Detection of the hepatitis C virus by rt-PCR.

The hepatitis C virus (HCV) is an orgainsm of the age of molecular biology, for its discovery and much of the research into the infection have relied heavily on molecular techniques. The development of molecular cloning enabled a successful strategy that finally identified HCV (1)as the cause of 90% of posttransfusion (2)and > 50% of sporadic non-A, non-B hepatitis (3) after the failure by immunological techniques to discover the responsible agent. It is an important infection as most infected patients developed chronic hepatitis (> 50%) that can progress to cirrhosis and hepatocellular carcinoma (4-6) . Following the identification of the viral genome, antibody tests were developed which could detect exposure to the virus (7). The presence of antibodies to HCV, however, does not distinguish between those with chronic infection and those who had cleared the virus. Chronic HCV infection can be difficult to diagnose as patients may be asymptomatic and have normal liver biochemistry (8),(9) despite abnormal liver histology. Therefore, demonstration of virus RNA (usually from serum samples) is often necessary to confirm Infection. Detection of HCV RNA requires the sensitivity of nucleic acid amplification (e.g., the polymerase chain reaction) as circulating levels of vnus RNA can be very low (10),(11). Such tests are now widely used to confirm infection, monitor the response to anti-viral therapy, and in epidemiological studies of HCV infection.

Clinical outcome of hypogammaglobulinaemic patients following outbreak of acute hepatitis C: 2 year follow up.

In 1994, an outbreak of hepatitis C virus (HCV) infection, genotype 1a, occurred in 30 hypogammaglobulinaemic patients in the UK from one batch of contaminated anti-HCV screened intravenous immunoglobulin. This study aimed to study prospectively the outcome of HCV in hypogammaglobulinaemic patients, and to assess the response to early treatment with interferon-alpha, 6 million units three times weekly for 6 months. Data were collected using standardized questionnaires. Five patients with secondary hypogammaglobulinaemia due to lymphoid malignancy were not treated and all have died of their primary malignancy. Of 25 patients with primary hypogammaglobulinaemia, one resolved HCV infection before treatment, 17 commenced on treatment, and seven declined or treatment was contra-indicated. Thirteen of 17 patients completed therapy and seven (54%) have a sustained response (normal transaminases, negative serum HCV RNA) at 6 and 12 months after treatment. Two of the 12 patients with primary hypogammaglobulinaemia, who were not treated or failed to complete treatment, have cleared the virus. Liver biopsy was performed in patients not clearing HCV and was abnormal in all. Four patients developed liver failure within 2 years, of whom three have died and one has been successfully transplanted. In conclusion, HCV can cause rapid severe liver disease in hypogammaglobulinaemic patients. Early treatment with high-dose interferon-alpha results in a high clearance of HCV.

Outbreak of acute hepatitis C following the use of anti-hepatitis C virus--screened intravenous immunoglobulin therapy.

BACKGROUND & AIMS: Hepatitis C virus (HCV) infection has been associated with intravenous (IV) immunoglobulin (Ig), and plasma donations used to prepare IV Ig are now screened to prevent transmission. Thirty-six patients from the United Kingdom received infusions from a batch of anti-HCV antibody-screened intravenous Ig (Gammagard; Baxter Healthcare Ltd., Thetford, Norfolk, England) that was associated with reports of acute hepatitis C outbreak in Europe. The aim of this study was to document the epidemiology of this outbreak. METHODS: Forty-six patients from the United Kingdom treated with Gammagard (34 exposed and 12 unexposed to the batch) returned epidemiological questionnaires. RESULTS: Eighty-two percent of the exposed patients (28 of 34) became positive for HCV RNA. Eighteen percent of the patients (6 of 34) who had infusions with this batch tested negative for HCV RNA, but 2 of the patients had abnormal liver function and subsequently seroconverted to anti-HCV antibody positive. Twenty-seven percent of the patients (9 of 34) developed jaundice, and 79% (27 of 34) had abnormal liver transferase levels. Virus isolates (n=21), including an isolate from the implicated batch, were genotype 1a and virtually identical by sequence analysis of the NS5 region, consistent with transmission from a single source. CONCLUSIONS: Hepatitis C infection can be transmitted by anti-HCV-screened IV Ig. Careful documentation of IV Ig batch numbers and regular biochemical monitoring is recommended for all IV Ig recipients.

Liver histology in hepatitis C infection: a comparison between patients with persistently normal or abnormal transaminases.

Forty two cases of confirmed hepatitis C virus (HCV) infection with available liver histology were studied. Most patients, 23 of 42 (55%) had abnormal liver function tests but 19 of 42 (45%) had persistently normal liver transaminases (mean aspartate transaminase (AST) 24.1 IU/l, mean follow up 10 months). Histological examinations in the group with normal AST activities were normal in two of 19 (11%), showed non-specific reactive hepatitis in eight of 19 (42%), chronic persistent hepatitis in six of 19 (31%), and chronic active hepatitis in three of 19 (16%). Twenty three of 42 (55%) had either persistently or temporary raised liver transaminases (mean AST 96.2 IU/l, mean follow up 16 months). Histological examinations in this second group with abnormal liver biochemistry showed reactive hepatitis in five of 23 (22%), chronic persistent hepatitis in six of 23 (26%), chronic active hepatitis in 10 of 23 (43%), and cirrhosis in two (9%). Average alcohol intake was significantly higher in the group within abnormal liver function (17.8 v 6.4 units, p = 0.01). Although serious pathology was more frequent in the abnormal transaminase group, significant liver pathology (chronic persistent hepatitis or chronic active hepatitis) was found in nine of 19 (47%) of cases with repeatedly normal transaminases. Liver biopsy is advised in all cases of chronic hepatitis C infection to accurately assess both the degree of fibrosis and the current activity of the disease.

Acute hepatitis C infection after sexual exposure.

A case is described of a woman with acute hepatitis C infection whose partner had chronic hepatitis C infection and where heterosexual contact was the only major risk factor. Infection of both partners was confirmed serologically and by the finding of virus RNA by reverse transcription and polymerase chain reaction amplification. Nucleotide sequence analysis of the NS5 region (RNA polymerase) was used to show that both partners were infected with virus of the same genotype (1a). The nucleotide sequence of virus RNA found in the female patient is closest to variants cocirculating in the male contact, consistent with transmission having occurred between the two.

Regression of columnar lined (Barrett's) oesophagus with continuous omeprazole therapy.

Twenty-three adult patients with a columnar lined (Barrett's) oesophagus are being treated with long-term omeprazole, 40 mg daily. Twelve had never undergone anti-reflux surgery (Group 1), the other eleven having previously had insertion of an Angelchik anti-reflux prosthesis (Group 2). Endoscopy was carried out six months before, immediately before and six months, one year and two years into treatment. Multiple and standardized biopsies were taken at each endoscopy. Results from the two groups were similar. During the 6-month run-in period there was a statistically non-significant increase in the linear extent of the columnar mucosa, but this showed a progressive, statistically significant decrease during the two years of treatment. Other evidence for regression of the Barrett's mucosa includes the emergence of large numbers of macroscopic squamous islands within the abnormal mucosa, an increase in the number of microscopic squamous islands, and microscopic squamous encroachment of the abnormal mucosa at the squamo-columnar junction. Histological assessment showed a reduction in the proportion of sulphomucin-rich intestinal metaplasia, but this only achieved statistical significance in Group 1. The results substantiate the importance of acid in the pathogenesis of Barrett's oesophagus. Omeprazole may have a therapeutic role in bringing about regression of the metaplastic epithelium.

Distribution of mucosal pathology and an assessment of colonic phenotypic change in the pelvic ileal reservoir.

The mucosa of the pelvic ileal reservoir undergoes adaptive changes--inflammatory, architectural, and metaplastic--on exposure to the faecal stream. Twenty three quadruple loop ileal pouches constructed for ulcerative colitis (20 patients) and familial adenomatous polyposis (FAP) (three patients) were studied. No patient fulfilled clinical, endoscopic, or histopathological criteria for pouchitis. Standard duplicate biopsy specimens were taken from the proximal limb, the anterior wall, the posterior wall, and the body of the reservoir. An established scoring system was used and showed a highly significant increase in inflammatory scores in posterior wall biopsy specimens compared with those from the anterior wall. These results suggest that the adaptive changes are the direct result of contact with static faecal contents. One patient only showed significant inflammation in the proximal limb. There was no evidence of mucosal prolapse in any anterior wall biopsy specimen. Patients with colitis showed substantially more inflammatory and architectural changes than those with FAP. Ninety six per cent of pouches showed some colonic phenotypic expression as defined by mucin histochemical and PR 3A5 immunohistochemical studies. Our results suggest, however, that there may not be complete colonic metaplasia and that the mucin changes and other phenotypic alterations may represent a non-specific response to pouch inflammation and not a prerequisite for the development of pouchitis. The focal nature of the inflammatory and architectural changes, which may be the result of direct contact with static faecal residue, are clearly shown. A single random biopsy specimen of pouch mucosa is of limited value in assessing pathological changes and screening for potential neoplastic change within the reservoir.

Comparison of noninvasive measurements of carbon dioxide tension during withdrawal from mechanical ventilation.

End tidal CO2 tension (PetCO2) and transcutaneous CO2 tension (PtcCO2) were compared with arterial CO2 (PaCO2) before and after withdrawal of mechanical ventilation in 20 patients predisposed to hypercarbia. With stable PaCO2 during mechanical ventilation, the correlation coefficient (r) between PaCO2 and PetCO2 was .9, and between PaCO2 and PtcCO2, .87. PtcCO2 considerably overestimated PaCO2 in three patients who were receiving dopamine. After withdrawal of mechanical ventilation, changes in PaCO2 were closely paralleled by changes in PetCO2 and PtcCO2 (r = .82 and .86, respectively). Nine of 20 patients had an increased PaCO2 of 10 torr or greater. In eight of these, PetCO2 and PtcCO2 rose by at least 5 torr, and in seven, the rise in PetCO2 and PtcCO2 was within 5 torr of the rise in PaCO2. During mechanical ventilation, PetCO2 and PtcCO2 estimated stable PaCO2 with sufficient accuracy for clinical use, except in patients with cutaneous vasoconstriction. After withdrawal of mechanical ventilation, changes in PetCO2 and PtcCO2 were predictive of important PaCO2 increases, warranting continued exploration and evaluation as to their use in monitoring patients predisposed to hypercarbia.