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Biomedical subjects

J L Dienstag

Publications and source records attributed to J L Dienstag.

At least 19 recordsLinked to original sources
PubMed1992

Prevalence and incidence of viral hepatitis in health workers in the prehepatitis B vaccination era.

To assess the impact of hepatitis B virus on health workers, the authors studied baseline prevalences of hepatitis B serologic markers and undertook prospective surveillance to assess hepatitis B attack rates in 837 health workers and 994 blood-donor controls between 1977 and 1982, before the introduction of hepatitis B vaccine. The baseline prevalence of all hepatitis B markers was 14% in health workers and 6% in controls (p < 0.001); exposure to hepatitis B virus was related to the intensity of blood exposure and its duration. In contrast, the frequency of exposure to hepatitis A virus, a nonblood-borne agent, was lower in health workers (11%) than in controls (16%) (p < 0.01) and increased as a function of age. Multivariate logistic regression analysis identified occupational categories with frequent blood contact, rather than duration of exposure, as being the dominant variable for exposure to hepatitis B virus; for hepatitis A virus exposure, age was the most significant variable. Among health workers susceptible to hepatitis B, the incidence of new definite hepatitis B infections was 1.0% per year in 362 health workers (804 person-years of follow-up observation) with frequent blood contact versus 0% per year in 258 health workers (534 person-years of observation) with limited blood contact (p = 0.017). For definite plus probable cases combined, the incidence of new hepatitis B infections was 1.5% per year versus 0.2% per year for the groups with frequent and limited blood exposures, respectively (p = 0.0013). There were no new cases of hepatitis A or B or seroconversions in controls and only one case of hepatitis A acquired outside the hospital by a health worker. These data confirm the high prevalence of hepatitis B exposure and document in a prospective study the high incidence over time of new hepatitis B virus infections in health workers unprotected by vaccination. Such findings reiterate the need for aggressive vaccination programs in health workers exposed to blood.

Hepatitis A Antibodies↗
PubMed1992

The high-risk liver allograft recipient. Should allocation policy consider outcome?

The Boston Center for Liver Transplantation has accumulated one of the larger series of liver allograft recipients. This review has provided an opportunity to examine recent pronouncements by Medicare regarding patient selection and survival and to question whether the current allocation scheme best utilizes a scarce supply of donor liver allografts. Patients with primary biliary cirrhosis, sclerosing cholangitis, and metabolic derangements have enjoyed excellent survival: in aggregate, 78.9% at 1 year. In contrast, patients suffering from acute hepatic failure, patients requiring life support, or patients with primary graft failure who need a second liver transplant did poorly compared with other recipient groups: 45% 1-year survival. This center's experience reflects a more realistic expectation of patient survival because it considers the high-risk recipient by diagnosis and urgency status. This study also suggests that assessment of outcome should be a component of allocation planning in the future.

Adult↗
PubMed1991

Role of hepatitis C virus in non-B chronic liver disease.

To assess the contribution of the recently identified hepatitis C virus to chronic liver diseases of unknown cause and chronic hepatitis attributed by exclusion to non-A, non-B hepatitis, we tested for antibody to hepatitis C in hepatitis B surface antigen-negative patients with a spectrum of chronic liver diseases. Antibody to hepatitis C virus, a marker of hepatitis C infection, was detected with a first-generation radioimmunoassay at the following frequencies in the following patient groups: 69% of transfusion-associated non-A, non-B hepatitis; 53% of non-transfusion-associated non-A, non-B hepatitis; 26% of hepatitis B surface antigen-negative hepatocellular carcinoma; 8% of cryptogenic cirrhosis; 5% to 7% of autoimmune chronic liver diseases; 19% of patients with miscellaneous types of chronic liver disease; and 0.67% of healthy controls. Among non-transfusion-associated cases, 81% with a history of intravenous drug use but only 18% with occupational exposure as health workers had antibody to hepatitis C virus. Among cases of hepatocellular carcinoma, 63% of Japanese patients but only 11% of American patients had evidence of hepatitis C infection. Comparison in a subgroup of 79 serum samples of a second-generation radioimmunoassay with the first-generation assay demonstrated a 12% increase in antibody frequency from 30% to 42%. We conclude that hepatitis C plays a substantial role in transfusion-associated and non-transfusion-associated non-A, non-B hepatitis as well as in hepatocellular carcinoma, especially in Japan, a limited role in cryptogenic cirrhosis, and essentially no role in autoimmune chronic liver diseases. Application of more sensitive immunoassays will increase the frequency of antibody seropositivity in all subgroups, but relative distinctions among risk groups are likely to remain.

Asian↗
PubMed1990

Prevalence of hepatitis C virus antibody in a cohort of hemophilia patients.

One hundred thirty-one patients followed at the New England Hemophilia Center (Worcester, MA) were tested for antibody to hepatitis C virus (HCV). All but two had used factor concentrate that had not undergone viral inactivation; two patients had used only cryoprecipitate. The overall prevalence of HCV antibody positivity was 76.3%. There was no significant difference in age or the amount of non-heat-treated factor concentrate used between the group that was HCV antibody positive and negative. There was also no significant difference between aminotransferase levels in the two groups. There was a positive association between HCV antibody and the presence of antibody to hepatitis B core antigen and antibody to human immunodeficiency virus. A group of 31 patients were tested twice for HCV antibody at intervals of 35 to 71 months. In this subset, 25 were repeatedly seropositive, 4 were repeatedly seronegative, and 2 went from seropositive to seronegative. These data confirm the previous impression that non-A, non-B hepatitis is a major sequela to the use of pooled coagulation factor concentrates. HCV infection may account for most of the chronic liver disease observed in this population. Anti-HCV testing of plasma donors and improved methods of viral inactivation should prevent new cases from developing.

Adolescent↗
PubMed1990

Treatment of chronic hepatitis C with recombinant alpha-interferon. A multicentre randomized, controlled trial. The Hepatitis Interventional Therapy Group.

To assess the efficacy of therapy with the antiviral agent interferon in chronic hepatitis C (non-A, non-B hepatitis), we randomly assigned 166 chronic hepatitis C patients to treatment with either 3 million or 1 million units of recombinant interferon alfa-2b three times weekly for 24 weeks, or to no treatment. The probability of normalization or near normalization of the serum alanine aminotransferase levels after 6 months of interferon therapy was 46% in patients treated with 3 million units of interferon (p less than 0.001) and 28% in those treated with 1 million units (p less than 0.02), but only 8% in untreated patients. Serum alanine aminotransferase levels became completely normal in 22 of the 26 patients (85%) who responded to treatment with 3 million units of interferon and 9 of the 16 patients (56%) who responded to treatment with 1 million units. The patients who received 3 million units of interferon had histological improvement because of the regression of lobular and periportal inflammation. Relapse within 6 months after the completion of treatment occurred in 51% of the patients treated with 3 million units of interferon and 44% of those treated with 1 million units. We conclude that a 24-week course of interferon therapy is effective in controlling disease activity in many patients with hepatitis C, although relapse after the cessation of treatment is common.

Chronic Disease↗
PubMed1979

Circulating immune complexes in non-A, non-B hepatitis. Possible masking of viral antigen.

Serial serum samples from 22 patients with transfusion-associated non-A, non-B hepatitis and 2 chimpanzees with the experimentally induced disease were tested for circulating immune complexes by Raji-cell radioimmunoassay. 13 patients (59%) and 1 chimpanzee had circulating immune complexes immediately before, coincident with, or during the return to normal of raised aminotransferase activity. 7 of the 10 patients with chronic non-A, non-B hepatitis had detectable complexes at levels which waxed and waned in parallel with changes in serum aminotransferase activity. Immune complexes may contain and mask viral antigens, and their presence may explain the failure of conventional immunological techniques to detect virus antigens.

Acute Disease↗
PubMed1979

Non-A non-B hepatitis associated with chronic liver disease in a haemodialysis unit.

To clarify the aetiology of an outbreak of HBsAg-negative acute hepatitis in the renal unit at Fulham Hospital in 1968--70, serological tests for antibody to hepatitis-A virus (anti-H.A.V.) were done retrospectively on serum samples obtained at the time of the outbreak. 7 patients had had two previous episodes of clinical HBsAg-negative hepatitis. Serum samples were available from 24 of the 29 infected patients, and these were paired in 12 instances. There was a slight increase in the titre of anti-H.A.V. in 1 patient, and a further 2 patients who subsequently developed chronic hepatitis showed a decrease in titre, but no changes in titre were detected in the remaining 21 cases. These findings do not provide evidence for the involvement of hepatitis-A virus in the outbreak of hepatitis and effectively exclude a role for this virus in the chrnoic liver disease which developed subsequently in 8 (28%) of the patients. This outbreak is therefore probably non-A non-B hepatitis, which has not been reported previously in Great Britain in a haemodialysis unit. The results confirm that this form of hepatitis may be related to a high frequency of persistent hepatic dysfunction.

Antibodies, Viral↗
PubMed1978

Circulating immune complexes and complement activation in primary biliary cirrhosis.

We evaluated 20 patients with primary biliary cirrhosis and seven controls with extrahepatic biliary obstruction for presence of circulating immune complexes, having found serologic evidence of alternate complement-pathway activation in eight of the 20. Immune complexes were isolated by cryoprecipitation from serum and measured directly by the sensitive Raji-cell radioimmunoassay. Cryoproteins, found in high concentrations in 90 per cent of the patients with cirrhosis but undetectable in the controls, were composed of IgM (60 per cent), IgG-IgM (25 per cent) and IgA-IgM (5 per cent) and were capable of activating the complement system in vitro. Immune complexes detected by the Raji assay were found in 95 per cent of the patients with cirrhosis and circulated in exceedingly high concentrations (474 microgram per milliliter; range, 16.2 to 2192) but were absent in the controls. Furthermore, the alternate complement pathway was activated in eight cirrhotic patients. These complement-fixing immune complexes differ from immune complexes isolated from other types of liver diseases and may be important in the pathogenesis of primary biliary cirrhosis.

Adult↗
PubMed1978

Hepatitis A virus infection: new insights from seroepidemiologic studies.

The prevalence of exposure to hepatitis A virus (HAV) increases with increasing age; decreases with increasing socioeconomic class; increases with increasing serologic evidence of prior hepatitis B virus (HBV) exposure but is much more common than HBV exposure; is independent of sex and race; varies in different parts of the world as a function of hygienic, developmental, and unrecognized geographic factors; and is not affected by immune deficiency or immaturity. Transmission of type A hepatitis is enhanced by poor personal hygiene such as that seen in institutions for the mentally retarded. On the other hand, there is no increased exposure to HAV among homosexuals, who have frequent and intimate contact with multiple sexual partners; among hemodialysis patients and staff; or among multiply transfused individuals, all of whom are at significantly increased risk of exposure to HBV. No epidemiologic evidence has confirmed the existence of viremic or intestinal carriers of HAV, and the virus is rarely, if ever, spread by parenteral mechanisms. Finally, HAV appears to play no role in chronic liver disease and a very minor role in fulminant hepatitis; however, HAV is responsible for a sizable proportion (approximately 20%--40%) of sporadic hepatitis among urban adults.

Age Factors↗
PubMed1978

Immunosuppressive characteristics of human AFP: effect on tests of cell mediated immunity and induction of human suppressor cells.

Murine AFP has been reported to be immunosuppressive in a variety of systems. However, the extent and degree of inhibition has varied in different species and laboratories. Therefore, we have examined the potential suppressive effect of purified human AFP on several in vitro tests of cellular immunity and the potential mechanism of its action. AFP purified from fetal and liver cancer sera significantly inhibited mitogen and antigen-induced proliferative responses but had no effect on lymphocyte E rosetting, MIF production or mitogen induced T cell cytotoxicity to Chang target cells. Purified human AFP induced human suppressor cell activity, capable of suppressing a one-way mixed lymphocyte reaction (MLC). In contrast to Con A induced suppressor cells, AFP induced suppressor cell activity was overcome by mitogen augmentation of the proliferative response in MLC. These data suggest that the inhibition of lymphocyte proliferation by human AFP may be mediated by the induction of a subpopulation of human suppressor cells. Furthermore, mitogen induced cell mediated cytotoxicity was partially inhibited by primary liver cancer serum and completely inhibited by newborn cord serum, in contrast to purified fetal or tumor AFP which had no effect. These data suggest that there are other immunosuppressive factors in fetal and tumor serum which require further characterization. These other serum factors may be responsible for some of the immunosuppressive effects attributed to AFP. Although AFP is unlikely to play a major immunosuppressive role physiologically in vivo, its selective effect on proliferative responses, apparently mediated by suppressor cells, may prove to be a useful pharmacologic probe of the mechanism of these in vitro lymphocyte responses and biological interactions.

Humans↗
PubMed1978

Urticaria associated with acute viral hepatitis type B: studies of pathogenesis.

To determine whether skin deposition of circulating immune complexes contributes to prodromal urticaria of acute hepatitis B, we studied two patients with hepatitis B who presented with urticaria and fever. During the urticarial prodrome but not thereafter, we found activation of both classic and alternative complement pathways. Hepatitis B surface antigen (HBsAg)-antibody complexes were identified (by electron microscopy) in cryoprecipitates from both patients and IgG (by immunodiffusion) in cryoprecipitates of one patient during urticaria. Light and electron microscopy of involved urticarial skin revealed necrotizing venulitis in both patients. Immunofluorescence microscopy showed fibrin within involved cutaneous vessel walls in one patient and C3, IgM, and HBsAg, which were not detected in simultaneously obtained uninvolved skin, in both patients. Our findings suggest that deposition of circulating immune complexes containing HBsAg is important in the pathogenesis of urticaria associated with acute hepatitis B virus infection.

Adult↗