Eosinophilia. 3. The anaphylactic release from isolated human basophils of a substance that selectively attracts eosinophils

Histamine 1 Receptor Blockade Enhances Eosinophil-Mediated Clearance of Adult Filarial Worms

Filariae are tissue-invasive nematodes that cause diseases such as elephantiasis and river blindness. The goal of this study was to characterize the role of histamine during Litomosoides sigmodontis infection of BALB/c mice, a murine model of filariasis. Time course studies demonstrated that while expression of histidine decarboxylase mRNA increases throughout 12 weeks of infection, serum levels of histamine exhibit two peaks—one 30 minutes after primary infection and one 8 weeks later. Interestingly, mice treated with fexofenadine, a histamine receptor 1 inhibitor, demonstrated significantly reduced worm burden in infected mice compared to untreated infected controls. Although fexofenadine-treated mice had decreased antigen-specific IgE levels as well as lower splenocyte IL-5 and IFNγ production, they exhibited a greater than fourfold rise in eosinophil numbers at the tissue site where adult L. sigmodontis worms reside. Fexofenadine-mediated clearance of L. sigmodontis worms was dependent on host eosinophils, as fexofenadine did not decrease worm burdens in eosinophil-deficient dblGATA mice. These findings suggest that histamine release induced by tissue invasive helminths may aid parasite survival by diminishing eosinophilic responses. Further, these results raise the possibility that combining H1 receptor inhibitors with current anthelmintics may improve treatment efficacy for filariae and other tissue-invasive helminths.

Filariae are tissue-invasive parasitic roundworms that infect over 100 million people worldwide and cause debilitating conditions such as river blindness and elephantiasis. One of the major factors limiting our ability to eliminate these infections is the lack of drugs that kill adult worms when given as a short course therapy. Additionally, the mechanisms by which adult worms are cleared from infected individuals remains poorly understood. In this study, we demonstrate that treatment of infected mice with fexofenadine, an inhibitor of histamine receptor 1, significantly reduces adult worm numbers through a mechanism dependent on host eosinophils. These findings suggest that histamine release induced by parasitic worms may aid parasite survival by decreasing eosinophilic responses. Further, as antihistamines are generally safe medications, these results raise the possibility that antihistamine therapy may be useful either alone, or potentially in combination with other antifilarial medications such as diethylcarbamazine (DEC), to eliminate adult filarial worms from infected individuals.

Eosinophil chemotactic factor in tumour tissue from a patient with Kimura's disease

An extract of tumour tissue from a patient with Kimura's disease was tested for eosinophil chemotactic activity using the Boyden chamber method. Eosinophil chemotactic activity was detected in the tissue extract, and after gel filtration maximum activity was found in the fraction with a molecular weight of approximately 1000 daltons. This factor may play a role in the tissue eosinophilia which occurs in Kimura's disease.

Eosinophilia VI, spontaneous synthesis of chemokinetics, chemotactic, complement receptor-inducing activities for eosinophils by bronchial t lymphocytes of asthmatic-bronchitic patients

T lymphocytes were separated from the bronchial mucus of five patients with extrinsic asthma and chronic and mild bronchitis and who had numerous eosinophils in the bronchial mucus but no significant blood eosinophilia. The bronchial lymphocytes spontaneously, that is without treatment with antigens or mitogens, released into serum-free synthetic medium one or more substances in the molecular weight range of 30 000 to 60 000 daltons. These substances when tested on eosinophils of normal persons stimulated random movement (chemokinesis), attracted them (chemotaxis), enhanced their chemotactic response to activated complement, and increased the expression of C4 and C3b receptors. Chemokinetic and chemotactic activity for neutrophils was weak. No eosinophil-stimulating activity was found in cultures of bronchial lymphocytes treated with puromycin to inhibit synthesis. The blood lymphocytes did not spontaneously synthesize the substance(s). It is not known if the several eosinophil-stimulating activities are due to one or more substance(s), but the nature of the eosinophil responses, molecular weight and other features, indicate similarities with the 'eosinophil stimulation promoter-chemotactic' factor reported to be released from mouse or human lymphocytes treated with antigen. Eosinophil stimulation resulting in increased expression of specific receptors, and potential for non-specific adherence, by trapping or arresting randomly migrating cells, is believed to mediate accumulation of cells in an affected organ. Prolonged synthesis of such products as from activated lymphocytes in the lung, could account for much of the local eosinophilia.

In vitro generation of eosinophil chemotactic factor from human and murine mononuclear phagocytes

Low molecular weight eosinophil chemotactic factor (ECF), which has previously been demonstrated in mast cells, basophils, neutrophils and eosinophils, was shown to be released by several types of mononuclear phagocytes. Highly purified rat peritoneal macrophages and human monocytes produced ECF on stimulation with the calcium ionophore A23187 (Ion) and with phagocytic stimuli in a time-dependent fashion, whereas lymphocyte- or mast cell-specific stimuli were ineffective. Two murine macrophage lines and a fibroblast cell line (L cells) also generated and secreted ECF with the different stimuli. ECF from macrophages was similar to that from neutrophils in its target cell specificity (eosinophils and neutrophils) and its elution profile on Sephadex G-10 columns (300-500 dalton). ECF secretion from monocytes was not affected by mitomycin C or cycloheximide, whereas indomethacin enhanced and a phospholipase A inhibitor decreased its production. These in vitro findings suggest that, through ECF, mononuclear phagocytes may potentially regulate eosinophil and neutrophil influx to sites of inflammatory reactions.

Eosinophil chemotactic factor (ECF) in blister fluid of dermatological diseases

The occurrence of low molecular weight (less than 500 dalton) eosinophil chemotactic factor (ECF) was studied in the blister fluid of patients with various dermatological diseases by an in vitro chemotaxis method. After chromatographic separation of the test substance on a small Sephadex G 25 column, ECF was demonstrated in blisters of five patients with bullous pemphigoid, in three patients with systemic drug reactions and in one patient with blisters are contact with primula. ECF was not found in blisters of patients with epidermolysis bullosa and herpes gestationis or in DNCB-induced blisters. Fluid obtained from suction blisters was negative in normal controls and in unaffected skin of patients with atopic eczema, but contained ECF in eczematous areas. The demonstration of ECF in tissue fluid suggests that this factor plays a role in the local accumulation of eosinophils at sites of certain inflammatory reactions.

Bone-marrow eosinophilia in the mouse. I. Eosinophil leukocyte levels in untreated mice

The number of eosinophil leukocytes in the bone marrow of untreated mice (Cpb:SE) has been shown to vary widely. A systematic investigation of this variability is reported here. The study was done a) within a group of mice, b) within groups of mice at roughly 3-month intervals, and c) within a group over a time course. The following are the most important results of this study: 1. Analysis of variance of eosinophils/1000 cells in 165 mice over a 35-day period showed that the results were consistent with the assumption that there are no changes during this interval (P is less than 0.05). 2. The number of eosinophils/1000 cells found in the various groups are not directly comparable; the mean number for the four groups investigated at intervals of about 3 months differed by a factor of up to 3. 3. On the basis of the variability found, the number of eosinophils/1000 cells in the bone marrow of a given untreated mouse in a group to be investigated cannot be reliably predicted. At a 99 per cent confidence level, the value would lie between 5 and 139.

Mediator release from basophil granulocytes in chronic myelogenous leukemia

Mediator release from the leukocytes of two patients with chronic myelogenous leukemia and basophilia was studied using rabbit antihuman IgE antibody. The release of histamine, slow reacting substance of anaphylaxis (SRS-A), platelet activating factor (PAF), chemotactic activity for neutrophils and eosinophils, and an inhibitor of eosinophil migration was observed. However, the release of SRS-A from the basophils of one patient and the release of chemotactic activity from both patients displayed unusual properties. During acceleration of the disease process, the basophils of one patient released maximal SRS-A activity at progressively lower concentrations of anti-IgE. Both patients released a high molecular weight factor (M.W. greater than 20,000) which enhanced the migration of neutrophils and eosinophils and a low molecular weight chemotactic factor (M.W. less than 500) which selectively attracted eosinophils. A double peak of eosinophil chemotactic activity was routinely observed for the low molecular weight factor; this was shown to represent the eosinophil chemotactic activity of histamine with relative inhibition of migration at the histamine peak. There was little release of the tetrapeptides, ECF-A, in these patients which facilitated demonstration of this eosinophilotactic activity of histamine. These results suggest that the eosinophil chemotactic activity observed in acute allergic reactions is the net effect of the release of multiple chemotactic factors.

Studies of the responses of basophil and eosinophil leucocytes and mast cells to the nematode Trichostrongylus colubriformis. II. Changes in cell numbers following infection of thymectomised and adoptively or passively immunised guinea-pigs

The role of the immune response in the generation of the basophilia and eosinophilia found during expulsion of the intestinal nematode parasite, Trichostrongylus colubriformis, by guinea-pigs was investigated by studying cell numbers in animals whose immune responsiveness had been modified by thymectomy and adoptive or passive immunisation. Basophilia, but not eosinophilia, was depressed in thymectomised guinea-pigs. Bone marrow basophil numbers were significantly increased in T. colubriformis-infected guinea-pigs following the infection of mesenteric lymph-node cells from both normal and T. colubriformis-immune syngeneic donors. Bone marrow basophil counts were also increased following the injection of immune lymph-node cells into uninfected recipients. Small intestine eosinophil numbers in adoptively immunised guinea-pigs showed a pronounced increase following infection with T. colubriformis. A smaller increase followed infection of passively immunised guinea-pigs. These results, and other work with this system, suggest that basophilia and eosinophilia during T. colubriformis infection, although associated with the immune response, might not be fully explained as direct consequences of the interaction of parasitic antigens and sensitised lymphocytes or antibodies.

Studies on interrelations between eosinophilia, serum IgE and tissue mast cells

In an examination of a variety of diseases associated with a peripheral blood eosinophilia it is evident that the eosinophilia is not necessarily accompanied by increased amounts of serum IgE. Tissue eosinophilia occurring with mast cell hyperplasia and usually increased amounts of IgE, indicate atopic allergy. It is considered that the eosinophilic granuloma of soft tissue (Kimura's disease) is an atopic disease and quite different from histiocytosis X.

Asthma due to inhaled chemical agents--the macrolide antibiotic Spiramycin

One year after starting work in the pharmaceutical industry a 35-year-old non-atopic maintenance engineer developed attacks of sneezing, coughing and breathlessness. These occurred at home during the evening and early morning, never at work during the day. His employment involved contact with a wide variety of chemical agents including the macrolide antibiotic spiramycin. Inhalation challenge tests carried out in hospital with gradually increasing quantities of spiramycin reproduced his symptoms and led to the development of late asthmatic reactions, during which the FEV1 fell by 25% and the FEV1/FVC ratio by 15%. No change occurred in the single breath CO transfer factor nor were crepitations heard over the lung fields which remained normal on chest X-ray. The patient showed positive immediate skin prick tests to spiramycin and developed blood eosinophilia during the late asthma attacks. Inhalation of sodium cromoglycate either before, or before and hourly after the provocation challenge for 6 hr, failed to prevent the late asthma, although its onset was further delayed. On leaving the pharmaceutical industry the patient's symptoms improved but did not finally clear until his wife, who had worked in a clerical capacity in the same factory also ceased her employment.

Appearance of basophils in the sputum of patients with bronchial asthma

A total of 108 samples of sputum obtained from twenty patients with bronchial asthma were examined for appearance of basophils and eosinophils. Both cell types are present in sputum during an asthmatic attack and disappear at the conclusion of the attack. Their presence correlates with the severity of the disease. It has previously been demonstrated that the blood basophils count falls during attacks of bronchial asthma, and the present study suggests that basophils move from the blood stream into bronchial tissue during the acute phase of an asthmatic attack.