Prevalence of Occult Hepatitis B Virus Infection in Hemodialysis Patients Using Nested PCR

Abstract

Background: Occult hepatitis B infection (OBI) is defined as the lack of detectable HBsAg in serum, despite the presence of intrahepatic viral DNA, and low levels of covalently closed circular DNA (cccDNA). Since the hemodialysis patients are at a greater disadvantage if they are a carrier of Hep B, as it can lead to OBI this study was designed to determine the prevalence of OBI in hemodialysis patients residing in Zanjan, Iran. Methods: We conducted an anti-HBc test (ELISA) on 166 HBsAg negative hemodialysis patient samples. OBI was evaluated using seropositive (anti-HBc and/or anti-HBs) and seronegative (anti-HBc and anti-HBs) using nested PCR. Results: Out of the total hemodialysis patients sampled, the study consisted of 58.4% male and 41.6% female participants. The age of the study group ranged from 58.89±15.49, and had received approximately 28.27±27.43 years of dialysis. Additionally, 5.4% of patients had a history of blood transfusions, while 58.4% were vaccinated against the hepatitis B virus (HBV). Moreover, 23.5% patients were anti-HBc positive, while 76.5% patients tested negative. Lastly, 66.3% of the patients were positive for anti-HBs, whereas 33.7% were negative for anti-HBs. Overall, the study revealed that the prevalence of OBI was 6%, and HBV DNA was detected in 2.1% of individuals who were vaccinated against hepatitis B (p < 0.01). Conclusions: Though no significant difference between the prevalence of OBI to the patients' age, sex, duration of dialysis, or history of blood transfusion was identified, however, a strong correlation between the prevalence of OBI to HBV vaccination was found.

Occult Hepatitis B Virus Infection among β-Thalassemia Major Patients in Ahvaz City, Iran

“…5 This broad-ranging OBI prevalence in different studies could be related to the sensitivity of HBV DNA detection assays, studied population size and characteristics, the endemicity of HBV in different regions, and vaccination status. 28,45 In this research, only one marker (HBsAg) was correlated to sex. To this extent Baruch and their collaborators indicated in most human populations, there is a higher prevalence of chronic carriers of HBV (persistently HBsAg1) among males than females (53).…”

High Prevalence of Occult Hepatitis B Virus Infection among Iranian Hemodialysis Patients

“…Similarly, recent studies in Zanjan (West of Iran) and Qazvin (West-Center of Iran) demonstrated that the prevalence of occult HBV infection among hemodialysis patients is not associated with age, gender, or duration of hemodialysis. 22,34 Another study from Northeast Brazil reported no association between occult HBV infection and age, gender, kidney transplant, or time on hemodialysis. 28 Previous studies from central Greece and Turkey reported no risk factor for occult HBV infection among hemodialysis patients.…”

“…4 The prevalence of 10.4% for occult HBV infection reported in this study is higher than those observed among hemodialysis patients in the other parts of Iran, 0.0% in Guilan (northern Iran), 19 0.0% in Isfahan (central Iran), 18 0.8% in Yazd (central Iran), 17 0.5% in Tehran (north-central Iran), 20 4.7% in Ahvaz (southwestern Iran), 21 and 6% in Zanjan (western Iran). 22 The prevalence of occult HBV infection detected in this study is also higher than those reported among hemodialysis patients of some other regions and countries, 0.0% in Al-Nasiriyah, Iraq 23 ; 0.3% in eastern Japan 24 ; 0.9% in central Greece 25 ; 1.3% in South Korea 26 ; 2.2% in London, United Kingdom 27 ; and 2.3% in northeastern Brazil 28 but lower than those reported among hemodialysis patients in Egypt (32%) 29 and Sudan (15.9%). 30 These discrepancies in the prevalence of occult HBV infection may attributable to differences in the endemicity of HBV infection in different geographic regions, preventive measures in hemodialysis units, and the sensitivity and specificity of the detection method used in different studies.…”

“…22 The prevalence of occult HBV infection detected in this study is also higher than those reported among hemodialysis patients of some other regions and countries, 0.0% in Al-Nasiriyah, Iraq 23 ; 0.3% in eastern Japan 24 ; 0.9% in central Greece 25 ; 1.3% in South Korea 26 ; 2.2% in London, United Kingdom 27 ; and 2.3% in northeastern Brazil 28 but lower than those reported among hemodialysis patients in Egypt (32%) 29 and Sudan (15.9%). 30 These discrepancies in the prevalence of occult HBV infection may attributable to differences in the endemicity of HBV infection in different geographic regions, preventive measures in hemodialysis units, and the sensitivity and specificity of the detection method used in different studies.…”

“…2 In addition, those studies using real-time PCR assay 17,18,20 to detect HBV DNA have reported a lower prevalence rate than the studies using nested PCR assay. 21,22,32 However, the probability of contamination with PCR product during procedures that can result in false-positive results considers as the main limitation of the nested-PCR method. 31 In the present study, strict quality controls and positive and negative controls were applied to avoid contamination and to ensure the accuracy of the results.…”