Treatment of hepatitis C virus leads to economic gains related to reduction in cases of hepatocellular carcinoma and decompensated cirrhosis in Japan.

Hepatocellular carcinoma (HCC) is a serious complication of hepatitis C virus (HCV) infection. Sustained virologic response (SVR) for HCV is associated with a reduction in cirrhosis, HCC and mortality and their associated costs. Japanese HCV patients are older with higher prevalence of HCC. Here we used a decision-analytic Markov model to estimate the economic benefit of HCV cure by reducing HCC and DCC burden in Japan. A cohort of 10 000 HCV genotype 1b (GT1b) Japanese patients was modelled with a hybrid decision tree and Markov state-transition model capturing natural history of HCV over a lifetime horizon. Treatment options were approved all-oral direct-acting anti-virals (DAAs) vs no treatment. Treatment efficacy was based on clinical trials and transition rates and costs obtained from Japan-specific data. Cases of HCC, decompensated cirrhosis (DCC) and quality-adjusted life years (QALYs) were projected for patients treated with DAAs vs NT. QALYs were monetized using a willingness-to-pay threshold of ¥4-to-¥6 million. Incremental savings with treatment were calculated by adding the projected cost of complications avoided to the monetized gains in QALYs. The model showed that DAA treatment vs no treatment, reduces 2057 cases of HCC and 1478 cases of decompensated cirrhosis and saves ¥850 446.73 and ¥338 229.90 per patient (ppt). Additionally, treatment can lead to additional 2.64 QALYs gained per patient. The indirect economic gains associated with treatment-related QALY improvements were ¥10 576 000, ¥13 220 000 and ¥15 864 000 ppt (willingness-to-pay thresholds of ¥4 million, ¥5 million and ¥6 million). Total economic savings of treatment with DAAs (vs no treatment) was ¥7 526 372.63, ¥10 170 372.63 and ¥12 814 372.63, at these different willingness-to-pay thresholds. In conclusion treatment of HCV GT1b with all-oral DAAs in Japan can lead to significant direct and indirect savings related to avoidance of HCC and DCC.

Effects of HLA-DPB1 genotypes on chronic hepatitis B infection in Japanese individuals.

Significant associations of HLA-DP alleles with chronic hepatitis B (CHB) infection are evident in Asian and Arabian populations, including Japanese, Han Chinese, Korean, and Saudi Arabian populations. Here, significant associations between CHB infection and five DPB1 alleles (two susceptibility alleles, DPB1(*) 05:01 and (*) 09:01, and three protective alleles, DPB1(*) 02:01, (*) 04:01, and (*) 04:02) were confirmed in a population comprising of 2582 Japanese individuals. Furthermore, odds ratios for CHB were higher for those with both DPB1 susceptibility alleles than for those with only one susceptibility allele; therefore, effects of susceptibility alleles were additive for risk of CHB infection. Similarly, protective alleles showed an additive effect on protection from CHB infection. Moreover, heterozygotes of any protective allele showed stronger association with CHB than did homozygotes, suggesting that heterozygotes may bind a greater variety of hepatitis B-derived peptides, and thus present these peptides more efficiently to T-cell receptors than homozygotes. Notably, compound heterozygote of the protective allele (any one of DPB1*02:01, *04:01, and *04:02) and the susceptible allele DPB1*05:01 was significantly associated with protection against CHB infection, which indicates that one protective HLA-DPB1 molecule can provide dominant protection. Identification of the HLA-DPB1 genotypes associated with susceptibility to and protection from CHB infection is essential for future analysis of the mechanisms responsible for immune recognition of hepatitis B virus antigens by HLA-DPB1 molecules.

Natural history of bleeding risk in colonic diverticulosis patients: a long-term colonoscopy-based cohort study.

BACKGROUND: The natural history of bleeding risk from colonic diverticulosis remains unclear. AIM: To identify the incidence of bleeding in colonic diverticulosis patients and associated risk factors. METHODS: A cohort of 1514 patients with colonoscopy-confirmed asymptomatic diverticulosis was selected between 2001 and 2013. Age, sex and location of colonic diverticulosis (right or left side, or bilateral) were assessed. The endpoint was a bleeding event, and data were censored at the time of last colonoscopy. The cumulative and overall incidences of bleeding were estimated using the Kaplan-Meier and person-years methods. The Cox proportional hazards model was used to estimate age- and sex-adjusted hazard ratios (aHRs). RESULTS: The median follow-up period was 46 months. Bleeding events occurred in 35 patients, and the median time-to-event interval was 50 months. Kaplan-Meier analysis showed that the cumulative incidence of diverticular bleeding was 0.21% at 12 months, 2.2% at 60 months and 9.5% at 120 months. By the person-years method, the overall incidence rate of bleeding was 0.46 per 1000 patient-years. On multivariate analysis, age ≥70 (aHR. 3.7) and bilateral diverticulosis (aHR, 2.4) were significant risk factors for bleeding. CONCLUSIONS: This long-term follow-up study demonstrated that the cumulative incidence of bleeding from diverticulosis was approximately 2% at 5 years and 10% at 10 years, and the overall incidence was 0.46 per 1000 patient-years. Bilateral diverticulosis increased the risk of bleeding.

Molecular epidemiology and genetic history of hepatitis C virus subtype 3a infection in Thailand.

OBJECTIVE: Among all hepatitis C virus (HCV) infections, subtype 3a is the most common genotype in Thailand. This study investigates the molecular epidemiology and epidemic history of HCV subtype 3a in Thailand. METHODS: Three hundred and fifty-six serum samples were collected from HCV-infected Thai patients. The virus was isolated, after which the core and NS5B regions were sequenced. Subsequently, the HCV genotype was classified by phylogenetic analysis based on the core and NS5B regions. Molecular evolution analysis of HCV subtype 3a was estimated using BEAST (Bayesian Evolutionary Analysis by Sampling Trees) v.1.5.4. RESULTS: Based on our phylogenetic analyses, subtype 3a (38.5%) was the most prevalent, followed by 1a (21%), 1b (13.8%), genotype 6 (19.9%) [comprised of subtypes 6e (0.3%), 6f (11%), 6i (1.9%), 6j (1.9%) and 6n (4.8%)] and 3b (5.6%). Our phylogenetic tree indicates the existence of a specific group of HCV subtype 3a strains in the Thai population. Molecular evolutionary analysis dated the most recent common ancestor of the Thai HCV subtype 3a strains as existing approximately 200 ago, and a Bayesian skyline plot showed that this particular strain spread to Thailand during the mid-1970s and early 1980s. This period overlaps with the Vietnam War (1955-1975) and the widespread use of injection stimulants introduced by the US Army during this time. CONCLUSION: The estimated history of HCV subtype 3a infection in Thailand may help to predict the future burden of HCV-related diseases and facilitate better public health control and surveillance.

Vegetable, fruit and antioxidant nutrient consumption and subsequent risk of hepatocellular carcinoma: a prospective cohort study in Japan.

In a population-based prospective study of 19,998 Japanese individuals, consumption of vegetables, green-yellow and green leafy vegetables was inversely associated with the risk of hepatocellular carcinoma (101 cases), with multivariable hazard ratios for the highest vs lowest tertile of 0.61 (95% confidence interval (CI)=0.36-1.03, P(trend)=0.07), 0.65 (95% CI=0.39-1.08, P(trend)=0.06) and 0.59 (95% CI=0.35-1.01, P(trend)=0.04), respectively.

Risk for hepatocellular carcinoma with respect to hepatitis B virus genotypes B/C, specific mutations of enhancer II/core promoter/precore regions and HBV DNA levels.

BACKGROUND/AIM: To examine the risks for hepatocellular carcinoma (HCC) with respect to hepatitis B virus (HBV) genotypes, specific viral mutations (MT), serum HBV DNA levels, and cirrhosis. METHODS: HBV genotypes, 1653/1753/core promoter (CP)/precore MT and HBV DNA levels were determined in 248 HBV patients with HCC and 248 HBV controls. RESULTS: Genotype C, CP-MT, T1653, HBV DNA levels >or=4 log(10) copies/ml and cirrhosis had a higher risk for HCC compared to patients with genotype B (p = 0.001, OR 1.9), CP wild-type (WT) (p<0.001, OR 4.1), C1653 (p = 0.028, OR 2.4), HBV DNA <4 log(10) copies/ml (p = 0.003, OR 2.1) and without cirrhosis (p<0.001, OR 4.0) respectively. Multivariate analysis showed that CP-MT, T1653, HBV DNA >or=4 log(10) copies/ml and cirrhosis were independent factors for HCC (all p<0.05). A receiver operating characteristics curve showed no cut-off HBV DNA level associated with minimal chance of HCC. Patients with CP-MT and cirrhosis had a 22.2-fold increased risk of HCC compared to patients with CP-WT and without cirrhosis. Patients with CP-MT and HBV DNA levels >or=4 log(10) copies/ml had a 7.2-fold increased risk of HCC compared to patients with CP-WT and HBV DNA levels <4 log(10) copies/ml. Patients with CP-MT and T1653 had a 9.9-fold increased risk of HCC compared to patients with wild-type for both regions. CONCLUSIONS: CP-MT, T1653, HBV DNA levels >or=4 log(10) copies/ml and cirrhosis are independent factors for development of HCC. The risks increased substantially in patients having these factors in combination.

Tracing hepatitis C and Delta viruses to estimate their contribution in HCC rates in Mongolia.

An estimated incidence of hepatocellular carcinoma (HCC) in Mongolia is currently one of the highest in the world. According to previous reports, the sero-prevalence of hepatitis B (HBV) and hepatitis C (HCV) viruses in general population of the country is very high (HBV, 10% and HCV, 15%, respectively). Moreover, the majority (75-100%) of the HBV-infected individuals have co-infection with hepatitis Delta virus (HDV). Despite reported observations that HBV + HDV/HCV co-infection have significantly stronger association with HCC when compared with HCV-monoinfection, the later is still frequently observed among Mongolian HCC patients (39%). In this study, an approach based on principles of population genetics and mathematical epidemiology was used to trace an epidemic history of HCV and HDV. In agreement with the sero-epidemiological and social-historical background of the country, the results have demonstrated that the viruses had different epidemic dynamics in Mongolia; HCV was characterized by earlier epidemic expansion, whereas HDV spread with approximately 50 years lag. This may explain the comparable contribution of the HCV-monoinfection and HBV + HDV co-infection in current HCC rate despite different levels of risk of carcinogenesis. Used approach is useful in evaluation of current and prospective disease burden.

Determination of hepatitis B virus genotype G by polymerase chain reaction with hemi-nested primers.

Hepatitis B virus (HBV) has been classified into six genotypes designated A-F by sequence divergence in the entire genome exceeding 8%. Very recently, the seventh genotype was reported and named genotype G. HBV genotype G is distinct from genomes of the other six genotypes in that it possesses an insertion of 36 nucleotides in the core gene, and has been found so far in France and the United States. A method for determining HBV genotype G was developed by polymerase chain reaction (PCR) with primers deduced from the 36-nucleotide (nt) insertion in five isolates of HBV genotype G the sequences of which have been deposited in DNA databases. The validity of this method, for specifically detecting HBV genotype G, was verified on a panel consisting of 142 HBV isolates of six major genotypes and four of genotype G. A total of 540 sera containing HBV in Japan covering symptom free carriers and patients with a spectrum of chronic liver disease were tested by this method, but not a single HBV genotype G sample was found. A possible method for serological determination of hepatitis B surface antigen of genotype G is suggested, without amplification or sequencing nucleotides, which would expand epidemiological and clinical researches on HBV genotype G.

Geographic distribution of hepatitis B virus (HBV) genotype in patients with chronic HBV infection in Japan.

The geographic distribution of hepatitis B virus (HBV) genotypes in Japan and its clinical relevance are poorly understood. We studied 731 Japanese patients with chronic HBV infection. HBV genotype was determined by the restriction fragment length polymorphism (RFLP) method after polymerase chain reaction (PCR). Of the 720 patients with positive PCR, 12 (1.7%) were HBV genotype A, 88 (12.2%) were genotype B, 610 (84.7%) were genotype C, 3 (0.4%) were genotype D, and 7 (1.0%) were of mixed genotype. Over 94% of patients on the Japanese mainland had genotype C, while 60% of the patients on Okinawa, the most southern islands, and 22.9% in the Tohoku area, the northern part of the mainland, harbored genotype B. Compared with genotype C patients, genotype B patients were older (53.6 to 42.2 years; P <.01), had a lower rate of positive hepatitis B e antigen (HBeAg) (18.4% to 50.6%; P <.01), and a lower level of serum HBV DNA (5.02 to 5.87 log genome equivalents (LGE)/mL; P <.01). The mean age of the genotype B patients with hepatocellular carcinoma was 70.1 +/- 9.2 years, compared with 55.2 +/- 9.7 of genotype C patients (P <.01). These results indicate that genotypes C and B are predominant in Japan, and there are significant differences in geographic distribution and clinical characteristics among the patients with the different genotypes.

Effect of interferon therapy on Japanese chronic hepatitis C virus patients with anti-liver/kidney microsome autoantibody type 1.

AIM: The aim of this study was to determine the prevalence of anti-liver/kidney microsome autoantibody type 1 (anti-LKM-1) among hepatitis C virus (HCV)-infected Japanese patients at various stages (chronic hepatitis, liver cirrhosis and hepatocellular carcinoma), and to assess the influence of anti-LKM-1 on interferon therapy. METHODS: A total of 390 serum samples from 215 HCV-infected patients with chronic hepatitis (HCV-CH), 81 HCV-infected patients with liver cirrhosis (HCV-LC), and 94 HCV-HCC infected patients were subjected to examination. Ninety-one HBsAg-positive patients and 137 healthy subjects served as controls. Anti-liver/kidney microsome autoantibody type 1 was determined by using a newly developed ELISA using recombinant cytochrome P450 IID6 as the antigen. RESULTS: Anti-liver/kidney microsome autoantibody type 1 was detected in six of the 390 (1.5%) chronic HCV-infected patients (four were HCV-CH and two were HCV-LC); in contrast, it was not detected in control groups. Among the 110 HCV-CH patients treated with interferon (IFN), four were positive for anti-LKM-1. No change in anti-LKM-1 immunoreactivity from negative to positive during interferon therapy was observed. Moreover, no increase in the serum alanine aminotransferase level was observed in these four patients with anti-LKM-1. CONCLUSION: Our study indicates that: (i) anti-LKM-1 does not aggravate the liver disease associated with HCV infection; and (ii) no change in anti-LKM-1 immunoreactivity from negative to positive or no aggravations of liver dysfunction were observed among HCV-CH patients during the IFN therapy for Japanese patients with liver disease.

Hepatitis B virus genotype distribution among chronic hepatitis B virus carriers in Shanghai, China.

OBJECTIVE: Hepatitis B virus (HBV) genotype distribution is still unclear in China, where a high prevalence of HBV infection exists, although it is well known that HBV can be classified into six genotypes based on intergroup divergence. The aim of this study was to investigate the epidemiological distribution of HBV genotypes and to clarify further the genotype-related differences in the pathogenicity of HBV. METHODS: Seminested PCR and restriction fragment length polymorphism analysis were conducted in 97 asymptomatic HBV carriers (ASC) and 46 chronic hepatitis (CH), 37 liver cirrhosis (LC) and 44 hepatocellular carcinoma (HCC) patients in Shanghai, China. RESULTS: Two hundred and twenty samples (98.2%) were positive for HBV DNA, and of these, 3 (1.4%), 38 (17.2%) and 179 (81.4%) were classified as genotype A, B and C, respectively. There was a statistically significant difference in the distribution of genotypes B and C among various categories of liver diseases (p < 0.01). The distribution of genotype C showed an increasing trend from ASC, CH and LC to the HCC group; in contrast, the distribution of genotype B showed a decreasing trend in the same order. HBeAg positivity was higher in genotype C than in genotype B in all the subjects or in the ASC group alone (p < 0.05, p < 0.01, respectively). More severe liver damage and a higher mean age were observed in genotype C than in genotype B (p < 0.01, p < 0.05, respectively). CONCLUSIONS: These results indicate the following: (1) genotypes A, B and C of HBV exist in Shanghai, China; (2) genotype C is the major genotype in this area; (3) genotype C is associated with the development of severe liver diseases, and (4) genotype B has a relatively good prognosis.

Evaluation of accumulation of hepatitis C virus mutations in a chronically infected chimpanzee: comparison of the core, E1, HVR1, and NS5b regions.

Four hepatitis C virus genome regions (the core, E1, HVR1, and NS5b) were amplified and sequenced from yearly samples obtained from a chronically infected chimpanzee over a 12-year span. Nucleotide substitutions were found to accumulate in the core, E1, and HVR1 regions during the course of chronic infection; substitutions within the NS5b region were not detected for the first 8 years and were found to be minimal during the last 4 years. The rate of accumulation of mutations in the core and E1 regions, based on a direct comparison between the first 1979 sequence and the last 1990 sequence, was 1.120 x 10(-3), while phylogenetic ancestral comparison using the 12 yearly sequences showed a rate of 0.816 x 10(-3) bases per site per year. Temporal evaluation of the sequences revealed that there appeared to be periods in which substitutions accumulated and became fixed, followed by periods with relative stasis or random substitutions that did not persist. Synonymous and nonsynonymous substitutions within the core, E1, and HVR1 regions were also analyzed. In the core and E1 regions, synonymous substitutions predominated and gradually increased over time. However, within the HVR1 region, nonsynonymous substitutions predominated but gradually decreased over time.

Genetic instability and aberrant DNA methylation in chronic hepatitis and cirrhosis--A comprehensive study of loss of heterozygosity and microsatellite instability at 39 loci and DNA hypermethylation on 8 CpG islands in microdissected specimens from patients with hepatocellular carcinoma.

A study was conducted to examine the significance of genetic instability and aberrant DNA methylation during hepatocarcinogenesis. Genomic DNA was extracted from 196 microdissected specimens of noncancerous liver tissue that showed no marked histologic findings or findings compatible with chronic hepatitis or cirrhosis, and 80 corresponding microdissected specimens of hepatocellular carcinoma (HCC) from 40 patients. Loss of heterozygosity (LOH) and microsatellite instability (MSI) were examined by polymerase chain reaction (PCR) using 39 microsatellite markers, and DNA methylation status on 8 CpG islands was examined by bisulfite-PCR. In noncancerous liver tissues, LOH, MSI, and DNA hypermethylation were found in 15 (38%), 6 (15%), and 33 (83%) of 40 cases, respectively. The incidence of DNA hypermethylation in histologically normal liver was similar to that in chronic hepatitis and cirrhosis, although neither LOH nor MSI was found in histologically normal liver. In cancerous tissues, LOH, MSI, and DNA hypermethylation were found in 39 (98%), 8 (20%), and 40 (100%) of 40 cases, respectively. CpG islands of the p16 gene and methylated in tumor 1, 2, 12, and 31 clones were frequently methylated in cancerous tissues, although neither the thrombospondin-1 nor the human Mut L homologue (hMLH1) gene was methylated. Absence of silencing of the hMLH1 gene by DNA hypermethylation is consistent with the low incidence of MSI in HCCs. The results of this study indicate that LOH and aberrant DNA methylation contribute to hepatocarcinogenesis; DNA hypermethylation in particular, which precedes or may even cause LOH, is as an early event during hepatocarcinogenesis.

Lack of integrated TT virus (TTV) genomes in cellular DNA in infected human hematopoietic cells.

TT virus (TTV) isolated from the serum of a patient with posttransfusion hepatitis has been characterized as a member of the Circoviridae, a family of small DNA viruses with single-stranded circular genomes. TTV appeared to infect not only the serum and liver, but also the peripheral blood mononuclear cells (PBMC). We investigated the prevalence of TTV DNA in human hematopoietic cells, based on 84 mononuclear cell samples obtained from the bone marrow or lymph nodes of patients with hematopoietic malignancies including leukemia, malignant lymphoma and aplastic anemia. Forty-nine (58.3%) out of the 84 samples were positive for TTV DNA with polymerase chain reaction analysis, which was almost similar to the frequency found in the patients' serum. Southern blot analyses using a 3.2-kb fragment derived from the TTV DNA, however, showed no evidence supporting the fact that the TTV genomes are integrated into the human hematopoietic cell genomes, thus suggesting their existence as episomal forms.

Prevalence and risk factors of hepatitis C virus infection among Koreans in rural area of Korea.

In a Korean rural area with a high incidence of liver cancer, a molecular epidemiological study was conducted to estimate the prevalence of hepatitis C virus (HCV) infection and to determine the distribution of HCV genotype and transmission routes of HCV infection. The study population is those who volunteered to participate in a health survey in 1993 and were over 10 years of age. Those who were anti-HCV-positive and 20 of their spouses were re-examined in 1995 and tested for HCV genotype. A phylogenetic tree was constructed after sequencing analysis of core and envelope regions from the subjects with genotype 2a without a blood transfusion history. The age- and sex-standardized prevalence of anti-HCV was 5.52%. In a multivariate analysis, transfusion history was not associated with anti-HCV-positivity, but a history of acupuncture (adjusted odds ratio=2.2, 95% confidence interval=1.0, 4.7) and a history of surgical operation (adjusted odds ratio=2.0, 95% confidence interval=1.0, 4.1) were associated. The prevalence of HCV genotype 2a was the highest, and genotype 1b was less frequent. The phylogenetic tree showed strong homology among our samples with Japanese HCV strains. The present study suggests that there is a highly endemic area of HCV infection in Korea and that this endemicity is probably associated with a parenteral source of HCV infection other than blood transfusion. The study also suggests that some of the HCV infection was spread through non-sterilized or non-disposable acupuncture needles in this HCV endemic area.

Relationship between histological prognosis of chronic hepatitis C and amount of hepatitis C virus core protein in serum.

BACKGROUND: Hepatitis C virus (HCV) viraemia is one of the factors for histological prognosis of chronic hepatitis C. METHODS: One hundred and thirty-five patients who received hepatic biopsies twice at intervals of 5 years or longer were followed up for a mean of 9.7 +/- 4.0 years were studied retrospectively. The amount of HCV viraemia present was measured as the concentration of HCV core protein by using the fluorescence enzyme immunoassay method. RESULTS: Multiple-regression analysis, using deterioration of the histological stage as a dependent variable, showed that greater age (P = 0.041), higher stage of hepatic histology at the start of follow up (P = 0.029), and higher serum concentration of core protein (P < 0.001) were independent factors affecting the deterioration of the liver's histological stage. At follow up, no significant difference in histological stage was seen between patients with serum HCV core protein > or = 100 pg/mL (n = 60) and those with serum core protein < 100 pg/mL (n = 75). The histological grade in patients with high serum core-protein levels tended to be significantly worse and the deterioration rate of the histological stage was significantly higher than in those with low HCV core protein levels (68 vs 35%, P < 0.001). The mutation rate of the HCV envelope-2/non-structural 1 (E2/NS1) nucleotide region was compared in two patients who had high serum concentrations of HCV core protein and whose histological stage had deteriorated with two patients who had low serum concentrations of the core protein and whose histological stages remained unchanged. No significant difference in E2/NS1 mutation was found. CONCLUSIONS: The amount of HCV viraemia was suggested to be a significant factor for determining histological outcome in patients with chronic hepatitis C. The mutation rate in the E2/NS1 region did not seem to be associated with the prognosis of chronic hepatitis C.

Single amino acid substitution in the Fc region of chimeric TNT-3 antibody accelerates clearance and improves immunoscintigraphy of solid tumors.

UNLABELLED: Recent studies in antibody catabolism have identified residues at the CH2-CH3 interface of the IgG heavy chain critical for serum persistence of immunoglobulins. Amino acid substitutions in the Fc region of murine IgG1 were shown to drastically accelerate antibody clearance in mice. Our laboratory has previously described a human-mouse chimeric TNT-3 (chTNT-3) monoclonal antibody directed against a universal nuclear antigen that has potential for the radioimmunotherapy of many solid tumors. In the current study, we engineered a chTNT-3 mutant containing a single amino acid substitution, to determine whether a more rapid clearance profile would make the antibody suitable for diagnostic imaging. METHODS: A single amino acid substitution in the CH2 domain of the human gamma1 constant region was made by polymerase chain reaction mutagenesis. High-level expression was achieved using the Glutamine Synthetase Gene Amplification System, and the chTNT-3 mutant was purified by protein A affinity and ion-exchange chromatography. A radioimmunoassay was performed to examine antigen binding, and in vivo studies were undertaken to evaluate clearance and tumor targeting in human tumor xenograft models. RESULTS: The chTNT-3 mutant retained the high affinity of chTNT-3, with a binding constant of 1.5 x 10(-9) mol/L. The mutant was eliminated rapidly from BALB/c mice, with a beta-phase half-life of 33.8 h, compared to 134.2 h for chTNT-3. Moreover, biodistribution studies in human colon tumor-bearing nude mice reflected this accelerated clearance. Tumor levels of the mutant were, respectively, 65%, 39%, and 36% of the tumor levels achieved with the parental chTNT-3 6, 12, and 24 h postinjection. The rapid clearance of the chTNT-3 mutant from the blood resulted in higher tumor-to-normal organ ratios for many normal tissues. Imaging of tumor-bearing mice with 99mTc-labeled chTNT-3 mutant demonstrated early visualization of tumors in 3 different solid tumor xenograft models. CONCLUSION: The accelerated clearance produced by a single amino acid substitution in the Fc region of chTNT-3 leads to improved imaging in tumor-bearing mice. These studies suggest that a rapidly clearing antibody generated by this approach may be useful for the immunoscintigraphy of human tumors.

Development of a TT virus DNA quantification system using real-time detection PCR.

Although TT virus (TTV) was isolated from a cryptogenic posttransfusion hepatitis patient, its pathogenic role remains unclear. It has been reported that the majority of the healthy population is infected with TTV. To elucidate the differences between TTV infection in patients with liver diseases and TTV infection in the healthy population, a quantification system was developed. TTV DNA was quantified by a real-time detection PCR (RTD-PCR) assay on an ABI Prism 7700 sequence detector. With this system, TTV DNA was quantified in 78 hepatitis C virus (HCV)-infected patients (63 with elevated serum alanine aminotransferase [ALT] levels and 15 with normal ALT levels) and in 70 voluntary blood donors (BDs). The quantification range was 2.08 to 7.35 log copies/ml. The intra-assay and interassay coefficients of variation were 0.37 to 6.33% and 0.60 to 7.07%, respectively. The mean serum TTV DNA levels in the HCV-infected patients with both elevated and normal ALT levels and BDs were 3.69 +/- 0.89, 3.45 +/- 0.76, and 3.45 +/- 0.67 log copies/ml, respectively. Comparison of the serum TTV DNA levels among the HCV-infected patients revealed that they were not related to the serum ALT and HCV core protein levels or to the histopathological score on liver biopsy. This study showed that (i) the RTD-PCR assay for the detection of TTV was accurate and had a high degree of sensitivity, (ii) the mean serum TTV DNA level was similar among HCV-infected patients, irrespective of their ALT level, and also among BDs, and (iii) a high serum TTV DNA level does not affect the serum ALT and HCV levels or liver damage in HCV-infected patients.

Quantification of serum HCV core antigen by a fluorescent enzyme immunoassay in liver transplant recipients with recurrent hepatitis C--clinical and virologic implications.

BACKGROUND: Monitoring hepatitis C viremia may be useful in the management of liver transplant patients with recurrent hepatitis C virus (HCV) infection. The clinical utility of a newly described fluorescent enzyme immunoassay for the detection of serum HCV core antigen was evaluated. METHODS: Serum samples prospectively collected from 57/63 consecutive patients transplanted for HCV-related end-stage liver disease were assayed for both serum HCV core antigen by fluorescent enzyme immunoassay and HCV RNA level using a branched chain DNA signal amplification assay. HCV genotype was determined by restriction fragment length polymorphism analysis based on 5' untranslated region. One- and 2-year annual protocol liver biopsies from these patients were graded for inflammation, fibrosis, and cholestasis RESULTS: Serum HCV core antigen and HCV RNA were detected in a similar proportion of samples (256/ 281 vs. 260/281, P=NS), and there was an excellent correlation between assays (r2=0.905, P<0.0001) independent of HCV genotype. A conversion equation between HCV core antigen and HCV RNA was constructed to estimate the HCV core antigen to RNA ratio to be around 231 to 1. Mean serum HCV core antigen levels peaked initially at 3 months posttransplant but there was significant interpatient variation as to when peak levels occurred. A high serum HCV core antigen level in the first 6 months was associated with histological deterioration in terms of bridging fibrosis, cirrhosis, severe cholestasis, or retransplantation by 2-year follow-up. CONCLUSION: Determination of serum HCV core antigen level reflects HCV viremia and may have clinical implications in liver transplant patients with HCV recurrence.

[Analysis of some viral infections, transmitted by parenteral and sexual routes, in the Republic of Azerbaijan]. / Analiz nekotorykh virusnykh infektsii, peredaiushchikhsia parenteral'nym i polovym putem, v Respublike Azerbaidzhan.

Representatives of various population groups in Azerbaijan were tested for infection with human T-lymphotropic (HTLV-I and HTLV-II) and hepatotropic viruses (HCV and HBV). A total of 835 sera were studied by screening and specific tests for virus-specific antibodies and/or antigens. Thirty-five DNA specimens from peripheral blood lymphocytes were analyzed in the PCR for HTLV-I-specific sequences. No HTLV-I or HIV were detected, but two cases with integration of the HTLV-I LTR gene into cellular DNA genome were detected. A high rate of infection with hepatitis B and C was revealed. The level of anti-HCV was 8.7%, HBsAg 4.1%, and antiHBs 23.4%. Six cases with double HBV-HCV infection were detected. High values of ALT among HBV/HCV-seronegative subjects prompts their testing for other types of hepatitis viruses.