Prevalence and molecular-genetic characteristics of hepatitis B virus in HIV-positive individuals at the Far Eastern Federal District
Current study was aimed at investigating prevalence of overt and occult hepatitis B infection in HIV-positive individuals as well as molecular-epidemiological characteristics of the circulating hepatitis B virus (HBV) strains in the Far Eastern Federal District (FEFD). A total number of 297 blood serum/plasma samples obtained from HIV-positive patients residing in the FEFD were enrolled in the study. The first control group included 351 blood serum/plasma samples of general population without indication on HIV and HBV-infection that underwent laboratory check up at the Centers for AIDS Prevention and Control. After evaluating the group of HIV-positive patients 20 HIV-HBV positive samples were selected for further detailed analysis. The second control group included 43 patients with chronic hepatitis B. All groups were age and gender-matched. The research included serological and molecular-genetic (real-time PCR, positive for HBV DNA samples underwent clonal sequencing of PCR-amplified HBV P/S gene) assessment of the biological material followed by a phylogenetic analysis of the HBV sequences. Our research revealed that HIV-positive patients are exposed to a higher risk of HBV infection compared to general population enrolled in the study, which is evident from the prevalence of anti-HBcAg antibodies in the groups examined. HIV-positive vs. first control group was positive for anti-HBcAg antibodies at higher rate (35.02%, CI 95: 29.59-40.45% versus 22.22%, CI 95: 17.87-26.57%, p = 0.0003). Abundance of ongoing HBV-infection markers was also higher in HIV-positive individuals compared to general population (6.73%, CI 95: 3.88-9.58% versus 0.85%, CI 95: 0-1.81%, p = 0.0001, respectively). Should be noted, that HBsAg-negative HBV infection in HIV-positive patient cohort comprised 1.01% (CI 95: 0-2.15%) whereas in general population this index was as low as 0.28% (CI 95: 0-0.84%). Virus hepatitis С and D were revealed at higher rate in HIV-positive individuals compared to patients with HIV-negative chronic HBV infection (p = 5.84 × 10-7 and p = 0.000001 respectively). HCV and HDV prevalence rates comprised 50.0% (CI 95: 27.46-77.46%) and 40.0% (CI 95: 17.97-62.03%) in HIV-positive patients. Similar indices in control group were 4.65% (CI 95: 0-10.94%) and 4.65% (CI 95: 0-10.94%), respectively. The phylogenetic analysis of the six isolated HBV sequences showed that the five samples belonged to genotype D, with dominant subtype D2 (verified in 4 cases). Further, HBV genotype С was detected only in one case. The obtained data indicate a necessity for further in-depth diagnostic examination of viral hepatitis in HIV-positive patients to lower a risk of developing life-threatening complications as well as preventing hepatitis spread in human population.