Prevalence of a non-A, non-B-associated antigen/antibody system detected by radioimmunoassay in acute and chronic liver disease

High risk of non-A non-B hepatitis after a first exposure to volunteer or commercial clotting factor concentrates: effects of prophylactic immune serum globulin

After a first exposure to factor VIII concentrates, 9/9 British patients treated with U.S.A.-derived commercial products, and 10/12 treated with British volunteer (NHS) products, developed acute non-A, non-B (NANB) hepatitis. Hepatitis following commercial products was more severe, and of shorter incubation. High previous exposure to NHS blood products seemed to prevent NHS but not commercial factor VIII-induced hepatitis; the latter was also not attenuated by administration of U.S.A.-derived commercial immune serum globulin (ISG). After a first exposure to NHS factor IX concentrates without ISG, 4/4 patients developed short incubation NANB hepatitis; one also contracted prolonged incubation hepatitis B. One patient treated with ISG and factor IX of proven infectivity did not develop hepatitis, suggesting protection by ISG. Observed differences between concentrates might be attributable to their content of different NANB agents, but dose-related effects could provide alternative explanations. This data provides a basis for comparative assessment of new products of possible reduced infectivity in only small numbers of patients.

Acute fulminant non-A, non-B hepatitis leading to chronic active hepatitis after treatment with cryoprecipitate

This report describes a carrier of haemophilia A who developed fulminant non-A, non-B hepatitis after transfusion with cryoprecipitate. She survived, but developed chronic active hepatitis.

Hepatitis D virus antibody in HBsAg-positive and HBsAg-negative substance abusers with chronic liver disease

The hepatitis D virus (HDV; previously called the "delta agent") is a defective organism which can replicate only in the presence of the hepatitis B virus (HBV). We tested the serum of 95 substance abusers, all of whom had sufficient evidence of chronic liver disease to warrant a liver biopsy, for hepatitis D virus antibody (anti-HDV). Anti-HDV was detected in five of eight hepatitis B surface antigen (HBsAg)-positive patients and 12 of 87 (14%) HBsAg-negative patients. Antibody to the hepatitis B core antigen (anti-HBc) was the sole hepatitis B marker in eight of the 12 (67%) anti-HDV-positive, HBsAg-negative patients but in only 14 of 75 (19%) anti-HDV-negative, HBsAg-negative patients (P less than 0.005). None of the anti-HDV-positive, HBsAg-negative patients had detectable IgM anti-HBc in the serum or hepatitis D antigen in liver tissue, and they had similar clinical features and liver biopsy diagnoses to HBsAg-negative patients without anti-HDV. We conclude that anti-HDV in HBsAg-negative substance abusers reflects infection with HDV and HBV in the distant past and does not indicate more severe liver disease than that seen in HBsAg-negative patients without anti-HDV.

AN6520 Ag: an antigen purified from liver with non-A, non-B hepatitis

An extract prepared from the liver of patient with chronic non-A, non-B (NANB) hepatitis was found to produce a precipitin line in immunodiffusion with a serum from a multiply transfused patient and those from patients convalescent from NANB hepatitis. The antigen was purified by gel filtration and density gradient centrifugation. The antigen had a buoyant density of 1.16-1.20 g/cm3 in cesium chloride, a sedimentation coefficient (S20,w) of 51.5, and a molecular weight of larger than 1.5 X 10(6) daltons. Electron microscopic examination revealed particles 29-34 nm in diameter (average 31.5 nm), which could be agglutinated by the specific antiserum. We developed a reverse passive hemagglutination (R-PHA) and a passive hemagglutination (PHA) technique for detection of the new antigen and antibody, respectively, and applied these to human sera. Antibody to the antigen was detected in 19/28 (67.9%) convalescent sera of NANB hepatitis. This prevalence was significantly higher than those found in convalescent sera of type A hepatitis patients (2/17 = 11.8%), type B hepatitis patients (2/15 = 13.3%), and normal blood donors (9/129 = 7.0%) (p less than 0.01); and the prevalence in hepatitis A and B patients did not differ significantly from that of normal donors. Furthermore, most (66.7%) of the cases of NANB hepatitis endemic in Shimizu City, Japan, showed clear seroconversion with respect to this antibody. These results suggest that the new antigen/antibody system is associated with NANB hepatitis.

Clinical evaluation of a monoclonal assay for hepatitis B surface antigen: identification of "HBsAg-like" polypeptides non-reactive in conventional radioimmunoassays

An immunoradiometric assay for hepatitis B surface antigen (HBsAg) that employs monoclonal antibodies directed against the common epitope(s) of HBsAg was used to analyse 3,694 samples of human serum. Further analysis of those sera identified as HBsAg-positive in this assay demonstrated that the findings with the monoclonal-antibody-based assay correlated with the presence of HBsAg as determined by Austria II. A small proportion of apparently false-positive reactions were observed, in that some sera, although reactive with the monoclonal antibodies, were not positive in conventional immunoassays using polyclonal antisera, nor were they neutralisable with polyclonal anti-HBs. The material purified by monoclonal immunoabsorbants from representative "true" and "false-positive" sera was run on polyacrylamide gels and examined under the electron microscope. The antigen in the apparently false-positive sera contained some polypeptides of similar size to those found in HBsAg, but no virus particles were seen by electron microscopy. The majority of patients with this monoclonal-antibody-reactive antigen gave either a history of hepatitis B virus (HBV) contact or had signs of liver disease.

Interactions between hepatotropic viruses in patients with haemophilia

Infections with the hepatotropic viruses non-A, non-B (NANB), hepatitis B (HBV) and delta agent (HDV) are described in two patients with haemophilia. The first patient illustrates the phenomenon of interference following a simultaneous exposure to NANB and HBV. The second patient, a carrier of hepatitis B surface antigen (HBsAg), acquired superinfection with HDV which resulted in acute hepatitis progressing to chronic hepatitis. Liver disease seen in multitransfused haemophiliacs may be significantly different to that seen in other patients. As a consequence of the infusion of blood clotting factor concentrates, these patients become the site of complex viral interactions.