Occult Hepatitis B infection [OBI] in vaccinated groups, a metanalysis

Nowadays, the presence of HBV DNA in the absence of HBsAg; occult hepatitis B infection; [OBI], is a known clinical entity along with the rapid influx of research being conducted on its clinical relevance. Biologists and clinicians alike have a recent-standing interest in this regards. OBI has been described in several clinical settings. However, the data on its prevalence among immunized and non-immunized healthy general population, in particular, among health care workers [HCWs] is ambigous. This review attemps to explore the significance of OBI in vaccinated groups as a special subject. The prevalence of OBI among general population, vaccinated children/general population and health care workers were: 157 [5.2%], 222 [6.7%] and 33 [1.8%], respectively. The prevalence of anti-HBc among OBI-positive subjects were: 64 [40.7%], 133 [82.7%] and 27 [81.8%], respectively. OBI is partly prevalent in general population and in vaccinated individuals, especially in those who born to HBsAg positive mothers. HBV serological surveys are not enough adequate and sensitive to rule out the presence of HBV DNA. For high-risk groups [subjects born to HBsAg mothers, health care workers, isolated anti-HBc, etc] sensitive molecular tests based on real time PCR should be applied for a proper diagnosis

Prevalence and molecular analysis of occult hepatitis b virus infection isolated in a sample of cryptogenic cirrhosis patients in Iran

The aims of this study are to investigate the prevalence of occult hepatitis B virus infection among patients with cryptogenic cirrhosis and to analyze the relationship between surface protein variability and occult hepatitis B virus infection, which may be related to the pathogenesis of occult hepatitis B virus infection in cryptogenic cirrhosis. Occult hepatitis B virus infection is a wellrecognized clinical entity characterized by the detection of hepatitis B virus DNA in serum and/or liver in the absence of detectable hepatitis B virus surface antigen, with or without any serological markers of a past infection. Sera from patients with cryptogenic chronic liver disease were tested for hepatitis B virus DNA using both real-time and nested PCR. In the detected hepatitis B virus DNA samples, the surface gene was analyzed for mutations. Hepatitis B virus DNA was detected in 38% of patients, all of whom had a viral load below 10,000 copies/mL. All hepatitis B virus belonged to genotype D. There were no significant associations between occult hepatitis B virus infection status and age, gender, ALT/AST levels, viral load or serologic markers of previous hepatitis B virus infection. There were 14 mutations found in 5 patients; 6 were in the major hydrophilic region, of which 4 were Y134F assigning for the "a" determinant region. All patients who acquired Y134F contained S207R [within HLA-A2-restricted CTL epitope] as a combination. Hepatitis B virus surface antigen variants may arise as a result of natural selection to evade the immune surveillance of the infected host, and subsequently may go undetected by conventional hepatitis B virus surface antigen screening tests. Etiological diagnosis of cryptogenic cirrhosis is significantly underestimated with current serology testing methods alone.

prevalence of hepatitis B virus surface antigen [HBsAg] variations and correlation with the clinical and serologic pictures in chronic carriers from Khorasan Province, North-East of Iran

This study was designed to determine the correlation of hepatitis B virus surface Ag [HBsAg] variations with the clinical/serological pictures among chronic HBsAg positive patients. The surface gene [S-gene] was amplified and directly sequenced in twenty-five patients. Eight samples [group I] contained at least one mutation at the amino acid level. Five showed alanine aminotransferase [ALT] levels above the normal range of which only one sample was anti-HBe positive. Group II [17 samples] did not contain any mutation, 4 were anti-HBe positive and 9 had increased ALT levels. In both groups, from a total of 18 mutations, 5 [27.5%] and 13 [72.5%] occurred in anti-HBe and HBeAg positive groups respectively. The small number of amino acid mutations might belong to either the initial phase of chronicity in our patients; or that even in anti-HBe positive phase in Iranian genotype D-infected patients, a somehow tolerant pattern due to the host genetic factors may be responsible

Hepatitis B virus surface antigen variants clustered within immune epitopes in chronic hepatitis B carriers from hormozgan province, south of Iran

The aim of this study was to characterize the hepatitis B virus surface protein genotypes and sequence variations among hepatitis B virus surface antigen [HBsAg] positive chronic patients in Hormozgan province, south of Iran. A total of 8 patients enrolled in this study. The surface gene was amplified and directly sequenced. Genotypes and nucleotide/ amino acid substitutions were identified compared to the sequences obtained from the database. All strains belonged to genotype D. Overall 77 "mutations" occurred at 45 nucleotide positions, of them, 44 [57.14%] were silent [no amino acid altering] and 33 [42.86%] were missense [amino acid changing]. A number of 24 [80%] out of 30 amino acid changes occurred in different epitopes within surface protein, of which, 9 [30%] in B cell epitopes in 7 residues [2 occurred in "a" determinant region]; 8 [42.1%] in T helper epitopes in 7 residues and 7 [10%] in 4 residues inside CTL epitopes. Hepatitis B virus genome containing mutated immune epitopes no longer could be recognized by specific T-cells of the host immune surveillance and did not enhance anti-HBs production. This could led to the progression of chronicity B virus infection

Propagation of hepatitis 8 virus in a rat hepatoma cell line stably transfected with human annexin-V

Hepatitis B virus [HBV] displays a distinct hepatotropism and a narrow host range in vivo. However, very little is known about the interaction of HBV with its host cells, mainly because of difficulties in the development of suitable tissue culture system. We present here confirmatory evidence of a putative role of annexin-V in HBV infection. HBV from both human sera and from culture supernatants from HepG2 2.15 cells were used to infect FTO9.1 cells [a rat hepatoma cell line transfected with a construct containing human annexin-V]. Cells and culture supernatants were assayed at various times post-infection by immunofluorescent microscopy [HBcAg staining in nucleus], and by HBV cccDNA-specific PCR. Supernatants from these initially infected cells were then used to infect fresh FTO9.1 cells with a similar outcome to primary infection. Core and surface gene PCRs were positive on days 2, 5 and following transfer experiments. cccDNA-specific PCR confirmed internalisation of the virus into the nucleus. HBcAg fluorescence showed nuclear staining on days 2, 5 and following transfer experiments. Addition of recombinant annexin-V and DMSO to the cell culture medium resulted in a greater efficiency of infection. Later washes were negative for HBV-DNA, ruling out contamination of the cells by external HBV particles. This cell line does appear to be useful in the study of the early stages of HBV infection, but requires further evaluation