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 that decreases the synthesis of hemoglobin. Repeated blood transfusion is the standard treatment for patients with beta-thalassemia major (BTM), and this increases the risk of exposure to infectious agents. The aim of this study was to investigate the prevalence of OCI among BTM patients. Plasma and PBMCs were collected from 90 BTM patients who were referred to Shafa Hospital in the city of Ahvaz and were screened for HCV antibody using a commercial ELISA kit as the first step. Next, nested RT-PCR was performed on extracts of plasma and PBMCs. HCV RNA from positive PBMCs was sequenced, the sequences were aligned, and a phylogenetic tree was constructed to determine their relationship to reference sequences retrieved from the GenBank database. Seventy-nine out of 90 patients (87.8%) were negative for HCV Ab (seronegative), while 11 patients (12.2%) were seropositive. HCV RNA was found in PBMCs of four patients (66.7%) who were negative for HCV Ab (seronegative) and two patients (33.3%) who were positive for HCV Ab (seropositive). HCV RNA was not detected in plasma samples from these six patients. Six out of 90 BTM patients (6.7%) had OCI. HCV genotyping revealed that all six patients were infected with HCV subtype 3a. We found a high frequency of OCI in BTM patients, which warrants more attention, considering the importance of this infection. Further studies are needed to determine the actual prevalence of OCI in BTM patients in Iran.

隐匿性丙型肝炎病毒感染 (OCI) 的定义是外周血单核细胞 (PBMC) 和肝组织细胞中存在 HCV RNA，尽管血浆中不存在 HCV RNA。目前，OCI分为血清阳性OCI（抗HCV阳性且血清HCV RNA阴性）和血清阴性OCI（抗HCV和血清HCV RNA阴性）两种。β-地中海贫血被描述为一种减少血红蛋白合成的血液疾病。重复输血是重型 β-地中海贫血 (BTM) 患者的标准治疗方法，这会增加接触传染源的风险。本研究的目的是调查 BTM 患者中 OCI 的患病率。从被转诊到阿瓦士市沙法医院的 90 名 BTM 患者收集血浆和 PBMC，并使用商业 ELISA 试剂盒筛选 HCV 抗体作为第一步。接下来，对血浆和 PBMC 的提取物进行巢式 RT-PCR。对来自阳性 PBMC 的 HCV RNA 进行测序，对序列进行比对，并构建系统发育树以确定它们与从 GenBank 数据库中检索到的参考序列的关系。90 名患者中有 79 名 (87.8%) 为 HCV Ab 阴性（血清阴性），而 11 名患者 (12.2%) 为血清阳性。在 HCV Ab 阴性（血清阴性）的 4 名患者（66.7%）和 HCV Ab 阳性（血清阳性）的 2 名患者（33.3%）的 PBMC 中发现了 HCV RNA。在这六名患者的血浆样本中未检测到 HCV RNA。90 名 BTM 患者中有 6 名 (6. 7%) 有 OCI。HCV 基因分型显示所有 6 名患者都感染了 HCV 亚型 3a。我们发现 BTM 患者的 OCI 频率很高，考虑到这种感染的重要性，这值得更多关注。需要进一步的研究来确定伊朗 BTM 患者中 OCI 的实际患病率。