Detection of hepatitis B virus DNA and determination of surface antigen expression in peripheral blood mononuclear cells from patients with AIDS

Study of the Association of Mutant HBsAg Gene and Hodgkin and Non-Hodgkin Lymphoma

Background:

Hepatitis B Virus (HBV) is responsible for chronic, acute, and fulminant hepatitis, which are prevalent worldwide. Chronic HBV may lead to cirrhosis and hepatocellular carcinoma. Several epidemiological studies have indicated that hepatitis B virus is involved in B-cell Hodgkin and Non-Hodgkin Lymphoma (NHL).

Objectives:

The aim of this study was to evaluate the association between hepatitis B infection and Hodgkin and non-Hodgkin Lymphoma.

Materials and Methods:

Paraffin embedded of 41 block samples including 12 (29.26%) Hodgkin and 29 (70.73%) non-Hodgkin patients were collected. Next, DNA extraction was carried out for all the samples followed by HBV DNA detection by the nested polymerase chain reaction (PCR). The positive HBV DNA samples were sequenced, and HBV genotypes and HBV subtypes were determined.

Results:

Three out of 12 (25%) Hodgkin samples and seven out of 29 (24.13%) non-Hodgkin showed positive HBV DNA results. The results of sequencing revealed that the D genotype was predominant among the positive HBV patients. Interestingly an unpredictable amino acid proline was detected in position 88 of the HBs gene, which indicates a new mutation in the “S” region of HBV DNA in patients with Hodgkin and non-Hodgkin lymphoma.

Conclusions:

A high rate of 25% and 24.13% of HBV DNA was detected among patients with Hodgkin and non-Hodgkin lymphoma, respectively.

Transcription of hepatitis B virus in peripheral blood mononuclear cells from persistently infected patients

Hepatitis B virus (HBV) has been reported to exist in peripheral blood mononuclear cells (PBMC), but it is not clear whether it replicates there. A precondition for replication should be the formation of covalently closed viral DNA and transcription of all essential viral mRNAs. The mRNAs of HBV form a nested box with common 3' ends. In order to detect even low levels of potential replication, we developed a quantitative reverse transcription-PCR method for detection of a smaller HBV mRNA species in the presence of the larger ones. All three highly viremic patients tested so far had mRNAs for the large and the small surface proteins and the X protein of the virus within PBMC but not in the virus from their sera. Furthermore, we detected by PCR covalently closed viral DNA in their PBMC. These data suggest that HBV may be not only taken up but also replicated by mononuclear blood cells and that these cells may be an extrahepatic site of viral persistence. X mRNA was detected in the largest amount. Possibly, X protein interferes with functions of the mononuclear cells during the immune response against the virus.

Antigen/antibody content of circulating immune complexes in HIV-infected patients

Dual infection with HIV and hepatitis B virus (HBV) is not an uncommon feature. Immunity impairment due to HIV infection can be the cause of a higher rate of HBV replication with less intensive liver damage and less effective immune response to HBV. Many HIV-infected patients have an elevated level of circulating immune complexes (CIC) in serum, throughout all stages of illness evolution. The aim of our study was to estimate p24 and HBsAg content of CIC in dually infected patients, and the prevalence of major classes of complexed antibodies (IgM and IgG). We examined 146 samples of sera from 105 HIV positive patients of the Institute for Infectious and Tropical Diseases during 1992 and 1993. On those sera we performed p24Ag and HbsAg detection, with and without prior dissociation of CIC, we determined serum level of CIC and immunoglobulin classes IgM and IgG level in sera and in polyethilenglycol (PEG) precipitates of sera. Acid dissociation of immune complexes revealed a high proportion of HIV antigen positive sera in all stages of HIV disease progression. HbsAg in serum of HIV positive patients was also found coupled in immune complexes much more frequently than in the HIV negative control group. In many instances both antigens were simultaneously found coupled in CIC. Immune complexes detected have been shown to contain both IgM and IgG immunoglobulins, while IgM antibodies were associated to immune complexes in higher proportion than IgG, compared to total serum immunoglobulins.

Association between HIV and other DNA viruses in vitro

To investigate the association of human immunodeficiency virus (HIV) with various DNA viruses, including hepatitis B virus (HBV), cytomegalovirus (CMV) and Epstein-Barr virus, (EBV), simultaneous detection of HIV p24 antigen, HBV surface antigen and DNA, CMV-DNA and EBV-DNA expression was performed in phytohemagglutinin-stimulated peripheral blood mononuclear (PBMC) culture supernatants obtained from 54 individuals at risk for HIV infection. HIV expression in PBMC culture supernatants never occurred alone; expression of other viruses was always detected in the 24 samples expressing HIV antigen in vitro. Furthermore, in 16 patients expression of other viruses was detected without HIV expression, and in 14 patients none of the tested viruses were detected. These results indicate a strong association between the presence of HIV antibody and expression of DNA viruses in vitro (p = 0.0001). The coexpression of these viruses could be related to the evolution of HIV infection and AIDS.