Immune response to a heat-inactivated hepatitis B vaccine in patients undergoing hemodialysis. Enhancement of the response by increasing the dose of hepatitis B surface antigen from 3 to 27 micrograms.

In a randomized trial, 227 patients undergoing hemodialysis who were seronegative for all markers of hepatitis B virus were immunized at monthly intervals with three doses of either 3 micrograms or 27 micrograms of heat-inactivated hepatitis B HB-vaccine (CLB). Five months after the first injection, 77% of the patients in the 3-micrograms group and 94% in the 27-micrograms group manifested antibodies against hepatitis B surface antigen (anti-HBs). At month 12 the proportions of subjects with anti-HBs in the 3-micrograms and 27-micrograms groups had dropped to 68% and 87%, respectively. At all times, the differences in the anti-HBs conversion rate between the two treatment groups were significant. These results show that the impaired immune reactivity to hepatitis B vaccines of patients undergoing hemodialysis can be overcome by increasing the dose of the vaccine.

The serum IgG subclass levels in healthy infants of 13--62 weeks of age.

The levels of IgG1, IgG2, IgG3, and IgG4 were determined in serum samples of 160 infants aged 13--62 weeks, and of their mothers. In addition the serum IgM, IgG, IgA, and IgD levels of the infants are presented. The results show that IgM, IgG1, and IgG3 slightly increase during the first year of life, whereas IgG2, IgG4, IgA, and IgD hardly do. This difference in the development of the various immunoglobulin isotypes reflects differences in the terminal maturation of subsets of B-lymphocytes into plasma cells. About 50% of the infants of this age had no detectable IgG4 and three children had no IgG2. These observations indicate that longitudinal investigations are needed in children suspected of a IgG2 or IgG4 subclass deficiency. No statistically significant influence of sex on the IgG subclasses could be demonstrated in these infants.

Serum immunoglobulins in healthy children and adults. Levels of the five classes, expressed in international units per millilitre.

Serum levels of IgM, IgG, IgA, IgD, and IgE were determined in serum samples of 270 healthy Dutch children (aged 4-13 years) and of 30 healthy Dutch adults, the amounts being expressed in International Units per millilitre. Special attention is given to the IgD and IgE results, since the IgM, IgG, and IgA levels in mg per 100 ml of these sera and their implications have already been reported. In the children's sera the occurrence of relatively high IgD and IgE levels was frequently observed, whereas the adult group did not show excessive variation in this respect. The mean IgD levels found for adult males and females are 21 I.U./ml and 24 I.U./ml, respectively; the mean IgE levels for the same groups are 68 I.U./ml and 88 I.U./ml, respectively. The mean IgD and IgE levels in the children of each year group were usually higher than those of each of the juvenile groups and the mean level of the adult group was not statistically significant. A statistically significant influence of sex and season on the IgD and IgE levels could not be demonstrated in this material either. Three of the 270 children's sera showed an exceptionally low IgA content. In two of these cases the serum was sampled and studied a second time after an interval of four years, when the IgA deficiency proved to be still present. The IgE levels in the sera of these healthy IgA-deficient children were normal, whereas the presence of IgD could not be demonstrated.

Interactions between IgE and house dust extract as studied by the radioallergosorbent test (RAST).

Several components in house dust extract can bind IgE, these interactions are not all immunologically specific. Non-immune interactions may conceivably contribute to the biological effects of house dust extract, they are actually found to interfere with the assay of allergen-specific IgE, especially when the serum under investigation has a high IgE content. By modification of the incubation medium, non-immune interactions can to a large extent be prevented. The immunological interactions between IgE and components in house dust extract have been investigated using twenty extracts, both in inhibition-type assay and in direct insolubilization assay. D. pteronyssinus-related allergens were found to be present in almost all extracts, however, not all house dust specific IgE reacted with mite-related allergens. Whether standardization of house dust extract is at all feasible, and if so, worthwhile, remains to be seen. It is clear, however, that no single figure can represent a completely reliable measure for the biological potency of a house dust extract.

The mechanism of passive sensitization: occupation of free IgE receptors or exchange with cell-bound IgE.

Leukocytes were passively sensitized, as judged by allergen-induced histamine release. Before and after passive sensitization, the amount of total IgE on basophil leukocytes was measured by quantitative immunofluorescence microscopy. No measurable increase in IgE load was observed. When leukocytes were incubated with acid buffer after passive sensitization, no allergen-specific IgE was found in acid eluates of these leukocytes. Preincubation of leukocytes with excess irrelevant IgE resulted in inhibition of a subsequent passive sensitization. Postincubation of in vivo- or in vitro-sensitized leukocytes with excess irrelevant IgE had no effect on the sensitivity of these cells towards allergen. When leukocytes were incubated with TNP-labeled myeloma IgE and subsequently with fluorescein-labeled anti-TNP antibodies, no fluorescence was observed on basophil leukocytes, although binding of TNP-labeled IgE was demonstrated by anti-TNP antiserum-induced histamine release. It is concluded that only small amounts of IgE become bound to basophil leukocytes during passive sensitization, compared with the amounts of IgE already present on these cells. Exchange of IgE between cells and sensitizing serum does not take place to a measurable extent during passive sensitization.

Comparison of sic 'Third-Generation' tests for the detection of HBsAg.

Six 'third-generation' techniques for the detection of HBsAg were compared, i.e. Ausria II-125, Travenol-RIA, Auszyme, Hepanostika, Auscell and a modified Auscell technique applying centrifugation instead of sedimentation. The Ausria II-125 was the most sensitive test, followed by Travenol-RIA, both Auscell techniques, Auszyme and Hepanostika. In the Ausria II-125, Hepanostika and Auscell techniques, 1-2% of false-positive results were found in serum and 2% in plasma specimens from blood donors. Both the Travenol-RIA and Auszyme tests gave an unacceptably high percentage (6-8%) of false-positive results in both serum and plasma specimens.

Prevention of chronic HBsAg carrier state in infants of HBsAg-positive mothers by hepatitis B immunoglobulin.

21 children of HBsAg-carrier mothers were given 0.5 ml/kg hepatitis B immunoglobulin (HBIg) within 48 h after birth and subsequently 0.16 ml/kg every month for 6 months; 20 children were not treated. None of the HBIg-treated children became HBsAg positive, compared with 5 of the untreated children (p less than 0.02). 2 of 3 children who were not started on HBIg until the fourth or fifth day after birth also became HBsAg positive. 4 children of mothers who had acute hepatitis B in the third trimester of pregnancy were treated with HBIg and remained HBsAg negative, whereas another, untreated, child became HBsAg positive.

Simultaneous passive and active immunization against hepatitis B: noninterference of hepatitis B immune globulin with the anti-HBs response to reduced doses of heat-inactivated hepatitis B vaccine.

The effect of simultaneous administration of hepatitis B immune globulin on the antibody response to a low dose of heat-inactivated hepatitis B vaccine was investigated in 175 health care workers. Subjects were divided into four groups: Groups I and II received 3 monthly injections of a reduced dose (0.6 microgram) of a heat-inactivated hepatitis B vaccine (the usual dose being 3 micrograms) along with 500 IU of hepatitis B immune globulin simultaneously with the first injection of vaccine; Groups III and IV received the vaccine only. In addition, Groups I and III received a final booster injection with 0.6 microgram of the vaccine 8 months after the initial injection. Anti-HBs passively acquired from hepatitis B immune globulin did not interfere with the development of an active antibody response to the vaccine: the anti-HBs conversion rates were similar in persons treated with the combined regimen (89%) as in those who received the vaccine only (91%). At 3 and 5 months after the first injection, however, anti-HBs titers in the recipients of vaccine alone were slightly but statistically significantly higher than those of persons who received both hepatitis B immune globulin and vaccine; but at 8 months, this difference was no longer statistically significant. After a booster inoculation at 8 months, the geometric mean titer of anti-HBs increased 7- to 8-fold in antibody-positive vaccinees, regardless of whether hepatitis B immune globulin had been given earlier. Moreover, 6 of 13 nonresponders to the initial three vaccine injections developed anti-HBs after the booster inoculation.(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatitis B among homosexual men in The Netherlands.

In 1980-1981 a study for the presence of markers of hepatitis B virus was done among 2, 946 homosexual men living in The Netherlands, mainly in Amsterdam. Serologic evidence of a past or present hepatitis B infection was found in 60.3% of this group, and the prevalence differed significantly among the different age groups. Of the total population studied, 4.8% were positive for HBsAg. This prevalence is very high in comparison to that in the general Dutch population, among whom the prevalence of hepatitis B is low, as is shown by the fact that the prevalence of HBsAg was 0.22% among a large group of Dutch first-time blood donors. Another blood sample was collected two to 20 months after the first sample from 316 male homosexuals who were initially negative for hepatitis B markers. It was found that 36 persons had seroconverted, most of them without clinical manifestations of hepatitis. The annual attack rate of hepatitis B in this group was calculated as 27.6% and differed significantly among the different age groups.

Follow-up of blood donors positive for hepatitis B surface antigen.

From 1973 to 1977 in Amsterdam the incidence of hepatitis B surface antigen (HBsAg) in blood donations from new donors was 0.224 and from known donors 0.034%. 65 donors, previously found positive for HBsAg, were re-examined. Persistence of HBsAg in new donors (28 of 31) occurred significantly (p less than 0.0005) more often than in known donors (15 of 34). All carriers were classified into HBeAg (21%) or anti-HBe (79%) by a sensitive Elisa technique. Abnormal liver function tests (LFTs) were observed in 30% of the carriers and were significantly (p less than 0.005) more often found in HBeAg than in anti-HBe-positive carriers. When the LFTs remained abnormal, in almost all (8 of 9) carriers moderate to severe histological liver disease was diagnosed.

Immunogenicity and safety of heat-inactivated hepatitis B vaccine (CLB) in low risk human volunteers and in patients treated with chronic haemodialysis in the Netherlands.

The immunogenicity and safety of a heat-inactivated hepatitis B vaccine (HB-vaccine) were studied in healthy human volunteers (n = 471) at a low risk to be infected with hepatitis B virus (HBV) and in patients on chronic haemodialysis (n = 227), who were treated in hepatitis B free centres. After vaccination with 3 injections of 3 micrograms heat-inactivated HBsAg adsorbed to A1PO4, given at monthly intervals, 93% of the healthy low risk volunteers had formed anti-HBs. The haemodialysis patients were randomly divided into 2 groups, which were vaccinated with 3 monthly injections of 3 micrograms and 27 micrograms heat-inactivated HBsAg, respectively. It appeared, that this 9-fold increase of the vaccine-dosage enhanced the anti-HBs response from 77% in the 3 micrograms vaccinees to 94% in the 27 micrograms recipients. Side-effects of the vaccination were negligible, formation of autoantibodies in consequence of the vaccine treatment was not demonstrated in any of the vaccinees.

Efficacy of a heat inactivated hepatitis B vaccine in male homosexuals: outcome of a placebo controlled double blind trial.

The efficacy of a heat inactivated hepatitis B virus vaccine, containing 3 micrograms hepatitis B surface antigen (HBsAg), was studied in a high risk group of 800 susceptible homosexual men by a randomised placebo controlled double blind trial. At the trial end point (21.5 months), 17 hepatitis B virus infections had occurred in vaccinated subjects (attack rate 4.8%) and 56 in subjects receiving a placebo (attack rate 23.8%). This reduction in the incidence of hepatitis B virus infections in vaccinated subjects was highly significant (p less than 0.0001). Two months after the first injection 72.3% of the vaccinated subjects had formed antibodies against hepatitis B surface antigen, and this percentage increased to 89% at four months. Maximum anti-HBs titres were reached five months after the first vaccination, the geometric mean titre being 107.6 mIU. Even vaccinated subjects with a low antibody response (greater than or equal to 1 and less than 10 mIU) were found to be protected from HBsAg-positive infections. The vaccine had no serious side effects.

Contributions to the optimal use of human blood. IX. Elimination of hepatitis B transmission by (potentially) infectious plasma derivatives.

Investigations were performed concerning the elimination of the risk of hepatitis B transmission of potentially infectious plasma derivatives by the addition of a low dose of hepatitis B immunoglobulin (HBIg). To this end, clotting factor VIII concentrate, prothrombin complex, C1 esterase inhibitor concentrate, plasminogen and antithrombin III were prepared from plasma strongly positive for hepatitis B surface antigen (HBsAg). To one half of every preparation, HBIg was added up to a final concentration of 0.4 IU anti-HBs/ml (test preparations), the other half was not treated (control preparations). Furthermore, to 10(-3) diluted infectious reference plasma (Bureau of Biologics, FDA, USA), an overdose HBIg was added to a final concentration of about 0.4 IU anti-HBs/ml. 6 chimpanzees, injected either with the control plasma derivatives or with the untreated infectious reference plasma, were infected with hepatitis B virus, whereas 5 chimpanzees, injected either with the test plasma derivatives or the infectious reference plasma to which the HBIg had been added, did not show any evidence of hepatitis B infection during the follow-up of 1 year. Addition of a low dose of HBIg to potentially infectious plasma derivatives appears to be a reliable measure to eliminate the hepatitis B transmission and is preferred to other methods for labile plasma derivatives.

Efficacy of heat-inactivated hepatitis B vaccine in haemodialysis patients and staff. Double-blind placebo-controlled trial.

The efficacy of a heat-inactivated hepatitis B vaccine, 3 micrograms of surface antigen (HBsAg), given at 0, 1, 2, and 5 months, was evaluated in 401 haemodialysis patients in 18 centres by a placebo-controlled, double-blind, randomised trial. The attack-rate of hepatitis B virus (HBV) infections in the control group was 18% over 435 days. The protective efficacy rate of the vaccine was 78% against all HBV infections in the entire study (p = 0.00016), and 94% against HBsAg-positive hepatitis more than 3 months after day 0. Those patients in whom HBV developed showed no evidence of vaccine-acquired anti-HBs. Among 152 similarly randomised staff members receiving three monthly injections, all 5 HBsAg-positive infections occurred in the placebo group (p = 0.022). The vaccine induced anti-HBs in 88% of the patients and 100% of the staff. Immediately after the fourth injection, anti-HBs levels were as high in responding patients as in staff. There were no serious side effects. In the four-dose schedule the vaccine provides dialysis patients with protection of the same order as that given by other hepatitis B vaccines to normal subjects.

Immunogenicity and safety of a plasma-derived heat-inactivated hepatitis B vaccine (CLB). Studies in volunteers at a low risk of infection with hepatitis B virus.

The safety and immunogenicity of a plasma-derived heat-inactivated hepatitis B vaccine (CLB) were evaluated in 471 healthy human volunteers, who, both in their occupations and in their private lives, had been at minimal risk of being infected with hepatitis B virus. The first 202 individuals received three 3-micrograms doses of heat-inactivated hepatitis B surface antigen (HBsAg) at one-month intervals (trial A). A total of 42% one month after the first injection, 84% after two months, and 93% after five months had become anti-HBs (antibody to hepatitis B surface antigen) positive. In a second randomized study (trial B), the immunogenicity of five different dosages of the vaccine was compared in 269 volunteers. When the dose of HBsAg was diminished from 3 micrograms to 1.5, 0.6, and 0.25 microgram, no decrease of the anti-HBs response was observed. However, when the dose was diminished to 0.1 microgram of HBsAg, the anti-HBs response dropped significantly to 63% (p less than 0.001). In the recipients of all five vaccine dosages, no influence of sex and age was found on the anti-HBs conversion rates. During the eight-month observation period, none of the vaccinees became HBsAg and/or anti-HBc (antibody to hepatitis B core antigen) positive, and none developed antibodies associated with autoimmune liver disease. No serious side effects were observed.

Prevention of the HBsAg carrier state in newborn infants of mothers who are chronic carriers of HBsAg and HBeAg by administration of hepatitis-B vaccine and hepatitis-B immunoglobulin. Double-blind randomised placebo-controlled study.

Newborn infants of Chinese HBeAg-carrier mothers in Hong Kong were randomly assigned to one of four study groups. Group I was treated with 3 micrograms heat-inactivated hepatitis B (HB) vaccine at birth and at 1, 2, and 6 months thereafter, in conjunction with seven monthly HBIg injections; group II was treated according to the same vaccine schedule but received only one HBIg injection at birth; group III received only the vaccine, at months 0, 1, 2, and 6; and group IV received placebos for both vaccine and HBIg. The first set of injections was given within 1 h after birth. Comparisons were made in the 140 children who were at least six months old at the close of the trial (495 days). In all three treatment groups development of the persistent carrier state was significantly (p less than or equal to 0.0001) less frequent than in controls (2.9%, 6.8%, and 21.0% versus 73.2%). Although vaccination alone was significantly less protective than vaccination plus multiple HBIg injections (p = 0.03), the degree of protection was still remarkable. 12 months after the first set of injections 96-100% of the infants in the three treatment groups were anti-HBs positive; the geometric mean titres of anti-HBs in the three groups did not differ significantly. This indicates that even high doses of HBIg do not interfere with the anti-HBs response to the vaccine. Probable intra-uterine HB infections were observed in 3 infants. No serious side-effects were observed from the interventions, even in the babies with intra-uterine infections who had received HBIg and HB-vaccine at birth. To prevent development of the persistent HBsAg carrier state, and thereby the consequent chronic liver disease and/or primary carcinoma of the liver, HB vaccine and HBIg should be administered as soon as possible after birth to all newborn infants at risk of perinatal hepatitis B infection.

Efficacy trial of heat-inactivated hepatitis B vaccine (CLB) in male homosexuals in the Netherlands.

The efficacy of a heat-inactivated hepatitis B virus (HBV) vaccine, containing 3 micrograms-HBsAg, was studied among a group of 800 susceptible homosexual men. The trial was conducted randomized, placebo-controlled and double blind. At the trial end point (21.5 months) the attack-rate for all HBV infections together was 4.8% among vaccinees and 23.8% among the placebos (p less than 0.0001). Four months after the first injection 89% of the vaccinees had formed anti-HBs and this percentage declined only slightly during the follow-up period. Maximum titers were reached 5 months after the first vaccination. None of the vaccinees who responded to the vaccine with anti-HBs greater than or equal to 1 mIU/ml developed a HBsAg positive infection. The vaccine had no serious side-effects.