Clinical correlations between long-term (IgE) and short-term (IgG S-TS) anaphylactic antibodies in atopic and 'non-atopic' subjects with respiratory allergic disease

Lyn but not Fyn kinase controls IgG-mediated systemic anaphylaxis

Anaphylaxis is a rapid, life-threatening hypersensitivity reaction. Until recently, it was mainly attributed to histamine released by mast cells activated by allergen crosslinking (XL) of FcεRI-bound allergen-specific IgE. However, recent reports established that anaphylaxis could also be triggered by basophil, macrophage, and neutrophil secretion of platelet-activating factor subsequent to FcγR stimulation by IgG/Ag complexes. We have investigated the contribution of Fyn and Lyn tyrosine kinases to FcγRIIb and FcγRIII signaling in the context of IgG-mediated passive systemic anaphylaxis (PSA). We found that mast cell IgG XL induced Fyn, Lyn, Akt, Erk, p38, and JNK phosphorylation. Additionally, IgG XL of mast cells, basophils, and macrophages resulted in Fyn- and Lyn-regulated mediator release in vitro. FcγR-mediated activation was enhanced in Lyn-deficient (knockout [KO]) cells, but decreased in Fyn KO cells, compared with wild-type cells. More importantly, Lyn KO mice displayed significantly exacerbated PSA features whereas no change was observed for Fyn KO mice, compared with wild-type littermates. Intriguingly, we establish that mast cells account for most serum histamine in IgG-induced PSA. Taken together, our findings establish pivotal roles for Fyn and Lyn in the regulation of PSA and highlight their unsuspected functions in IgG-mediated pathologies.

Signaling through Fc gamma RIII is required for optimal T helper type (Th)2 responses and Th2-mediated airway inflammation

Although inhibitory Fc gamma receptors have been demonstrated to promote mucosal tolerance, the role of activating Fc gamma receptors in modulating T helper type (Th)2-dependent inflammatory responses characteristic of asthma and allergies remains unclear. Here, we demonstrate that signaling via activating Fc gamma receptors in conjunction with Toll-like receptor 4 stimulation modulated cytokine production from bone marrow-derived dendritic cells (DCs) and augmented their ability to promote Th2 responses. Ligation of the low affinity receptor Fc gamma RIII was specifically required for the enhanced Th2 responses, as Fc gamma RIII(-/-) DCs failed to augment Th2-mediated airway inflammation in vivo or induce Th2 differentiation in vitro. Further, Fc gamma RIII(-/-) mice had impaired Th2 cytokine production and exhibited reduced airway inflammation, whereas no defect was found in Fc gamma RI(-/-) mice. The augmentation of Th2 immunity was regulated by interleukin 10 production from the DCs but was distinct and independent of the well-established role of Fc gamma RIII in augmenting antigen presentation. Thus, our studies reveal a novel and specific role for Fc gamma RIII signaling in the regulation of Th cell responses and suggest that in addition to immunoglobulin (Ig)E, antigen-specific IgG also contributes to the pathogenesis of Th2-mediated diseases such as asthma and allergies.

IgG4 response to fur animal allergens among fur workers

OBJECTIVE

The aim of this study was to determine whether IgG(4) antibodies to allergens in urine extracts from fur animals associated with positive prick tests to the same allergens and with the occurrence of respiratory symptoms among fur workers, especially among highly exposed fur farmers.

METHODS

Among the fur workers and among their referents, IgG(4) antibodies to mink and silver fox urine were analysed in three groups; all workers with a positive skin prick test to any fur animal allergen (n=50), all workers who had reported shortness of breath or rhinitis or eye symptoms (n=159), and to a random sample of asymptomatic persons (n=178). In the two last groups none of the workers had a positive skin test to any fur animal allergen.

RESULTS

The fur farmers had higher level of IgG(4) values than other groups and also had positive IgG(4) antibodies to urine extract more frequently than the other groups. Among the exposed subjects, there was a distinct overlapping of a positive skin prick test to fur urine allergens and positive IgG(4) antibodies to responding allergens. Among the fur farmers the IgG(4) levels were associated with symptoms.

CONCLUSIONS

IgG(4) antibodies were shown to be a good indicator of exposure. Because of an overlapping of positive skin prick tests and IgG(4) response to the same allergens, and an association between symptoms and IgG(4) response, it is recommended that the potential role of IgG(4) antibodies as an indicator of alternative sensitisation should be further examined in prospective studies.

Allergy skin tests for inhalants and foods. Comparison of methods in common use

Many types of skin tests have evolved from Blackley's early scratch tests. This review highlights both the similarities between current skin tests and their differences. All current skin tests are capable of detecting allergic hypersensitivity, but the tests differ in their sensitivity, specificity, safety, reproducibility, and applications. Common factors in initial and final test doses, and in test dose increments, are identified. Test methods that quantitatively measure a range of allergen concentrations have diagnostic advantages in terms of safely detecting a wide range of allergic sensitivities. Failure to detect the full spectrum of allergic disease can lead to treatment failure; therefore, complete skin testing is desirable. This is especially important when dealing with exquisitely sensitive patients, such as many grass or ragweed sensitized patients, but is equally vital when evaluating low sensitivity patients, including many who are mold or food sensitive. Quantitation also improves test reproducibility, which is why it is used for antigen standardization. Finally, quantitation has advantages when used to initiate and escalate allergen immunotherapy. In vivo testing continues to evolve. New types of prick testing devices, and refinements of intradermal and patch test methods, continue to be reported. All allergists need to stay current with developments in vivo testing, so that they can offer their patients diagnosis that is appropriate to each individual situation.

Distribution of IgE and IgG antibody levels against house dust mites in schoolchildren, and their relation with asthma

Although asthmatic patients are known to have increased levels of IgG antibody against house dust mite (HDM), it is not clear whether or not the presence of HDM-specific IgG antibody is associated with the etiological mechanism of asthma. To address this problem, we evaluated the relationship between HDM-specific IgG antibody levels and incidence of asthma in a general pediatric population. IgE and IgG antibody levels against Dermatophagoides farinae (Df) were examined by RAST and ELISA in a total of 722 randomly selected schoolchildren including 26 subjects with asthma, and the relative prevalence rates of asthma in this population were evaluated in relation to both Df-specific IgE and IgG levels. The incidence of asthma correlated not only with levels of Df-specific IgE, but also with those of Df-specific IgG. There was a significant correlation between Df-specific IgE and IgG levels both in the total population and in the asthmatic children. Because IgG and IgE responses occurred in parallel in this population, the clinical significance of HDM-specific IgG anti-body remains unclear. However, our findings have suggested that clinical expression of asthma in children is primarily dependent on their capacity to mount a immune response to HDM, which includes both IgE and IgG responses.

Anaphylactic/anaphylactoid reactions to anaesthetic and associated agents. Skin prick tests in aetiological diagnosis

Fifty-one patients were referred in one year (1992) for investigation of immediate type anaphylactic/anaphylactoid reactions during anaesthesia. Skin prick tests were made with 23 anaesthetic and associated agents in the concentrations used clinically. Definite or probable causes were identified by immediate type wealing reactions, supported by the clinical history in 36 of the 46 in whom a diagnosis of anaphylaxis was made. These comprised mainly the neuromuscular relaxants, chiefly suxamethonium (18); atracurium (6); gallamine (2); one each alcuronium; pancuronium; vecuronium and tubocurarine, as well as alfentanil (1); Gelofusine (2); cefuroxime (1) and latex (2). The materials for performing the skin prick test are readily available and it can be very helpful in making important aetiological diagnoses.

Allergic asthma to Bacillus subtilis enzyme: a model for the effects of inhalable proteins

The passage of 24 years since the diagnosis of allergic asthma in heavily exposed workers and in a few consumers due to dusty enzyme preparations of Bacillus subtilis compounded with laundry powder makes it possible to review objectively the many problems it raised. It emphasizes the lessons to be learned, relevant to inhalable enzyme products and to other inhalable proteins in general. Occupational allergic respiratory diseases were little studied at the time and the enzyme problems stimulated interest in what has now become a well-established and important field of medicine involving not only protein allergens but low molecular weight chemicals as well.

Determination of IgG subclass antibodies against wheat flour antigens by an ELISA technique

We describe the assay conditions for an enzyme-linked immunoassay for the determination of IgG and IgG subclass antibodies in serum to water-soluble wheat flour antigens. The optimal antigen coating concentration was 5 micrograms/ml for total IgG, IgG1, IgG4 and 100 micrograms/ml for IgG2. Serial dilutions of test sera were used and commercially available monoclonal mouse anti-human IgG isotype antibodies (as ascites fluid) were diluted 1:500-1:1000. Specific wheat flour antibodies belonging to the IgG1, IgG2 and IgG4 subclasses were detected. Despite the lack of standardized isotype-specific second mouse monoclonal antibodies, the subclass antibody levels between flour-exposed bakers and controls could be compared. We observed significantly higher IgG1, IgG2, and IgG4 subclass antibodies among 23 bakers than among 12 non-exposed controls, but no IgG3 antibodies were detected. The differences in biological activities of the IgG subclass antibodies may explain the clinical and pathophysiological features for fluor-induced occupational allergic diseases among bakers.

Latent anaphylactic sensitivity of infants to cow's milk proteins. Histamine release from blood basophils

Approximately 25% of infants tested released greater than 9% of their blood basophil histamine content in the presence of cow's milk proteins, indicating a degree or level of latent anaphylactic sensitivity to these allergens. Approximately 10% of infants show a considerably higher level of sensitivity (14-63% histamine release). These findings fulfil an essential tenet of the modified anaphylactic hypothesis for cot-death.

Clinical associations with serum allergen-specific IgG4 antibodies

Serum total and allergen-specific IgE and IgG4 antibodies, were measured in eighty-seven atopic and nineteen non-atopic asthmatics. The allergens studied were: Dermatophagoides pteronyssinus, grass pollens, cat dander, dog dander, milk and egg. Sixty-eight atopic asthmatics and fourteen non-atopic asthmatics were found to have allergen-specific IgG4 antibodies, to at least one of the allergens tested. IgG4 antibodies to milk and egg were common in both groups of asthmatics, and to animal danders in the non-atopic asthmatics. Skin prick tests were always negative when allergen-specific IgG4 antibodies occurred alone, but in such cases, intradermal skin tests were positive. Seventy-five per cent of a group of patients with normal levels of serum total IgG4, were found to have at least one positive IgG4 RAST.

Anaphylaxis due to succinylcholine. Immunoallergological study of thirteen cases

The antigen non-specific release of histamine by synthetic neuromuscular blocking agents is well known, though our review of thirty-two cases reported in the literature of anaphylactoid reactions to succinylcholine, shows that there is insufficient evidence to determine whether the signs are due to anaphylactic or to anaphylactoid reactions. We have examined thirteen cases in whom evidence of anaphylactic sensitization was examined by direct skin tests (in eleven cases) Prausnitz--Küstner tests (in five), rabbit basophil degranulation, Shelley test (in twelve) and human basophil degranulation (in seven). These tests were done on two to four occasions, and the optimal period for the first test ascertained to be 6 to 12 weeks after the episode. All eleven patients examined by direct skin tests showed evidence of anaphylactic sensitivity, and in three of five cases the sensitivity could be transferred by the Prausnitz--Küstner procedure. In one of these P--K tests there was evidence of both IgE and of IgG S-TS antibodies (heat-stable antibody conferring sensitivity for 2 hr). Particular susceptibilities to adverse reactions of this drug appear to be prior drug allergy (in 50% of cases), several previous anaesthetics, and atopy.