Alain L. de Weck

Bird-Egg Syndrome

87 adult patients from our allergy clinic were skin tested with budgerigar and canary feathers, hen’s egg white and egg yolk and common inhalant allergens. Of 59 patients found to be atopic, 17 (29%)

Dog allergy, a model for allergy genetics.

Experimental sensitization in dogs has revealed that the capacity to produce high levels of IgE against a variety of allergens (high IgE responders), an essential characteristic of the atopic state, is a genetic trait inherited in a dominant manner. In high IgE responder dogs spontaneous development of IgE to inhaled allergens, such as house dust mites, on the other hand, represents an apparent phenotype very similar to that observed in human atopic families. The full potential of the high IgE response gene appears to be fulfilled only under some conditions such as early and repeated exposition to allergens. It is therefore quite possible that the true phenotype of human atopy would also be inherited in a dominant fashion but not constantly expressed. This would explain why the increase in the prevalence of allergic diseases started long before the environmental factors currently accused could have been at play. This hypothesis, which can be verified experimentally, has important implications for the future of allergy.

T cell reactivity to penicillin: Phenotypic analysis of in vitro activated cell subsets☆

Patients with penicillin allergy demonstrate a T cell proliferative response after in vitro stimulation with penicillin G (Pen G) and other beta-lactam antibiotics. To understand better penicillin-allergic reactions, T cell subset stimulation with Pen G was studied and compared with other soluble (tetanus toxoid and purified protein derivative [PPD]) and membrane-bound viral (influenza A and Epstein-Barr viruses) antigens. A double fluorescence method for flow cytometry was used to evaluate the activated cells simultaneously by pyronin Y staining of RNA and by indirect immunofluorescence of cell surface T4, T8, or Leu 8 antigens. The antigens used stimulated mainly the T4+ subset (greater than 90%), whereas the number of activated T8 cells was slightly increased only in Pen G- and influenza A-triggered cultures (5% to 15%). Leu 8 antigen was used to analyze more precisely the activated T4+ cells. Pen G and influenza A and Epstein-Barr viruses stimulated both T4+, Leu 8+ (greater than 50% of activated cells, inducers for suppressor cells), and T4+, Leu 8- (helpers for B cells) subsets, whereas PPD activated mainly T4+, Leu 8- subpopulations. These results indicate that penicillin-allergic patients with skin symptoms demonstrate a T cell subset stimulation that resembles more the reaction versus viral antigens (membrane incorporated) than to soluble antigens like PPD. These results suggest that Pen G is presented to T cells like viral proteins and might thus cause allergic reactions resembling skin symptoms observed in viral diseases.

Mechanisms of serotonin-induced lymphocyte proliferation inhibition

When human peripheral blood lymphocytes were stimulated with phytohemagglutinin in the presence of serotonin, inhibition of [3H]thymidine incorporation occurred, the most marked inhibition occurring at high (10(-3)M) serotonin concentrations. This effect could not be reversed by the addition of Interleukin 2 (IL-2)-containing supernatants. Cytofluorometric analysis showed that virtually all of the cells remained in the G0 phase (unactivated) at 24 hr while some of the cells entered the G1a and G1b phases of the cell cycle by 42 hr. The cellular production of IL-2 was not affected by serotonin, as supernatants of treated cultures contained essentially the same IL-2 titers as did control cultures. Serotonin seemed to primarily affect cell activation and had little or no effect on proliferating cells. This was further confirmed by the lack of effects of serotonin on a variety of established proliferating lymphocyte, macrophage, and fibroblast cell lines. By contrast, dose-dependent inhibition of IL-2-dependent CTLL cells occurred. Serotonin was not toxic even at 10(-3) M concentrations. A marked decrease in IL-2 receptors and a change in their distribution on responder cells was seen when treated cultures were examined with the anti-Tac monoclonal antibody. At 24 hr this effect was contrastingly not seen for the OKT-8 marker, although a slight decrease in OKT-4-positive cells was seen. Serotonin thus produced an inhibition of lectin-stimulated lymphocyte proliferation via a mechanism independent of IL-2 production, and caused a decrease in the expression and distribution of IL-2 receptors on the surface of responder cells.

Flow-cytometric analysis of human basophil degranulation. II. Degranulation induced by anti-IgE, anti-IgG4 and the calcium ionophore A23187.

Quantification of human basophil degranulation induced by anti‐IgE, anti‐IgG4, and by ionophore was performed using a flow‐cytometric system. It was shown that these antibodies and ionophore can degranulate basophils in a dose‐dependent manner, and that there is a wide variation in the response of basophils obtained from different individuals to these stimuli. A significant correlation was observed between the degree of degranulation induced by anti‐IgE and anti‐IgG4, while this was not the case for anti‐IgE and ionophore. It was also shown that IgG4 myeloma protein can passively sensitize basophils. In general, degranulating efficacy was in the order of ionophore > anti‐IgE >anti‐IgG4, both in allergic and non‐allergic individuals.

Dot-immunobinding assay with monoclonal anti-IgE antibodies for the detection and quantitation of human IgE

This paper describes a dot immunobinding assay for determining total human IgE with a tandem of monoclonal anti-IgE antibodies. Minute quantities of monoclonal anti-IgE antibodies were adsorbed on nitrocellulose discs. IgE bound to this solid phase monoclonal anti-IgE antibody was detected by a second monoclonal antibody conjugated with horseradish peroxidase. Using 4-chloro-1-naphthol as a chromogen results in a stable colour reaction that can be semiquantitatively analysed by the naked eye. The colour intensities of the reaction were also analysed by densitometry, yielding a very reproducible quantitation of human serum IgE. Using a serum dilution of 1:50, IgE could be detected in the range of 12.5-2500 U/ml. Using non-diluted serum samples IgE levels between 0.05-50 U/ml were reproducibly measured. Total serum IgE as determined by this dot assay correlated very well with IgE determinations performed by the commercial PRIST assay.

Age-related changes of mitogen responsiveness in different lymphoid organs from outbred NMRI mice

Lymphocytes from spleen, thymus and lymph nodes from individual young adult (3--4 months) and aged (26--30 months) NMRI mice were stimulated with the mitogens Con A, PHA and LPS. 24 hours later, the number of cell with increased RNA-content (G1 cells) was determined by cytofluorometry. In parallel the 3H-thymidine incorporation after 48 hours was measured for the same cell samples. Aged animals in average produced less G1 cells and incorporated less 3H-thymidine as compared to young adults. By calculating the 3H-thymidine incorporation per G1 cell, the proliferative capacity of mitogen-induced G1 cells can be estimated. These ratios are lower in aged mice as compared to young adult, suggesting that in these animals not only less cells can be activated as measured by cytofluorometry, but also from these activated cells again fewer continue the cell cycle by initiating DNA-synthesis. In response to Con A and PHA, aged mice in average produce less G1 cells in all of the three lymphoid organs tested. In response to LPS, however, the young adult produced only few G1 cells in lymph nodes and practically none in thymus, whereas in aged animals a considerable number of G1 cells was found in both organs. Corresponding results were found for the 3H-thymidine incorporation. These results indicate that in addition to the reduction of the mitogen-response an age-related change in the distribution of mitogen-responsive cells in the different lymphoid organs takes place.

Interleukin 8-inhibitor and inducer of histamine and leukotriene release in human basophils.

We have shown previously that interleukin 8 (IL-8) induces histamine and leukotriene release in human basophils exposed to interleukin 3 (IL-3). We now found that pretreatment with low concentrations of IL-8 selectively inhibits this response. Inhibition was significant at 0.01 nM IL-8 and virtually complete at 1 nM, which is about 100-fold lower than the concentration required for induction of mediator release. IL-8 dependent responses were also inhibited, albeit to a lesser extent, by preincubation with neutrophil-activating peptide 2 (NAP-2), but not with connective tissue-activating peptide III (CTAP-III) or platelet factor 4 (PF4). Release induced by C5a, fMet-Leu-Phe, or anti-IgE antibody, by contrast, was not affected.

Anti-amiodarone antibodies: Detection and relationship to the development of side effects**

PURPOSE It has become evident in the past few years that amiodarone, a powerful antiarrhythmic agent, induces considerable side effects. These may be due to an amiodarone-elicited lipid storage disease and to the iodine content of amiodarone, but might also be causally related to amiodarone-induced immune reactions. The latter possibility prompted us to develop a sensitive anti-amiodarone antibody detection assay based on the immunodot technique. PATIENTS AND METHODS Sera were obtained from 10 untreated control subjects and 33 patients receiving amiodarone. Using serum dilutions of 1:500 and 1:1,000, the lower detection limit was 0.3 microgram/ml of anti-amiodarone antibodies as calculated from a simultaneously performed IgG standard curve. RESULTS Screening of sera from the untreated control subjects and amiodarone-treated patients revealed that the untreated subjects had no anti-amiodarone antibodies, that only one of 16 patients without clinical side effects had elevated anti-amiodarone antibodies, but that seven of 12 patients with amiodarone-induced thyroid disease and four of five patients with other side effects had elevated anti-amiodarone antibody titers (1.2 to 2.5 micrograms/ml). The combined evaluation of anti-amiodarone antibody titers and cumulative dose was found to be a highly reliable indicator of side effects, as all patients with more than 100-g cumulative dose of amiodarone and more than 0.6 microgram/ml of anti-amiodarone antibodies had side effects. CONCLUSION The detection of anti-amiodarone antibodies in patients with amiodarone-elicited side effects underscores the possible contribution of immunologic reactions to the development of certain side effects.

Assessment of interleukin 1 and interleukin 2 effects on cycling and noncycling murine thymocytes

Abstract When mouse thymocytes are stimulated with PHA, the proliferative response is very low, unless the culture medium is enriched with interleukin 1 (IL-1)- or interleukin 2 (IL-2)-containing supernatants. Cytofluorometric analyses show, however, that PHA stimulation generates a significant number of cells with increased RNA content (transition from the G 0 to G 1 phase of the cell cycle). If IL-2 is added to such cultures, the activated cells complete their process of RNA synthesis and then enter the S phase. The use of IL-2-containing culture medium thus permits one to obtain a high correlation between the number of g 1 cells and [ 3 H]thymidine incorporation ( r = 0.97). Enrichment with IL-1-containing supernatants also results in a statistically significant correlation ( r = 0.68), but the regression lines are markedly different for the two interleukins ( s = 20.3 for IL-2 and s = 9.2 for IL-1), when analyzed after 48 hr of incubation. These observations suggest that the G 1 phase must be divided into two subcompartments, G 1a and G 1b , the G 1a -G 1b transition being an IL-2-dependent event. If the number of G 1b cells is used to establish correlations with [ 3 H]thymidine incorporation, all values fall on the same regression line, regardless of culture conditions and of the addition of interleukins. It is concluded that IL-2 regulates lymphocyte proliferation at the level of RNA synthesis (G 1a -G 1b transition) rather than that of DNA synthesis (G 1 -S transition).