Assessment Of Hepatitis Research Articles

Assessment of hepatitis B virus DNA stability in serum by the Chiron Quantiplex branched-DNA assay.

Quantification of hepatitis B virus (HBV) DNA in serum is used to establish eligibility for treatment and to monitor therapeutic response. With the trend toward centralized testing, defining the conditions that preserve sample integrity is of paramount importance. We therefore evaluated the stability of HBV DNA in 26 previously frozen (PF) and 5 fresh, never previously frozen serum specimens. PF specimens, covering a 3-log10 HBV DNA dynamic range, were thawed and stored at -70, 4, 23, 37, and 45 degrees C (+/-1.5 degrees C) for 0, 24, 72, and 120 h (+/-2 h) and were refrozen at -70 degrees C prior to testing. Five fresh specimens were split into two groups. Both group FG1 and group FG2 specimens were handled as described above; however, group FG1 specimens were subsequently maintained at 4 degrees C and were never frozen prior to testing. Linear regression analysis of PF specimens demonstrated no significant HBV DNA degradation at < or =4 degrees C over 5 days; however, HBV DNA levels decreased by 1.8, 3.4, and 20% per day at 23, 37, and 45 degrees C, respectively. Three independent statistical methods confirmed that the probability of specimen failure, defined as a loss of 20% or more of HBV DNA and/or coagulation of serum, was lowest at < or =4 degrees C and increased with temperature. Because only 10 to 20% of individual patient specimens demonstrated losses of HBV DNA of > or =20% at 23 or 37 degrees C, sufficient numbers of serum specimens must be evaluated to determine overall statistical trends. In conclusion, HBV DNA integrity in separated serum specimens is preserved for at least 5 days when the specimens are stored at -70 or 4 degrees C.

Assessment of hepatitis C virus quasispecies heterogeneity by gel shift analysis: correlation with response to interferon therapy.

Hepatitis C virus (HCV) quasispecies heterogeneity was assessed in pretreatment sera of 22 patients treated with interferon (IFN). Quasispecies heterogeneity was quantitated by analysis of 490 hypervariable region 1 (HVR1) clones using gel shift analysis (GSA), which allowed determination of two components of HCV quasispecies heterogeneity: genetic complexity (number of variants) and genetic diversity (mean genetic distance between variants). HCV genotype and pretreatment RNA titer were similar between responders (n = 12) and nonresponders (n = 10). GSA correlated well with nucleotide sequencing for estimating HCV genetic diversity (R = .952; P < .001). A positive correlation of .666 (P < .001) was observed between genetic diversity and complexity, suggesting that these components of quasispecies heterogeneity were related. However, while there were no significant differences in pretreatment complexity or genetic diversity among response groups, higher pretreatment genetic diversity was predictive of response failure (P = .041). Assessment of HVR1 heterogeneity by GSA revealed important relationships between quasispecies genetic diversity, complexity, and response to IFN therapy and suggested a need for analysis of other HCV genes.

Comparison of Three Different Tests for Assessment of Hepatitis C Virus in Dialysis Patients

Objective To evaluate the relationship between hepatitis C virus antibodies (HCV-Ab) and viremia and to compare the prevalence of HCV-Ab and HCV viremia in hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) patients. Design Cross-sectional study. Setting Dialysis unit of a nephrology division in a public university hospital. Patients All dialysis patients who came for routine clinic visits during the study period. None denied informed consent. Forty-eight patients on HD and 79 on CAPD were examined. Intervention Blood samples were tested by second generation enzyme-Iinked immunosorbent assay (ELISA II) and recombinant immunoblot assay (RIBA II) to look for HCV-Ab and by the polymerase chain reaction (PCR) to look for HCV viremia. Results ELISA II was positive in 52% of HD patients and in 14% of CAPD patients. RIBA II was positive in 48% of HD patients and in 11% of CAPD patients. HCV viremia was positive by PCR in 41.6% of HD patients and in 12% of CAPD patients. Two of these PCR-positive patients did not show HCV-Ab by ELISA II and RIBA II. The sensitivity and specificity of ELISA II were 93% and 92%, the sensitivity and specificity of RIBA II were 86% and 94%. Conclusions Our data confirm a higher prevalence of HCV viremia in HD than in CAPD patients. The absence of Ab against virus C in 2 patients positive with PCR might be due to recent HCV infection or to weak virus replication or to a poor immune response.

Comparison of Three Different Tests for Assessment of Hepatitis C Virus in Dialysis Patients

To evaluate the relationship between hepatitis C virus antibodies (HCV-Ab) and viremia and to compare the prevalence of HCV-Ab and HCV viremia in hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) patients. Cross-sectional study. Dialysis unit of a nephrology division in a public university hospital. All dialysis patients who came for routine clinic visits during the study period. None denied informed consent. Forty-eight patients on HD and 79 on CAPD were examined. Blood samples were tested by second-generation enzyme-linked immunosorbent assay (ELISA II) and recombinant immunoblot assay (RIBA II) to look for HCV-Ab and by the polymerase chain reaction (PCR) to look for HCV viremia. ELISA II was positive in 52% of HD patients and in 14% of CAPD patients. RIBA II was positive in 48% of HD patients and in 11% of CAPD patients. HCV viremia was positive by PCR in 41.6% of HD patients and in 12% of CAPD patients. Two of these PCR-positive patients did not show HCV-Ab by ELISA II and RIBA II. The sensitivity and specificity of ELISA II were 93% and 92%, the sensitivity and specificity of RIBA II were 86% and 94%. Our data confirm a higher prevalence of HCV viremia in HD than in CAPD patients. The absence of Ab against virus C in 2 patients positive with PCR might be due to recent HCV infection or to weak virus replication or to a poor immune response.

Assessment of hepatitis B "e" antigen and "e" antibody status--tests of status or status of tests?

Forty-seven sera that gave positive results in tests for hepatitis B surface antigen and core antibody were examined for the presence of "e" antigen and "e" antibody by various commercially available assays. Considerable discordance was observed between results of tests performed on the same sample in different assays. Examination of the sera for the presence of hepatitis B DNA failed to resolve the discrepancies. Increasingly, "e" antigen and its antibody are used as measures of infectivity in carriers of hepatitis B. The absence of reliable tests has implications for patients, for infection control within hospitals and for the implementation of Department of Health guidelines on safe working practices for hepatitis B-infected health care workers.

Assessment of hepatitis B virus immunization status among north American surgeons

Assessment of hepatitis B virus immunization status among north American surgeons

Assessment of Hepatitis C Virus RNA Levels by Quantitative Competitive RNA Polymerase Chain Reaction: High-Titer Viremia Correlates with Advanced Stage of Disease

A quantitative competitive RNA polymerase chain reaction (QC-PCR) assay was developed for measuring absolute levels of hepatitis C virus (HCV) RNA in the sera of 121 viremic persons, including 64 asymptomatic blood donors, 39 symptomatic patients referred for treatment of chronic hepatitis C, and 18 patients with end-stage liver disease referred for liver transplantation. Mean HCV RNA levels (log molecules per milliliter) were lowest among blood donors with normal alanine aminotransferase (ALT) values (5.8 +/- 1.5), higher among blood donors with elevated ALT (6.9 +/- 0.8) and clinic patients with chronic active hepatitis (6.9 +/- 0.7), and highest among patients with cirrhosis (7.1 +/- 0.8) or end-stage liver disease (7.6 +/- 1.0). High-titer viremia ( > or = 7.5 logs/mL) was more frequent among patients with end-stage liver disease (14/18; 78%) than either blood donors (10/64; P < .001) or patients with chronic active hepatitis (7/26; P < .001). Thus, 121 (94.5%) of 128 anti-HCV-positive persons were viremic. QC-PCR may be valuable for monitoring HCV infection status and selecting individuals for therapy.

Assessment of hepatitis B virus immunization status among North American surgeons.

We hypothesized that many surgeons have not been vaccinated against hepatitis B virus (HBV), despite the existence of effective recombinant vaccines. Prevalence of HBV vaccination among surgeons, attitudes of those not vaccinated, estimated HBV infection rates, and respondents' knowledge of the epidemiology of HBV exposure were determined. Survey conducted by mail just before implementation of mandatory HBV vaccination for health care workers. Private and academic general surgical, trauma and transplantation practices. Two thousand one hundred twenty-five surgeons received the survey. Response rates are as follows: in the Surgical Infection Society, 196 (50%) of 393 surgeons; in the American Association for the Surgery of Trauma, 223 (52%) of 433 surgeons; in the American Society of Transplant Surgeons, 194 (44%) of 438 surgeons; and among the Fellows of the American College of Surgeons, 403 (47%) of 861 surgeons. Prevalence of HBV exposure and active immunization by specialty and society. Prevalence of HBV exposure was 19.6%, was higher among trauma and transplantation surgeons compared with general surgeons (P < .0001), and increased significantly with age in all groups (P < .05). Despite greater exposure, probable immunity was lower at an older age because young surgeons (age, < 46 years) are more likely to be vaccines (P < .05). Most surgeons (55%) were vaccinated more than 5 years ago; many recipients of recombinant vaccines (26%) received an inadequate amount of vaccine or were improperly vaccinated. Knowledge of the epidemiology was uniformly poor, with rates of correct responses to the three questions below 50%. Vaccination does not equal immunity. Between 38% and 50% of practicing surgeons may not have adequate immunity to HBV.

Quantitative assessment of hepatitis C virus (HCV) RNA and HCV core IgM antibodies

Quantitative assessment of hepatitis C virus (HCV) RNA and HCV core IgM antibodies

Laboratory techniques in the diagnosis and assessment of hepatitis B virus infection.

Laboratory techniques in the diagnosis and assessment of hepatitis B virus infection.

Assessment of hepatitis B virus DNA levels in chronic HBsAg carriers with or without hepatitis delta virus superinfection

In order to document the incidence of hepatitis delta virus (HDV) replication markers and their relationship to HBV replication, 91 HBsAg chronic carriers were studied. Of these, 51 were anti-HD-positive (19 HBeAg-positive and 32 anti-HBe-positive). Liver HDAg was found in 75% of anti-HD-positive patients. Of the 19 patients who had anti-HD and HBeAg, 13 were HBV-DNA-positive. None of the anti-HBe patients were HBV-DNA-positive. No differences with respect to HBV-DNA concentration were observed between anti-HD-positive and -negative patients. Liver HDAg was detected with similar frequency in patients who were HBeAg- and HBV-DNA-positive (63.6%) and in those who were anti-HBe-positive (78.5%), with no statistically significant difference. HBcAg and HDAg were simultaneously detected in 36% of the anti-HD cases. Patients with anti-HD and HBV-DNA had the highest levels of transaminases (SGPT). Our results suggest that in certain patients HDV and HBV replication coexists without mutual inhibition.