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Background Stings from bees and wasps can cause systemic reactions which can be fatal in some individuals. In these venom-sensitive patients, specific IgE to the venom is produced and is considered to participate in the adverse reactions. This immune response requires antigen presentation by human leucocyte antigens (HLA) class II molecules, which includes DR and DP, which are present on antigen presenting cells. Objective To test for associations between HLA class II DRB1 and DPB1 alleles and life-threatening sensitivity to both bee and wasp venoms. To establish further whether any associations are independent of the atopy phenotype. Methods A total of 33 bee- and 44 wasp-venom-sensitive patients was studied, DRB1 genotypes were determined by single stranded oligonucleotide (SSO) probing of PCR products, and DPB1 genotypes by amplified fragment length polymorphism (AFLP) analysis. Total and specific IgE were measured using the Pharmacia Immunocap, FEIA. Patients with specific IgE to the venom antigens only were termed monosensitive and those with additional specific IgE to HDM and/or GP were termed polysensitive. Results Allele frequencies were compared to an unrelated control population. The 33 bee-sensitive patients had a greater prevalence of DRB 1*07 alleles than the control subjects, 26% vs 14%, with an odds ratio (OR) of 2.1 (95%CI, 1,2–3.7, P = 0.015, corrected for multiple comparisons, Pc = ns). This association was confined to the 15 monosensitive bee patients, who had a 43% DRB 1*07 allele frequency when compared with 11% in the 18 polysensitive bee patients, OR 6.1 (95%CI, 1.73–22, P = 0.004, Pc = 0.05), and when compared with a control group of non-venom subjects, 43% vs 16%, OR 3.9 (95% CI, 1.72–9.0, P = 0.002, Pc = 0.02). The 44 wasp-sensitive patients had an increase in the DRB1*11 allele when compared with the control subjects, 13% vs 6%, with an OR 2.2 (95%CI, 1.0–4.6, P = 0.04, Pc = NS), and a decreased prevalence of DRB 1*04 alleles, 10% vs 19%, with an OR 0.33 (95%CI, 0.24–0.99, P = 0.04, Pc = NS), but these were not significant when multiple comparisons were taken into account. The DPB1 alleles were not significantly different between the venom sensitive patients and the controls. Conclusion Patients monosensitive to bee venom had a significantly greater prevalence of DRB 1 *07 alleles than the non-venom, control population suggesting that IgE responses in these patients may, in part be controlled by immune response HLA class II genes. These results are also suggestive of wasp-sensitive patients having a higher prevalence of DRB1*11 and a lower prevalence of DRB 1*04 than the control population. [ABSTRACT FROM AUTHOR]

The results of testing for linkage between atopy and the chromosome 11 marker D11S97 is shown for all the 723 subjects genotyped by us up to January 1992. Lod score estimations were confounded by the high population prevalence of atopy, maternal inheritance of atopy at the 11q locus, genetic heterogeneity, and excess of atopy in families not ascertained through a single proband. Affected sib-pair analysis shows evidence for linkage which is not dependent on the definition of atopy or model specification. We suggest that presentation of sib-pair data will be suitable for meta-analysis of the different studies of genetic linkage and atopy. [ABSTRACT FROM AUTHOR]

We have undertaken a double blind placebo controlled study of the effect of nasal beclomethasone on the tendency to wheeze in 20 unselected hay fever sufferers, half with a history of previous seasonal wheezing. We found no difference between either bronchial hyperresponsiveness, as measured by methacholine challenge, home-monitored PHFR, nor recorded wheeze nor cough between treated and placebo groups although the numbers were small. All were allowed the antihistamine cetirizine hydrochloride 10 mg daily. Eighteen out of the 19 patients had either bronchial hyperresponsiveness (PD20 methacholine < 8 μmol or a > 2 doubling dose change in their PD20 during the pollen season). We have shown u significant positive correlation between a hay fever score (HFS) (created by taking the sum of the home scored: nasal discharge, nasal blockage, eye irritation, sneeze and antihistamine use) and peak seasonal specific IgE to mixed grass pollen (Spearman correlation coefficient 0.5 P<0.02). There was also a positive correlation between the rise in specific IgE from pre to peak season and the HFS, correlation coefficient 0.6 p=0 03). [ABSTRACT FROM AUTHOR]

Twenty-five atopic children under 11 years of age were studied, using skin and RAST tests, for their specific IgE response to four species of pyroglyphid house dust mites, Dermatophagoides pteronyssinus. D. farinae, D. microceras and Euroglyphus maynei. All of the children were sensitive to D. pteronyssinus, 20 (80%) of these children were also sensitive to D. farinae and D. microceras, and 16 of the latter (64%) were also sensitive to E. maynei. Dust samples from various sites in the homes of the children revealed D. pteronyssinus in all homes studied but no D. farinae or D. microceras. E. maynei, although identified, was not present in significant numbers in any site. A control group of 20 atopic children of similar age who were not sensitive to house dust mite allergens had a similar exposure to the four mite species. These results suggest that factors in addition to mite exposure are important in the development of specific IgE responses to house dust mites. [ABSTRACT FROM AUTHOR]