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.

Longitudinal assessment of vascular calcification in generalized arterial calcification of infancy

BACKGROUND

Generalized arterial calcification of infancy (GACI), also known as idiopathic infantile arterial calcification, is a very uncommon genetic disorder characterized by calcifications and stenoses of large- and medium-size arteries that can lead to end-organ damage.

OBJECTIVE

To describe changes in imaging findings in 10 children with GACI at a single institution from 2010 to 2021.

MATERIALS AND METHODS

In this retrospective study we reviewed initial and follow-up body imaging in children with genetic confirmation of GACI at our hospital. All initial images were analyzed for the presence and distribution of arterial calcifications, stenoses and wall thickening/irregularity within the chest, abdomen and pelvis. We compared available follow-up studies to the initial imaging findings. We extracted clinical information including prenatal and postnatal treatment from the children's medical records.

RESULTS

We evaluated 10 children (five boys) with a diagnosis of GACI. Median age at first body imaging was 8 days (range: 1 day to 5 years). Six children were identified prenatally and four postnatally. Postnatal presentation included cardiac failure, seizures and hypertension. Images in newborns (n = 8) most commonly showed diffuse arterial calcifications (6/8; 75%), while stenoses were less common (2/8; 25%) during this period. Two children were diagnosed after the neonatal period - one in infancy and one during childhood. In total, half the children (5/10; 50%) had arterial stenoses - three cases visualized at first imaging and two identified on follow-up images during infancy. Stenoses had completely resolved in one child (1/5; 20%) at last follow-up. Eight children received prenatal or postnatal treatment or both. All children who received both prenatal and postnatal treatment (n = 4) had completely resolved calcifications at last follow-up.

CONCLUSION

Children with GACI might have characteristic vascular calcifications at birth that raise the suspicion of this disease. Arterial calcifications decrease or disappear spontaneously or after treatment, but arterial stenoses usually persist. Calcifications and arterial stenoses can be easily identified and followed with non-contrast CT and CT angiography.

Tailor-made therapy for viral hepatitis: recent advances

Combination therapy of pegylated interferon-α with ribavirin (PEG-IFN/RBV) is a standard of care for chronic hepatitis C (CHC). The majority of CHC patients are infected with HCV genotype I. The recent discovery revealed by a genome-wide association study technology provides the important role of interleukin-28B (IL28B) and inosine triphosphatase (ITPA) in HCV infection. In addition, response to PEG-IFN/RBV therapy is correlated with insulin resistance, hepatic steatosis, and hepatic fibrosis in CHC patients. Double-filtration plasmapheresis together with IFN therapy has proved to be effective in the reduction of viral load during the early stage of treatment. In CHC patients, not only IL28B status, but also the treatment period of PEG-IFN/RBV is important. Even when new polymerase/protease inhibitors are introduced in the treatment of CHC, tailor-made treatment for CHC using IL28B, inosine triphosphatase testing or double-filtration plasmapheresis treatment prolonged treatment strategy is highly recommended. The relative etiologic role of prior hepatitis B virus infection in the development of non-B non-C hepatocellular carcinoma is also known in hepatitis B-endemic areas.

Interleukin28B and inosine triphosphatase help to personalize hepatitis C treatment

In the therapy using a combination of pegylated interferon-α and ribavirin (PEG-IFN/RBV) for chronic hepatitis C (CHC), approximately 50% of CHC patients infected with high viremia of HCV genotype 1 reached sustained viral response. The recent discovery revealed by a genome-wide association study technology provides the unexpected role of IL28B and inosine triphosphatase (ITPA) in HCV infection. The former single nucleotide polymorphisms (SNPs) around the IL28B gene could improve the diagnostics on the prediction of spontaneous clearance and the response to anti-HCV treatment, suggesting that these findings could be strong evidence to enhance the development of a novel therapeutic strategy and the basic study of IFN-λs. Interestingly, the discovered IL28B SNPs revealed the enigma that the viral clearance rate was dependent on ethnicity. The latter functional SNP in ITPA locus was the most significant SNP associated with RBV-induced anemia as well as IFN-induced thrombocytopenia. Note that severe Hb decline, which is mainly found in ITPA-CC patients, was inversely correlated with platelet reduction, contributing to an association between severe anemia and relative reactive increase in platelet count. These data may provide a valuable pharmacogenetic diagnostic tool for tailoring PEG-IFN/RBV dosing to minimize drug-induced adverse events and for further optimization of clinical anti-HCV chemotherapeutics.