Improvement of virus safety of a S/D-treated factor VIII concentrate by additional dry heat treatment at 100 degrees C

In order to increase the virus safety of a solvent/detergent-treated Factor VIII concentrate in regard to non-lipid coated viruses and to respond to the continuous discussion about reports on hepatitis A transmission by Factor VIII preparations, we have investigated the effect of a terminal dry heat treatment (30 min 100 degrees C) on HAV and various other viruses. By this treatment Hepatitis A virus was inactivated below detectable level after a few minutes (> 5.3 log10). Other RNA viruses such as the Human Immunodeficiency Virus (> 6.6 log10), bovine viral diarrhoea virus (> 6.6 log10) and vesicular stomatitis virus (> 5.8 log10) were also inactivated below detectable level. Pseudo rabies virus and reovirus Type 3 are inactivated by 5.7 and > 6.0 log10, respectively. SV40 and bovine parvo virus showed significant resistance to dry heat treatment. We conclude that the involvement of two strong virus inactivation steps, acting by different mechanisms, improves the virus safety of Factor VIII concentrates without destroying the Factor VIII activity. Moreover, the terminal 100 degrees C heat treatment for 30 min represents an effective measure to inactivate non-lipid enveloped viruses, in particular hepatitis A, which is resistant to solvent/detergent treatment.

Activation of a heterogeneous hepatitis B (HB) core and e antigen-specific CD4+ T-cell population during seroconversion to anti-HBe and anti-HBs in hepatitis B virus infection

Overcoming hepatitis B virus infection essentially depends on the appropriate immune response of the infected host. Among the hepatitis B virus antigens, the core (HBcAg) and e (HBeAg) proteins appear highly immunogenic and induce important lymphocyte effector functions. In order to investigate the importance of HBcAg/HBeAg-specific T lymphocytes in patients with acute and chronic hepatitis B and to identify immunodominant epitopes within the HBcAg/HBeAg, CD4+ T-cell responses to hepatitis B virus-encoded HBcAg and HBcAg/HBeAg-derived peptides were studied in 49 patients with acute and 39 patients with chronic hepatitis B. The results show a frequent antigen-specific CD4+ T-cell activation during acute hepatitis B infection, a rare HBcAg/HBeAg-specific CD4+ T-cell response among HBeAg+ chronic carriers, and no response in patients with anti-HBe+ chronic hepatitis. An increasing CD4+ T-cell response to HBcAg/HBeAg coincides with loss of HBeAg and hepatitis B virus surface antigen (HBsAg). Functional analysis of peptide-specific CD4+ T-cell clones revealed a heterogeneous population with respect to lymphokine production. Epitope mapping within the HBcAg/HBeAg peptide defined amino acids (aa) 1 to 25 and aa 61 to 85, irrespective of the HLA haplotype, as the predominant CD4+ T-cell recognition sites. Other important sequences could be identified in the amino-terminal part of the protein, aa 21 to 45, aa 41 to 65, and aa 81 to 105. The immunodominant epitopes are expressed in both proteins, HBcAg and HBeAg. Our findings lead to the conclusion that activation of CD4+ T lymphocytes by HBcAg/HBeAg is a prerequisite for viral elimination, and further studies have to focus on the question of how to enhance or induce this type of T-cell response in chronic carriers. The immunodominant viral sequences identified may have relevance to synthetic vaccine design and to the use of peptide T-cell sites as immunotherapeutic agents in chronic infection.

Immunosuppressive serum factors in viral hepatitis. III. Prognostic relevance of rosette inhibitory factor and serum inhibition factor in acute and chronic hepatitis

Two immunosuppressive serum factors, serum inhibition factor (SIF) and rosette inhibitory factor (RIF), were studied in sera from patients with acute and chronic viral hepatitis. In a study of 30 patients with acute viral hepatitis, an association was found between RIF, SIF, and biochemical and virological parameters in 27 patients (90%), 25 of whom recovered completely; two had a protracted course. In three patients, the clinical course was not reflected by the immunosuppressive factors. In 26 patients with chronic persistent hepatitis, 3 had RIF and 7 had SIF of low activity. In patients with HBsAg-positive and -negative chronic active hepatitis, 32 of 47 had RIF and 24 had SIF. SIF activity was significantly increased in HBsAg positive as compared to -negative cases. There was no correlation between RIF and SIF activity at any stage of viral hepatitis. Although SIF was demonstrated in patients with various infectious and other inflammatory diseases, RIF was infrequently detected in nonviral liver disorders, and was not present in any of the nonhepatic diseases tested. It was confirmed that RIF is associated with the beta-lipoprotein fraction. RIF was easily separated from SIF by density gradient ultracentrifugation. The evaluation of SIF and RIF may be helpful in determining the outcome of acute viral hepatitis. In chronic hepatitis, RIF was a better indicator of disease activity than was SIF. These clinical data support previous findings that SIF may be related to the immune response whereas RIF is associated with liver cell damage.

Sporadic non-A, non-B hepatitis: frequency and epidemiology in an urban U.S. population

Patients with acute viral hepatitis were identified at five hospitals in Baltimore, Maryland between February 1979-August 1980. Of the 295 patients with serologically diagnosed hepatitis, 42% had non-A, non-B hepatitis; 48% had hepatitis B; and 10% had hepatitis A. Compared with matched control patients with no liver disease, patients with non-A, non-B hepatitis more often had received a blood transfusion (11% vs. O, P less than 0.001), used parenteral drugs (42% vs. 4%, P less than 0.001), were employed as health workers in direct patient care or hospital laboratory work (6% vs. 3%, P less than 0.05), had personal contact with others who had hepatitis (16% vs. 1%, P less than 0.001), or had ingested raw shellfish (34% vs. 20%, P less than 0.01). A history of previous clinical hepatitis and serologic markers indicating previous hepatitis B infection were found in patients with non-A, non-B hepatitis more often than in the control patients. Chronic non-A, non-B hepatitis was found in 34 (42.5%) of 80 patients with non-A, non-B hepatitis.

[Destroying of antigenicity and influencing the immunochemical reactivity of hepatitis B virus antigens (HBsAg, HBcAg and HBeAg) through disinfectants--a proposed method for testing (author's transl)]

So far, hepatitis B virus cannot be grown in tissue cultures. Consequently, the inactivating effect of disinfectants upon the infectivity of hepatitis B virus could only be insufficiently investigated. Investigations using the only suitable test animal, the chimpanzee, are associated with substantial efforts and high cost and are also limited in their extent. A relatively simple and probably reliable method as test model for disinfectants used in hepatitis B prophylaxis is outlined: the destruction of the antigenicity and the decrease in the immunochemical reactivity of hepatitis B virus antigens (HBsAg, HBcAg and HBeAg). Effects of one alcoholic antiseptic and two peracetic acid containing disinfectants are investigated.

Clearance of hepatitis B e-antigen in chronic hepatitis B infection

HBeAg and anti-HBe were determined by radioimmunoassay (Abbott HBe) in serial serum samples from 22 patients who had been HBsAg-positive for more than 1 year. Seventeen patients (77%) were HBeAg-positive at onset of illness. Eight of these patients were persistently HBeAg-positive during 2.5-8.5 years' follow-up study (mean, 5.4 years). Chronic persistent hepatitis (CPH) developed in one of these patients and chronic active hepatitis (CAH) in seven patients. Nine persistently HBsAg-positive patients were transiently HBeAg-positive. Seven of these patients developed CPH, and they all lost HBeAg within 2 years of onset of illness. One patient, who was HBeAg-positive for 4 years, developed CAH with cirrhosis after loss of HBeAg. In five patients, HBeAg could not be detected. They were anti-HBe-positive at onset of illness; four developed CAH and/or cirrhosis, and one developed CPH. Progression from CPH or nonspecific reactive hepatitis to CAH was observed in two persistently HBeAg-positive patients. Prolonged detection of HBeAg in CPH is a reason for repeated liver biopsy to reevaluate the diagnosis. The behaviour of the e-antigen system in CAH seems to be more complex than in CPH, perhaps indicating a different pathogenetic mechanism of chronicity in CAH.

[Hepatitis B vaccine trial in healthy adults - an immunogenicity study (author's transl)]

The clinical and immunological response in healthy adults to active and passive - active immunization with a vaccine prepared from purified HBsAg (Merck Sharp and Dohme) in combination with a hepatitis B immune serum globulin (HBIG) were determined and compared with each other. The subjects were randomly assigned to one of three groups: group I received 3 doses of vaccine (20 micrograms per dose) at 0, 1 and 6 months, group II received in addition with the first dose of vaccine 3 ml of HBIG and group III received HBIG together with the first and the second doses of vaccine. No serious side effects were seen during the observation period. Antibody response was comparable in all three groups after 6 months, showing that the passive antibodies did not interfere with active antibody formation. Our results also prove the safety and efficacy of the hepatitis B vaccine and establish the feasibility of passive-active immunization.

Acute hepatitis non-A, non-B following administration of factor VIII concentrates

A retrospective survey on clinical hepatitis in patients with bleeding disorders was performed. Nine episodes of hepatitis non-A, non-B occurred in 8 out of 20 patients (40%) with mild hemophilia A or von Willebrand's disease, who had been treated with commercial factor VIII concentrates. Only two episodes of hepatitis B occurred during the study period. The non-A, non-B attack rate after the first treatment was 40% with factor VIII concentrate obtained from large plasma pools (= 2,000 donors) including professional plasma donors as compared to 8% after treatment with factor VIII concentrate obtained from smaller (100-250 donors) plasma pools from Scandinavian donors.

Cloning of hepatitis A virus genome

Hepatitis A virus (HAV) was highly purified from faeces. The genomic RNA was transcribed to cDNA and this DNA was then cloned into plasmid pBR 322 at the Pst I site, and clones were selected in presence of tetracycline. Most clones contained inserts which hybridized to HAV-specific RNA isolated from HAV-infected cell cultures derived from a human hepatocellular carcinoma. Two clones expressed low amounts of viral antigens.

[Non-A, non-B viral hepatitis: occurrence, epidemiology and prognosis]

Out of 117 cases with acute viral hepatitis, 37 (32%) were classified as hepatitis A, 50 (43%) as hepatitis B and 30 (25%) as hepatitis non-A-non-B (NANB). In 21 of the 30 patients with hepatitis NANB, a possible mode of parenteral transmission could be found. The mean incubation period was 53 days. Only 3 patients had had blood transfusions. 14 (52%) of the 27 patients with sporadic hepatitis (without transfusions) had a mild course of the acute illness without, or with only mild, jaundice and transaminase values below 500 IU. The remaining 13 patients had a more severe form of acute hepatitis (bilirubin above 5 mg/dl, GPT above 500 IU), and in 11 of these 13 cases confluent necrosis was demonstrable on liver biopsy. 10 (37%) of the sporadic cases, of whom 8 had a mild form of acute hepatitis, and the 3 cases of posttransfusion hepatitis, were followed by a chronic course.

[Hepatitis A antibody: placental transmission and disappearance in the first year of life (author's transl)]

Sera of 114 mothers and their newborn (cord blood) were tested for the presence of antibodies to hepatitis A virus (Anti-HAV) by a competitive solid phase radioimmunoassay. Antibodies were detectable in 80 pairs of sera but not in another 31 pairs. 3 newborns proved to be anti-HAV positive, while their mothers had not detectable antibodies. 72 infants could be followed up for about one year. The disappearance of antibodies occurred between the first and 14th month of life. 50% of the tested infants were still(Anti-HAV positive at the age of 7-8 months.

Hepatitis B virus markers, alpha-fetoprotein and survival in fulminant viral hepatitis

The serological markers of hepatitis B virus and serum alpha-fetoprotein (AFP) levels have been studied in 28 consecutive cases of fulminant hepatitis, correlating the data with survival. On admission, 20 patients were found to be positive for HBsAg and eight for anti-HBs. All anti-HBs-positive cases showed high titers of anti-HBc, and six patients were positive for specific anti-HBc-IgM. DNA polymerase activity was detected in serum of 11 HBsAg-positive (55%) and four anti-HBs-positive (50%) patients. HBeAg was detected in six (21.4%) subjects (five HBsAg-positive and one anti-HBs-positive), whereas anti-HBe was present in nine (32.1%) subjects (six HBsAg-positive and three anti-HBs-positive). AFP levels greater than 60 ng/ml were found in sera of 14 patients (50%). No significant difference was evidenced in the survival rate between HBsAg-positive and anti-HBs-positive and between HBeAg-positive and HBe Ag-negative patients. However, a statistically significant difference (P less than 0.05) in the survival rate was found in patients positive and negative for DNA polymerase activity and in those with AFP levels higher and lower than 60 ng/ml (P less than 0.005). Pathogenetic and prognostic significance of these findings are discussed.

Serum immunoglobulin levels in hepatitis non-A, non-B: a comparison with hepatitis A and B

The serum levels of IgA, IgG and IgM were determined by the single radial immunodiffusion method in 86 patients with acute viral hepatitis serologically differentiated by radioimmunoassays. The levels of IgA and IgG were similar in patients with hepatitis A, B and non-A, non-B, while differences in IgM levels were observed between the three groups. The hepatitis non-A, non-B group had significantly lower levels of IgM than both the hepatitis A and hepatitis B group, a finding which may be diagnostically useful if hepatitis A serology fails.