Immunohistochemical research on HDV infection in Chinese patients with chronic liver disease

Analysis of intrahepatic HBVDNA in serologic HBV markers-negative or HBsAg-negative patients with chronic hepatitis

To explore HBV infection status in a group of serologic HBV markers-negative or HBsAg-negative patients with chronic hepatitis, in situ hybridization to hepatocellular HBVDNA was carried out in combination with detection of HBsAg and HBcAg in the liver tissues. It was found that prevalence of intrahepatic HBVDNA, HBsAg and HBcAg was 43%, 39% and 17% respectively, and 15 out of 23 cases studied were sure to bear one or more positive marker(s) of intrahepatic HBVDNA, HBsAg and HBcAg. These findings suggest that more than half of the patients with chronic hepatitis were still undergoing HBV infection, despite serologic HBV markers or HBsAg negative. Furthermore, we found that hepatocytes containing HBVDNA or surface or core antigen were often close to hepatic necrosis foci, indicating that HBV replication and its antigen(s) expression in hepatocytes could account for chronic, active and necrotic inflammation occurring in the liver of the patients mentioned above.

Comparison of pre-S1 and pre-S2 proteins in hepatocytes with replication by in situ hybridization assay

To compare the relationship of pre-S1 and pre-S2 proteins in hepatocytes with HBV replication, HBVDNA in situ hybridization was performed for a group of patients with chronic hepatitis by bio-probe, in conjunction with detection of intrahepatic HBsAg, HBcAg, pre-S1 and-S2 antigens. It was found that the expression of intrahepatic pre-s1 and pre-S2 proteins was visualized as cytoplasmic homogeneous and inclusion types, on some occasions as membranous localization. However, the positive rate for pre-S1 protein was up to 75% (15/20), being significantly higher than that of pre-S2 protein (35%; 7/20) in the same group (P less than 0.05). What in more important, the pre-S1 expression, rather than pre-s2, was in parallel with the presence of intrahepatic HBVDNA and HbcAg. All these findings suggest that the pre-S1 protein might be mainly expressed at the HBV replication phase, thus, to some extent, the detection of pre-S1 protein might complement HBe system and HBVDNA clinical routine.

The cytoplasmic HBVDNA implication: HBV replication or non-replicative status

Intrahepatocellular HBVDNA was investigated in patients with chronic hepatitis B by in situ hybridization assay, employing biotin-labelled HBVDNA as the specific probe. It was found that HBVDNA was predominantly present in the cytoplasm of hepatocytes. In general the cases with cytoplasmic HBVDNA could be grouped as follows: 1) cytoplasmic HBVDNA coinciding with intrahepatic envelope protein and nucleocapsid component expression, this pattern of the cytoplasmic HBVDNA would be replicative; 2) cytoplasmic HBVDNA accompanied by intrahepatic single HBsAg expression, common to HBVDNA integrated into host genome with only HBsAg being found frequently in liver; 3) with only cytoplasmic HBVDNA, with neither HBsAg nor HBcAg expression, representative for non-replicative status. It is speculated that the reason for the occurrence of the cytoplasmic hybridization signal in cases with non-replicative HBVDNA may be due to DNA-RNA transcript hybrid. The prudent way to evaluate the implication of the cytoplasmic HBVDNA is to consider the combination of HBVDNA location, intrahepatic gene product expression, and HBV markers in the serum.

Laboratory and clinical diagnosis of human cytomegalovirus infection after transplantation

Urine and blood specimens from 32 recipients of allograft organ transplant were investigated for human cytomegalovirus (HCMV) by conventional cell culture, indirect immunofluorescent assay subsequent to the rapid cell culture and DNA-DNA hybridization. The results showed that the rapid cell culture technique might be the best method for rapid detection of active HCMV infection after transplantation because it possesses the advantages of simplicity, speediness, sensitiveness, and high reliability of detecting productive HCMV infection. The major symptoms were prolonged or intermittent fever unresponsive to antibiotics, dysfunction or loss of function of the transplanted organ, pulmonary infiltrates and leukopenia. As our results suggested, reactivation of a latent infection appears to be the most probable etiologic factor contributing to HCMV infection after transplantation.

Etiology of acute exacerbation in patients with severe chronic active hepatitis by in situ HBVDNA hybridization technique

To explore etiology of acute exacerbation in severe chronic active hepatitis, in situ HBVDNA hybridization was carried out combined with detection of HBV markers in the serum and the liver as well as intrahepatic HDAg in 15 cases. Four subgroups were identified based on the etiological evidence: 1) 9 cases were still undergoing HBV active replication or reactivation with cytoplasmic and membraneous HBcAg expression, often associated with the hepatic necrosis foci; 2) 3 cases showed HBsAg or/and HBVDNA positivity despite absence of HBcAg expression, the membranous and homogeneous HBsAg expression being closely related with hepatic necrosis; 3) 2 cases were HDAg positive; 4) the remaining case exhibited no HBV infection evidence. All findings suggested that HBV active replication or reactivation was the major cause of the exacerbation in severe chronic active hepatitis. In addition, HBV superinfection accounted for over 10% of cases with acute exacerbation. Hepatitis A or C may contribute to some episodes of exacerbation.

Intrahepatic HBVDNA replication and gene products expression correlated with foci of hepatic necrosis

Intrahepatic HBVDNA of patients with chronic hepatitis B was detected by in situ cytohybridization assay in combination with demonstration of HBsAg and HBcAg expression, and correlated with the foci of hepatic necrosis. It was found that HBsAg and HBcAg expressing sites appeared in the same areas where HBVDNA replicated; when HBsAg and HBcAg simultaneously expressed in the liver, one antigen usually dominated, the other declined. This unbalanced expression may be caused by the gene or transcripts variance which encodes the surface or core antigen, or by the activity of each replication. The other observation is that HBVDNA-positive hepatocytes outnumbered liver cells containing HBsAg and HBcAg in a few cases. It is supposed that a part of cytoplasmic HBVDNA was on replicative phase with gene production expression, on the contrary, another part of cytoplasmic HBVDNA may be out of replication with no gene product expression during chronic hepatitis B. Finally HBsAg and HBcAg expressing sites corresponding to HBVDNA-positive hepatocytes were closely attached to the foci of hepatic necrosis. There was no significant difference in the frequency of HBsAg and HBcAg expression correlating to hepatic necrosis.

Investigation of HBV infection status in anti-HBe Chinese patients with chronic hepatitis by in situ hybridization assay

To investigate HBV infection in anti-HBe positive Chinese patients with chronic hepatitis, demonstration of intrahepatocellular HBV-DNA was performed by in situ hybridization technique, coupled with detection of intrahepatic HBcAg and HBsAg. Based on the presence or absence of HBV-DNA, HBcAg and HBsAg of 15 cases, three subgroups were identified: 1) 4 cases with HBV active replication characterized by intrahepatic HBV-DNA, HBcAg and HBsAg copositive; 2) 8 cases with HBV incomplete replication or antigen expression defined as positivity of both intrahepatic HBV-DNA and HBsAg; 3) 3 cases with HBV inactive replication described as absence of intrahepatic HBV-DNA, HBcAg and HBsAg. All findings strongly suggest that different HBV infection status could be distinguished among Chinese patients with seroconversion from HBeAg to anti-HBe positivity: a small number of cases had stopped replication; but part of the cases was still undergoing HBV active replication; on the other hand, HBV infection status in half of the remaining cases seemed to stay in an intermediate phase from active virus replication to inactive replication.