David A. Levy

Immunotherapy of pollinosis in children: investigation of the immunologic basis of clinical improvement.

Abstract To evaluate the immunotherapy of ragweed hay fever in a controlled study, 18 of 35 children were given a preseasonal course of whole ragweed extract and showed a significant decrease in clinical symptomatology (p less than 0.001); 13 of these had fewer symptoms than any of the 17 control patients. Immunologic criteria were studied with in vitro histamine-release methods. Reaginic-antibody (IgE) levels did not change significantly in either group; blocking-antibody (IgG) levels increased more than 20-fold in the treated group. The leukocytes of the control patients became, on the average, more sensitive to ragweed antigen whereas those of the treated patients tended to become less sensitive. The cells of a third of the treated children became unable to respond maximally at any antigen concentration. The three children whose cells showed the greatest decrease in reactivity to ragweed antigen had essentially no symptoms attributable to ragweed hay fever.

Does hyperimmunoglobulinemia-E protect tropical populations from allergic disease?

The Waorani Indians of eastern Ecuador have the highest blood concentration of IgE reported in a human population. Evidence obtained by medical history, physical examination, and immediate hypersensitivity skin tests suggests that pollen allergy and other atopic diseases are rare among the Waorani. A similar association between parasite-induced hyperimmunoglobulinemia-E and a low prevalence of conventional atopic disease has been reported in numerous other tropical populations. Saturation of mast cell IgE receptors with antibodies directed to the parasite and/or other antigens and competitive inhibition of passive binding of pollen allergen-specific IgE is one hypothetical cause of this association. We have tested this interesting conjecture by passively sensitizing the skin of Waorani Indians with serum containing pollen allergen-specific IgE antibodies. Waorani Indians with hyperimmunoglobulinemia-E can be adoptively sensitized with human ragweed or rye grass hyperimmune IgE antisera. This suggests that the cutaneous mast cells of healthy Waorani have active IgE receptors. The high circulating plasma concentrations of IgE in the Waorani do not prevent adoptive cutaneous sensitization with pollen-specific IgE antibodies.

The collaborative study of the international standard of dog, Canis domesticus, hair/dander extract

A collaborative study was carried out to assess the suitability of a chosen preparation to serve as the international standard (IS) for dog (Canis domesticus) hair/dander extract. Sets of five coded preparations of dog extract, including the proposed IS, were delivered to each participating laboratory in glass-sealed ampules. Fifteen laboratories in nine different countries examined the preparations by RAST inhibition, crossed immunoelectrophoresis/crossed radioimmunoelectrophoresis, histamine release, and by other methods. In spite of the use of different versions of methods and different reagents, quite consistent results were obtained, and the proposed IS was found to have a satisfactory activity in all assays and to be useful as a calibrator when allergenic potency of similar dog allergenic extracts was estimated. Four laboratories estimated the specific content of allergens Ag 3, Ag 13, and albumin and found the proposed IS to be a suitable standard for these assays. On the basis of the results from this study, the World Health Organization established the preparation as the international standard for dog hair/dander extract with an assigned unitage of 100,000 IU per ampule. The units refer to both the total allergenic activity of the ampule and to that of individual allergens.

Production and testing of an international reference standard of short ragweed pollen extract

A lyophilized candidate International Reference Standard of short ragweed pollen extract was prepared by use of defined source material. In preliminary experiments, this extract was demonstrated by RAST inhibition and crossed radioimmunoelectrophoresis assays to contain several well-characterized ragweed allergens and to contain multiple antigenic bands by crossed immunoelectrophoresis analysis. In a subsequent multinational collaborative study involving 12 laboratories in five countries, the candidate extract was compared with existing national reference or commercial ragweed extracts by a variety of immunochemical, biochemical, and physicochemical procedures. The candidate extract could be used to assign relative orders of potency to the comparison-test extracts. In separate studies, the candidate extract was demonstrated to be stable when it was stored at either -20 degrees C or +5 degrees C for at least 2 yr. The candidate extract has been accepted as an International Reference Standard with an assigned arbitrary potency of 100,000 units per ampule .

Influence of Temperature on the Inhibition by Colchicine of Allergic Histamine Release

Summary Colchicine inhibited the release of histamine from sensitized human leukocytes reacted with pollen antigens. Inhibition was significantly greater when cells were treated with colchicine at 0° prior to their reaction with antigen at 37° than when cells were pretreated at 37°. These observations are discussed in terms of the effect of colchicine and low temperatures on cytoplasmic microtubules. Involvement of these structures in the allergic secretion of histamine is proposed.

Nippostrongylus brasiliensis: peripheral leukocyte responses and correlation of basophils with blood histamine concentration during infection in rats.

Abstract Rats infected on Day 0 with 3000 infective L 3 larvae of Nippostrongylus brasiliensis , and uninfected controls, were monitored daily through Day 23 postinfection for changes in peripheral leukocytes and blood histamine concentrations. A generalized leukocytosis was observed between Days 7 and 18, the period leading up to and immediately following the time of expulsion of adult worms from the small intestine. The total number of lymphocytes was elevated between Days 11 and 17 post-infection; however, there was no change in the percentage of lymphocytes relative to other white blood cell types. The total number and percentage of monocytes were no different from controls, with the exception of Day 5 postinfection. On that day, there was a significant elevation in the number (614/mm 3 blood in infected rats, as compared to 160/mm 3 blood in controls) and relative proportion (2.7% of total leukocytes in infected animals, compared to 0.8% in controls) of monocytes, coinciding with the termination of the pulmonary migration of larvae. A period of moderate neutrophilia occurred between Days 7 and 12, but this was not accompanied by any changes in the proportion of neutrophils. A biphasic eosinophil response was observed. An early elevation of eosinophils occurred between Days 3 and 5, corresponding to the period of larval migration through the lungs. A second period of eosinophilia began on Day 11, when worm expulsion was beginning, and continued through Day 19, i.e., beyond the period of worm expulsion. Basophilia was observed as early as Day 6 after infection, rising to a peak on Day 13 (6.8% of total leukocytes in the infected animals, as compared to 0.5% in controls), and declining thereafter, but remaining above control levels until termination of the experiment on Day 23. The histamine content of blood samples, as determined by an enzymic-isotopic assay, closely paralleled the development and decline of basophilia; histamine levels also peaked on Day 13 postinfection (422.5 pg histamine/mm 3 blood in infected rats, compared to 66.0 pg histamine/mm 3 blood in controls). As basophilia progressed during the course of infection, there was a decline in the amount of histamine per basophil. In uninfected rats and during the first week after infection, basophils contained about 1.5–2.0 pg histamine per cell. In the third week of infection, there was about 0.6 pg histamine per basophil. The time course of the basophilia suggests that these cells may be involved in the expression of immunity to N. brasiliensis .

Is ‘Desensitization’ for Ragweed Hay Fever Immunologically Specific?

Cell reactivity (the peak percentage release of histamine) to ragweed antigen E and timothy pollen extract was studied in the leukocytes of children chosen for clinical ragweed sensitivity and treated

A microassay for mammalian histidine decarboxylase

Abstract This report describes a microassay procedure for mammalian histidine decarboxylase (HDC) based on the measurement of [ 14 C]O 2 formed from l -[1- 14 C]histidine. This assay is particularly useful for quick measurement of HDC activity both in microgram quantities of cell or tissue extract and in tissues that contain significant levels of endogenous histamine. Using this assay, we have shown that the pH optimum, K m and thermolability of HDC are similar for extracts prepared both from normal rat peritoneal mast cells and from the Furth mouse mastocytoma. HDC activity could be detected in homogenates prepared from 10 5 rat mast cells, and it was expressed on a per cell basis. Mast cell HDC activity varied with the strain of rat from which the cells were obtained and with the season when they were assayed.

Interleukin-1 Induces Mucus Secretion from Mouse Intestinal Explants

Secretion of goblet cell (GC) mucus occurs during immune reactions in the gut. As human macrophages produce a substance that induces mucus secretion from lung explants, we tested the effect of macrophage-derived factor(s) on mucus secretion from intestinal explants. Fragments of mouse duodenum were incubated with macrophage culture supernatants and purified interleukin-1 (IL-1) preparations, and the amount of mucus released was estimated by an enzyme-linked lectin assay. Both the culture supernatants and the IL-1 preparations induced dose- and time-dependent mucus release. Lipopolysaccharide-induced culture fluids were shown to contain IL-1. Thus, stimulation of mucus secretion from GC can be added to the list of biological activities attributable to IL-1.

IMMUNOLOGIC ASPECTS OF HUMAN REAGINIC ALLERGY: AN IN VITRO METHOD AND SOME APPLICATIONS.

SummarySuspensions of human leukocytes have been used for in vitro studies of reaginic allergy. These cells when isolated from ragweed sensitive patients, release histamine on reaction with antigen at threshold levels of 10−6 μg. The release process is characterized by a lag phase and a requirement for both calcium and magnesium. The divalent metal requirement has been observed throughout the reaction course. Physiologically competent cells are required for the release process, since cells subjected to 40°C, or treated with di-isopropylfluorophosphate show an impaired response. On these grounds, it has been concluded that the release process is a multi-step phenomenon and that the passage of histamine to the extracellular environment cannot be accounted for in terms of diffusion following membrane injury. Human leukocytes carry γ-globulins which can react with specific antibody in complement fixation, or in histamine release experiments.Leukocytes from nonallergic individuals can be sensitized passively in vitro. The fixation of antibody to this cell surface is characterized by a high temperature coefficient and is enhanced by ethylenediaminetetraacetate.Serum from untreated allergic donors as well as from donors who have received specific pollen therapy, binds antigen in the fluid phase of reaction mixtures, thereby inhibiting the release of histamine from the leukocytes.