Pharmacokinetics of troglitazone, a PPAR-gamma agonist, in patients with hepatic insufficiency.

OBJECTIVE: Troglitazone is an agonist of the peroxisome proliferator-activated receptor-gamma (PPAR-gamma), which has been shown to improve the metabolic control of type 2 diabetes. Troglitazone undergoes hepatic metabolism to an inactive sulphate conjugate and an oxidative quinone metabolite with minor activity. The objective of this study was to compare the pharmacokinetics of troglitazone in patients with hepatic insufficiency and normal subjects. METHODS: Three groups of eight subjects with normal liver function and moderate or severe hepatic impairment (Pugh-Child classification) completed this open study. Subjects received a single 400-mg dose of troglitazone 30 min after breakfast. Plasma concentrations of troglitazone and its metabolites were measured and standard pharmacokinetic parameters derived. RESULTS: A 46% increase in area under the plasma concentration-time curve (AUClast) was observed for troglitazone, together with a 154% increase for the quinone metabolite in the patients with moderate hepatic impairment compared with normal subjects, but these did not reach statistical significance. Corresponding increases of 18% and 53% in the severe group also failed to reach statistical significance. For the sulphate conjugate, the AUClast values for both moderate and severe hepatic impairment were in the order of fourfold higher than those in the normal group. There were reductions in the maximum observed plasma concentration (Cmax) of troglitazone to 61% of the normal group in the severe group for troglitazone, and twofold increases in sulphate metabolite Cmax in the moderate and severe groups. There was an approximately threefold increase in the half-life of the sulphate conjugate in subjects with both moderate and severe impairment of liver function compared with normal individuals. First times to maximum concentrations of troglitazone, its sulphate conjugate and the quinone metabolite were significantly longer in all severely impaired subjects compared with those with normal hepatic function, although the range was wide in all cases. Plasma protein binding was high in all subjects measured (mean unbound fraction range 0.7-5.1%), but there were insufficient samples to compare across groups. CONCLUSION: The formation of metabolites of troglitazone following a single dose is not impaired in the presence of reduced liver function although the capacity to eliminate the metabolites is altered. The clinical significance of the effect of liver disease on the conjugates is not clear.

Two dose regimens of recombinant interferon-alpha-2b in chronic hepatitis C virus infection. Biochemistry, hepatitis C virus RNA, and liver histology as response indices.

BACKGROUND: Recombinant interferon remains the cornerstone of treatment of chronic hepatitis C virus (HCV) infection. Still, evaluation of treatment on the basis of response indicators and long-term effect of the treatment raises several questions. METHODS: Seventy-four patients with chronic HCV infection were randomized to a high (3 MIU, 3/7 days) or low (1 MIU, 3/7 days) dose of recombinant interferon-alpha-2b for 48 weeks after a 4-week course of 3 MIU, 3/7 days. Response to treatment was assessed by means of liver enzymes (transaminases), HCV RNA, and liver histology. RESULTS: The higher maintenance dose was associated with a significantly higher rate of sustained alanine aminotransferase (ALAT) response (45% versus 19%) and with a significantly better chance of becoming HCV RNA-negative during therapy (47% versus 23%). In the high maintenance dose group 14 of the 29 (48%) patients with available HCV RNA data were negative at the 3-month follow-up, compared with 4 of 27 (15%) in the low maintenance dose group. Significantly more patients had improved liver biopsy findings after interferon in the high maintenance dose group (79%) than in the low maintenance dose group (36%). There was a close correlation between ALAT response and HCV RNA response. Of 17 patients who were HCV RNA-negative 3 months after the end of treatment, 10 remained HCV RNA-negative 2-4 years later. CONCLUSION: The study demonstrates a higher response rate as assessed by biochemistry, HCV RNA, and liver histology in the higher dose group.

The lipoic acid containing components of the 2-oxoacid dehydrogenase complexes mimic trifluoroacetylated proteins and are autoantigens associated with halothane hepatitis.

Anti-CF3CO antibodies, monospecific toward trifluoroacetylated proteins (CF3CO-proteins), which are elicited in experimental animals and humans exposed to the anesthetic agent halothane, cross-react with an unknown protein of approximately 52 kDa, constitutively expressed in tissues of experimental animals and humans not previously exposed to the agent. Using anti-CF3CO antibody, the protein(s) of 52 kDa could be immunoprecipitated from solubilized rat heart homogenate. Two-dimensional gel electrophoretic analysis revealed the presence of distinct major (P1, P2) and minor (P3, P4, P5) protein components with apparent molecular masses of 52 kDa. From each of the components P1 and P2, the amino acid sequences of three peptides were determined and found to exhibit 100% identity with the corresponding amino acid sequences of the E2 subunit of the rat 2-oxoglutarate dehydrogenase complex (OGDC). Additionally to the E2 subunit of OGDC, anti-CF3CO antibody also recognized on immunoblots the purified E2 subunit of the branched chain 2-oxoacid dehydrogenase complex (BCOADC) and protein X, a constituent of the pyruvate dehydrogenase complex (PDC), in a manner sensitive to competition by N6-(trifluoroacetyl)-L-lysine (CF3CO-Lys), 6(RS)-lipoic acid, and N6-(6(RS)-lipoyl)-L-lysine (lipoyl-Lys). Furthermore, a discrete population of autoantibodies was identified in sera of patients with halothane hepatitis which could not discriminate between the lipoylated target epitope present on the E2 subunit of OGDC and epitopes on CF3CO-RSA, used as model for CF3CO-proteins. These data suggest that the autoantigenicity of these proteins in halothane hepatitis is based on the molecular mimicry of CF3CO-Lys by lipoic acid, the prosthetic group common to protein X and the E2 subunits of OGDC and BCOADC.

[Fulminant liver failure before and after introduction of liver transplantation at Rikshospitalet]. / Fulminant leversvigt før og efter indførelse af levertransplantation på Rigshospitalet.

The impact of liver transplantation on the survival in fulminant hepatic failure was evaluated in a retrospective study including 87 patients admitted to Rigshospitalet over a three and a half year period before and a three and a half year period after the Danish liver transplantation programme was started. The number of admissions increased by 178% in the second period. Fifty-two percent of the patients had acetaminophen induced liver failure, which over the last seven years has become the most common cause of severe acute liver disease in Denmark. In about half of the patients high volume plasmapheresis was used as liver-assist either alone or in combination with liver transplantation. Three patients in grade 4 hepatic coma (one with Hepatitis B, two with acetaminophen intoxication) were withdrawn from the waiting list for emergency liver transplantation after high volume plasmapheresis due to recovery. In patients with an estimated survival chance of less than 5-10% liver transplantation was performed with a survival rate of 60%. The survival rate for the non-liver transplanted patients was 49% in the same period compared to 30% in the three and a half year period before liver transplantation started.

Drug metabolism and genetic polymorphism in subjects with previous halothane hepatitis.

To test the hypothesis that halothane hepatitis is caused by a combination of altered drug metabolism and an immunoallergic disposition, the metabolism of antipyrine, metronidazole, sparteine, phenytoin, and racemic R- and S-mephenytoin was investigated in seven subjects with previous halothane hepatitis. The HLA tissue types and the complement C3 phenotypes were also determined. The metabolism of antipyrine and metronidazole was within normal range in all subjects, and they were all fast or extensive metabolizers of sparteine, mephenytoin, and phenytoin. HLA tissue types were unremarkable. Five of the seven subjects had complement C3 phenotypes F or FS. In the general population phenotype S is the most common, but the difference in complement C3 phenotypes is not statistically significant (p = 0.07). We conclude, although in a limited number of patients, that subjects with previous halothane hepatitis do not appear to be different from controls with regard to drug metabolism and HLA tissue type. The possibility of a higher frequency of complement C3 phenotype F and FS needs further investigation.

[Fulminant hepatic failure]. / Fulminant leversvigt.

Fulminant hepatic failure is a rare disorder with a high lethality. It is characterized by the development of acute hepatic symptoms and encephalopathy, in the absence of underlying chronic liver disease. The main causes are viruses, adverse drug effects and toxins. The major causes of death in patients with fulminant hepatic failure are cerebral edema, infections, gastrointestinal hemorrhage and renal failure, or a combination of these. Treatment of fulminant hepatic failure with a variety of medical therapies has hitherto been found to have little overall influence on outcome. With high volume plasmapheresis the clinical condition of the patients improves, and if there is no sign of spontaneous regeneration, emergency liver transplantation is the only solution.

Cyclosporin A treatment in primary biliary cirrhosis: results of a long-term placebo controlled trial.

BACKGROUND: Effective treatment for primary biliary cirrhosis (PBC) resulting in slower progression and improved survival remains elusive. Cyclosporin A (CyA), which has been so effective in preventing human allograft rejection, has shown promise in small numbers of patients in early studies. METHODS: Three hundred forty-nine patients with PBC were randomized to receive CyA, 3 mg.kg-1.day-1, or placebo in a multicenter study with follow-up for 6 years. The end point was death or liver transplantation. RESULTS: Cox multivariate analysis showed time from entry to death or transplantation was significantly prolonged (by up to 50%) in the CyA-treated group. Liver-related mortality was also significantly lower. However, a univariate analysis of survival showed no statistical differences between the two groups. Biochemical liver indices deteriorated more slowly in the CyA-treated group, but serum creatinine concentration was elevated > 150 mumol/L in 9%, necessitating permanent discontinuation in half of these. A reduction in the dose of CyA was required in 11% because of hypertension. CONCLUSIONS: CyA has some therapeutic potential in primary biliary cirrhosis, providing blood pressure and renal function are closely monitored.

Glutathione treatment of hepatocellular carcinoma.

This prospective study was undertaken to substantiate observations that glutathione (GSH) inhibits or reverses tumor growth in humans with hepatocellular carcinoma (HCC), a neoplasm with an extremely poor prognosis. Eight patients with biopsy-proven HCC not amenable to surgery were given 5 g of GSH daily from the time of diagnosis. Two patients withdrew shortly after receiving GSH due to intolerable side-effects. Of the six eligible patients, two had mildly advanced tumors and four moderately advanced tumors. At 1-2-month intervals the liver was CT and ultra-sound scanned to assess the growth status of the tumor (progression, stagnation or regression). All the patients, except a male with a fibrolamellar type of HCC, died within 1 year after diagnosis. Two women with moderately advanced tumors survived almost 1 year, tumor growth stopped or regressed and in one of the women an initially abnormal alfa-1-fetoprotein (AFP) returned to normal after GSH treatment. AFP remained normal throughout the treatment period in the other women. These observations indicate that GSH may have a sex-dependent effect on HCC. However, further studies involving more patients are required to pursue this hypothesis.

DNA polymorphism of HLA class II genes in primary biliary cirrhosis.

We investigated the DNA restriction fragment length polymorphism of the major histocompatibility complex class II genes: HLA-DRB, -DQA, -DQB, DPA, -DPB, the serologically defined HLA-A, B, C, DR antigens, and the primed lymphocyte typing defined HLA-DP antigens in 23 Danish patients with primary biliary cirrhosis (PBC) and in healthy Danes. The following genetic markers were found with increased frequencies in PBC: HLA-B8 (relative risk, RR = 2.4, P less than 0.05, 'corrected' P greater than 0.05), HLA-DR3 (RR = 3.4, P less than 0.01, 'corrected' P less than 0.05), the DRB3*01/02/03 (DRw52) associated DRB Bgl II 9.1 kilobase (kb) fragment (RR = 2.9; P less than 0.05, 'corrected' P greater than 0.05), the DQA1*0501 associated DQA Taq I 4.8 kb fragment (RR = 3.1; P less than 0.05, 'corrected' P greater than 0.05), the DQB1*0201 (DQw2) associated DQB Hin dIII 11.5 kb fragment (RR = 3.1; P less than 0.05, 'corrected' P greater than 0.05). No DNA fragments specific for DRB1*0301 (DR3) could be identified. The frequencies in PBC of other genetic markers including DRw8, DRB1*08, HLA-DP antigens, DPA, and DPB genes did not differ significantly from those in controls. The associations between PBC and B8, DR3, DQA1*0501, and DQB1*0201, which are frequently found together on the same haplotype, are at variance with recent reports on associations between PBC and Drw8. The discrepancy suggests that PBC is genetically heterogenous.

The influence of disulfiram on acetaminophen metabolism in man.

1. Acetaminophen clearance and its partial clearance to its major metabolites has been determined before and after 5 days treatment with the anti-alcohol abuse agent disulfiram (200 mg daily). The study was conducted in 10 subjects, five without liver disease and five with alcoholic cirrhosis of the liver. Acetaminophen was given i.v. at a dose of 500 mg. Plasma samples were obtained up to 8 h after injection and urine collected for 24 h. 2. Across all subjects acetaminophen plasma clearance was reduced from 0.249 +/- 0.061 to 0.217 +/- 0.066 l/min after disulfiram treatment (mean +/- SD, P less than 0.05). Thus no change in acetaminophen dosage would be required in patients treated with disulfiram. 3. The partial clearance of acetaminophen to its glucuronide, sulphate and glutathione derivatives (i.e. cysteine and N-acetyl cysteine) was not significantly changed by disulfiram treatment. Thus it seems unlikely that the previously observed protective effects of disulfiram against acetaminophen-induced hepatotoxicity in animals due to inhibition of metabolism will be seen in man.

NcoI restriction fragment length polymorphism (RFLP) of the tumour necrosis factor (TNF alpha) region in primary biliary cirrhosis and in healthy Danes.

The restriction fragment length polymorphism of the human tumour necrosis factor (TNF alpha) region was investigated by means of 20 different restriction enzymes and a human TNF alpha cDNA probe. Only one of the enzymes, NcoI, revealed a polymorphic pattern consisting of fragments of 10.5 and 5.5 kb, which behaved as alleles. In a panel of 108 random, healthy, unrelated Danes, the phenotype frequencies of the 10.5 and 5.5 kb bands were 0.94 and 0.53 and the gene frequencies were 0.71 and 0.29, respectively. The test for Hardy-Weinberg equilibrium showed no significant deviation from the expected values. The 5.5 kb band was strongly positively associated with HLA-DR3, HLA-B8, and HLA-A1. In 22 patients with primary biliary cirrhosis a significantly (corrected P = 0.024) decreased frequency of the 10.5 kb fragment was found. Additional studies are in progress to substantiate this association.

Cerebral blood flow and liver function in patients with encephalopathy due to acute and chronic liver diseases.

The purpose of the present investigation was to study changes in cerebral blood flow (CBF) in hepatic encephalopathy, to ascertain whether this was related to the changes in liver function and whether these changes gave any prognostic information. CBF, determined by the intravenous xenon-133 method, and liver functions, assessed by the prothrombin index, bilirubin concentration, and the galactose elimination capacity, were studied in patients with acute fulminant liver failure and in patients with encephalopathy due to chronic liver diseases--that is, cirrhosis of various etiologies. The CBF range in healthy young subjects (age, 23-42 years) was 44-61 ml/100 g/min; in patients with grade I + II encephalopathy (mean +/- SEM) it was 32.8 +/- 3.6 ml/100 g/min in acute (n = 4; age, 28 +/- 8 years) and 37.0 +/- 3.3 ml/100 g/min in chronic liver patients (n = 10; age, 51 +/- 2 years). In grade III + IV encephalopathy it was 28.7 +/- 3.8 ml/100 g/min in acute (n = 8; age, 28 +/- 3 years) and 32.9 +/- 3.7 ml/100 g/min in chronic patients (n = 12; age, 49 +/- 3 years). CBF did not correlate with the liver function and was of no prognostic value. The liver function was markedly reduced in all the patients, without any differences between patients with acute or chronic liver diseases or the different degrees of hepatic encephalopathy. In conclusion, a marked reduction of the CBF was seen in hepatic encephalopathy, irrespective of the etiology of the disease.

Vitamin D, parathyroid hormone, and bone mineral content of lumbar spine and femur in primary biliary cirrhosis.

In order to elucidate the pathogenesis and degree of osteopoenia in primary biliary cirrhosis (PBC) we conducted a cross-sectional study of 47 non-selected female patients with biopsy-proven PBC. Bone mineral content (BMC) of the lumbar spine, femoral neck and femoral shaft was determined using dual photon absorptiometry. Compared to healthy females of corresponding decades the PBC patients exhibited significantly decreased mean BMC-values in lumbar spine (88%, P less than 0.05) and femoral neck (92%, P less than 0.05) but not in femoral shaft (96%, NS). Bone mineral content was not significantly associated with duration of liver disease, impairment of liver function (serum concentrations of albumin, clotting factors II + VII + X, bilirubin, alkaline phosphatase galactose elimination capacity or histology), variables reflecting calcium homeostasis (serum concentrations of ionized calcium, parathyroid hormone, vitamin D binding protein, 25-hydroxy vitamin D3 and 1,25-dihydroxy vitamin D3) or previous treatment with glucocorticosteroids. In view of our negative findings we suggest that future studies in this field should focus on physical activity and female sex hormones as determinants for the prevention of osteopoenia in females with primary biliary cirrhosis.

Delta infection and hepatitis B virus replication in Danish patients with fulminant hepatitis B.

The presence of hepatitis B virus and delta agent markers was investigated in 41 patients referred during the years 1970-1985 with fulminant hepatitis classified as type B or non-A non-B and compared to findings in patients with uncomplicated hepatitis B and chronic hepatitis B infection. 13 patients had no markers of hepatitis B and delta infection and were classified as non-A non-B hepatitis. The remaining 28 patients were all HBsAg and IgM anti-HBc positive and 14 (50%) had evidence of delta infection. In contrast, only 13/71 patients (18%) with acute benign hepatitis B had evidence of delta coinfection (p less than 0.005). This corresponds to an odds ratio of 4.5 for development of fulminant hepatitis among patients with hepatitis B and delta coinfection. In 100 chronic HBsAg carriers 29% were positive for delta markers. 12 of the delta infected patients with fulminant hepatitis were positive for total antibody to the delta antigen, and 2 were delta antigen positive. Three were HBeAg positive/anti-HBe negative. None had hepatitis B virus DNA. Among the 14 patients without delta infection, hepatitis B virus DNA was found in 2/4 HBeAg positive/anti-HBe negative patients and in 1/8 patients negative for both markers. The present data indicate that a high proportion of Danish patients with fulminant hepatitis B have hepatitis B and delta agent coinfection. Further, the findings suggest that hepatitis B and delta coinfection may be associated with an increased risk of development of fulminant hepatitis as compared to that of hepatitis B alone.