Prevalence of Occult Hepatitis C Virus Infection in Beta-Thalassemia Major Patients in Ahvaz, Iran

Abstract

Background: Occult hepatitis C virus infection (OCI) is defined by the presence of HCV RNA in peripheral blood mononuclear cells (PBMCs) and liver tissue cells despite the absence of HCV RNA in plasma. Currently, OCI is classified into two types: seropositive OCI (anti-HCV positive and serum HCV-RNA negative) and seronegative OCI (anti-HCV and serum HCV-RNA negative). Beta-Thalassemia is described as a blood disorder, which decreases the synthesis of hemoglobin. Repeated blood transfusion is the standard treatment for patients with beta-thalassemia major (BTM) that increases the risk of exposure to infectious agents. This study aimed to investigate the prevalence of OCI among BTM patients.Materials and Methods: plasma and PBMCs were collected from 90 BTM patients and screened for HCV antibody using the ELISA kit commercially as the first step. Then nested-RT PCR was performed on extractions of plasma and PBMC. Positive samples of HCV RNA from PBMCs were sequenced and aligned to construct the HCV phylogenetic tree to assess the homology of sequences compared to the reference sequences retrieved from GenBank.Results: Seventy-nine out of 90 cases (87.8%) indicated negative results for HCV Ab (seronegative), while 11 patients (12.2%) were seropositive. HCV RNA was found in PBMCs samples of four patients (66.66%) with negative HCV Ab (seronegative) and two patients (33.3%) with positive HCV Ab (seropositive). HCV RNA was not detected in plasma samples of these six patients. Overall six out of 90 patients (6.7%) had OCI. HCV genotyping revealed that all six patients infected with HCV subtype 3a.Conclusion: We indicated the high frequency of OCI in BTM patients. Nevertheless, more attention is warranted, considering the importance of this infection. Also, further studies are necessary to determine the actual prevalence of OCI among BTM patients in Iran.