at baseline and after 4 weeks in 42 HCV/HIV-1 co-infected patients, randomized to receive either fluvastatin 80 mg qd or no treatment. CD36 expression and markers of T-cell activation were evaluated by means of flow cytometry. Plasma interleukin (IL)-10, IFN-gamma and IL-7 were measured by ELISA. Serum cholesterol and LDL decreased significantly in the treatment group (P = 0.0001 and 0.01, respectively). Surprisingly a significant increase of HCV-RNA levels was seen after 4 weeks of fluvastatin (P = 0.03). The percentages of naive/activated/apoptotic cells and CD36 expression remained unchanged. Fluvastatin did not inhibit HCV-RNA replication in vivo; conversely we observed a significant increase of HCV-RNA levels. CD36 expression on monocytes were not up-regulated by statins as previously reported in vitro. The correlation between HCV infectivity, oxidized-LDL receptor and statins in HCV infection need further evaluation.

Does fluvastatin favour HCV replication in vivo? A pilot study on HIV-HCV coinfected patients

Fluvastatin showed anti-hepatitis C virus (HCV) activity in vitro, through the inhibition of geranylgeranylation of cellular proteins, and a synergistic effect with interferon (IFN)-alpha. Nevertheless statins up-regulate low-density lipoprotein (LDL) receptor, required for HCV cell entry, and the closely related scavenger receptors SRBI and CD36; moreover they reduce class II major histocompatibility complex expression on antigen presenting cell, modulating T-cell activation. In vivo LDL levels have been identified as prognostic indicator of sustained viral response to IFN in patients with HCV infection, suggesting that lipid-lowering agents might conversely favour HCV entry into the hepatocytes and translate into higher viral replication. We evaluated the effect of fluvastatin on HCV-RNA levels, CD36 expression and T-cell homeostasis in HCV-RNA positive patients. HCV-RNA was measured at baseline and after 4 weeks in 42 HCV/HIV-1 co-infected patients, randomized to receive either fluvastatin 80 mg qd or no treatment. CD36 expression and markers of T-cell activation were evaluated by means of flow cytometry. Plasma interleukin (IL)-10, IFN-gamma and IL-7 were measured by ELISA. Serum cholesterol and LDL decreased significantly in the treatment group (P = 0.0001 and 0.01, respectively). Surprisingly a significant increase of HCV-RNA levels was seen after 4 weeks of fluvastatin (P = 0.03). The percentages of naive/activated/apoptotic cells and CD36 expression remained unchanged. Fluvastatin did not inhibit HCV-RNA replication in vivo; conversely we observed a significant increase of HCV-RNA levels. CD36 expression on monocytes were not up-regulated by statins as previously reported in vitro. The correlation between HCV infectivity, oxidized-LDL receptor and statins in HCV infection need further evaluation.