Incidence of anaphylaxis with circulatory symptoms: a study over a 3-year period comprising 940,000 inhabitants of the Swiss Canton Bern.

BACKGROUND: Diagnosis of anaphylaxis is clinically based and usually straightforward. However, data on the epidemiology of anaphylaxis, particularly the most profound and life-threatening form such as anaphylactic shock are limited and thought to be under-reported. OBJECTIVE: The primary aim of this study was to investigate the incidence and the causes of severe anaphylaxis with circulatory signs in the Canton Bern, which comprises about 940 000 inhabitants or approximately one-seventh of the population of Switzerland. METHODS: During a 3-year period, 1 January 1996 to 31 December 1998, all medical records (7739 documents) from the two allergy clinics of the Canton Bern have been reviewed. In addition, all seven board-certified specialists of the Foederatio Medicorum Helveticorum (FMH) in Allergology and Clinical Immunology of this Canton as well as all 17 hospitals with emergency units of this area have been contacted for cases with an anaphylactic event not referred to the allergy clinics. RESULTS: Overall, 226 individuals, 106 females (47%) with a mean age of 41 years (range, 5-74 years) and 120 males (53%) with a mean age of 38 years (8 months-83 years) were diagnosed as having presented generalized, life-threatening anaphylaxis with circulatory symptoms. Altogether, these patients experienced 246 episodes of severe systemic reactions. In addition, death due to anaphylaxis occurred in three subjects. The annual incidence of anaphylaxis per 100 000 inhabitants per year ranged between 7.9 and 9.6 cases. Hymenoptera stings (58.8%), drugs (18.1%), and foods (10.1%) were the most commonly identified culprits for anaphylaxis. In 5.3% of all anaphylactic events, the cause could not be identified. CONCLUSION: The incidence rate of severe life-threatening anaphylaxis with circulatory signs in the Canton Bern, Switzerland, with 7.9-9.6 per 100 000 inhabitants per year is comparable to the findings of other epidemiological investigations. In most events, a causal agent or allergen could be identified by a careful allergological examination.

Superior biologic activity of the recombinant bee venom allergen hyaluronidase expressed in baculovirus-infected insect cells as compared with Escherichia coli.

BACKGROUND: Hyaluronidase (Hya) is one of several allergens in honeybee venom. Its cDNA sequence was recently described. OBJECTIVE: We sought to express recombinant Hya in prokaryotic and eukaryotic systems and to compare it with natural (n)Hya for biologic activity. METHODS: In Escherichia coli Hya was produced as inclusion body 6 x His-fusion protein. In baculovirus-infected insect cells expression was obtained by cotransfection of linearized Bac-N-Blue DNA and pMelBac transfer vector into Spodoptera frugiperda cells. RESULTS: Enzymatic activity of Hya from the baculovirus system was equal to nHya, and that of the enzyme expressed in E. coli was only 20% to 30% of nHya. In vitro IgE binding was similar in nHya and the enzyme from baculovirus but markedly lower in Hya expressed in E. coli. CONCLUSIONS: Biologic activity of Hya expressed in baculovirus-infected insect cells was comparable with that of the natural enzyme, indicating a native-like conformation of the recombinant protein. In contrast, the enzyme expressed in E. coli as an inclusion-body protein and reconstituted in vitro reached only 20% to 30% of the activity of nHya.

Local nasal immunotherapy for ragweed-allergic rhinitis. III. A second year of treatment.

In 1979, pre-seasonal local nasal immunotherapy (LNIT) was found to be an effective treatment for ragweed hay fever. In 1980, this study was continued to evaluate the clinical and immunologic responses of a second year of LNIT. Patients received either pre-seasonal treatment with an unmodified ragweed extract (RW) or a polymerized ragweed extract (PRW), or no treatment. The results of the second year of treatment were the same as the first year. Adverse reactions were significantly higher in the RW-treated group than in the PRW-treated group (P less than 0.001). Symptom/medication scores (SMS) in the RW-treated group were significantly lower than in the control group (P less than 0.005). Although SMS in the PRW-treated group were lower than in the control group, this difference was not significant. The immunologic response was evaluated by measurements of serum (S) RW-specific IgE and IgG and nasal secretory (NS) RW-specific IgE, IgG, and IgA. After treatment, serum IgE titres and secretory IgA titres rose in the RW-treated patients. Nasal secretory-IgG and NS-IgA titres increased with PRW treatment. The only immunologic response observed in the control group was a rise in S-IgE titres after the ragweed season. There was no substantial difference in immunologic measurements observed in the 1979 and 1980 seasons, except that the pre-treatment NS-IgE level was higher in 1980 (P less than 0.02). No significant correlations were found between antibody response and SMS. This study supports the efficacy of LNIT but does not support the protective role for NS-ragweed-specific IgA or IgG.

Local intranasal immunotherapy for grass-allergic rhinitis.

In a double-blind controlled study, local intranasal immunotherapy was evaluated for the treatment of grass pollenosis. On the basis of serum grass-specific IgE levels, 50 grass-allergic patients were randomly divided into three groups and treated with either an aqueous solution of mixed-grass extract, a formaldehyde-modified mixed-grass extract (allergoid), or a histamine solution (placebo). Intranasal solutions were administered in gradually increasing doses over a preseasonal 10 wk period, adverse local reactions from the aqueous grass extract were frequent during treatment. Few adverse reactions occurred from the allergoid or histamine solutions. During the pollen season, patients receiving both grass extracts had much lower symptom/medication scores than patients receiving placebo. The severity of eye symptoms was the same in all groups. After treatment, serum grass-specific IgE rose in patients receiving aqueous and allergoid extract; no change was noted in patients receiving placebo therapy. Grass nasal secretory-specific IgA titers in each group did not change during the study. The results of this study suggest that local intranasal immunotherapy with either aqueous or allergoid grass extracts is clinically effective for the treatment of grass pollenosis. Adverse reactions associated with the aqueous extract may limit its usefulness. No correlation was present between the secretory immune response and clinical benefit.

Comparison of the allergenicity and antigenicity of Polistes venom and other vespid venoms.

The crossantigenicity of Polistes venom with other vespid venoms was examined with rabbit and human antisera. Venom preparations from various Polistes species were obtained by electrical stimulation of individual insects and venom sac dissection. Rabbit antibodies were raised to the venom (P. apachus) and venom sac extract (P. exclamans). Human antisera were obtained from patients allergic to Polistes and other vespid venoms. The venom appeared to be more potent than the venom sac preparations in reactions with rabbit IgG and human IgE antibodies. Among the Polistes species, P. exclamans, P. instablis, and P. apachus venoms showed several lines of precipitation with rabbit antisera, and P. annularis and P. fuscatus venoms only one line, suggesting quantitative or qualitative antigenic differences. In RAST analysis, most sera reacted equally to all Polistes species but occasional exceptions were noted, again suggesting differences in venom allergens. P. exclamans-coupled discs gave the most consistent results. In gel diffusion experiments, there was no crossreactivity between Polistes and yellow jacket venoms and only limited crossreactivity between Polistes and hornet venoms. Patients sensitive to Polistes venom showed varying degrees of reactivity to yellow jacket and hornet venoms in RAST analysis. Patients sensitive to other vespid venoms also showed varying degrees os sensitivity to Polistes venom. Polistes venom appears to contain a genus-unique antigen (allergen). In addition, there appear to be some crossreacting antigens in Polistes and other vespid venoms but to a much lesser degree than found previously in the analysis of the relationship of yellow jacket and hornet venoms.