The late, but not early, asthmatic response is dependent on IL-5 and correlates with eosinophil infiltration.

Early-phase reactions (EPRs) and late-phase reactions (LPRs) are characteristic features of bronchial asthma, although the pathogenetic mechanisms responsible for each of the responses are not fully defined. A murine model of EPRs and LPRs was developed to investigate the role of IL-5 and eosinophils in development of both responses. After initial intraperitoneal sensitization and airway challenge to ovalbumin (OVA), mice were provoked by additional exposure to OVA. An EPR, characterized by a transient increase in airway responsiveness, was observed 5-30 minutes after antigen provocation. This response was followed by an LPR that reached its maximum at 6 hours after challenge and was characterized by increased airway responsiveness and significant lung eosinophilia. The EPR was blocked by cromoglycate and albuterol, whereas the LPR was abolished by cromoglycate and hydrocortisone. Before provocation with allergen, administration of anti-IL-5 antibody prevented the influx of eosinophils into the lung tissue and abolished the LPR but not EPR. These results suggest that IL-5 and eosinophils are essential for development of the LPR, but not EPR, in this model.

Inhaled corticosteroid improves bronchial reactivity and decreases symptoms in patients with mitral stenosis.

STUDY OBJECTIVE: To determine if treatment with inhaled budesonide forte can diminish increased bronchial hyperreactivity and improve symptoms in patients with mitral valve stenosis. DESIGN: The study was randomized, double blind, and placebo controlled. SETTING: Outpatient/university hospital. PATIENTS: Twelve subjects, 8 female and 4 male, who qualified for mitral valve replacement. All subjects presented with increased bronchial reactivity to histamine at the time of the study. INTERVENTIONS: Patients received placebo or budesonide forte twice a day (1,200 mg/d) for 6 weeks. During the study, patients were treated with the same doses of diuretics and other medications that could affect bronchial reactivity. MEASUREMENTS: Spirometry, provocative concentration of histamine causing a 20% fall in the FEV1 (PC20H), symptom scores. RESULTS: In the treated group, the initial PC20H was 0.82+/-0.72 mg/mL; in the placebo group 1.39+/-1.3 mg/mL. After 6 weeks of treatment, PC20H was significantly higher (3.07+/-2.28 mg/mL; p > 0.01) in the budesonide-treated group and remained unchanged in the placebo group (1.49+/-0.91). Symptom scores were significantly lower after administration of budesonide forte (mean change, 4.0+/-2.6). CONCLUSIONS: Six weeks of treatment with budesonide forte significantly decreased bronchial reactivity to histamine and improved symptoms in patients with mitral valve stenosis.

[Effect of loratadine--selective antagonist of histamine (H1) receptor--on allergen-induced bronchoconstriction in atopic asthmatics]. / Wplyw loratadyny--wybiórczego antagonisty receptorów histaminowych (H1)--na wczesna i pózna faze poalergenowego skurczu oskrzeli u chorych na astme atopowa.

The aim of this study was to evaluate the effect of loratadine on allergen-induced bronchoconstriction. The study was performed in 7 asthmatic patients with sensitivity to Dermatophagoides pteronyssinus, 4 women and 3 men. aged from 19 to 37 years. The allergen inhalatory--challenge test was performed according to Chai et al. Early phase of Dermatophagoides pteronyssinus--induced bronchoconstriction appeared in all examined patients, but late phase of bronchial obstruction was observed only in 3 persons. 30 mg orally administered of loratadine have no protect effect on early phase of allergen--induced bronchoconstriction. After loratadine ingestion the late phase of this bronchial obstruction disappeared.

[Effect of loratadine (LO), a selective H1 antagonist, on histamine-induced bronchoconstriction]. / Wplyw loratadyny, wybiórczego antagonisty receptorów histaminowych (H1), na skurcz oskrzeli wywolany wziewaniem histaminy.

The influence of single and repeated LO (10 mg/day) doses on histamine-induced bronchoconstriction was studied in 11 patients with stabile bronchial asthma. Bronchial reactivity was estimated as histamine content potent to elicit a 20% FEV, fall, i.e. PC20H. A single dose gave a significant (5.5 fold) reduction in bronchial reactivity to inhaled histamine. Application of LO during 6 days gave a similar effect. Withdrawal of LO for 6 days yielded an increase in bronchial hyperreactivity.

[Course of non-specific bronchial reactivity to histamine after bronchospasm induced by allergen challenge in patients with bronchial asthma]. / Przebieg reaktywnosci oskrzeli na histamine po skurczu oskrzeli wywolanym wziewnie podanym alergenem u chorych na astme oskrzelowa.

Bronchial hyperresponsiveness is the characteristic feature of bronchial asthma. Inhalation of allergen can cause dual asthmatic response--early and late reaction. Thirteen patients with mild and moderate asthma underwent bronchial allergen challenge. Non-specific bronchial reactivity was measured before, 90 minutes, on the 2nd, 7th, 14th day after provocation. Peak Expiratory Flow was measured every hour during 12 hours after challenge to search for late phase reaction. Increased bronchial reactivity was discovered as early as 90 minutes after challenge, it was still observed on the 2nd and 7th but not on the 14th day after allergen provocation. No relationship was found between appearance of late asthmatic reaction and increased bronchial reactivity.

[Effect of loratadine, selective antagonist of histamine H1 receptors, on histamine-induced bronchoconstriction]. / Wplyw loratadyny wybiórczego antagonisty receptorów histaminowych H1 na pohistaminowa reaktywnosc oskrzeli.

The aim of this study was to assess the duration of Loratadine effect on histamine H1 receptor in the airway. Six patients with mild or moderate asthma were examined. Bronchial reactivity to histamine was measured according to Cockcroft. The significant blockade of histamine H1 receptors in airway was observed from the 2nd day when 10 mg of Lo was given daily. The maximal protection with 10 mg doses was observed after 3-4 days. After another 5-6 days without Loratadine bronchial responsiveness return to the initial values. Single dose of 30 mg Loratadine given better protection against histamine bronchoconstriction than 10 mg given for 5 days. This effect was observed as early as 60 minutes after administration of Loratadine.

[The effect of bronchial allergen provocation on spontaneous production of histamine releasing factor (HRF) by mononuclear cells in patients with bronchial asthma]. / Wplyw wziewnej prowokacji alergenem na samoistne wytwarzanie czynnika uwalniajacego histamine z bazofili (HRF) przez komórki jednojadrowe krwi obwodowej u chorych na astme oskrzelowa.

The study was performed in 8 patients suffering from mild asthma. Bronchial allergen challenges with Dermatophagoides pretonyssinus were performed according to Chai et al method. Nonspecific bronchial reactivity to histamine (PC20H in mg/ml) were determined before the allergen challenge and in 90 min. and 24 hrs. after allergen provocation. Blood samples for mononuclear cells culture were collected before the trial and after the allergen challenge in 15, 90 min. and 8 and 24 hrs. The supernatants were assayed for HRF activity with basophils from a single donor. The significant increase of PC20H was observed xgPC20H in mg/ml 0.43 before allergen challenge and 0.08 and 0.125 after allergen provocation. Blood samples did not reveal any significant changes in HRF % activity--mean and SD before challenge test 47.7 16.2 and 49.9 15.0 in 15 min, 53.3 19.0 in 90 min, 56.6 15.8 in 8 hr, 52.5 20.4 in 24 hr after allergen provocation. The correlation between postallergen, nonspecific bronchial reactivity and spontaneous production of HRF activity was not found. The authors discuss the role of HRF in pathogenesis of nonspecific bronchial reactivity of asthmatic patients.

[The influence of multiple histamine inhalation on nonspecific airway hyperresponsiveness to histamine in patients with bronchial asthma]. / Wplyw wielokrotnego wziewania histaminy na nieswoista nadreaktywnosc oskrzeli na histamine u chorych na astme oskrzelowa.

The study was performed in 19 patients with stable mild/moderate asthma aged from 16 to 66. Nonspecific airway hyperresponsiveness (AH) to histamine was measured according to Cockcroft's et al. method and expresses as PC20H in mg/ml. The study was controlled by inhalation of PBS. The histamine or PBS challenges were performed three times at 45 min. intervals on the third day in case when the stability of AH on two preceding days was observed. The geometric means of PC20H (xg PC20H) during the consecutive three days did not change. They were 0.97, 0.92, 0.87 mg/ml (p > 0.05) respectively. Three times histamine challenges performed on the same day induced the decrease of AH (xg PC20H increased from 1.48 to 6.55 mg/ml) in 5 patients. In 4 other subjects the increase of AH was observed (xg PC20H decreased from 1.14 to 0.20 mg/ml). In 10 subjects the three times histamine challenges performed on the same day had no influence on AH to histamine.

[An increase of nonspecific airway hyperreactivity after repeated challenge with subthreshold doses of allergen in asthma patients]. / Wzrost nieswoistej nadreaktywnosci oskrzeli po wielokrotnej prowokacji podprogowa dawka alergenu u chorych na atopowa astme oskrzelowa.

The study was performed in 11 patients suffering from stable mild and moderate atopic asthma. Bronchial allergen challenges were performed according to Chai et al method. Airway hyperreactivity-AH (PC20H in mg/ml) was determined in each study day before subthreshold allergen inhalation dose, meaning the dose which did not induce asthmatic responses. Then FEV1 was measured in 2, 5, 15, 30 i 60 min. after allergen provocation throughout 4 to 9 consecutive days. A significant increase of PC20H was observed in 8 patients (xg PC20H in whole group decreased from 0.93 to 0.35 mg/ml after allergen challenges). The authors conclude that allergen inhalation challenge without asthmatic bronchial responses can cause an increase AH.

[Examinations of cell mediated immunity in diffuse peritonitis]. / Badania nad odpornoscia komórkowa w rozlanym zapaleniu otrzewnej.

Phagocytic index and rosette test E have been determined in 50 patients, including 15 with diffuse peritonitis and the noncomplicated diffuse peritonitis, 20 patients with septic complications, and 15 patients who underwent abdominal surgery. It was found, that phagocytic index is decreased in all patients after abdominal surgery. The most marked decrease of this index was found in patients with complicated peritonitis. It still decreases in the course of peritonitis and increases in the reference group. The marked decrease in the number of T-cells was observed in complicated peritonitis during the whole period of follow-up while it normalizes in case of noncomplicated peritonitis as in the reference group. Using the tests under study it was possible to assess cell-mediated immunity which is depressed in peritonitis. The tests enable also the prediction of septic complications of peritonitis.

[Allergic reaction to products made of natural rubber]. / Reakcja alergiczna na produkty z gumy naturalnej.

In the previous few years, there has been a startling escalation in intraoperative and radiologic anaphylactic episodes, some of them lethal, that have been assigned to rubber exposure. Immediate hypersensitivity reactions to natural rubber pose a significant risk to patient with spina bifida and urogenital abnormalities, health care workers, and rubber industry workers. It has been estimated that 2% to 10% of physicians and nursing personnel are latex allergic. The clinical syndromes associated with reactions to latex may be divided into three broad categories a) contact dermatitis--limited to skin directly in contact with latex, b) contact urticaria syndrome a broad spectrum of contact reactions including not only immediate wheal and flare reactions, but also dyshidrotic vesiculation, and accelerated contact reactions including erythema, burning or pruritus occurring within 10-30 minutes after contact, c) systemic allergic reactions-including generalized urticaria or pruritus, rhinoconjunctivitis or asthma, as well as the multiple presentations of anaphylaxis. Contact dermatitis reactions are thought to be a T-cell mediated type IV reaction, systemic reactions to latex appear to be an IgE-mediated phenomenon. Contact urticaria syndrome seems to be a heterogeneous group of reactions. Diagnosis of latex allergy is made on clinical grounds, however, history alone is insufficient to recognize all patients at risk, and conscientious testing materials are not yet available. Prick tests utilizing extracts from latex gloves or from raw latex preparation can be used but the specificity of this test remains unknown. Skin prick testing must be considered experimental and should be only done by experienced physician. Serologic testing for latex allergy remains a safe alternative, although the sensitivity and specificity of this procedure is still undefined. Prophylactic regimes to avoid rubber exposure and decrease the antigen content of natural rubber products by the rubber industry should be implemented to decrease the rate of sensitization in the future and prevent allergic reactions.

Eotaxin-1-deficient mice develop airway eosinophilia and airway hyperresponsiveness.

BACKGROUND: The accumulation of eosinophils in the lung is a hallmark of asthma. In addition to cytokines such as IL-5 which are essential, chemokines have been implicated in the recruitment of eosinophils to the airway. In particular, eotaxin has been shown to be a selective and potent eosinophil chemoattractant, important in the pathogenesis of allergic disease. The goal of the present study was to define the role of eotaxin-1 in the development of allergen-induced eosinophilic airway inflammation and airway hyperresponsiveness (AHR) to inhaled methacholine (MCh). METHODS: Eotaxin-1-deficient mice were sensitized and exposed to a single challenge with allergen. Airway function and airway and tissue as well as peripheral blood and bone marrow eosinophilia were examined 18 and 48 h after the last challenge. RESULTS: Following allergen sensitization and challenge, eotaxin-1-deficient mice developed levels of AHR to inhaled MCh at 18 and 48 h comparable to controls. Further, levels of bronchoalveolar lavage (BAL) and tissue eosinophilia at the same time points were comparable in the two strains of mice. Tissue eosinophilia, assessed by quantitating major basic protein staining cells, preceded BAL eosinophilia in a similar manner. Bone marrow and peripheral blood eosinophilia were unimpaired in deficient mice. CONCLUSION: The results demonstrate that the major eotaxin, eotaxin-1 is not essential for the development of airway eosinophilia or AHR, implying that other chemokines, alone or in combination, can overcome this deficiency.

The failure of STAT6-deficient mice to develop airway eosinophilia and airway hyperresponsiveness is overcome by interleukin-5.

While signal transducer and activator of transcription protein 6 (STAT6) is important in interleukin-4 (IL-4)-induced commitment of CD4(+) T cells to the T helper cell, type 2 (Th2) phenotype and IgE isotype switching in B cells, its role in other IL-4-mediated events and their impact upon the allergic response is less evident. In the present study we demonstrate the critical role of STAT6 in the development of allergic airway eosinophilia and airway hyperresponsiveness (AHR) after allergen sensitization and challenge. STAT6-deficient (STAT6-/-) mice did not develop a Th2 cytokine response or an allergen-specific IgE response. Further, STAT6-/- mice had a reduced constitutive and allergen-induced expression of CD23 as well as lower mucus production in the airway epithelium. Critically, we show that IL-5 alone can reconstitute airway eosinophilia and AHR in sensitized and challenged STAT6-/- mice. This emphasizes the essential nature of the IL-4-dependent signaling of T cells to the Th2 phenotype and secretion of IL-5, resulting in the airway eosinophilia and AHR. These observations underscore the importance of targeting this pathway in new antiallergic asthma drug development.

CD8 T cells are essential in the development of respiratory syncytial virus-induced lung eosinophilia and airway hyperresponsiveness.

Viral respiratory infections can cause bronchial hyperresponsiveness and exacerbate asthma. In mice, respiratory syncytial virus (RSV) infection results in airway hyperresponsiveness (AHR) and eosinophil influx into the airways. The immune cell requirements for these responses to RSV infection are not well defined. To delineate the role of CD8 T cells in the development of RSV-induced AHR and lung eosinophilia, we tested the ability of mice depleted of CD8 T cells to develop these symptoms of RSV infection. BALB/c mice were depleted of CD8 T cells using anti-CD8 Ab treatment before intranasal administration of infectious RSV. Six days postinfection, airway responsiveness to inhaled methacholine was assessed by barometric body plethysmography, and numbers of lung eosinophils and levels of IFN-gamma, IL-4, and IL-5 in bronchoalveolar lavage fluid were monitored. RSV infection resulted in airway eosinophilia and AHR in control mice, but not in CD8-depleted animals. Further, whereas RSV-infected mice secreted increased amounts of IL-5 into the airways as compared with noninfected controls, no IL-5 was detectable in both bronchoalveolar lavage fluid and culture supernatants from CD8-depleted animals. Treatment of CD8-depleted mice with IL-5 fully restored both lung eosinophilia and AHR. We conclude that CD8 T cells are essential for the influx of eosinophils into the lung and the development of AHR in response to RSV infection.

Temporal association between airway hyperresponsiveness and airway eosinophilia in ovalbumin-sensitized mice.

The temporal association between airway inflammation and airway hyperresponsiveness (AHR) has been analyzed in BALB/c mice sensitized to, and subsequently exposed to, a single intranasal challenge of ovalbumin (OVA). In OVA-sensitized/challenged animals only a small increase in responsiveness to methacholine (MCh) was seen at 8 h, peaked at 24 to 48 h, and resolved by 96 h. An early bronchoalveolar lavage fluid (BALF) neutrophil infiltrate (peaking at 8 h postchallenge; approximately 72% total cells was observed) that returned to baseline by 48 h. BALF eosinophil numbers did not increase until 48 h (approximately 32% of total cells), peaked at 96 h (approximately 38% total cells), and remained elevated at 8 d (approximately 27% total cells). Airway tissue eosinophilia preceded changes in BALF. Eosinophil peroxidase (EPO) levels in BALF were elevated in OVA-sensitized/challenged mice at 48 h only. BALF TNF-alpha levels peaked at 8 h, whereas IL-5 and IL-4 levels peaked at 24 h. IL-13 levels were increased at both 24 and 48 h. Mucus-positive cells were not observed in the airway epithelium until 48 h. Administration of IL-5 or VLA-4 antibody prior to OVA challenge prevented the development of AHR in sensitized mice as well as BALF and tissue eosinophilia. These data identify a temporal association between Th2 cytokine production, tissue eosinophil infiltration and activation, and, importantly, both the development and resolution kinetics of AHR. Moreover, the antibody studies further support the association of eosinophilia with the pathogenesis of AHR.

Transfer of the enhancing effect of respiratory syncytial virus infection on subsequent allergic airway sensitization by T lymphocytes.

In mice, respiratory syncytial virus (RSV) infection enhances allergic airway sensitization, resulting in lung eosinophilia and in airway hyperresponsiveness (AHR). The mechanisms by which RSV contributes to development of asthma and its effects on allergic airway sensitization in mice are not known. We tested whether these consequences of RSV infection can be adoptively transferred by T cells and whether depletion of T cell subsets prevents the effects of RSV infection on subsequent airway sensitization. Mononuclear cells, T lymphocytes, or CD4 or CD8 T cells from peribronchial lymph nodes (PBLN) of RSV-infected mice were transferred into naive BALB/c mice which were then exposed to OVA via the airways. Additionally, RSV-infected mice were depleted of CD4 or CD8 T cells following acute RSV infection but prior to airway sensitization. Following sensitization, airway responsiveness to inhaled methacholine, numbers of lung eosinophils, and levels of IFN-gamma, IL-4, and IL-5 in PBLN cell cultures were monitored. Transfer of T cells from RSV-infected mice resulted in increased eosinophil influx into the lungs, increased IL-5 production, and development of AHR following airway sensitization to allergen. Transfer of CD8 but not CD4 T cells from the PBLN of RSV-infected mice also resulted in AHR following 10 days of OVA exposure. Further, depletion of CD8 T cells prevented these consequences of RSV infection while CD4 T cell depletion reduced them. We conclude that T cells, in particular CD8 T cells, are critical in mediating RSV-induced development of lung eosinophilia and AHR following allergic airway sensitization.

IL-5 and eosinophils are essential for the development of airway hyperresponsiveness following acute respiratory syncytial virus infection.

Viral respiratory infections can cause bronchial hyperresponsiveness and exacerbate asthma. In mice, respiratory syncytial virus (RSV) infection, which induces an immune response dominated by IFN-gamma, results in airway hyperresponsiveness (AHR) and eosinophil influx into the airways, both of which are prevented by pretreatment with anti-IL-5 Ab. To delineate the role of IL-5, IL-4, and IFN-gamma in the development of RSV-induced AHR and lung eosinophilia, we tested the ability of mice deficient in each of these cytokines to develop these symptoms of RSV infection. Mice deficient in either IL-5, IL-4, or IFN-gamma were administered infectious RSV intranasally, and 6 days later, airway responsiveness to inhaled methacholine was assessed by barometric body plethysmography, and numbers of lung eosinophils and production of IFN-gamma, IL-4, and IL-5 by mononuclear cells from peribronchial lymph nodes were monitored. RSV infection resulted in airway eosinophilia and AHR in both IL-4- and IFN-gamma-deficient mice, but not in IL-5-deficient mice. Reconstitution of IL-5-deficient mice with IL-5 restored these responses and enhanced the responses in IL-4-deficient mice. Anti-VLA-4 (very late Ag-4) treatment prevented lung eosinophilia and AHR following RSV infection and IL-5 reconstitution. We conclude that in response to RSV, IL-5 is essential for the influx of eosinophils into the lung and that eosinophils in turn are critical for the development of AHR. IFN-gamma and IL-4 are not essential for these responses to RSV infection.

Local treatment with IL-12 is an effective inhibitor of airway hyperresponsiveness and lung eosinophilia after airway challenge in sensitized mice.

BACKGROUND: Systemic administration of IL-12 can prevent airway hyperresponsiveness (AHR) in mice after sensitization and repeated allergen challenge. However, systemic IL-12 has been associated with severe adverse effects. OBJECTIVE: We determined whether IL-12 administration to the airways in a dose sufficiently low so as not to result in systemic effects can modify allergic inflammation and AHR after allergen challenge. METHODS: Mice were sensitized to ovalbumin by intraperitoneal injection and challenged with ovalbumin aerosol on 3 consecutive days. During the period of challenge, IL-12 was administered intranasally following 2 regimens, designated high (1500 ng) or low (150 ng). We monitored airway responsiveness to inhaled methacholine by barometric body plethysmography, lung inflammatory cells, local cytokine production, and, to assess systemic effects of IL-12 treatment, spleen weights and numbers of eosinophils in the bone marrow. RESULTS: Allergen challenge resulted in increases in airway responsiveness and in numbers of lung eosinophils. These increases were prevented by both high- and low-dose IL-12. Additionally, IL-12 administration resulted in enhanced local interferon-gamma production and prevented the increases in local IL-4 and IL-5 production after airway challenge. A high dose, but not a low dose, of IL-12 resulted in increased spleen weights and prevented the increase in numbers of bone marrow eosinophils after allergen challenge. CONCLUSION: These data indicate that local administration of IL-12 can prevent AHR and reduce lung eosinophilia after allergen challenge in sensitized mice without eliciting systemic adverse effects. IL-12 exerts these effects by inducing local T(H1)-type responses in the airways in a setting that is normally dominated by T(H2)-type responses.

Anti-interleukin 5 but not anti-IgE prevents airway inflammation and airway hyperresponsiveness.

The role of IL-5 and allergen-specific IgE in the development of eosinophilic airway inflammation and airway hyperresponsiveness (AHR) was investigated in a murine model. BALB/c mice were sensitized to ovalbumin (OVA) by intraperitoneal injection on Days 1 and 14, followed by airway challenge with OVA on Days 28 and 29. Anti-IL-5 (TRFK-5) or anti-IgE (antibody 1-5) was administered before each airway challenge. Sensitized and challenged mice developed increased OVA-specific IgE serum levels, Th2 cytokine production by peribronchial lymph node (PBLN) cells, increased numbers of eosinophils (predominantly located in the peribronchial regions of the lungs), and increased airway responsiveness to methacholine (MCh). Anti-IgE treatment significantly decreased serum anti-OVA IgE levels and prevented the development of anaphylaxis but failed to affect T cell function, eosinophil airway infiltration, and AHR in sensitized and challenged mice. In contrast, treatment with anti-IL-5 antibody did not affect B cell (Ig serum levels), T cell (cytokine production), or mast cell function (immediate cutaneous reactivity) but completely inhibited development of eosinophilic lung inflammation and AHR. These data identify IL-5-mediated eosinophilia as a major target for development of AHR in this model, with little effect resulting from neutralization of IgE.

Assessment of IgE allergen specificity among latex-allergic health care workers: review of IgE-binding components of various latex extracts.

BACKGROUND: Allergic reactions to natural rubber latex have increased during the past 10 years, especially in many health care workers who have high exposure to latex allergens both by direct skin contact and by inhalation of latex particles from powdered gloves. Development of satisfactory diagnostic methods to verify the presence of latex allergy in health care workers requires characterization of the immunoreactive proteins in latex products and identification of specific IgE antibodies in sensitized patients. A number of different latex preparations are now available for in vitro evaluations. OBJECTIVES: Utilizing different in vitro methods, this study examines IgE sensitization to components of latex in a selected population of hospital employees, employing a raw natural latex glove extract and various commercial latex extracts. METHODS: Two hundred hospital employees exposed to latex were evaluated using an allergy history questionnaire. To further identify sensitized patients, two different specific IgE tests and leukocyte histamine release tests were performed using a panel of latex extracts obtained from different manufacturers. Sodium dodecylsulfate polyacrylamide electrophoresis (SDS-PAGE) profiles were obtained. Sera from 34 subjects suspected to be latex-sensitized were IgE immunoblotted to assess the presence of IgE antibodies directed toward specific latex proteins. RESULTS: Thirty-four participants (17%) were considered sensitized to latex by a positive clinical history in conjunction with positive specific IgE tests (18 individuals) and/or positive histamine release tests (26 individuals). Significant extract differences in both the histamine release response profile and the frequency of positive test results were noted in the histamine release test. Significant individual differences in patients' latex epitope-specificity were found by IgE immunoblotting, substantiated by sodium dodecylsulfate polyacrylamide profiles revealing differences in protein band patterns among the various extracts. The IgE immunoblots indicated that the majority of patients reacted to proteins with molecular weights of 14, 21, 30 to 35, and 42 kD; the 30 to 35 kD protein being predominant. Seven subjects (22%) of the 34 considered to be latex-sensitized did not reveal binding of specific IgE in immunoblots. One latex extract (Stallergene) with the widest IgE-reacting protein repertoire identified the majority of subjects (63%) as latex sensitive by leukocyte histamine release and also provided the best quantitative histamine release test results. CONCLUSION: Only by testing with a combination of latex extracts were all sensitized individuals identified. This study demonstrates that currently several in vitro methods may be necessary to detect IgE sensitization to latex. Latex extracts to be employed in future skin tests must contain a wide epitope repertoire of IgE-binding proteins to identify all latex-sensitized individuals.