Investigation of Hepatitis B and Hepatitis C Virus Infections by Serological and Molecular Methods in Hemodialysis Patients

Abstract

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are significant causes of morbidity and mortality in hemodialysis patients, since those patients are highly susceptible to infections due to immune suppression. The aims of this study were to investigate the presence of HBV and HCV infections in chronic hemodialysis patients by serological and molecular methods, and to determine the rate of occult HBV infection and the viral genotypes. A total of 201 patients who were under hemodialysis due to end-stage renal disease, were retrospectively evaluated. The study involved the patients at three different centers in Antalya, Turkey during 2006. HBV and HCV markers in the patients' sera were screened by ELISA method, viral nucleic acids were investigated by real-time polymerase chain reaction (PCR) in patients' plasma and viral genotypes were determined by DNA sequence analysis. Detection of at least one of the HBV markers HBsAg, anti-HBc total, and HBV DNA, was accepted as HBV infection, and detection of anti-HCV and/or HCV RNA was accepted as HCV infection. HBsAg positive patients with negative HBV DNA were considered as occult HBV infection. Of the patients 80 (40%) were female, 121 (60%) were male and the mean age was 51.16 ± 16.28 (range 17-93) years. In our study, sole anti-HBs positivity due to HBV vaccination, was detected in 89 (44.3%) patients. One hundred (50%) patients were found positive in terms of HBV infection and 40 (20%) were positive for HCV infection, while 24 (12%) patients had HBV and HCV co-infections. Eighty-five (42.3%) patients had no HBV and HCV infection. Among the 5 (2.5%) patients who were HBsAg positive, four were also HBV DNA positive. Occult HBV infection was detected in 1 (0.5%) patient. Anti-HCV and HCV RNA were found positive in 37 (18.4%) and in 24 (12%) patients, respectively. Among the HCV-RNA positive patients, 3 (12.5%) were anti-HCV negative. ALT and AST levels were found normal in all of the HBV DNA positive patients, and 62.5% (15/24) of HCV RNA positive patients. All of the HBV isolates were identified as genotype D and HCV isolates as genotype 1b. No statistically significant correlation was detected between the HBV infection and patients' age, duration of hemodialysis and elevation of serum transaminase levels (p> 0.05). On the other hand, HCV infection was seen to increase with age (p= 0.047). HCV infection showed a statistically significant increase with the duration of hemodialysis. HCV infection risk was increased in patients who were under hemodialysis for ≥ 25 months (p< 0.001, OR: 0224, 95% CI= 0089-0562). There was also a statistically significant correlation between the presence of HCV infection (anti-HCV and/or HCV RNA positive) and high levels of serum transaminases (p< 0.001). However, in two of the three cases who were anti-HCV negative and HCV RNA positive, serum transaminase levels were normal while the viral loads were high. Therefore to follow-up HCV infection in the hemodialysis patients, anti-HCV and serum transaminase levels may not be sufficient alone and these patients should be evaluated periodically for HCV RNA. In addition, the detection of occult HBV infection in one of the study patients, indicated that HBV DNA should also be investigated at regular intervals in the hemodialysis patients.