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The purpose of this in situ immunophenotyping study was to assess the nature of lymphoid cells involved in chronic hepatitis B with various levels of replication. Replicative status was studied in 25 patients with chronic hepatitis B. Different subsets of T cells, B cells, natural killer cells, and follicular dendritic cells were counted with a computerized image analyzer. Twelve patients had chronic hepatitis B with a high level of replication, nine without replication, and four with a low level of replication. The number of CD3+ T cells was significantly higher in the liver of patients with replication. In all cases, CD8+ T cells were the most numerous cells in the lobules and CD4+ T cells were the most numerous cells in the portal tract. Intra-portal lymphoid follicles were observed in 33% of patients with a high level of replication. The CD57+ natural killer cells were more numerous in patients with a low level of replication. This study suggests that in immunocompetent patients, the intensity and type of hepatic immune response are directly determined by the HBV replication.

Background/aims: Complement activation is one of the mechanisms involved in inflammatory lesions. Initiation of the complement terminal pathway at a cell surface leads to the formation of a cytolytic membrane attack complex. Our study assess whether a membrane attack complex-associated mechanism is involved in liver cell necrosis of fulminant and subfulminant hepatitis., Methods: Immunostaining for membrane attack complex was compared with immunostaining for cytokeratin and complement inhibitory proteins such as membrane cofactor protein, decay-accelerating factor, and homologous restriction factor in 15 patients with fulminant hepatitis and 5 patients with nonfulminant acute hepatitis., Results: In all patients, hepatocytes surrounding necrotic areas, but not those at a distance, were stained for membrane attack complex, whereas the opposite staining pattern for membrane cofactor protein was observed. In controls, no hepatocyte staining for membrane attack complex was observed, whereas membrane cofactor protein, but not decay-accelerating factor or homologous restriction factor, was detected on hepatocytes., Conclusions: Complement activation by antibody-dependent or non-antibody-dependent mechanisms might be involved in the pathogenesis of either fulminant or acute hepatitis. Modulation of membrane cofactor protein expression on hepatocytes might contribute to the sensitivity of hepatocytes to membrane attack complex and subsequent cell lysis.

The aim of this study was to assess the causes of histologically proven chronic hepatitis in a series of 357 consecutively admitted patients. Patients with chronic alcohol intake above 50 g per day, Wilson's disease, idiopathic hemochromatosis or homozygous alpha-1 antitrypsin deficiency were excluded. Sera of all patients were tested for antibodies to hepatitis C virus with second-generation enzyme-linked immunoassay and recombinant immunoblot assay, for markers of hepatitis B and hepatitis D viruses, and for autoantibodies. Detection of hepatitis C viral RNA by polymerase chain reaction was attempted if recombinant immunoblot assay was indeterminate, or if both viral and autoimmune markers were absent. If no serum markers, including HCV RNA, were found, the cause of chronic hepatitis was considered as unknown. The cause of chronic hepatitis was found in 343 cases (96.4%), including three patients with HCV RNA as the only marker. Chronic hepatitis was related to hepatitis C virus in 51.8%, to hepatitis B virus in 32.8% (including hepatitis D infection in 3.1%), and to autoimmune hepatitis in 5.9% of cases, respectively. No case of drug-induced chronic hepatitis was observed in this series, and in 5.9% of cases, there were probably multiple causes. Finally, in 3.6% of the cases the cause of chronic hepatitis remained unknown despite extensive evaluation suggesting the existence of a non-A, non-B, non-C viral agent.

T lymphocytes have been assumed to play an essential role in tissue injury in patients with chronic hepatitis B. As hepatitis B virus (HBV) is considered as a major factor controlling liver inflammation, we assessed whether a particular T lymphocyte subset could be preferentially detected in the liver in accordance with viral replication. Liver-derived lymphocytes and peripheral blood lymphocytes were analysed by flow cytometry in 21 patients with histologically confirmed chronic hepatitis B without cirrhosis. Viral replication was quantified by hybridization of serum HBV DNA. Eleven patients exhibited an active viral replication with serum HBV DNA ranging from 10 to 388 pg/ml at the time of the liver biopsy, whereas 10 patients had no detectable serum HBV DNA. In patients exhibiting viral replication, CD4+/CD8+ ratios of liver-derived lymphocytes were significantly higher (P < 0.05) than those obtained in patients without viral replication. In contrast, the percentage of T cells expressing the gamma/delta receptor and that of CD2+/CD57+ cells were similar in both groups of patients. Furthermore, in patients exhibiting viral replication, CD4+CD8+ ratios of liver-derived lymphocytes correlated with serum HBV DNA levels (P < 0.001). No relationship between CD4+/CD8+ ratio of liver-derived and peripheral blood lymphocytes was observed. Our data indicate that, in patients with chronic hepatitis B, the CD4+/CD8+ ratio of liver-derived lymphocytes correlates with viral replication. This suggests that in situ helper/inducer CD4+ T lymphocytes may positively regulate the cytotoxic T cell activity in patients with HBV-related chronic hepatitis.

To determine the prevalence of hepatitis C virus (HCV) infection in homosexuals with chronic hepatitis, we tested for anti-HCV antibodies 113 (47 anti-HIV positive) French non-drug-addicted homosexual men admitted for chronic viral hepatitis. Anti-HCV were detected with second- and third-generation ELISAs (ELISA2 and ELISA3) and RIBAs (RIBA2 and RIBA3). Chronic hepatitis was related to non-A, non-B infection in four, to hepatitis D virus (HDV) infection in five and to hepatitis B virus (HBV) infection in 104 patients. Anti-HCV positivity was found in 50.4% and 12.4% of the 113 patients, with ELISA2 and ELISA3, respectively. Positivity with RIBA2 and RIBA3 was found in only six of the 57 ELISA2 positive patients (all six were ELISA3 positive). The high prevalence of positivity with ELISA2 not confirmed by RIBA2 or RIBA3 suggests false-positive results. ELISA2 positive results were more frequent with frozen serum samples than with fresh serum samples (62% vs 23.5%, p = 0.0003). However, even with fresh serum, ELISA2-positive RIBA-negative results remained frequent in anti-HIV positive patients. ELISA3 seems to give more specific results. We conclude that the prevalence of HCV infection, as assessed with RIBA, was 5.3% among French homosexual men with chronic hepatitis (3.8% after exclusion of transfused patients). This low prevalence suggests that homosexual transmission of HCV is relatively uncommon.

Essential mixed cryoglobulinemia is frequently associated with chronic hepatitis. This report presents four cases of cryoglobulinemia with vasculitis associated with chronic hepatitis related to hepatitis C virus infection. Hepatitis C virus infection was ascertained in the four patients by both the presence in the serum of anti-HCV antibodies detected by the four-antigen recombinant immunoblot assay and of HCV RNA detected by polymerase chain reaction. In two patients tested, anti-HCV antibodies were not detected after centrifugation in the purified cryoglobulin but were detected in the supernatant. HCV RNA was detected in the purified cryoglobulin in all four patients and was detected in the supernatant in three patients. In one patient receiving recombinant interferon alfa, serum aminotransferases normalized and cryoglobulin disappeared; in another patient receiving recombinant interferon alfa, serum aminotransferases remained high and the cryoglobulin persisted. The presence of HCV RNA in the cryoglobulin and the parallelism of the changes of the cryoglobulinemia and of the serum aminotransferases during recombinant interferon alfa administration suggest that HCV infection is responsible for the production of cryoglobulinemia and vasculitis. It is proposed that HCV infection is a cause of cryoglobulinemia associated with chronic hepatitis.

We have demonstrated, with optical and transmission electron microscopy, that Trypanosoma cruzi trypomastigotes infect and multiply inside T lymphocytes. The infection rate we have observed in T cells was similar to that seen in the case of macrophage or polymorphonuclear cell infection. Flow cytofluorometric analysis of T lymphocytes purified from mice in the acute phase of the disease, revealed the presence of parasite-derived antigens on their surface. These antigens appear to be specific to T. cruzi and they could be the result of intracellular parasite antigens as well as adsorption of T. cruzi antigens on the surface of noninfected T cells. Antibodies recognizing these surface antigens were present in both T. cruzi-infected mouse and human sera. They were able to induce antibody-dependent cell-mediated cytotoxicity (ADCC) in the presence of nonimmune mononuclear cells both in autologous and in heterologous combinations. Consequently, we provided evidence suggesting that T lymphocytes could be destroyed during the acute phase of Chagas' disease either by cell infection or by an ADCC mechanism against cells bearing parasite antigens on their surface. Thus, the ability of trypomastigotes to invade T cells may play a crucial role in the immunopathogenesis characteristic of Chagas' disease.

A case of nonfamilial juvenile polyposis coli was associated ganglioneuromatous proliferation in the polyps is described. The ganglioneuromatous proliferation was characterized by clusters of mature ganglion cells and nerve fiber bundles in the lamina propria and submucosa of the juvenile polyps. The patient had no history of von Recklinghausen's disease or multiple endocrine neoplasia syndrome, type 2b. The implications of this peculiar finding are discussed and the literature is reviewed.

A new brain-cutting box aids in the sectioning of autopsied brains along planes that correspond to computerized axial tomographic (CT) scans levels. There are two plastic boxes, one inside the other. The inner one has a platform slanted at a 15 degree angle from the horizontal plane. The brain, resting on this platform, can be raised by elevating the inner box and can be sectioned along the horizontal upper free edges of the outer box. The resulting sections, cut at appropriate intervals, correspond to CT scans. This box has numerous advantages over existing brain-cutting devices.