Today medical-scientific data are diluted by the marketing strategies of the biomedical industry making it difficult for practising physicians to decide what is correct or wrong. One typical example is the use of pegylated interferons for treatment of chronic hepatititis C. In this report the arguments pro and contra weight-based dosing are critically discussed. The factors contributing to success or failure to eradicate the virus are manifold, and include the sensitivity of the virus to interferon, viral genotype, age, gender stage of fibrosis, presence or absense of steatosis. Weight by itself plays just a minor role. The impact of weight-based dosing in general is overestimated and certainly not needed when 40 kD branched PEG-IFNα2a with a restricted volume of distribution is used. Whether weight-based dosing of 12 kD linear PEG-IFNα2b provides any benefit over a flat dose of the drug remains to be studied.
Serum levels of GABA (gamma-aminobutyric acid)-like activity were measured by a radioreceptor assay in 22 healthy subjects and 170 patients with liver diseases. Levels were within normal limits (mean±SEM in healthy controls 0 ·52±0·04 μmol/l; range 0·2-0·8 μmol/l GABA equivalents) in most patients with uncomplicated acute viral hepatitis, compensated chronic hepatitis, and primary biliary cirrhosis (PBC). In 96% of patients with compensated (non-PBC) cirrhosis levels were slightly high (1·5+0·06 μmol/l). In 4 patients with
The efficacy of antiviral therapy with pegylated interferon (PEGIFN) plus ribavirin (RBV) in patients with HIV and hepatitis C virus (HCV) coinfection is limited. Intravenous silibinin (ivSIL), a milk thistle extract with proven antiviral effects represents a novel therapeutic strategy for virological nonresponders.
Thirty patients with chronic non-A, non-B hepatitis (24 male, six female; median age 38 years, range: 15–68 years) were treated with recombinant interferon alfa-2b for 1 year. Treatment was started with 5 million units interferon alfa-2b daily for 2 weeks followed by 2 million units daily for another 2 weeks. Further doses were titrated according to alanine aminotransferase values. After 1 year, treatment was stopped and a follow-up biopsy was obtained. Thereafter, patients were followed for 6 months. Of the 24 patients who completed the 1-year treatment period, 14 (58%) had normal alanine aminotransferase values at the end of the study, eight of whom showed transient increases while on treatment. In another seven (29%), alanine aminotransferase levels decreased by more than 50% of pre-treatment values but remained above the normal range. Biopsies at the end of treatment showed a complete disappearance of inflammatory activity in four and a marked improvement in eleven other patients. The results of this study indicate that a 1-year treatment with recombinant interferon alfa-2b of patients with non-A, non-B hepatitis was very effective at normalizing or improving serum transaminases and liver histology. However, the overall relapse rate was 57%, with relapse occurring in a greater proportion of patients with temporary breakthroughs during therapy (requiring dosage increase), and particularly of patients with only a partial response to treatment (serum transaminases decreased by ⩾ 50%). Thus, further studies are needed to establish the optimal dose and duration of treatment to induce a complete resolution of the disease.
The increase of the brain levels of 5-hydroxyindoleacetic acid (5-HIAA) in hepatic encephalopathy (HE) suggests an increased turnover of serotonin (5-HT). To study the role of tryptophan on the increased brain 5-HT metabolism in HE, we attempted to monitor brain levels of tryptophan in rats with thioacetamide-induced acute liver failure by intravenous infu-sion of branched-chain amino acids (BCAA). The effect of this treatment on 5-HT synthesis and metabolism was investigated in five brain areas. BCAA-infusions (1 and 2 gm/kg/24 h) increased the ratio BCAA/aromatic amino acids in plasma two- and fourfold, respectively, and lowered both plasma and brain levels of tryptophan. At the higher BCAA-dose all parameters suggesting an altered brain 5-HT metabolism (increased brain levels of 5-HT and 5-HIAA, increased 5-HIAA/5-HT ratio) were almost completely normalized. These results provide further evidence for the role of tryptophan in the elevation of brain 5-HT metabolism and for a potential role of BCAA in the treatment of HE.