The role of insulin resistance in HIV/hepatitis C virus-coinfected patients

FTO rs9939609 polymorphism is associated with metabolic disturbances and response to HCV therapy in HIV/HCV-coinfected patients

BACKGROUND

The Fat Mass and Obesity-Associated Protein (FTO) gene rs9939609 single nucleotide polymorphism (SNP) has been associated with obesity, metabolic syndrome, insulin resistance (IR), and type 2 diabetes mellitus in the general population. The aim of our study was to examine for the first time the association of the rs9939609 polymorphism with metabolic disturbances, liver disease and virologic response to hepatitis C virus (HCV) therapy with pegylated-interferon-alpha plus ribavirin (pegIFNα/RBV) in human immunodeficiency virus (HIV)/HCV coinfected patients.

METHODS

We carried out a cross-sectional study in 261 patients, of whom 178 were subsequently treated with pegIFNα/RBV therapy. FTO rs9939609 and IFNL3 rs12980275 polymorphisms were genotyped by GoldenGate®. The main outcomes were: 1) metabolic disturbances: insulin resistance (homeostatic model assessment (HOMA-IR)) and overweight (body mass index (BMI)); 2) liver disease (Metavir score): significant fibrosis (F ≥2) and steatosis (>10% fatty hepatocytes); and 3) virologic response to HCV treatment: sustained virologic response (SVR).

RESULTS

The rs9939609 AA genotype was associated with higher values of BMI (adjusted arithmetic mean ratio (aAMR) = 1.08; 95% confidence interval (95%CI) = 1.03 to 1.14; P = 0.002) and HOMA-IR (aAMR = 1.32; 95%CI = 1.03 to 1.69; P = 0.027). Patients with an rs9939609 AA genotype had higher likelihoods of achieving values of BMI ≥27.5 kg/m2 (adjusted odds ratio (aOR) = 3.46; 95%CI =1.17 to 10.21; P = 0.024), HOMA-IR ≥2.5 (aOR = 2.09; 95%CI = 1.02 to 4.32; P = 0.045), significant fibrosis (aOR = 2.34; 95%CI =1.02 to 5.36; P = 0.045) and steatosis (aOR = 3.65; 95%CI = 1.29 to 10.36; P = 0.015). The rs9939609 AT/AA genotype decreased the likelihood of achieving SVR (aOR = 0.58; 95%CI = 0.34 to 0.99; P = 0.044). A decision tree was performed with the genotypes of HCV, IFNL3 and FTO. The incorporation of rs9939609 significantly improves the prediction of SVR (P <0.05). The overall accuracy was 68.2%.

CONCLUSIONS

Patients carrying the unfavourable AT/AA genotype of rs9939609 polymorphism had higher odds of metabolic disturbances and a lower likelihood of achieving successful virologic response to HCV therapy.

PPARγ2 Pro12Ala polymorphism is associated with sustained virological response in HIV/HCV-coinfected patients under HCV therapy

OBJECTIVES

To analyze whether peroxisome proliferator-activated receptor gamma (PPARγ2) rs1801282 (Pro12Ala) polymorphism is associated with the response to pegylated-interferon-alpha plus ribavirin treatment in HIV/hepatitis C virus (HCV)-coinfected patients, and whether it is able to predict the outcome of HCV treatment.

DESIGN

Retrospective follow-up study.

METHODS

Two hundred eighty-five naive patients, who started HCV-treatment, were genotyped for PPARγ2 and interleukin 28B polymorphisms. Genetic data were analyzed under dominant inheritance model. Sustained virological response (SVR) was defined as undetectable HCV viremia through 24 weeks after the end of HCV treatment.

RESULTS

The variables significantly associated with SVR in a multivariate analysis were HCV-genotype (GT) 3 {adjusted odds ratio [aOR] = 7.66 [95% of confidence interval (95% CI): 3.96 to 14.81] P < 0.001}, HCV-viremia <500,000 IU/mL [aOR = 2.20 (95% CI: 1.16 to 4.15] P = 0.015), no/mild liver fibrosis (F < 2) [aOR = 1.92 (95% CI: 1.08 to 3.42) P = 0.026], IL28B rs12980275 AA genotype [aOR = 2.70 (95% CI: 1.54 to 4.71) P < 0.001], and PPARγ2 rs1801282 CG/GG genotype [aOR = 2.93 (95% CI: 1.27 to 6.72) P = 0.011]. When PPARγ2 rs1801282 genotype was included in a decision tree analysis, HCV-GT3 patients with CG/GG genotype had increased SVR from 80.3% to 100%. In GT1/4 patients, rs12980275 AA carriers had increased SVR from 58.7% to 78.6%, and rs12980275 AG/GG carriers had increased SVR from 28.7% to 35.7%. The overall percentage of patients correctly classified was 71.6% and the area under the receiver operating characteristic curves was 0.766 ± 0.028.

CONCLUSIONS

The presence of PPARγ2 rs1801282 G allele (Ala variant) was associated with increased odds for achieving SVR in HIV/HCV-coinfected patients on HCV treatment.

Revisiting predictors of virologic response to PEGIFN + RBV therapy in HIV-/HCV-coinfected patients: the role of metabolic factors and elevated GGT levels

Evaluation of metabolic factors and elevated γ-glutamyltransferase (GGT) levels as independent predictors of treatment failure in a thoroughly documented cohort of HIV-/HCV-coinfected patients (HIV/HCV). Sixty-four HIV/HCV patients treated with pegylated interferon-α-2a plus ribavirin (PEGIFN + RBV) at the Medical University of Vienna within a prospective trial were included in this study. In addition, 124 patients with HIV/HCV from the AIFA-HIV and AHIVCOS cohorts were included as a validation cohort. Advanced liver fibrosis, GGT elevation, insulin resistance (IR) and low CD4+ nadir were defined as METAVIR F3/F4, GGT levels >1.5× sex-specific upper limit of normal, homoeostasis model assessment of insulin resistance >2 and CD4+ nadir <350 cells/μL, respectively. HCV-genotype 1/4 (OR26.3; P = 0.006), advanced liver fibrosis (OR20.2; P = 0.009), interleukin 28B rs12979860 non-C/C SNP (OR8.27; P = 0.02) and GGT elevation (OR7.97; P = 0.012) were independent predictors of treatment failure, while both IR (OR3.51; P = 0.106) and low CD4 + nadir (OR2.64; P = 0.263) were not independently associated with treatment failure. A statistically significant correlation between GGT elevation and prior alcohol abuse (r = 0.259; P = 0.039), liver steatosis (r = 0.301; P = 0.034) and low-density lipoprotein-cholesterol (r = -0.256; P = 0.041) was observed. The importance of GGT elevation as an independent predictor of treatment failure was confirmed in a validation cohort (OR2.76; P = 0.026). While GGT elevation emerged as an independent predictor of treatment failure in both the derivation and the validation cohort, no independent associations between metabolic factors and treatment failure were observed. Thus, our findings suggest that GGT elevation is an independent predictor of treatment failure in HIV/HCV that can easily be incorporated into predictive algorithms.

Vitamin D deficiency is associated with severity of liver disease in HIV/HCV coinfected patients

OBJECTIVE

To study the association of plasma 25-hydroxy vitamin D (25(OH)D) levels in HIV/HCV coinfected patients with severity of liver disease and virological response to hepatitis C virus (HCV) therapy with pegylated-interferon-alpha plus ribavirin (pegIFNα/RBV).

METHODS

A cross-sectional study in 174 HIV/HCV coinfected patients that underwent a liver biopsy previously to start HCV therapy and a retrospective study of 125 of them. Plasma 25(OH)D levels were quantified by enzyme immunoassay. Liver biopsies were evaluated by METAVIR score. A sustained virological response (SVR) was defined as an undetectable serum HCV viral load (<10 IU/mL) up through 24 weeks after the end of HCV treatment.

RESULTS

The median of plasma 25(OH)D level was 48 nmol/L (p25th: 32.5; p75th: 56.1) and 27 (15.5%) had 25(OH)D deficiency (<25 nmol/L). The percentage of 25(OH)D deficiency was higher in patients with significant fibrosis (F ≥ 2) (92.6% vs. 57.1%; p = 0.010) and moderate necroinflammatory activity grade (A ≥ 2) (85.2% vs. 60%; p = 0.043). However, adjusted logistic regression analyses showed that 25(OH)D deficiency was only associated with severity of liver disease [F ≥ 2 (OR = 8.47 (95% of confidence interval (CI) = 1.88; 38.3); p = 0.005) and A ≥ 2 (OR = 3.25 (95%CI = 1.06; 10.1); p = 0.040)]. Moreover, any significant relationship was found between 25(OH)D deficiency and SVR after HCV therapy.

CONCLUSION

Plasma 25(OH)D deficiency was associated with liver disease severity in HIV/HCV coinfected patients, but it was not associated with HCV treatment failure.