[Show abstract][Hide abstract] ABSTRACT: Whether differences in the natural history of hepatitis C virus (HCV) can be explained by differences in the infecting HCV type is unknown. The aim of this study was to investigate whether the HCV type might influence the clinical outcome of infection. Study serum samples were assembled from 749 individuals enrolled into the UK HCV National Register from which data on clinical outcomes were extracted. HCV-RNA-positive specimens were genotyped and HCV-RNA-negative specimens serotyped. Logistic regression analysis was used to investigate the independent effect of HCV type on viral clearance by comparing patients who were HCV RNA negative (n = 86) with those who were HCV RNA positive (n = 508). The same method was used to investigate whether HCV type was associated with histological stage of liver disease. The prevalence of HCV type 1 among those who cleared infection was 69% and among those who remained HCV RNA positive was 51%: Type 1 infections were more likely to be HCV RNA negative than non-1 types (OR 0.47, 95% CI 0.29-0.78, P = 0.003). Type 1 infections were also more likely to be associated with histological stage scores above the median when compared with non-1 types (OR 2.03, 95% CI 1.07-3.83, P = 0.03). In conclusion, HCV type 1 infection was more often HCV RNA negative, suggesting that spontaneous clearance may occur more commonly with this type. Among the RNA-positive infections, type 1 infection may be more aggressive than types 2/3.
[Show abstract][Hide abstract] ABSTRACT: To determine the clinical course of hepatitis C virus in the first decade of infection in a group of patients who acquired their infections on a known date.
Clinical centres throughout the United Kingdom.
924 transfusion recipients infected with the hepatitis C virus (HCV) traced during the HCV lookback programme and 475 transfusion recipients who tested negative for antibodies to HCV (controls).
Clinical evidence of liver disease and survival after 10 years of infection.
All cause mortality was not significantly different between patients and controls (Cox's hazards ratio 1.41, 95% confidence interval 0.95 to 2.08). Patients were more likely to be certified with a death related to liver disease than were controls (12.84, 1.73 to 95.44), but although the risk of death directly from liver disease was higher in patients than controls this difference was not significant (5.78, 0.72 to 46.70). Forty per cent of the patients who died directly from liver disease were known to have consumed excess alcohol. Clinical follow up of 826 patients showed that liver function was abnormal in 307 (37.2%), and 115 (13.9%) reported physical signs or symptoms of liver disease. Factors associated with developing liver disease were testing positive for HCV ribonucleic acid (odds ratio 6.44, 2.67 to 15.48), having acquired infection when older (at age > or = 40 years; 1.80, 1.14 to 2.85), and years since transfusion (odds ratio 1.096 per year, 1.00 to 1.20). For patients with severe disease, sex was also significant (odds ratio for women 0.38, 0.17 to 0.88). Of the 362 patients who had undergone liver biopsy, 328 (91%) had abnormal histological results and 35 (10%) of these were cirrhotic.
Hepatitis C virus infection did not have a great impact on all cause mortality in the first decade of infection. Infected patients were at increased risk of dying directly from liver disease, particularly if they consumed excess alcohol, but this difference was not statistically significant.
[Show abstract][Hide abstract] ABSTRACT: The aim of this paper is to describe the development of a national hepatitis C register and the completeness of the data it contains. This is a descriptive report of the structure and function of the register, including case definitions, registration and follow-up procedures, and methods used to maximize data quality and to obtain comparative data sources. The register contains data on HCV-infected individuals who acquired their infections on a known date and by a known route; to date all are transfusion recipients identified during the UK lookback exercise, who tested positive or indeterminate for anti-HCV after receiving 'infected' blood issued before the introduction of routine testing of the blood supply for anti-HCV. By 31 December 1999, 871 (87%) of 996 eligible transfusion recipients had been registered, and 984 (99%) flagged in the NHS Central Registers. Registered patients had been infected for an average of 11.1 years (SEM 0.1); around half were being cared for by clinicians with a specialist interest in liver disease. Except for the information on tobacco use, current alcohol use, and hepatitis B status, data were more than 80% complete, and for most variables, more than 90% complete. The consistency of data abstraction was found to be 98% (SEM 0.5). In conclusion, the Register contains high quality anonymised data on one of the largest cohorts of individuals with HCV infections acquired on a known date and by a known route. It could serve as a model for other chronic disease registers; developers may find the structure, design, and methodological issues addressed useful.