Hazelnut allergy differs between children and adults in frequency of severity, aetiology and relevance of diagnostic parameters.

BACKGROUND: Hazelnut allergy in adults is often birch pollen related, whereas in children, non-pollen-related hazelnut allergy is more frequent. OBJECTIVE: To compare the differences in hazelnut allergy between children and adults with regard to severity, aetiology and diagnostic value of routinely available data. METHODS: Adults (n = 120) who underwent a double-blind placebo-controlled food challenge (DBPCFC) for hazelnut were selected and compared to 151 hazelnut-challenged children from a previous study. Univariate and multivariate logistic regression analyses were performed to build a prediction model. The area under the curve (AUC) of the ROC curve was determined for level of hazelnut-specific IgE, skin prick test (SPT) and the prediction model. RESULTS: Hazelnut allergy was confirmed by DBPCFC in 95/120 (79%) adults, 77% had only subjective and 23% objective symptoms, whereas in children, 63% had objective symptoms to hazelnut. Within the group of children, the frequency of severe hazelnut allergy was higher in younger than in older children. A concomitant birch pollen allergy was more common in adults (82%) than in children (39%) with a hazelnut allergy. A detailed history with allergic symptoms to previous ingestion of hazelnut had the highest diagnostic value in adults, while in children, SPT to hazelnut extract showed the highest level of discrimination between clinical reactivity and tolerance to hazelnut. CONCLUSIONS AND CLINICAL RELEVANCE: Hazelnut allergy differs between children and adults with respect to frequency of severity, aetiology and relevance of diagnostic parameters. Therefore, age has to be taken into account in the diagnostic work-up of a hazelnut allergy.

Protective immunisation against hepatitis B with an internal antigen of the virus.

Preparations of hepatitis B virus (HBV) core antigen (HBcAg) synthesised in Escherichia coli have been shown previously to confer partial immunity against infection by the virus [Murray, Bruce, Hinnen, Wingfield, van Eerd, de Reus, and Schellekens: EMBO Journal 3:645-650, 1984]. In a further experiment reported here, immunisation of chimpanzees with a similar preparation of HBcAg that had been treated with sodium dodecyl sulphate in order to expose e antigen epitopes was found to protect one animal completely and another quite substantially upon challenge with the virus. The results are used to support the argument for trials in humans of a vaccine against HBV based upon or containing HBcAg and its e antigen derivative, and in discussion of a more general role for internal antigens in generating immunity against viral infection.

The protection of chimpanzees against hepatitis B viral infection using a recombinant yeast-derived hepatitis B surface antigen.

In order to determine the efficacy of the SmithKline Biologicals recombinant DNA yeast-derived hepatitis B vaccine in inducing protection against hepatitis B infection, two chimpanzees were injected intramuscularly with 20 micrograms according to a 0-, 1-, and 2-month schedule. After the second dose, the vaccinated animals already showed a significant antibody response. One month after the last injection, the animals were challenged with hepatitis B virus. The vaccinated animals were protected while the two unvaccinated controls showed all signs of hepatitis B infection. One year after vaccination, antibodies remained high and were comparable with levels produced by plasma-derived vaccines.

Hepatitis B virus antigens made in microbial cells immunise against viral infection.

Chimpanzees have been vaccinated successfully against hepatitis B virus with preparations of the viral antigens made in microbial cells by genetic engineering methods.

Antiviral activity of interferon in rats and the effect of immune suppression.

The antiviral effect of interferon was studied in a number of experimental virus infections in the rat. Interferon was shown to protect rats infected with pseudorabies virus, herpes simplex virus or vesicular stomatitis virus. The antiviral activity was not inhibited by immune suppression induced by azothioprine, prednisolone or cyclosporin A treatment. Cyclophosphamide completely blocked the in vivo activity of interferon in rats.

Structure and expression in Escherichia coli of a cloned rat interferon-alpha gene.

DNA synthesized by in vitro transcription on rat interferon (IFN) mRNA has been cloned and amplified as recombinant DNA. The nucleotide sequence of these rat IFN cDNA clones revealed i. the partial presence of the coding region of the gene and ii all cDNA clones were derived from the same subtype of rat IFN-alpha mRNA. Purified inserted fragments were used as a hybridisation probe against chromosomal "Southern blots" to show that at least twelve rat IFN-alpha-related sequences are present in the genome. A lambda-linked rat gene library was screened with the cDNA probes, resulting in an equivalent number of rat IFN-alpha-related hybrid phages. By use of a 3'-noncoding region as a probe, the chromosomal counterpart of the cDNA clones could be detected and the nucleotide sequence of its coding region has been determined. Expression of the coding region in E. coli yielded biologically active IFN, when tested for in vitro or in vivo antiviral activity.

The chimpanzee as a model to test the side effects of human interferons.

Interferon are naturally occurring proteins that are currently under evaluation as potential antiviral and antitumor agents. Currently all human interferons can in principle be produced in adequate amounts by recombinant DNA technology. Human interferons produce side effects, but because they are species-specific the toxicity cannot be tested in lower mammals. The chimpanzee is the only species in which the side effects of human interferon can be reproduced, and only in this species the toxicity of human interferons can be screened.

Circulating interferon in rabbits and monkeys after administration of human gamma interferon by different routes.

Rabbits and rhesus monkeys were injected with 3 X 10(5) units of human gamma interferon (IFN) prepared in human leukocyte suspensions. Circulating IFN was detected up to 4 h after intravenous administration. Intramuscular injection maintained a relatively stable serum IFN level of about 50 units/ml for 7 to 9 h. The results in both species were similar. Little or no circulating IFN was detected after subcutaneous injection of 3 X 10(5) units, but 1.5 X 10(6) units maintained about 50 units per ml of serum for 30 h. Pharmacokinetically, human gamma IFN resembled human alpha interferons rather than human beta IFN.

Antiviral and side effects of interferons produced by recombinant DNA techniques as tested in rhesus monkeys.

Human interferon type alpha 2 (HuIFN-alpha 2) produced by Escherichia coli was found to be as active as natural leukocyte interferon in protecting rhesus monkeys against intradermal vaccinia virus infection. HuIFN-beta 1 produced in E. coli had similar but less pronounced activity. HuIFN-alpha 2 induced fever but not leukopenia, while HuIFN-beta 1 had opposite effects. Concurrent treatment with acetosalicylic acid and prednisolone/azothioprine combinations did not interfere with the efficacy of the human interferons.

In vivo immune stimulation by interferon during viral infection.

Treatment of Rhesus monkeys with human leukocyte interferon prevents the development of skin lesions after intradermal infection with vaccinia virus. The treatment does not prevent the development of immunity to vaccinia. Inactivated vaccinia virus, which is non-immunogenic in untreated monkeys, induced immunity under interferon treatment, indicating that interferon had an immune-stimulating effect.

Dissociation of serum LATS activity and hyperfunction and autonomy of the thyroid gland in Graves' disease.

LATS was measured with the double isotope technique in IgG serum concentrates of 23 patients with Graves' disease before treatment and of 18 patients during treatment with carbimazole and triiodothyronine. LATS activity was present in 18 out of 23 patients before treatment (78%). When the second measurement was taken into account the incidence did increase to 95%. No difference could be found in the mean values of total thyroxine, thyroid 131-I uptake and thyroid weight of the group of LATS positive and LATS negative patients before treatment. Also no relation could be established between LATS activity and suppressibility of thyroid 131-I uptake during treatment. It was found that LATS positive patients who suppress during therapy have lower initial LATS blood levels than LATS positive patients who remain unsuppressed. It is concluded that it is more likely that LATS is a "marker" of Graves' disease rather than the cause of the hyperthyroidism.