L. Mazzoran

Clinical and virological findings in mixed cryoglobulinaemia

Abstract. Objectives. As a close relationship has been established between mixed cryoglobulinaemia and hepatitis C virus (HCV) infection, the clinical, histological and virological findings of patients affected by mixed cryoglobulinaemia were determined.

Ethnic difference in the prevalence of monoclonal B-cell proliferation in patients affected by hepatitis C virus chronic liver disease.

BACKGROUND/AIM In previous studies we demonstrated that all patients affected by HCV-positive type II mixed cryoglobulinaemia have a monoclonal B-cell population in peripheral blood mononuclear cells, and that a large fraction of HCV-infected patients develop a monoclonal B-cell expansion, even in the absence of dosable serum cryoglobulins. However, the prevalence of Type II mixed cryoglobulinaemia in HCV-infected individuals seems to be high in Italy, whereas it is very low in Japan. This study was performed to investigate whether there are ethnic differences in the prevalence of asymptomatic HCV-associated monoclonal B-cell expansions. METHODS Forty-four Japanese patients affected by HCV-positive chronic liver disease (two healthy carriers, 31 chronic hepatitis and 11 cirrhosis) were compared with a group of 60 Italian patients (one healthy carrier, 49 chronic hepatitis, and 10 cirrhosis) without dosable levels of cryoglobulins. The monoclonality of peripheral blood mononuclear cells was investigated by RT/PCR analysis of Immunoglobulin gene rearrangements. Liver function tests, rheumatoid factor, cryocrit level, anti-HCV antibodies, HCV-RNA, and HCV genotype were performed according to standard methodology. RESULTS A B-cell monoclonal population was found in 26% of Italian patients, whereas all Japanese patients were negative. No correlation was found between B-cell monoclonality and severity of liver disease, length or source of the infection, HCV genotype, sex, clinical and biochemical parameters. CONCLUSIONS This study indicates that a monoclonal B-cell proliferation in peripheral blood mononuclear cells is common in HCV infection, but only in Italy, whereas it is absent in Japan. This explains the very low prevalence of Type II mixed cryoglobulinaemia in HCV-positive Japanese subjects, and suggests that HCV is able to determine a B-cell expansion only in the presence of, presently undetermined, host factors.

Hepatic glutathione determination after ethanol administration in rat: Evidence of the first-pass metabolism of ethanol

As a fraction of ingested ethanol is metabolized by gastric mucosa, different amounts of alcohol should reach the liver when the same dose is administered by oral or intravenous route. Therefore, we investigated the time-course of hepatic reduced glutathione (GSH) concentrations after intra-peritoneal or intra-gastric load of the same amount of ethanol in the rat. The test was also performed in fasted and Cimetidine-treated rats. The oral ethanol administration was followed by a less pronounced decrease and by a quicker recovery of hepatic content of GSH than after intraperitoneal route. In the fasted rat, basal hepatic GSH significantly decreased; after alcohol administration the decrease of hepatic GSH was more severe and prolonged than in the fed rat. Cimetidine was shown to be a potent inhibitor of gastric ADH. Pre-treatment with Cimetidine did not change the basal levels of hepatic GSH, but after oral ethanol load, the decrease of the hepatic GSH content was significantly (p < 0.005) more pronounced than in controls. This study demonstrates the beneficial effects of gastric ethanol metabolism on the liver. The reduced gastric ethanol metabolism, induced by fasting or by Cimetidine resulted in a decreased content and delayed recovery of liver GSH content.

Effects of interferon therapy on fibrosis serum markers in HCV-positive chronic liver disease.

Objective To evaluate serum levels of prolyl-hydroxylase and helical domain of Type IV° collagen, markers of hepatic fibrogenesis, in patients with HCV-positive chronic liver disease and the effects of Interferon therapy on these markers. Design Prolyl-hydroxylase and Type IV collagen were determined before therapy and each month during the treatment and follow-up. Methods Fifty-seven HCV-positive patients were studied. All the subjects received α2a recombinant interferon, 6 MU subcutaneously three times a week for 4 weeks, followed by 3 MU thrice weekly for 5 months. After cessation of treatment, each patient was followed for 12 months. Prolyl-hydroxylase and helical domain of Type IV° collagen were measured by using immunoenzymatic methods. HCV-RNA and HCV genotype were determined according to the method of Okamoto. Results In the patients prolyl-hydroxylase (39.8 ± 8.9 ng/ml) was not different from controls (39.1 ± 5.9 ng/ml). On the contrary, the patients showed a mean Type IV collagen (133.6 ± 93.3 ng/ml) significantly (P< 0.01) higher than controls (100.2 ± 10.5 ng/ml). A good relationship between the degree of liver fibrosis and the Type IV° collagen serum level was found (r = 0.68; P < 0.005). In both responders and non-responders the Type IV collagen levels decreased during interferon therapy. During the follow-up, in responders the Type IV° collagen did not show modifications, while in non-responders/relapsers it returned rapidly to the pretreatment levels (139.1 ± 100.7 ng/ml). Conclusion In HCV-positive chronic liver disease, prolyl-hydroxylase is not a good marker of hepatic fibrosis, while Type IV collagen is a useful tool for evaluating fibrogenic activity. Interferon seems to be able to reduce the liver fibrosis even without the inhibition of viral replication and independently from liver necrosis.

Hepatic glutathione after ethanol administration in rat: effects of cimetidine and omeprazole.

As a fraction of ingested ethanol (EtOH) is metabolized by gastric mucosa, different amounts of alcohol reach the liver, when the same dose is administered by oral or intravenous route. In previous experiments, we demonstrated that the decrease of hepatic reduced glutathione (GSH) is less pronounced and is followed by a quicker recovery after oral than after intraperitoneal administration of the same amount of EtOH. Therefore, the time-course of hepatic GSH concentration seems to be an indirect assay of EtOH metabolism by the liver. On the basis of these findings, any condition causing a reduced function of gastric alcohol dehydrogenase (ADH) should show up as a more severe depletion of hepatic GSH. In the same rat experimental model we determined the effects of cimetidine and omeprazole administration on gastric ADH activity and on the time-course of hepatic GSH after EtOH load. Cimetidine was shown to inhibit gastric ADH with a Ki of 0.167 +/- 0.009 mmol l-1; accordingly, the pretreatment with this drug (20 mg kg-1 b.w. per day for 1 week) determined, after oral EtOH load, a marked reduction of hepatic GSH, likewise after intraperitoneal administration. Omeprazole exerted only a marginal inhibition on gastric ADH and this drug (0.3 mg kg-1 b.w. per day for 1 week) did not modify the time-course of hepatic GSH concentrations after EtOH load. This study indicates that the inhibition of gastric ADH, when associated with EtOH intake, induces depletion of the hepatic GSH concentration and, therefore, possible liver damage.