Occurrence and clinical characteristics of occult hepatitis C virus infection in hemodialysis units at Ismailia, Egypt.

Background And Aims: Occult hepatitis C infection is defined as the presence of hepatitis C virus RNA in peripheral blood mononuclear cells (PBMC) ± hepatocytes in the absence of HCV-RNA in serum. It has been a lot of debate and controversy in recent years and not discussed well. This issue has not been discussed or investigated in Egypt, especially in patients on hemodialysis in Ismailia. This study is the first one to investigate the prevalence of occult HCV infection in large populations of chronic hemodialysis (CHD) patients in Ismailia, Egypt.

Methods: Our study is cross-sectional analytic and included 204 CHD patients; who are negative for HCV infection. Sensitive commercial real-time assay was used to detect HCV-RNA in PBMC. In our study, the presence of genomic HCV-RNA in PBMCs of all these patients was detected by real-time PCR. On the other hand, 22 patients on hemodialysis with an established diagnosis of chronic hepatitis C virus infection were included as a control group and examined by real-time PCR was used to evaluate HCV infection.

Results: Occult HCV infection is defined as the presence of HCV-RNA in PBMNCs in patients on chronic hemodialysis, and it was found in 14/204 (7%) of the patients. Patients who were on CHD for a longer time are susceptible to occult HCV infection, and their mean alanine aminotransferase levels are significantly higher during the last 3 months before study entry. In comparison, chronic HCV patients have elevated bilirubin, aspartate transferase and alanine transferase than occult HCV infection.

Conclusions: The prevalence of occult HCV infection was 7% in our CHD patients. No available data are showing the virulence of this form of virus. However, further studies in other geographic populations with high HCV endemicity are needed to clarify the significance of occult HCV infection in these patient groups, in addition to test for the presence of negative antigenomic strand to confirm or disconfirm the reliability of occult HCV.