Polysaccharide in delayed hypersensitivity. I. Pneumococcal polysaccharide as inducer and elicitor of delayed reactivity in guinea pigs.

A highly purified pneumococcal polysaccharide (Type II SSS) is a very efficient inducer of delayed hypersensitivity in random-bred guinea pigs. The cellular reactivity induced by this polysaccharide administered subcutaneously in complete Freund's adjuvant is of "tuberculin type"; it increases in intensity with time after the sensitizing injection, as judged by skin tests, the macrophage inhibition reaction and transfer of reactivity by peritoneal exudate cells. By contrast, the cellular reactivity induced by this immunogen in the absence of mycobacterial adjuvant has the characteristics of "Jones-Mote" reactivity. It is best seen at about 1 wk after sensitization; the reactions are characteristically little indurated and show histologic differences from tuberculin type responses; and the reactive state begins to disappear by 2-3 wk, with the accession of Arthus reactivity. This type of delayed reactivity may be related to an early phase of antibody synthesis.

Hepatitis B virus infection and primary hepatocellular carcinoma.

Ninety-three patients with biopsy-proven primary hepatocellular carcinoma (PHC) from Uganda, Zambia, and the United States were examined for serologic evidence of hepatitis B virus (HBV) infection. Patients were tested for hepatitis B surface antigen (HBsAg) and its antibody (anti-HBs), antibody to the hepatitis B core antigen (anti-HBc), hepatitis B e antigen (HBeAg), and its antibody (anti-HBe). Active HBV infection, as indicated by positive tests for HBsAg (with or without anti-HBs) and anti-HBc (without anti-HBs), was present in 62% of PHC patients (58 of 93), in contrast with 10% of African controls (9 of 90), and less than 1% of most United States adult populations reported in the literature. The presence of HBeAg or anti-HBe was rare among PHC patients and controls.

Negative serology for hepatitis A and B viruses in 18 cases of neonatal cholestasis.

Serologic evidence of hepatitis A virus (HAV) or hepatitis B virus (HBV) infection was sought in 14 patients with biliary atresia and in four patients with neonatal hepatitis; maternal serum was also analyzed. Specific sensitive radioimmunoassays were used to detect HBV surface antigen (HBsAg) and antibody (anti-HBs); complement fixation was used to detect antibody to HBV core antigen (anti-HBc). Antibody to HAV (anti-HAV) was assayed by radioimmunoassay, as well as by immune adherence hemagglutination. There was no evidence of active or past HBV infection in any infant or mother studied. All three infants with detectable anti-HAV were born to mothers similarly anti-HAV positive; serial testing of sera from two of these infants documented disappearance of detectable anti-HAV by 9 months of age. It is unlikely, therefore, that either HAV or HBV had an etiologic role in neonatal cholestasis in these patients. The role of other (non-A, non-B) hepatitis viruses or nonviral etiologies must be investigated.

Prevalence of hepatitis B in a high-risk setting: a serologic study of patients and staff in a pediatric oncology unit.

The prevalence of serologic markers for hepatitis B virus (HBV) among 188 patients and 158 employees in a pediatric oncology unit was evaluated. Evidence of past or present HBV infection was detected in 33 patients (18%) and in 25 employees (16%). The prevalence was higher among patients receiving chemotherapy (19%) than among those not receiving chemotherapy (7%). The prevalence of HBV serologic markers, while much higher than generally found among healthy children in the United States, was low compared to previously reported prevalences in such settings, and may reflect the use in recent years of blood and blood products screened by "third generation" methods (radioimmunoassay and reversed passive hemagglutination) for hepatitis B surface antigen and the use of all volunteer blood donors. This prevalence suggests that perhaps there is less urgent need for the use of hepatitis B immune globulin and hepatitis B vaccine (when it becomes available) in oncology units than had been anticipated from earlier data in oncology units.

Asymptomatic viral hepatitis types A and B in an adolescent population.

Sera from 95 adolescents were examined for markers of hepatitis B virus (HBV) infection and hepatitis A virus (HAV) infection. HBV markers were found in eight adolescents (8%) and evidence of previous HAV infection was found in 18 adolescents (19%); none had a history of clinically recognizable hepatitis. These findings support the growing evidence that HBV and HAV infections are diseases of the pediatric age group, and that testing of HBV vaccines when they become available for patient use will have to include a pediatric population.

Varicella vaccine (VARIVAX) in healthy children and adolescents: results from clinical trials, 1987 to 1989.

A total of 3303 healthy children and adolescents, aged 12 months to 17 years, were vaccinated with one of five production lots of a live attenuated varicella vaccine (VARIVAX) containing 1000 to 1625 plaque-forming units per dose. The vaccine was generally well tolerated. Ninety-six percent (2381/2475) of vaccinees responded to vaccination by producing antibody as measured by a glycoprotein-based enzyme-linked immunosorbent assay; 99% (569/576) of those tested maintained antibody at 1 year following vaccination. The incidence of varicella following household exposure in vaccinees was approximately 12%; household contact historically results in 87% infection. Nearly all of the vaccinees who had varicella after vaccination had a clinically modified disease.

Absence of an association between past infection with hepatitis A virus and primary hepatocellular carcinoma.

Serum samples from 77 caucasians of Greek origin with primary hepatocellular carcinoma (PHC) and 77 age- and sex-matched controls were tested for antibody to the hepatitis A virus (anti-HAV). Anti-HAV was detected in 63 patients with PHC (82%) and in 70 controls (91%). These data suggest that past infection with hepatitis A virus is not related to the development of PHC, in marked contrast to the strong association between PHC and HBV.

Evaluation of hepatitis B antigen testing in federally licensed blood banks in the United States.

Between August 1972 and January 1974, the Burear of Biologics distributed four panels of 20 coded serum samples to all federally licensed blood banks for hepatitis B antigen testing. Initially, all but six blood banks reported results by counterelectrophoresis (CEP) only, but by January 1974, 152 of 247 banks reported results by radioimmunoassay (RIA). On the four panels distributed, correct results were reported for 63 to 83% of all potentially detectable samples by CEP and for 98 to 100% of all samples potentially detectable by RIA. Perfect scores were obtained by only 5 to 25% of blood banks using CEP but by 77 to 100% using RIA. Nonreproducible results on duplicate reactive samples, included to evaluate internal consistency, ranged from 0.5 to 25% by CEP and from zero to 5% by RIA. These results demonstrate greater reliability in addition to greater sensitivity of "third generation" RIA testing in comparison with "second generation" CEP testing.

Serologic markers of hepatitis A and B in the population of Bali, Indonesia.

A total of 343 sera from Balinese subjects in different age groups and geographic locations were tested by radioimmunoassay (RIA) for serum antibodies to hepatitis B surface antigen (anti-HBs) and hepatitis B core antigen (anti-HBc); most sera were also tested for hepatitis B surface antigen (HBsAg), and for antibody to hepatitis A virus (anti-HAV). One hundred percent of the adult population was found to have anti-HAV, with antibody acquisition beginning in early childhood and reaching a level of 95% by the age of 10 years. Antibodies to hepatitis B virus were also frequent in young children, rapidly peaking to near 80% in older children and adolescents, then declining to a plateau that fluctuated between 40% and 60% throughout adult life. Overall, anti-HBc (49%) was detected slightly more often than anti-HBs (45%), but the relative frequencies of the 2 antibodies varied considerably from group to group. Despite these high antibody prevalences, HBsAg was detected in only 1.5% of the general population, and in no woman of child-bearing age. In utero infection is thus far less likely to account for the early acquisition of antibody to hepatitis B virus than inapparent percutaneous transmission occurring under conditions of close personal contact.

Production and immunological analysis of recombinant hepatitis B vaccine.

The synthesis of the hepatitis B surface antigen (HBsAG) in cells of Saccharomyces cerevisiae and its subsequent isolation, purification and analysis is described. The final, purified HBsAg particle exhibits close structural and biochemical similarities to particles derived from the plasma of chronically infected humans. Particles of yeast and human origin have been found, by chimpanzee efficacy studies and by various in vitro analyses, to be immunologically equivalent. The antigenic expression of a determinant-specific epitopes, as measured by antibody binding to synthetic peptides, has also been shown to be equivalent.

Antibody to hepatitis B core antigen.

Two distinct antigen-antibody systems are associated with the hepatitis B virus (HBV): hepatitis B surface antigen (HBs Ag) and antibody (anti-HBs) and the more recently described hepatitis B core antigen (HBc Ag) and antibody (anti-HBc). Testing of serial serum samples from patients with type B hepatitis demonstrates the regular occurrence of anti-HBc during the course of this disease. In general, highest titers of anti-HBc are seen with prolonged circulation of HBs Ag as in the chronic carrier state. Titers of anti-HBc begin to fall with recovery from HBV infection and anti-HBc appears to be shorter lived than anti-HBs. As such, anti-HBc testing is important in documenting the occurrence of infection with HBV and is of great value in epidemiologic studies and in evaluating the safety and efficacy of hepatitis B immune globulin and HBV vaccines.

Combination of ketamine and xylazine for effective anaesthesia of juvenile chimpanzees (Pan troglodytes).

Intramuscular administration of ketamine at 15-20 mg/kg bodyweight provided effective levels of anaesthesia for venipuncture in 23 chimpanzees aged 12-36 months. For procedures such as plasmaphereses or percutaneous needle biopsy requiring longer anaesthetic times, xylazine (1 mg/kg) was given with the ketamine. More than 1600 procedures were performed under anaesthesia on the 23 chimpanzees over a period of 18 months with no mortality. Recovery was smooth and uneventful.

Plasma derivatives and viral hepatitis.

Plasma derivatives can be separated into those with either a low or a high risk of transmitting viral hepatitis. Low-risk products, with few exceptions, will remain low-risk irrespective of the plasma from which they are manufactured because they are heated at 60 degrees C for 10 hours (Albumin, Plasma Protein Fraction) or because they contain protective antibodies (Immune Globulin). This would appear to be the case not only for hepatitis B but also for non-A, non-B hepatitis. The risk of hepatitis B associated with plasma derivatives is reduced but not eliminated by HBsAg screening of donors. Further decreasing the risk of hepatitis B associated with AHF or Factor IX lots, as well as newer products like AT-III, alpha-1 antitrypsin, Fibronectin, C-1 Inactivator, and Factor XIII, may be accomplished either by the combination of stabilization and heating or by assuring that these products contain an excess of anti-HBS. For highly-purified products with little residual immunoglobulin it may be necessary to add anti-HBs. The addition of antibodies against non-A, non-B hepatitis agents when they are identified, could prevent transmission of both forms of viral hepatitis by plasma derivatives. Methods to stabilize and heat high-risk plasma derivatives to inactivate hepatitis viruses have the potential to remove both hepatitis B and non-A, non-B hepatitis infectivity.

A glycoprotein associated with the non-A, non-B hepatitis agent(s): isolation and immunoreactivity.

A glycoprotein was isolated and purified to homogeneity from the serum of a patient with chronic non-A, non-B hepatitis. NaDodSO4/PAGE of the glycoprotein revealed a single major band at Mr approximately 77,000. Antibodies to this glycoprotein were shown to possess the following immunoreactivity: (i) they reacted by radioimmunoassay with sera obtained at the time of diagnosis from 17 of 42 patients with non-A, non-B hepatitis and with only 2 of 58 sera from either matched controls or patients with hepatitis A or hepatitis B, (ii) they reacted with sucrose gradient fractions from a proven infectious non-A, non-B hepatitis serum at a peak density of 1.14 g/ml and in the soluble protein fractions on top of the gradient, and (iii) they reacted in ELISA with disrupted human T-cell lymphocytotropic virus type III (HTLV-III), and (iv) they reacted in immunoblots with a protein of Mr 74,000 derived from HTLV-III.

Key issues in the selection of an expression system for vaccine antigens.

Three criteria by which the appropriate host cell is chosen for the expression of a recombinant-derived vaccine antigen are efficacy, safety, and scale-up. Efficacy for a vaccine antigen refers to the ability of the host cell to produce a vaccine antigen capable of eliciting a protective immune response. A concern for safety of a vaccine antigen relates to residual DNA in the final product, especially when derived from continuous mammalian cell lines as opposed to microbial cells. Since tens (or hundreds) of millions of doses of a widely used vaccine might be injected into healthy infants and young children during the lifetime of the product, safety is a critical issue, such that the use of a microbial expression system might be preferable to the use of a continuous cell line in certain circumstances.

Inactivation of an agent of human non-A, non-B hepatitis by formalin.

Samples of serum (0.1 ml each) containing an agent of human non-A, non-B hepatitis of documented infectivity were incubated with formalin in a concentration of 1:1,000 at 37 C for 96 hr. Three colony-born infant chimpanzees were then inoculated with this formalin-treated serum; one received a single intravenous inoculation, and two received two subcutaneous inoculations one month apart. A fourth uninoculated chimpanzee served as a control. None developed recognizable non-A, non-B hepatitis during seven months of observation, as judged by normal aminotransferase levels in weekly serum samples, normal liver histology in liver biopsy specimens, and the absence of non-A, non-B hepatitis-associated antigen and antibody in their sera. All four chimpanzees were subsequently shown to be susceptible to non-A, non-B hepatitis when challenged with 0.1 ml of the untreated infectious serum 31 weeks after the initial inoculations.

Hepatitis B virus infection in infants and toddlers in Nigeria: the need for early intervention.

One or more serologic markers of hepatitis B were detected in serum samples from 29 of 61 (48%) Nigerian children between ages 6 months and 2 years who were followed for three months. Eight (13%) had acute infections, nine (15%) had chronic infections, and 12 (20%) had transplacentally acquired maternal antibody. Of 17 with active hepatitis B, 13 had been infected prior to the first serum sample (76% of infections) and four were infected during the three months of this study (24% of infections). These data indicate that effective intervention at an early age would have prevented 24% of the HBV infections which occurred in these infants, and intervention soon after birth might have prevented all of the cases.