ITPA gene polymorphism (94C>A) effects on ribavirin-induced anemia during therapy in Egyptian patients with chronic hepatitis C

Impact of ITPA gene polymorphism for predicting anemia and treatment outcome in HCV infected patients taking Sofosbuvir Ribavirin therapy

BACKGROUND

Globally, 80 million people are suffering from chronic Hepatitis C virus (HCV) infection. Sofosbuvir ribavirin-based anti-HCV therapy is associated with anemia and other adverse effects. Polymorphisms of Inosine triphosphatase (ITPA) gene may cause functional impairment in the Inosine triphosphate pyrophosphatase enzyme, resulting in enhanced sustained viral response (SVR) and protection from ribavirin-associated anemia in patients on therapy. The study objective was to investigate the effect of Inosine triphosphatase gene polymorphism on SVR achievement, hemoglobin decline and ribavirin dose reduction in patients on therapy.

METHODS

This prospective cohort study was of 170 hepatitis C infected patients received 6-month sofosbuvir ribavirin therapy. Patient viral load, reduction in ribavirin amount, liver function test, and complete blood count were noted monthly. Inosine triphosphatase variants rs1127354 and rs7270101 were assessed through the restriction fragment length polymorphism and confirmed using Sanger sequencing. The impact of polymorphism on cumulative reduction of ribavirin, and anti-HCV therapy outcome were studied.

RESULTS

A total of 74.3% of patients had ITPA rs1127354 CC genotype, 25.7% were CA and AA 0%. The frequency of ITPA genotype rs7270101-AA was 95%, AC 5%, and CC was 0%. ITPA rs1127354-CA had a notably positive impact on SVR achievement with a zero-relapse rate. ITPA rs1127354-CA genotype was significantly (P ˂0.05) protective against ≥ 2 g/dl Hb reduction from baseline to 1st, 2nd and 6th months of therapy. During treatment, Hb reduction ≥ 10 g/dl was frequently observed in rs1127354-CC genotype and rs7270101-AA genotype patients. Ribavirin dose reduction was significantly (P ˂0.05) high in rs1127354-CC genotype as compared to genotype CA whereas no significant difference was observed in ribavirin dose reduction in rs7270101 AA and non-AA genotype. Patient baseline characteristics such as age, body mass index, rs1127354-CC genotype, and baseline Hb were significantly associated with significant Hb reduction.

CONCLUSION

Pretreatment evaluation of ITPA polymorphism can be a diagnostic tool to find out patients at risk of anemia and improve treatment adherence. ITPA genotype rs1127354-CA contributes to improved compliance with ribavirin dose and protects against hemoglobin decline in HCV patients while taking ribavirin-based therapy. However, ITPA rs1127354, rs7270101 polymorphism have no significant impact on SVR achievement.

Analysis of Different Types of Interferon-Associated Retinopathy in Patients with Chronic Hepatitis C Virus Infection Treated with Pegylated Interferon Plus Ribavirin

This retrospective cohort study aims to investigate interferon (IFN)-associated retinopathy incidence in patients with chronic hepatitis C virus (HCV) infection treated with pegylated interferon (PegIFN) plus ribavirin (RBV). We selected 1688 patients undergoing PegIFN/RBV therapy for HCV (HCV-treated cohort), 3376 patients not receiving HCV treatment (HCV-untreated cohort) and 16,880 controls without HCV (non-HCV cohort) from the Taiwan Longitudinal Health Insurance Database. The patients were frequency-matched by age, sex, and index date at a 1:2:10 ratio, and followed up until the end of 2013. Cox proportional hazard regression models were used to compare the incidences of any retinal vascular events, including subtypes, among the three cohorts. Compared with the non-HCV cohort, the HCV-treated cohort had a significantly increased risk of retinopathy (hazard ratio (HR) = 4.98, 95% confidence interval (CI): 2.02–12.3). The risk was particularly prominent for retinal hemorrhage (HR = 12.7, 95% CI: 3.78–42.9). When the HCV-untreated cohort was used as the reference, the aforementioned HRs increased to 9.02 (95% CI: 3.04–26.8) and 32.3 (95% CI: 3.94–265), respectively. This study suggested that PegIFN/RBV therapy significantly increased the risk of retinal hemorrhage but not retinal vascular occlusions in the HCV-treated cohort.

Association between inosine triphosphatase rs1127354 polymorphisms and ribavirin-induced anaemia and outcome in hepatitis C virus-infected patients: A meta-analysis

WHAT IS KNOWN AND OBJECTIVES

The association between inosine triphosphatase (ITPA) rs1127354 polymorphisms in HCV-infected patients receiving ribavirin (RBV)-based therapy, and the risk of adverse drug reaction and outcomes is still unclear. A meta-analysis was conducted to summarize and clarify this association systematically.

METHODS

A comprehensive search was performed in PubMed, Embase and Web of Sciences, and twenty-two studies were selected from the literature search. Pooled odds ratio (OR) and 95% confidence interval (95% CI) were estimated by either fixed- or random-effects models.

RESULTS

Four outcomes were evaluated: (a) haemoglobin decline: significant associations with haemoglobin decline were found for rs1127354 CC VS CA + AA (OR = 10.59, 95% CI = 6.39-17.54); (b) severe anaemia: significant association with severe anaemia was observed for rs1127354 CC VS CA + AA (OR = 16.24, 95% CI = 6.21-42.43); (c) sustained virological response (SVR): CC genotype carriers had a decrease SVR during treatment (OR = 0.65, 95% CI = 0.52-0.81); (d) RBV dose reduction or stopping treatment: although statistical evidence of an association was found between the polymorphism and RBV dose reduction during treatment (OR = 1.80, 95% CI = 1.03-3.13), the sensitivity analysis suggested this result was not robust.

WHAT IS NEW AND CONCLUSION

Patients with ITPA rs1127354 CC polymorphism are more likely to develop haemolytic anaemia, severe anaemia and decreased SVR. Testing for this genetic polymorphism may benefit patients.

Inosine triphosphate pyrophosphatase polymorphisms are predictors of anemia in Chinese patients with chronic hepatitis C during therapy with ribavirin and interferon

BACKGROUND AND AIM

Polymorphisms of inosine triphosphate pyrophosphatase (rs1127354 and rs6051702) and interferon lambda 4 (IFLN4) (rs12979860) are indicators of anemia and/or sustained virological response (SVR) in patients with chronic hepatitis C on ribavirin/interferon. The study aims to investigate the associations of rs1127354, rs6051702, and rs12979860 with hemoglobin levels and SVR in patients on ribavirin/interferon.

METHODS

Polymorphisms were detected by pyrosequencing. Levels of hemoglobin and hepatitis C virus (HCV) RNA were measured at weeks 2, 4, 12, 24, 36, 48, and 72 of treatment.

RESULTS

A total of 351 patients (median age, 50 years; male, 71.2%) were recruited and had HCV genotypes 1b (55.8%) or 2a (37.0%). Vedian baseline hemoglobin and HCV RNA were 155 g/dL and 6.07 log₁₀ IU/mL. Major allele homozygosity was observed in 76.3% for rs1127354 (CC), 70.9% for rs6051702 (AA), and 89.7% for rs12979860 (CC). At 4 weeks of ribavirin/interferon treatment, a more significant reduction in hemoglobin was observed with rs112754 CC than with AC/AA (P < 0.05). A decline ≥3 g/dL was more common in patients with the rs112754 CC than with the other two polymorphisms. No significant change was observed regarding rs6051702 and rs12979860 variants. In the multivariable analysis, rs1127354 AA/AC (vs CC) were independently associated with lower odds of hemoglobin decline of > 3 g/dL at 4 weeks (odds ratio, 0.21; 95% CI, 0.09-0.46; P < 0.0001). In 258 patients with 72-week outcome data available, rs1127354, rs6051702, and rs12979860 were not associated with SVR (all P > 0.05).

CONCLUSION

rs1127354 polymorphisms are associated with hemoglobin levels in Chinese patients with chronic hepatitis C treated with ribavirin/interferon.