Immunohistochemical study of HLA class 1 antigens on the hepatocytes of patients with chronic hepatitis B

Serum concentrations of soluble HLA-class I and CD8 forms in patients with viral hepatic disorders

Soluble HLA-class I and CD8 molecules were determined by sandwich ELISA in patients with viral-induced hepatic disorders. As a whole, the patients with hepatic disorders (acute hepatitis: AH; chronic hepatitis: CH; liver cirrhosis: LC; hepatocellular carcinoma: HCC) showed higher sHLA-class I and sCD8 levels than normal controls (P < 0.001). AH patients had the highest sHLA-class I levels (mean, 3513 +/- 2112 ng/ml), followed by CH (2896 +/- 1290 ng/ml), LC (2293 +/- 1266 ng/ml), and HCC (2221 +/- 1212 ng/ml) sCD8 levels wer highest in AH, followed by HCC, LC, and CH, in that order. Among histologically defined C virus-positive patients, sHLA-I levels were higher in those with chronic active hepatitis (CAH) 2A (3802 +/- 1124 ng/ml) than in those with chronic persistent hepatitis (CPH; 2200 +/- 711 ng/ml; P < 0.01), the levels then decreased as the disease progressed (CAH2B, 3564 +/- 1783 ng/ml, LC, 2376 +/- 1265 ng/ml). In contrast, sCD8 values showed little difference among the disorders. sHLA-class I levels showed a positive correlation with sCD8 values both in whole patients and in patients with AH (P < 0.01), but no correlation was shown, in any patients, with biochemical parameters such as GPT and GOT. These findings, taken together, suggest that hepatic destruction is not the only cause of sHLA-class I production, but that sHLA-class I levels, together with sCD8 levels, may reflect immunological activity in hepatic disorders.

Possible association between HLA antigens and the response to interferon in Japanese patients with chronic hepatitis C

Correlation between the major histocompatibility complex class I antigens (HLA-A, -B and -C) and the elimination from serum of hepatitis C virus in patients with chronic hepatitis C has not been understood. We analyzed HLA phenotypes and their relationship to the efficacy of interferon treatment. Of the 172 patients who were treated with 9 million units of interferon-alpha 2a three times a week for 6 months, 54 patients were responders and 118 patients were non-responders. No significant difference was observed between the 172 patients and 199 healthy subjects with regard to the frequencies of HLA-A, -B and -C antigen phenotypes. However, HLA-B55, B62, CW3 and CW4 frequencies were significantly higher in responders than in non-responders to the interferon treatment. CW4 was found to link with B62, but other phenotypes were independent each other. Patients with HLA B55, B62 and CW3 had a significantly lower viral load, and showed a better response to interferon. These results suggest that HLA system does not have an influence on the evolution towards chronicity of the disease due to hepatitis C virus, but HLA B55, B62 or CW4, and CW3 may be a virus quantity-regulating factors which then affect to response to the interferon treatment, indicating that these HLA antigens in conjunction with a viral peptide is a key target antigen for cytotoxic T lymphocytes in patients with chronic hepatitis C.

Detection of interferon-alpha expression by PCR in patients with chronic hepatitis C and hepatitis non-A, non-B

The polymerase chain reaction (PCR) was used to examine expression of interferon-alpha (IFN A) genes in general and the expression of messenger RNA (mRNA) encoding the subtypes IFN-alpha-2 and IFN-alpha-4 in blood and liver biopsy samples from patients with chronic hepatitis C or hepatitis non-A, non-B (HC/HNANB) infection entered into a trial of IFN-alpha-2a therapy. Peripheral blood mononuclear cells (PBMC) from healthy controls and HC/HNANB infected patients were studied for their capacity to produce transcripts encoding IFN-alpha after stimulation with Sendai virus. Expression at the level of mRNA for IFN A and the subtypes IFN A2 and A4 was detected in both controls and HC/HNANB infected patients PBMC and no significant difference was seen in expression of IFN A transcripts or level of total IFN-alpha secreted into culture supernatants between controls and patients. Interferon A, and specifically IFN A2 and IFN A4 transcripts were detected in a high proportion of liver biopsies from patients with HC/HNANB infection. The presence of IFN A mRNA (and specifically IFN A2 and IFN A4) showed no correlation to histological improvement nor response to therapy. The use of PCR to detect those IFN A genes that are not expressed, thereby identifying subtypes that may be lacking, could be the key to the choice of IFN-alpha subtypes that are used for effective therapy.

Immunohistochemical study of the distribution of intercellular adhesion molecule-1 and lymphocyte function-associated antigen-1 in chronic type B hepatitis

The expression of intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen-1 (LFA-1) in the livers of 11 patients with chronic hepatitis B was studied immunohistochemically by light and electron microscopy to clarify the role of these adhesion molecules in tissue damage in chronic hepatitis B. On hepatocytes, ICAM-1 expression was confined to the bile canalicular surface when the liver inflammation was mild. In contrast, when the liver inflammation was severe, ICAM-1 was distributed on the entire surface of the hepatocyte, including the sinusoidal and lateral membranes; lymphocytes which were mostly positive for LFA-1, were often observed invading deeply among these hepatocytes. The degree of ICAM-1 expression on the hepatocytes was also related to the expression of HLA class 1 antigen. In liver showing diffuse expression of ICAM-1 on the hepatocytes, strong expression of HLA class 1 antigen was observed, and amounts of HBV in the liver were decreased. Diffuse expression of ICAM-1 and HLA class 1 antigen was mostly observed after acute exacerbation of liver inflammation. These results suggest that the ICAM-1/LFA-1 pathway is involved in the immunological mechanism responsible for liver cell damage in chronic hepatitis B.

Soluble HLA class I antigens in sera of patients with chronic hepatitis

Soluble HLA Class I antigens in sera (serum-HLA Class I, s-HLA Class I) of patients with chronic hepatitis (CH) were measured with an enzyme-linked double determinant immunoassay (E-DDIA). The mean titers of s-HLA Class I antigens of patients with CPH (mean +/- standard deviation, 2.22 +/- 1.60), CAH2A (2.24 +/- 1.65) or CAH2B (2.73 +/- 1.46) were significantly higher than that of normal subjects (0.36 +/- 0.27) (P less than 0.01). The titer of s-HLA Class I correlated significantly with the level of serum glutamic pyruvic transaminase (s-GPT) (r = 0.73), and weakly with serum level of beta 2-microglobulin (r = 0.43). In patients with chronic hepatitis type B (CH-B) treated with human lymphoblastoid interferon alpha (IFN-alpha), the titer of s-HLA Class I antigens increased. The increased level of s-HLA Class I antigens in the clinical course of chronic hepatitis may be caused by their release from necrotizing hepatocytes which have acquired the expression of HLA Class I antigens on the cell-surface membrane during viral infection.

Liver transplantation in HBs antigen (HBsAg) carriers. Prevention of hepatitis B virus (HBV) recurrence by passive immunization

Liver transplantation in HBs-antigen (HBsAg) positive allograft recipients is associated with a high risk of HBV recurrence some time after surgery. So far, results of measures to prevent recurrent HBV-infection by means of treatment with interferon, hepatitis B vaccination and short-term passive immunization with hepatitis B immunoglobulin (HBIg) or monoclonal antibody to HBsAg (anti-HBs) have been disappointing. In the present study the results of long-term, anti-HBs monitored passive immunization with HBIg is reported. In 23 HBsAg-positive liver transplant recipients an anti-HBs level of greater than or equal to 100 IU/l was maintained for 6 or 12 months, respectively. The rate of recurrent infection was found to be less than 20% under HBIg substitution, whereas 11 graft recipients with no or only short-term HBIg prophylaxis were reinfected by month 15 after transplantation. HBV recurrence was associated with chronic liver disease and recurrent cirrhosis in the allograft.