Telaprevir impairs renal function and increases blood ribavirin concentration during telaprevir/pegylated interferon/ribavirin therapy for chronic hepatitis C

We aimed to examine the relationship between renal dysfunction and anaemia that may develop during combination therapy involving pegylated interferon, ribavirin and telaprevir (PEG-IFN/RBV/TVR) for the treatment of chronic hepatitis C. Sixty-eight patients with genotype 1b high viral loads were treated with PEG-IFN/RBV/TVR. Peg-IFN and RBV doses were administered according to body weight. TVR was prescribed at 2250 mg/day for 44 patients and at 1500 mg/day for 24 patients who had low haemoglobin level (<12 g/dL). When anaemia had developed, the RBV dose was decreased. The serum TVR concentration at day 8 was measured, and the serum RBV concentration was measured serially. The estimated glomerular filtration rate (eGFR) was estimated to assess renal function. At week 1, serum TVR concentration was not correlated with a decrease in eGFR; however, the TVR dose, on a weight basis (mg/kg), and eGFR were correlated (r = 0.2691; P = 0.0265). Moreover, there was a negative correlation between eGFR and RBV serum concentration (r = −0.3694; P = 0.0025), and the serum RBV concentration and decrease in the haemoglobin were significantly correlated from week 1 to week 8. In triple therapy, the TVR dose per weight is correlated with a decline in renal function. Thus, the serum concentration of RBV increases, with a concomitant decrease in haemoglobin. It is important to adjust the doses of TVR and RBV to avoid excessive serum RBV levels and the development of severe anaemia, to achieve a good clinical effect.

Virological response and safety of 24-week telaprevir alone in Japanese patients infected with hepatitis C virus subtype 1b

Hepatitis C virus (HCV) subtype 1b, which infects approximately 70% of Japanese carriers, is likely to be more eradicable by a telaprevir regimen than subtype 1a because of the higher genetic barrier of Val(36) and Arg(155) substitutions. The aims of this exploratory study were to evaluate the virological response and safety of 24-week oral administration of telaprevir alone in chronic HCV subtype 1b infection. Fifteen treatment-naïve patients were treated with telaprevir 750 mg every 8 h for 24 weeks. All patients were Japanese whose median age was 58.0 years (range: 45-68), and six patients (40%) were men. Median baseline HCV RNA level was 6.80 log(10) IU/mL (range: 3.55-7.10). The HCV RNA levels decreased to undetectable in five patients (33%) within 8 weeks. Three patients (20%) with negative HCV RNA by Week 4 achieved end of treatment response. One patient (7%) who achieved sustained virological response had a low baseline viraemia of 3.55 log(10) IU/mL. Most of the adverse events including anaemia and skin disorders were mild to moderate. Developed variants were T54A and A156V/T/F/Y with or without secondary substitutions rather than V36M ± R155K. Telaprevir alone for 24 weeks in Japanese patients with HCV subtype 1b resulted in an sustained viral response rate of 7% (1/15) and was well tolerated for 24 weeks. These results will support the implementation of further studies on oral combination of telaprevir with other direct-acting antiviral agents in patients infected with HCV subtype 1b.

Efficacy and safety of telaprevir, a new protease inhibitor, for difficult-to-treat patients with genotype 1 chronic hepatitis C

The aims of this phase III study were to assess the efficacy and safety of telaprevir in combination with peginterferon alfa-2b (PEG-IFN) and ribavirin (RBV) for difficult-to-treat patients who had not achieved sustained virological response (SVR) to prior regimens in Japan. The subjects were 109 relapsers (median age of 57.0 years) and 32 nonresponders (median age of 57.5 years) with hepatitis C virus genotype 1. Patients received telaprevir (750 mg every 8 h) for 12 weeks and PEG-IFN/RBV for 24 weeks. The SVR rates for relapsers and nonresponders were 88.1% (96/109) and 34.4% (11/32), respectively. Specified dose modifications of RBV that differed from that for the standard of care were introduced to alleviate anaemia. RBV dose reductions were used for 139 of the 141 patients. The SVR rates for relapsers did not depend on RBV dose reduction for 20-100% of the planned dose (SVR rates 87.5-100%, P < 0.05). Skin disorders were observed in 82.3% (116/141). Most of the skin disorders were controllable by anti-histamine and/or steroid ointments. The ratios of discontinuation of telaprevir only or of all the study drugs because of adverse events were 21.3% (30/141) and 16.3% (23/141), respectively. A frequent adverse event leading to discontinuation was anaemia. Telaprevir in combination with PEG-IFN/RBV led to a high SVR rate for relapsers and may offer a potential new therapy for nonresponders even with a shorter treatment period.

The efficacy and safety of thymosin alpha-1 in Japanese patients with chronic hepatitis B; results from a randomized clinical trial

Thymalfasin (thymosin alpha-1; Talpha1) is a 28-amino acid polypeptide that has shown efficacy in the treatment of chronic hepatitis B virus (HBV) infection. The objective of this study was to evaluate the long-term, dose-related efficacy and safety of Talpha1 treatment in chronic hepatitis B patients with positive HBV-DNA and abnormally high alanine aminotransferase (ALT) levels. A total of 316 patients were randomized to receive either 0.8 or 1.6 mg of Talpha1 monotherapy for 24 weeks. At the end of the 72-week observation period (12 months after cessation of therapy), 36.4% of patients in the 1.6-mg treatment group achieved normalization of ALT, 30% achieved clearance of HBV-DNA by branched DNA vs 15% by transcription-mediated amplification, and 22.8% achieved clearance of HBe-antigen. Patients in the 0.8-mg treatment group achieved similar efficacy rates, although patients with advanced fibrosis demonstrated a significantly better response rate when treated with 1.6 mg of Talpha1 monotherapy vs 0.8 mg (as determined by intragroup analysis; patients were not stratified by liver biopsy). All adverse drug reactions were mild and most involved the fluctuation of liver enzymes, which was most likely related to the positive immune effects caused by the response to Talpha1 treatment. Adverse event incidence was similar in the 1.6- and 0.8-mg treatment groups. In conclusion, Talpha1 at doses of 0.8 and 1.6 mg exhibits long-term efficacy against hepatitis B with a good safety profile.

Detection of hypermethylation of the p16(INK4A) gene promoter in chronic hepatitis and cirrhosis associated with hepatitis B or C virus

BACKGROUND/AIM

Inactivation of the p16(INK4A) (p16) tumour suppressor gene by promoter region hypermethylation has been demonstrated not only in many types of tumours, including hepatocellular carcinoma (HCC), but also in early preneoplastic lesions in the lung, colon, oesophagus, and pancreas. The aim of this study was to examine the methylation status of the p16 promoter in pre- and/or non-neoplastic liver diseases. PATIENTS/SUBJECTS/METHODS: The methylation status of p16 was evaluated in 22 HCC, 17 cirrhosis, 17 chronic hepatitis, nine primary biliary cirrhosis (PBC), eight autoimmune hepatitis, seven drug induced liver disease, six fatty liver, and three normal liver tissues using methylation specific polymerase chain reaction (MSP). p16 protein expression was also examined by immunohistochemical staining.

RESULTS

Methylation of the p16 promoter was detected in HCC (72.7%, 16/22) and also in cirrhosis (29.4%, 5/17) and chronic hepatitis (23.5%, 4/17), all of which were positive for hepatitis B or C virus infections. Methylation was not detected in any of the other samples. All methylation positive HCC, cirrhosis, and chronic hepatitis samples showed loss of p16 expression, and a significant correlation was found between methylation and loss of expression. Analysis of serial samples from individual patients with methylation positive HCC revealed that loss of p16 expression with promoter methylation occurred in 18 of 20 patients at the stage of chronic hepatitis without clinically detectable carcinoma.

CONCLUSIONS

Our results suggest that methylation of the p16 promoter and the resulting loss of p16 protein expression are early events in a subset of hepatocarcinogenesis and that their detection is useful in the follow up of patients with a high risk of developing HCC, such as those with hepatitis B or C viral infections.

Frequent hypermethylation of CpG islands and loss of expression of the 14-3-3 sigma gene in human hepatocellular carcinoma

The 14-3-3 sigma gene has been implicated in G2/M cell cycle arrest by p53. Frequent inactivation of the 14-3-3 sigma gene by hypermethylation of CpG islands has recently been reported in human breast carcinoma. The aim of this study was to examine the methylation status of CpG islands of the 14-3-3 sigma gene in hepatocellular carcinoma (HCC). The methylation status of the 14-3-3 sigma gene was evaluated in four normal liver tissues and 19 paired specimens of carcinoma and adjacent non-tumorous liver tissues using bisulfite-single strand conformation polymorphism (bisulfite-SSCP), a combination of sodium bisulfite modification and fluorescence-based polymerase chain reaction (PCR)-SSCP. The 14-3-3 sigma protein expression was examined by immunohistochemical staining. Hypermethylation of CpG islands of the 14-3-3 sigma gene was detected in 89% (17/19) of the HCC tissues but not in any of the four normal liver tissues. All of the 14 methylation-positive HCC samples analysed by immunohistochemistry showed loss of 14-3-3 sigma expression, while both of the methylation-negative HCC samples retained the expression, and a significant correlation was found between methylation and loss of expression. Lower levels of methylation were detected in adjacent non-tumorous liver tissues (6/16 in cirrhotic tissues and 1/3 in chronic hepatitis tissues), but the 14-3-3 sigma expression was retained in all of these tissues. In a methylation-positive HCC cell line, HLE, 5-aza-2'-deoxycytidine (5-aza-dC)-induced demethylation of CpG islands led to reactivation of gene expression, indicating that hypermethylation plays a causal role in inactivation of the 14-3-3 sigma gene in HCC. Hypermethylation and the resulting loss of expression of the 14-3-3 sigma gene corresponds to one of the most common abnormalities reported to date in HCC, suggesting their crucial role in the development and/or progression of HCC.

Early mutation of precore (A1896) region prior to core promoter region mutation leads to decrease of HBV replication and remission of hepatic inflammation

To evaluate the relationship between mutations and clinical courses, we investigated precore (preC) and core promoter (CP) mutations and serum HBV DNA levels in HBe-antibody-positive HBV carriers. Fifty-six asymptomatic carriers (ASC), 29 patients with chronic hepatitis who showed normal ALT levels for more than two years (CH-ASC), 31 patients with chronic hepatitis (CH), and 32 patients with hepatocellular carcinoma (HCC) were studied. Almost all patients (99.2%) had mutations in either CP or preC. Mutation only in preC (A1896) was present in 52.2% with ASC, 25.0% with CH-ASC, 16.1% with CH, and 8.0% with HCC, and was significantly higher in ASC (P < 0.01). The patients with only preC mutation showed low HBV DNA levels in each clinical stage. The mutation of preC (A1896) prior to the mutation of CP might control the replication of HBV, which leads to the remission of hepatitis.

Gastric varices with splenic vein occlusion treated by splenic arterial embolization

A 53-year-old man was admitted to our hospital in August 1997 with enlarged gastric varices. Computed tomography (CT) showed splenic vein occlusion, gastric varices, and extra-gastric wall collateral veins. Color flow images of gastric varices were clearly visualized, and the velocity in the gastric varices was 19.6 cm/s via endoscopic color Doppler ultrasonography (ECDUS). The patient was diagnosed with gastric varices according to angiographic findings of splenic vein occlusion, and splenic arterial embolization was performed. Two weeks after the splenic arterial embolization, CT showed peripheral areas of low attenuation in the spleen, due to splenic infarction, with 70% of the spleen volume showing low attenuation. Eight months after the splenic arterial embolization, ECDUS revealed a decrease in gastric variceal color flow images, with the velocity in the gastric varices being 10.3 cm/s.

Infrequent widespread microsatellite instability in hepatocellular carcinomas

Widespread or high-frequency microsatellite instability (MSI) due to the defective DNA mismatch repair (MMR) occurs in the majority of hereditary non-polyposis colorectal cancer and a subset of sporadic malignant tumors. The incidence of MSI and underlying DNA MMR defects have been well characterized in gastrointestinal carcinogenesis, but not in hepatocarcinogenesis. To address the issue, we analyzed 55 Japanese hepatocellular carcinomas using several indicators of DNA MMR defects, such as microsatellite analysis, loss of heterozygosity (LOH) and mutation analysis of MMR genes, methylation of hMLH1 promoter, and frameshift mutations of mononucleotide repeat sequences within possible target genes. Mutation of beta2-microglobulin gene, which is presumably involved in MSI-positive tumor cell escape from immune surveillance was also examined. Some of these analyses were also carried out in 9 human liver cancer cell lines. None of the 3 quasi-monomorphic mononucleotide markers sensitive for MSI, BAT26, BAT25, and BAT34C4 presented shortened unstable alleles in any of the carcinoma, cirrhosis, chronic hepatitis tissues, or cell lines. LOH at MMR genes was infrequent (4.4 approximately 7.1%), and no mutations were detected. Neither hMLH1 hypermethylation nor frameshift mutation in the target genes was detected. No mutations were found in beta2-microglobulin. Widespread MSI due to the defective DNA MMR appears to play little if any part in Japanese hepatocarcinogenesis.

Eradication of Helicobacter pylori using 30 mg or 60 mg lansoprazole combined with amoxicillin and metronidazole: one and two weeks of a new triple therapy

A new triple therapy using a proton pump inhibitor and two antibiotics shows high efficiency against Helicobacter pylori infection. The aim of this study was to determine the optimal dose and duration of lansoprazole (LA) administration in combination with amoxicillin (AMPC) and metronidazole (MNZ). A total of 91 patients were enrolled in this study. They were divided into four groups: group A, 2 weeks of 30mg LA once daily, 500mg AMPC tid, and 250mg MNZ tid; group B, 2 weeks of 30mg LA bid, 500mg AMPC tid, and 250mg MNZ tid; group C, 1 week of 30mg LA once daily, 500mg AMPC tid, and 250mg MNZ tid; group D, 1 week of 30mg LA bid, 500mg AMPC tid, and 250mg MNZ tid. H. pylori status was determined by the rapid urease test, culture, histology, and 13C-urea breath test before and at least 4 weeks after the end of therapy. The cure rates in a per-protocol analysis and the incidence of adverse events in the evaluated patients were, respectively, 89.5% and 21.1% in group A, 100% and 20.0% in group B, 96.8% and 12.9% in group C, and 92.3% and 26.9% in group D. Most of the adverse events were tolerated. All four regimens in this study showed the same cure rates, and they were effective and well tolerated. One week of triple therapy using once-daily administration of 30mg LA is a good alternative.

Evaluation of magnetic resonance angiography in detection of gastric varices

We evaluated the detection of gastric varices, inflowing blood vessels to gastric varices, and outflowing blood vessels from gastric varices via magnetic resonance (MR) angiography in 31 patients with gastric varices. Twenty-four patients had F2 type varices and 7 had F3 type, classified according to the Japanese Research Society for Portal Hypertension. Seventeen patients had cardiofornical varices, and 14 had fundal varices. All patients were examined with an MR system operating at 1.5T. MR angiography was performed using the two-dimensional time-of-flight method. With MR angiography, the imaging of gastric varices was clearly delineated in 28 of the 31 patients (90.3%). From the images of MR angiography, flow direction itself cannot be determined. The outflowing blood vessels of gastric varices were reported to be the gastro-renal shunt and the subphrenic vein, and angiographic findings have shown the inflowing blood vessels to be the left gastric vein (LGV), the short gastric vein (SGV), and the posterior gastric vein (PGV). In 25 of the 31 patients (80.7%), the outflowing blood vessels from gastric varices were detected (gastro-renal shunt in 24; subphrenic vein in 1). MR angiography provided clear images of the inflowing blood vessels to gastric varices in 18 of the 31 patients (58.1%). These inflowing vessels were categorized as SGV in 7 patients, LGV in 5, LGV and SGV in 4, and LGV and PGV in 2. We suggest that MR angiography be used as a routine method for detecting and diagnosing collateral veins in patients with gastric varices.

Multicenter experience with maxillary prostheses supported by Brånemark implants: a clinical report

This retrospective study involved Japanese patients with prostheses supported by Brånemark implants following maxillectomy. Questionnaires were sent to 75 institutions, and data on 19 patients were collected from 8 institutions. The mean age of patients at the time of implant placement was 64.2 years (range 22 to 82 years). The mean follow-up time was 27.6 months. Of the 81 implants placed, 16 were lost for an implant survival rate of 80.2%. The effects on implant survival rate of radiotherapy, chemotherapy, hyperbaric oxygen therapy, and the support system of the prosthesis were analyzed, but no significant differences were observed.

Early loss of serum hepatitis C virus RNA can predict a sustained response to interferon therapy in patients with chronic hepatitis C

OBJECTIVES

We evaluated whether the loss of serum hepatitis C virus (HCV) RNA early in interferon (IFN) therapy would indicate a subsequent response to IFN therapy.

METHODS

One hundred fourteen patients with chronic hepatitis C were treated with IFN-alpha for 24 weeks. All patients were positive for anti-HCV antibodies and serum HCV RNA. Serum HCV RNA was measured by highly sensitive and specific RT-PCR (modified Amplicor HCV).

RESULTS

Of 114 patients who were treated with IFN-alpha for 24 weeks, 22 of 29 patients (75.9%) who lost HCV RNA at the first week of treatment, 5 of 14 patients (35.7%) who lost HCV RNA at the second week, and 2 of 16 patients (12.5%) who lost HCV RNA at fourth week were judged as sustained responder (SR). The SR rate was significantly higher in patients who lost HCV RNA at the first week of therapy (p < 0.05). On the contrary, none of 55 patients who retained HCV RNA during the first 4 weeks of IFN therapy were judged as SR. Concerning the patients who lost HCV RNA at the first week of therapy, there were no significant differences in the SR rate in either HCV genotype (1b, 2a, and 2b).

CONCLUSIONS

Our study confirms that the early response to IFN (loss of HCV RNA at the end of the first week of IFN therapy) can be a predictor of the subsequent sustained response to IFN therapy. Additionally, positivity of HCV RNA at the fourth week of IFN therapy can be a predictor of the subsequent nonsustained response to IFN therapy.

Nucleotide sequences of the hepatitis C virus core region in patients without anti-core antibody

Second-generation assays for detection of hepatitis C virus (HCV) infection that include reactivity of antibodies to core, NS3, NS4 are used because of their high sensitivity. Among these antibodies, anti-core antibody seems to be the most sensitive. However, there are some patients without anti-core antibodies, although HCV RNA is detectable by reverse transcription-polymerase chain reaction and branched DNA assay. The mechanism for the absence of anti-core antibody on its own is unclear. We therefore determined the nucleotide and deduced amino acid sequences of the core region obtained from two anti-core antibody-negative patients with HCV RNA (genotype 1b) and compared them with those of four anti-core antibody-positive patients and a previously reported sequence. Amino acids spanning 1-47, which seemed to exist in major B cell epitopes, were found to be completely conserved among these patients. Furthermore, the predictive binding motif to HLA DR4 (a.a 81-90) was completely conserved in both of the anti-core antibody-negative patients. There were various mutations in the residual amino acids spanning 49-108, but specific mutations could not be found in anti-core antibody-negative patients. These data indicate that the absence of anti-core antibody in two patients is not due to the presence of some formerly unknown viral variants, but due to a possible defect in the host's immune system.

Significance of 2',5'-oligoadenylate synthetase activity and HCV genotype in IFN therapy for type C chronic hepatitis

Although the mechanisms of elimination of HCV by IFN have not been fully elucidated, the 2-5A system was reported to be one of the mechanisms of the anti-viral effect of IFN. Therefore, the relationship between HCV genotype, induction of 2-5AS and clinical effect was investigated. As for the anti-viral effect during IFN therapy, in type III or IV, most patients lost HCV-RNA regardless of serum 2-5AS induction even in high HCV-RNA concentration cases. In contrast, in type II, the negativity rate of HCV-RNA became high along with an increase of serum 2-5AS activity, but in patients with high HCV-RNA concentration, HCV-RNA was persistently positive. As for the long term clinical effect of IFN therapy judged 6 months after completion of IFN therapy, HCV genotypes were closely related to the effect; that is, the patients with type III or type IV HCV genotype showed a higher complete response rate compared with the patients with type II HCV genotype. However, the relationship between the long term clinical effects and induction of serum 2-5AS during IFN therapy was obscure. These results suggest that induction of 2-5AS is closely related to the anti-viral effect during IFN administration, but the viral factors appeared to be related to long term clinical effects after cessation of IFN therapy.

[Classification of hepatitis C virus into two major groups in serologic activity: correlation with response to interferon]

Genotypes of HCV have been reported to be one of the predictors of response to IFN therapy in patients with chronic hepatitis C. HCV genotypes were determined enzyme-linked immunoblot assay based on group I and II specific recombinant peptides of the NS-4 region (amino acid No. 1676-1670). We examined the correlation between HCV groups and response to IFN in patients with chronic hepatitis C. Among the 84 patients with chronic hepatitis C who underwent IFN treatment, 16 of 51 (31.4%) patients with group I and 12 of 23 (52.2%) patients with group II showed complete sustained response. These results suggest that HCV group assay may improve the ability to predict IFN treatment outcomes.

[Interstitial pneumonia induced by interferon therapy in type C hepatitis]

Interstitial pneumonia is known as one of the serious side effect of drugs. Recently, many investigators have reported that interstitial pneumonia (IP) which occurred during interferon (IFN) therapy for type C chronic hepatitis, and its appearance rate is considered to be more than 0.2% of patients who receive IFN. Though the mechanisms of IP during IFN therapy remains to be elucidated, one of the possible explanations is that excessive focal immune response in the lung derived from IFN might leads to the inflammation. For safe treatment, we must recognize that IFN induces IP during IFN therapy and give attention to its occurrence.

A new disaccharide Fuc alpha 1-2Man found in human urine

Human urine collected from healthy individuals was ultrafiltered and the filtrate was gel-filtered. The fraction including disaccharides was pyridylaminated to convert the reducing sugars to fluorescent pyridylamino (PA)-derivatives. A PA-disaccharide consisting of Fuc and Man was purified by gel filtration, reversed-phase HPLC, and size fractionation HPLC. Structural analysis revealed that the disaccharide was Fuc alpha 1-2Man-PA. The disaccharide is considered to be a metabolite of unknown glycoconjugates.

Identification of trisaccharide Xyl alpha 1-->3Xyl alpha 1-->3Glc in human urine

Oligosaccharides in human urine were converted to pyridylamino (PA)-derivatives. From the PA-oligosaccharides, a saccharide that was chromatographically identical with a synthetic standard, Xyl-alpha 1-->3Xyl alpha 1-->3Glc-PA, was isolated by gel filtration and HPLC. Structure analysis showed that the saccharide was Xyl alpha 1-->3Xyl-alpha 1-->3Glc-PA. It is likely that Xyl alpha 1-->3Xyl alpha 1-->3Glc originated from such glycoconjugates as blood coagulation factors VII and IX, and protein Z.

Treatment of chronic non-A, non-B hepatitis with interferon

The efficacy of interferon therapy (IFN) was investigated in 46 patients with chronic non-A, non-B (NANB) hepatitis, of would 40 (87.0%) were positive for anti-HCV antibody (Ab) (C-100-3). Three kinds of IFN were used; human lymphoblastoid interferon (HLBI), interferon alpha-2b and interferon beta. Total doses of IFN ranged from 1 million units (MU) to 10 MU and treatment duration ranged from 2 weeks to 144 weeks. Of 46 patients 34 (73.9%) responded to IFN. Nine patients have maintained normal ALT levels and 5 patients have maintained near-normal ALT levels for more than 6 months after cessation of IFN treatment. In these cases the titers of anti-HCV Ab had decreased significantly at the end of IFN therapy and 6 months after IFN therapy respectively. The mean age was young and the mean disease duration was short in effective cases. As for doses and treatment duration of IFN, low doses of IFN requires long treatment duration to acquire continuous efficacy and high doses of IFN requires rather short treatment durations. Therefore, early IFN treatment, higher doses and longer periods of IFN treatment may improve the response rate of patients with chronic NANB hepatitis.

Serum 2'-5'oligoadenylate synthetase as a monitoring marker of anti-viral effect during interferon therapy for chronic type B hepatitis

We evaluated the usefulness of serum 2'-5'oligoadenylate synthetase (2-5AS) activity assay in monitoring the anti-viral activity of chronic type B hepatitis patients during IFN therapy. The serum 2-5AS activity was rapidly increased during the above therapy and was maintained at a medium-to-high level throughout the therapy period, although the capacity for increase reflected differences among individuals. The kinetics of serum 2-5AS activity during the therapy was almost consistent with that of the PBMCs 2-5AS activity. 2-5AS activity had an inverse correlation with DNA-P; i.e. DNA-P often disappeared from serum after interferon treatment in patients with a marked response in serum 2-5AS activity. The enhancement of serum 2-5AS activity during IFN therapy seemed to correlate with an increase in anti-viral activity. The results suggest that the serum 2-5AS activity assay is a useful probe for monitoring the anti-viral activity of chronic type B hepatitis patients during interferon therapy.

Activities of 2'-5'oligoadenylate synthetase in peripheral blood mononuclear cells of patients with viral hepatitis, and chronic type B hepatitis during interferon therapy

The activities of the interferon-induced enzyme 2'-5' oligoadenylate synthetase in peripheral blood mononuclear cells were determined in patients with viral hepatitis. Increased levels of the enzyme were found in patients with acute type B hepatitis at the early phase and also in those with chronic type B hepatitis at the active stage. The levels of this enzyme activity were not significantly increased in patients with acute type A hepatitis or in those with acute type non A non B hepatitis. However, in two patients with acute type A hepatitis the levels of this enzyme were elevated shortly at the onset. These results support the hypothesis that an endogenous interferon response in patients with acute type A hepatitis and in those with acute type B hepatitis may be instrumental in the modulation of these types of hepatitis virus infections. Whereas hepatitis non A non B virus replication in patients with acute type non A non B hepatitis may be associated with poor interferon response. The activities of the enzyme in peripheral blood mononuclear cells were determined in patients with chronic type B hepatitis during interferon therapy. Increased levels of the enzyme were found in all patients during interferon therapy. This increase correlated well with the decreased DNA-polymerase activities. The data also showed that assay of this enzyme activity is useful to determine the optimal dosage and means of interferon therapy for chronic type B hepatitis.