Occult Hepatitis B Virus Infection in a Cohort of Egyptian Chronic Hemodialysis Patients

Background: Replication of hepatitis B virus (HBV) in the absence of a detectable hepatitis B surface antigen (HBsAg) and occasionally other HBV serologic markers has been called occult hepatitis B infection. As the presence of OBI represents a possible threat to those on hemodialysis, being a high risk group, this study was carried out to investigate the prevalence of OBI in a cohort of Egyptian patients maintained on hemodialysis and to evaluate the protocol of HBV detection in the Alexandria Main University Hospital dialysis unit. Methods: Patients enrolled in the study included ninety three HBs-Ag negative Egyptian patients maintained on hemodialysis. Liver function tests, serological HBV markers, HCV antibodies, and quantification of HBV viral DNA titer were assayed for all participants in the study. Results: Twenty five individuals were HBV DNA-positive, representing 26.8% of the tested patients. As regards HBV DNA-positive cases, eighteen (72%) patients were HCV-Ab positive. Three patients (12%) were positive to both anti-HBc and anti-HBs and only one patient (4%) was negative to both antibodies. Fifteen patients (60%) were positive to anti-HBc only, while 6 patients (24%) were positive to anti-HBs only. Conclusions: OBI is relatively common in Egyptian dialysis patients at the Alexandria Main University Hospital dialysis unit, and it might be a possible mechanism of transmission of HBV infection between them. The protocol implemented in the Alexandria Main University Hospital dialysis unit for detection of HBV positive patients should be refined to screening with sensitive PCR-based assays for all dialysis patients regardless of biochemical or serological findings. (Clin. Lab. 2012;58:1057-1061. DOI: 10.7754/Clin.Lab.2012.120121)