Late cutaneous allergic responses in isolated IgE-dependent reactions

Early/late response model: implications for control of asthma and chronic cough in children

The observed airways inflammation in asthma and chronic cough supports the conclusions of clinical trials, namely, that our treatment regimens should emphasize inhaled cromolyn. The need for bronchodilators as backup therapy is real but represents testimony to the fact that in some cases it has not been possible to entirely eliminate the inflammation and the consequent airways hyperresponsiveness.

Effect of levocabastine, a new H1 antagonist, in a conjunctival provocation test with allergens

Levocabastine is a new, highly potent, and specific H1 antagonist. The effects of this drug, administered topically, were evaluated in a conjunctival provocation test (CPT) with allergens. CPT was performed by the instillation of one drop of allergen at increasing concentrations in the inferior conjunctival sac of each eye, alternatively, and stopped when both itching and redness of the conjunctiva were present. The concentration of allergen at this step was considered as the reaction threshold. Eleven patients, allergic to grass pollen, underwent, in winter, a first CPT without pretreatment (screening test); the CPT was then repeated twice after a 24-hour treatment, once, with a placebo, and once, with levocabastine (one drop twice a day, 0.5 mg/ml), administered in a double-blind fashion and in random order. The minimal interval between the two tests was 1 week. There was no significant difference between the thresholds determined in the two CPTs performed without medication (screening test and placebo), whereas the threshold was significantly increased (p less than 0.001) after pretreatment with levocabastine. Individually, the threshold increased in 10/11 patients (p less than 0.01). Levocabastine prevented both redness and itching. A late allergic reaction was observed by the patient in 6/11 CPTs performed after placebo treatment and 8/11 after levocabastine treatment. We conclude that, in this model of allergic conjunctivitis, levocabastine increased the conjunctival tolerance to an allergen. Further studies should help to determine the true place of this H1 antagonist in the treatment of allergic conjunctivitis.

Inflammatory changes in conjunctival scrapings after allergen provocation in humans

This study was performed to investigate the inflammatory changes occurring in the human conjunctiva at different time periods after allergen provocation. Twenty-three ryegrass-sensitive patients with allergic conjunctivitis (19 with hayfever and four with vernal conjunctivitis) were challenged by topical administration of ryegrass antigen to the eye. Allergen concentrations were increased in increments until an immediate ocular allergic reaction was elicited. Numbers of various inflammatory cells (neutrophils, eosinophils, lymphocytes, and monocytes) found in conjunctival scrapings were quantified and correlated with the clinical profile, total serum IgE, and serum IgE to Rye I antigen. Twenty minutes after some level of antigen topical challenge to the eye, all patients had ocular redness, tearing, and itching. Compared with findings in seven control subjects, significant inflammatory cells were found in the conjunctival scrapings of patients before challenge (p less than 0.05) and 20 minutes (p less than 0.001) and 6 hours (p less than 0.002) after effective challenge. Significant increases in neutrophils of patients occurred after 20 minutes (p less than 0.001), and in eosinophils at 6 hours (p less than 0.005), compared with values of control subjects. When each case was evaluated individually, nine of the 23 patients had highly evident inflammatory changes 6 hours after allergen provocation. The levels of total serum IgE and serum IgE to Rye I antigen of these nine patients did not differ significantly from the other patients in the study. Our data provide the first evidence in humans that significant inflammatory changes in conjunctival scrapings are present long after allergen exposure has ended.

Atopic dermatitis: clinical relevance of food hypersensitivity reactions

Forty-six patients with atopic dermatitis ranging from mild to severe were evaluated for food hypersensitivity with double-blind placebo-controlled food challenges. Twenty-eight (61%) patients had a positive prick skin reaction to one of the foods tested. Sixty-five food challenges were performed; 27 (42%) were interpreted as positive in 15 (33%) patients. Egg, milk, and peanut accounted for 78% of the positive reactions. As in previous studies, patients developed skin (96%), respiratory (52%), or gastrointestinal (30%) symptoms during the challenge. These studies indicate that children who have atopic dermatitis unresponsive to routine therapy or who continue to need daily treatment after several months would benefit from evaluation for food hypersensitivity.

The influx of inflammatory cells into nasal washings during the late response to antigen challenge. Effect of systemic steroid pretreatment

Previous studies have demonstrated symptoms and mediator release occurring as long as 11 h after nasal challenge with antigen in selected allergic subjects. Pretreatment with systemic steroids reduced symptoms and mediators including histamine, TAME-esterase activity, and kinins. The aims of the present study were to characterize the cell influx during the late-phase response to antigen challenge and to determine the effect of pretreatment with systemic steroids on this response. We examined cytospin slides of nasal washings obtained before and hourly for 11 h after nasal antigen challenge in 10 asymptomatic allergic subjects with a history of seasonal rhinitis and 5 normal, nonallergic subjects. Allergic subjects received oral prednisone (20 mg 3 times a day) or placebo in a random, double-blind crossover manner for 2 days before each of 2 challenges 1 month apart. On placebo days, a mixed cell influx occurred in allergic subjects during the late response that was 50-fold greater than the cell influx in the nonallergic control subjects (p less than 0.005). During the first 3 h after antigen challenge, eosinophils (p less than 0.005), but not neutrophils or mononuclear cells, were observed. During the late phase (4 to 11 h), neutrophils, eosinophils, and mononuclear cells were all increased. Oral steroid pretreatment blocked the influx of eosinophils (p less than 0.005), but not that of other cells. These data demonstrate an inflammatory cell influx associated with the nasal late-phase response and suggest an important pathogenetic role for the eosinophil.(ABSTRACT TRUNCATED AT 250 WORDS)

Inhibitory effect of oral cetirizine on in vivo antigen-induced histamine and PAF-acether release and eosinophil recruitment in human skin

The use of a noninvasive skin chamber technique in vivo in pollen-sensitive patients allowed us to quantify the time-course release of histamine and the recruitment of inflammatory cells (i.e., neutrophils, monocytes, and eosinophils) in skin sites challenged with pollen, histamine, and compound 48/80. The new H1-receptor antagonist, cetirizine 2 HCl, orally administered with 10 mg once a day to pollen-sensitive patients in a double-blind, crossover study versus placebo, induced a significant decrease in the wheal-and-flare cutaneous reaction induced by intradermal injection of pollen, histamine, and compound 48/80. It also significantly inhibited the immediate histamine release occurring in skin chambers after pollen introduction, whereas it did not significantly inhibit the late release. In patients receiving placebo, we detected platelet-activating factor-acether in media collected at the sixth hour from chambers filled with pollen. With cetirizine 2 HCl treatment, platelet-activating factor-acether was not detected in chamber media. Interestingly, cetirizine 2 HCl significantly reduced the eosinophil recruitment observed on the superficial dermis 24 hours after pollen challenge.

Prostaglandin D2 and histamine during the immediate and the late-phase components of allergic cutaneous responses

With a skin blister technique in which the mediators generated by the trauma of forming the blister are allowed to subside, we have collected human interstitial skin fluid during the course of allergic reactions to ragweed, and measured levels of histamine and prostaglandin D2 (PGD2). Of 18 ragweed-allergic individuals tested, 11 developed both an immediate and a late-phase reaction (LPR) with fivefold-elevated levels of histamine (40 ng/ml) at 30 minutes and a peak level of PGD2 (6.5 ng/ml) later at 2 1/2 hours after ragweed challenge. The other seven allergic individuals had immediate reactions without an LPR lesion and demonstrated somewhat smaller elevations of histamine (25 ng/ml) but much lower levels of PGD2 (1.6 ng/ml; p less than 0.05). The time course of appearance of these mediators was identical in both groups of patients. The fluids from unchallenged blisters of allergic and nonallergic patients and the fluids of nonallergic patients challenged with ragweed had similar levels of histamine, at the lower limit of detection, and undetectable PGD2 levels. The peak levels of PGD2 in allergic individuals correlated with the size of the LPR lesion (p less than 0.05). These data suggest that the LPR involves the secondary elaboration of mediators different from mediators responsible for the immediate manifestations of the allergic skin reaction.

Prednisone inhibits late asthmatic reactions and airway inflammation induced by toluene diisocyanate in sensitized subjects

To determine the importance of airway inflammation for late asthmatic reactions induced by toluene diisocyanate (TDI), we investigated whether prednisone prevented them [corrected] by modifying the associated airway inflammatory reaction. We measured FEV1 before and at regular intervals after exposure to TDI and performed bronchoalveolar lavage at 8 hours after TDI in two groups of subjects with previously documented late asthmatic reactions, in one group, after no treatment, and in the other group, after treatment with prednisone (50 mg/day for 4 days). After no treatment, each subject developed a late asthmatic reaction, an increase in airway responsiveness, polymorphonuclear leukocytosis, and increased albumin in bronchoalveolar lavage. By contrast, after treatment with prednisone, no subject developed a late asthmatic reaction or an increase in airway responsiveness, and the number of leukocytes and the concentration of albumin were normal in bronchoalveolar lavage. These results suggest that late asthmatic reactions induced by TDI may be caused by airway inflammation and that prednisone may block them [corrected] by inhibiting the inflammatory reaction of the airway induced by TDI in sensitized subjects.

Bronchoalveolar neutrophilia during late asthmatic reactions induced by toluene diisocyanate

The mechanism by which late asthmatic reactions are induced by toluene diisocyanate (TDI), a low molecular weight chemical that causes occupational asthma in exposed subjects, is unknown. We investigated whether early and late asthmatic reactions induced by TDI are associated with changes in airway responsiveness to methacholine and airway inflammation as determined by bronchoalveolar lavage. We measured FEV1 before and at regular intervals after exposure to TDI, and performed dose-response curves to methacholine and bronchoalveolar lavage at 8 h after TDI in a group of 6 subjects with late asthmatic reactions and in 6 subjects with only early asthmatic reactions. The same procedure was followed 2 h after TDI in a group of 6 subjects with previously documented late asthmatic reactions and in a group of 6 subjects without any previously documented asthmatic reaction after TDI. In subjects with late asthmatic reactions, neutrophils were increased at both 2 and 8 h, and eosinophils and airway responsiveness were increased only at 8 h. By contrast, neutrophils, eosinophils and airway responsiveness were not increased at 8 h after TDI in subjects with an early asthmatic reaction or at 2 h after TDI in normal control subjects. These results suggest that late asthmatic reactions to TDI, and the associated increase in airway responsiveness, may be caused by airway inflammation.

Occupational asthma

This article review recent developments in the study of occupational asthma and implications for the overall understanding of asthma. Occupational asthma is a clinical syndrome caused by many different agents. Contribution of studies of experimental inhalation challenge using occupational agents to the knowledge of asthmatic reactions and their mechanisms is discussed. Investigations in the occupational environment into predisposing factors and persistence or recovery after exposure to an allergic agent or nonspecific irritant are reviewed. Approaches to diagnosing asthma in the occupational environment and to assessing functional impairment and disability are outlined. Directions for future research are identified.

Late-phase reaction and tear fluid cytology in the rat ocular anaphylaxis

Tear fluid cytology is described for the early and late phases of ocular anaphylaxis in actively immunized Sprague-Dawley rats. Tears were collected from both eyes of the rats before challenge and at 1, 2, 4, 6, 8, 10, 12, 24, and 48 h after topical challenge with di-DNP-lysine in one eye and PBS in the fellow eye. Results showed a statistically significant increase in the Aggregate Cell Rating, which represents the aggregate scores in neutrophil, eosinophil, lymphocyte, and atypical epithelial cell levels, in antigen-treated vs control eyes. This report is the first to use a cytologic study of tear film to detect the late phase of ocular anaphylaxis in the rat. Cytology of the tear film could be applied to the study of allergic conjunctivitis in both animals and humans.

Changes in bronchial responsiveness to histamine at intervals after allergen challenge

Bronchial responsiveness to inhaled histamine was measured two, seven, and 30 hours after allergen inhalation challenge in 19 atopic subjects. The provocative histamine concentrations causing a 20% fall in FEV1 (PC20) at these three times were compared with the baseline value, with values obtained two and seven hours after diluent inhalation, and with those obtained five to seven days after allergen challenge in the 12 late responders. Seven subjects had allergen induced isolated early asthmatic responses (delta FEV1 22.6% (SD 6.6%)) with less than a 5% late fall in FEV1. There was no change in the six histamine PC20 values measured in these seven subjects; the geometric mean PC20 was 1.0-1.3 mg/ml on all six occasions. Twelve subjects had an allergen induced early asthmatic response (delta FEV1 26.3% (9.8%)) followed by a definite (greater than 15% delta FEV1, n = 7) or equivocal (5-15% delta FEV1, n = 5) late asthmatic response. The geometric mean histamine PC20 was not significantly different two hours after allergen inhalation either from baseline (0.67 v 0.78 mg/ml) or from that seen two hours after diluent (0.67 v 0.95). It was significantly reduced at seven (0.24 mg/ml) and at 30 hours (0.44 mg/ml) but had returned to baseline when repeated five to seven days later (0.74 mg/ml). In 10 subjects with a dual response who had a repeat antigen challenge the mean early and late response and delta PC20 at seven and 30 hours were similar. These data show that bronchial responsiveness to a non-allergic stimulus has not increased two hours after allergen inhalation following spontaneous recovery of the early asthmatic response but before the start of the late asthmatic response.

Mast cell numbers in rheumatoid synovial tissues. Correlations with quantitative measures of lymphocytic infiltration and modulation by antiinflammatory therapy

Synovial biopsy specimens from 20 patients with rheumatoid arthritis were subjected to quantitative analysis for several parameters of inflammation and for enumeration of synovial tissue mast cells. Strong positive correlations were found between numbers of mast cells per cubic millimeter of synovial tissue and the following synovial tissue parameters: inflammatory index (a quantification of lymphocytic infiltration), Leu-3a grade (T helper/inducer lymphocytes), Leu-1 grade (T lymphocyte), and plasma cell grade. A strong negative correlation was found between the synovial mast cell count and the extent of sublining layer fibrin deposition. Correlations between synovial mast cell count and Leu-2a grade, ratio of Leu-3a grade:Leu-2a grade, OKM1 grade, HLA-DR grade, and lining layer thickness grade did not reach statistical significance. In addition, we obtained synovial specimens from 6 of the patients both before and after long-term therapy with oral methotrexate and from 3 of the patients before, and 1 week after, an intraarticular injection of steroid. The 3 patients who had an intraarticular steroid injection showed a 67-96% decrease in the number of synovial tissue mast cells; there was no significant change in the number of synovial mast cells in the tissues of the 6 patients who received oral methotrexate. These observations are the first documentation of a quantitative relationship between the number of mast cells and the number and phenotypic profile of infiltrating lymphocytes in an inflamed tissue, which in this case, is human synovium. Our findings suggest that mast cells are involved in the pathologic interactions in rheumatoid arthritis and might play a role in the early phases of exacerbations of disease activity.

Bronchial reactivity increases soon after the immediate response in dual-responding asthmatic subjects

To determine whether bronchial reactivity is augmented soon after an allergen-induced immediate asthmatic response, we compared reactivity to histamine before and immediately upon resolution of the immediate asthmatic response in seven subjects with mild asthma who were known to develop dual asthmatic responses after inhalation of Kentucky bluegrass allergen. Using a body plethysmograph and quiet breathing technique, specific airway resistance (SRaw) and reactivity to aerosol histamine were assessed on two days prior to allergenic challenge. The dose of histamine that doubled SRaw (PC200His) was determined by interpolation from histamine dose-response curves. On the day of allergenic challenge, each subject inhaled a concentration that was sufficient to induce a dual asthmatic response. Upon resolution of the immediate asthmatic response (45 to 105 minutes) after allergen, the PC200His in all cases had decreased more than 50 percent of its original value (PC200His for the group was 0.29 +/- 1.42 mg/ml [mean +/- SE], compared to 0.84 +/- 1.23 mg/ml initially). Seven or more days after the allergen, each subject had a PC200His comparable to original values. Our data indicate that airway reactivity in dual-responding asthmatic subjects markedly increases soon after the immediate asthmatic response and much before the late asthmatic response manifests clinically. Whether this early increase in bronchial reactivity is a putative requirement for, or shares common characteristics with the late asthmatic response requires further study.

Increase in bronchial responsiveness to methacholine and late asthmatic response after the inhalation of ultrasonically nebulized distilled water

We studied ten subjects who had an asthmatic response after the inhalation of ultrasonically nebulized distilled water and did not show any refractory period to repeated challenge with such water. The change in responsiveness to methacholine after inhalation of distilled water and the occurrence of any water-induced late asthmatic response were investigated on separate days. All of the tested subjects showed a significant increase in bronchial responsiveness to methacholine after prior stimulation with ultrasonically nebulized distilled water, which waned within two hours in eight of them. The other two subjects showed a progressive increase in responsiveness to methacholine, and they also had a further reduction in the caliber of the airways three to four hours after inhalation of distilled water. The late responses were less severe than the initial responses and lasted four to five hours. After the spontaneous recovery, no significant increase in responsiveness to methacholine was detected. Our results confirm previous observations on hyperresponsiveness induced by ultrasonically nebulized distilled water and demonstrate the occurrence of late reactions after inhalation of such water.

Cutaneous mast cell heterogeneity: response to antigen in atopic dogs

Because mast cells (MCs) in skin of atopic dogs are heterogeneous with respect to tissue fixation and staining properties, we determined the effect of antigen on each type of MC in vivo. Skin biopsies were done in anesthetized, ragweed-sensitized dogs before and at 1, 3, 6, and 24 hours after intradermal injections of ragweed antigen (n = 5) or glycerin diluent (n = 4). In each case, one biopsy specimen was fixed with formalin, and a second specimen from an adjacent abdominal site was fixed with basic lead acetate. In sections stained with Alcian blue, 49.7% more MCs (p less than 0.05) were detected in tissue fixed with basic lead acetate ("typical" plus "atypical" MCs: 2916 +/- 581/mm3; mean +/- SEM) than in tissue fixed with formalin ("typical" MCs: 1955 +/- 537/mm3). After antigen, the number of "typical" MCs detectable in tissue sections progressively decreased during the 24-hour period, whereas the number of "atypical" MCs was lowest at 1 hour and had increased at 24 hours. After diluent, MC numbers did not change significantly over time. A late-phase response (LPR), detected clinically as induration and edema, was present 6 hours after antigen in four of five dogs, but LPR was not detected after diluent. The size of LPR was correlated (r = 0.85; p less than 0.05) with the decrease in the number of "typical" MCs at 6 hours. We conclude that the response of the "typical" and "atypical" MC to antigen in vivo differs markedly. The "atypical" MCs participate in the early, acute response to antigen, and the "typical" MCs may be associated with the development of the LPR.

A study on late allergic reactions to house dust mite in bronchial asthmatics

Patterns of skin and bronchial reactions to the allergen were examined in thirty perennial asthmatics who showed a positive early cutaneous reaction (ECR) to the skin prick test with Dermatophagoides farinael. A dualcutaneous reaction (DCR) was elicited in nine subjects by the skin prick test and in twenty-four by the intradermal test. The size of the late cutaneous reaction (LCR) to the intradermal test was found to correlate with that of the preceding ECR. A bronchial provocation test resulted in no reaction in six, and isloated early asthmatic reaction (EAR) in three, and a dual asthmatic reaction (DAR) in twenty-one. A large LCR was associated with the occurrence of DAR and the patients with a large LCR required a lower allergen concentration to elicit an EAR.

The effect of exposure of hospital employees to patients with tuberculosis on dermal reactivity to four new tuberculins

An early (6-8 h) erythematous response to Purified Protein Derivative and to sonicate antigens (new tuberculins) prepared from Mycobacterium tuberculosis, M. vaccae, M. scrofulaceum, and M. leprae occurred much more frequently amongst hospital employees exposed to patients with tuberculosis than amongst factory workers. Biopsies taken from the skin test sites at 48 h revealed a more intense inflammatory cell infiltrate in response to PPD and the sonicate of M. tuberculosis, but not to the antigens of the other mycobacteria, amongst the hospital employees thus indicating a degree of specificity. The early response appears to be directed towards species specific antigens, but not, apparently, to the same as those that elicit the 48 h reactions. The hospital employees also had higher peripheral blood B-cell counts and total IgG levels, suggestive of an adjuvant effect. It is postulated that the early reaction results from repeated exposure to tubercle bacilli and the possible nature of the reaction is discussed.

IgE antibody and resistance to infection. II. Effect of IgE suppression on the early and late skin reaction and resistance of rats to Schistosoma mansoni infection

Most helminth parasites induce a strong IgE antibody and elevated eosinophil response in their mammalian hosts and a number of in vitro studies have suggested that IgE, possibly in association with eosinophils, may be an essential element of the host protective immunity against helminth infections. To assess the role of IgE in protective immunity, we examined the effect of suppressing the IgE antibody response on rat immunity to Schistosoma mansoni. Suppression was achieved in neonates by injections of rabbit anti-epsilon chain gamma-globulins, control rats received injections of unspecific gamma-globulins. IgE suppression caused a marked reduction of the inflammatory reaction that developed in the skin of immune rats at the site of a cercarial challenge: the early (30 to 60 min) wheal and flare reaction was abolished, and the late cutaneous reaction (6 to 18 h) associated with intense pruritus, edema and local eosinophilia was greatly reduced. This shows that IgE was critical to the recruitment of effector cells and molecules in the skin during the first 24 h following parasite invasion. Worms were recovered 18 to 30 days after a primary infection and 18 days after a challenge infection from IgE-suppressed and control rats. IgE-suppressed rats cured a first infection as rapidly as the control rats; however, they were two to three times less efficient than the controls at eliminating a second or a third challenge. These observations demonstrate that IgE antibodies are essential for the full development of rat acquired protective immunity against Schistosoma mansoni.

Worm antigen-induced ocular anaphylaxis in rats infected with Nippostrongylus brasiliensis

A model of topically induced conjunctival anaphylaxis has been developed. Male Sprague-Dawley rats were immunized by infection with 3000 Nippostrongylus brasiliensis larvae and challenged topically on the eye 4 weeks later. Application of worm antigen alone did not induce clinical (conjunctival edema) or histologic (mast-cell degranulation) signs of anaphylaxis. Topical challenge with antigen 15 min after topical application of dithiothreitol (DTT), a mucolytic agent, elicited conjunctival edema and mast-cell degranulation within the first hour after challenge. At 6 and 24 hr, no clinical change was evident and conjunctival mast cells had again become granulated. At none of the three intervals (1, 6 and 24 hr) was there a significant increase in neutrophils, lymphocytes, eosinophils or macrophages in tissues from DTT-pretreated, antigen-eyes. The present model of ocular anaphylaxis resembles the ocular component of human hay fever in that sensitization prior to challenge is essential, the antigen is presented topically to the ocular tissues, conjunctival edema is the clinical manifestation and mast cell degranulation characterizes the histologic changes.

Nasal challenge with ragweed pollen in hay fever patients. Effect of immunotherapy

Challenge of the nasal mucosa of allergic subjects with specific allergen induces not only the expected sneezing and rhinorrhea, but also the appearance in nasal secretions of mediators commonly associated with activation of mast cells or basophils: histamine, leukotrienes, prostaglandin D2 (PGD2), kinins, and TAME ([3H]-N-alpha-tosyl-L-arginine methyl ester)-esterase. To determine whether specific immunotherapy alters mediator release in vivo, nasal pollen challenge was used to compare 27 untreated highly sensitive ragweed (RW)-allergic subjects with 12 similarly sensitive patients receiving long-term immunotherapy (3-5 yr) with RW extract (median dose, 6 micrograms RW antigen E). The two groups were equally sensitive based on skin tests and basophil histamine release. The immunized group had a diminished response as demonstrated by (a) the treated group required higher pollen doses to excite sneezing or mediator release; (b) significantly fewer subjects in the treated group released mediators at any dose (TAME-esterase [P = 0.005], PGD2 [P = 0.04]), and (c) the treated group released 3-5-fold less mediator (TAME-esterase [P = 0.01], and histamine [P = 0.02]).

Food hypersensitivity and atopic dermatitis: evaluation of 113 patients

One hundred thirteen patients with severe atopic dermatitis were evaluated for food hypersensitivity with double-blind placebo-controlled oral food challenges. Sixty-three (56%) children experienced 101 positive food challenges; skin symptoms developed in 85 (84%) challenges, gastrointestinal symptoms in 53 (52%), and respiratory symptoms in 32 (32%). Egg, peanut, and milk accounted for 72% of the hypersensitivity reactions induced. History and laboratory data were of marginal value in predicting which patients were likely to have food allergy. When patients were given appropriate restrictive diets based on oral food challenge results, approximately 40% of the 40 patients re-evaluated lost their hypersensitivity after 1 or 2 years, and most showed significant improvement in their clinical course compared with patients in whom no food allergy was documented. These studies demonstrate that food hypersensitivity plays a pathogenic role in some children with atopic dermatitis and that appropriate diagnosis and exclusionary diets can lead to significant improvement in their skin symptoms.

Dual cutaneous reactions to anti-human IgE; no change in plasma level of the split product complement C3d or effect of heparin

The possible dependence of the dual cutaneous reaction (DCR) on activation of the complement and coagulation systems was further elucidated. Heterologous whole anti-human IgE was injected intradermally (i.d.) on the volar aspect of the forearms of 17 drug-free healthy volunteers and venous samples for the selected laboratory test collected from the adjacent cubital vein. Plasma level of C3 split products (C3d) did not change significantly 6 h and 96 h after the injection of anti-IgE inducing immediate cutaneous reactions (ICRs) or DCRs as compared with prechallenge values. Conventional heparin, a compound with anti-coagulant and anti-complementary effects, injected i.d. (200 IE) concomitantly with and by s.c. (1000 IE) infiltration of the whealing 15 and 90 min subsequently to anti-IgE challenge produced no significant inhibition of the resulting ICRs or DCRs. The results suggest that the previously reported involvement of the coagulation process is a secondary phenomenon and do not support the concept that activation of the complement system is necessary for the evolution of DCRs.

Inflammatory mediators in late antigen-induced rhinitis

To investigate the mechanisms responsible for the late-phase response in patients with allergies, we measured four biochemical mediators (histamine, tosyl-L-arginine methyl ester [TAME]-esterase, kinin, and prostaglandin D2) in nasal secretions after nasal challenge with pollen antigen in 12 patients with allergy. Nine patients had an immediate response and a recurrence of symptoms 3 to 11 hours after challenge. The clinical symptoms during recurrence were accompanied by a second increase in levels of histamine, TAME--esterase, and kinin over base-line values, although kinin levels were lower than during the immediate response. In contrast, although the levels of prostaglandin D2 were significantly increased during the immediate response, they did not increase above base line during the late response. Rechallenge with allergen 11 hours after the initial provocation, however, was associated with reappearance of all four biochemical mediators, including prostaglandin D2. We conclude that the late response to nasal challenge with allergen is accompanied by a second increase in the concentrations of histamine and TAME--esterase but differs from the immediate response in the lack of prostaglandin D2 production and in the amount of kinin generated. Since histamine is released only by mast cells and basophils and prostaglandin D2 is not produced by basophils, we suggest that these cells are partly responsible for the late-phase response.

Late asthmatic responses: inquiry into mechanisms and significance

Late asthmatic responses are common, simulate a chronic phase of asthma, and are associated with an influx of inflammatory cells. The precise sequence of events leading to late inflammatory responses and increased hyperresponsiveness of the airways is uncertain, but likely begins with the triggering of mediator release from local (luminal or interstitial) mast cells or, conceivably, alveolar macrophages. Consequent influx and activation of granulocytes, including eosinophils and neutrophils, possibly T lymphocytes, basophils, and platelets, and subsequently later-arriving monocytes and macrophages, may be responsible for a continuing inflammatory reaction, airways hyperresponsiveness, and continuing active bronchial asthma. Identification of the relative importance of responsible cells and mediators will help clarify pathogenesis of bronchial asthma and should lead to a better understanding and design of therapeutic regimens and preventive measures in the management of this common and important disease.

Non-steroid anti-inflammatory drugs in asthma: dangerous or useful therapy?

The therapeutic potential of non-steroid anti-inflammatory drugs in clinical asthma is offset by the real possibility of hypersensitivity and induction of severe airways obstruction. The influence of indomethacin on the antigen-induced asthmatic response was tested. Early and delayed asthmatic responses were recorded after antigen challenge in 13 subjects. Indomethacin pretreatment totally or partially inhibited the delayed asthmatic response in 10 of 11 subjects. Inhibition by indomethacin of products of the arachidonic cascade which participate in the pathogenesis of the delayed asthmatic response could explain this phenomenon. A similar therapeutic response was documented without adverse drug reactions when five subjects were restudied after several months. In the same group the early asthmatic response was suppressed in six, enhanced in two and unchanged in four of 12-subjects. This variable response indicates that spasmogenic prostaglandin breakdown products may be important for certain individuals, but are generally of less importance in the early asthmatic response. Clinical trials with indomethacin as a steroid saving agent in allergic asthma appear feasible and can be conducted safely.

Autoimmune progesterone dermatitis with persistent amenorrhoea

A case of autoimmune progesterone dermatitis is reported. The patient developed a recurrent eruption, primarily on the extremities, after receiving oral progesterone for the treatment of persistent amenorrhoea. Intradermal injection of 17 alpha-hydroxyprogesterone produced a positive skin reaction after 30 min, but no delayed onset reaction was observed. A patch test with progesterone in petrolatum was negative. The lymphocyte transformation test was normal. Histamine release from passively sensitized peripheral blood leukocytes was increased by progesterone preincubated in normal serum as a stimulating antigen. Conjugated oestrogen therapy suppressed the rash. Cyclical eruptions with elevated basal body temperature persisted for more than 20 months without menstruation.

Equivalent inhibition by terbutaline of anti-human IgE skin responses in atopic and non-atopic subjects

Previous studies have shown that pretreatment of skin with beta 2-adrenoceptor stimulants antagonizes anti-human IgE elicited wheal and flare reactions in atopic and non-atopic subjects. This experimental system was employed to further study the hypothesis that atopic disease and bronchial asthma unrelated to atopy might be associated with a beta-adrenoceptor defect. Eight patients with extrinsic and 10 patients with intrinsic asthma deprived of oral bronchodilator treatment and corticosteroids for at least a week, and in a clinically stable condition, 10 patients with extrinsic rhinitis and on no treatment, as well as age and sex matched healthy control subjects showed almost identical dose-response relations for the inhibitory effect of intradermally injected terbutaline (0.25-100 ng), on anti-IgE elicited skin reactions. In four asthmatic patients the inhibitory effect of terbutaline did not change following a treatment period with oral terbutaline and theophylline. The data do not support the presence of a cutaneous mast cell beta 2-adrenoceptor defect in patients with atopy or bronchial asthma unrelated to atopy.

Leukocyte activation in allergen-induced late-phase asthmatic reactions

Some patients with allergen-induced asthma have both an early and late reaction to allergen (dual asthmatic reactions). To investigate the role of leukocyte activation in dual asthmatic reactions, we measured neutrophil chemotactic activity, percentages of neutrophil and monocyte complement rosettes, and one-second forced expiratory volume (FEV1) in 11 patients with allergen-induced dual asthmatic reactions after a challenge with allergen. To control for the effects of bronchoconstriction, the same studies were done after a challenge with methacholine. In all subjects there was a biphasic increase in neutrophil chemotactic activity and the percentages of neutrophil and monocyte complement rosettes, accompanied by a reduction in the FEV1. After methacholine, there were no significant changes in neutrophil chemotactic activity or percentages of complement rosettes, despite bronchoconstriction. Six patients with single-phase allergen-induced asthma had similar responses, but they were monophasic. We conclude that allergen-induced early and late asthmatic reactions are accompanied by activation of leukocytes and that these alterations probably reflect the release of mediators from mast cells rather than an effect of bronchoconstriction.

Immunologic mechanisms in pulmonary disease

This article reviews some concepts about the organization of the immune system and the immunopathologic mechanisms of hypersensitivity. This is followed by a discussion of the effect of excessive or inappropriate immunologic resources on the respiratory tract.

Prediction of late asthmatic responses to inhaled allergen

Relationships between cutaneous and bronchial responses to allergen were examined in nineteen atopic asthmatics. Allergen inhalation tests elicited an isolated early asthmatic response (EAR) in ten subjects and a dual asthmatic response (DAR) in nine subjects. Ragweed IgE RAST, performed with the sera of those patients tested with ragweed antigen, yielded higher values in all but one patient who experienced DAR than any of the patients with EAR. In one patient with annual symptoms in the ragweed season, positive skin tests with ragweed antigen and DAR to inhaled ragweed extracts, the IgE RAST was entirely negative and the serum IgE concentration was low. Dilutions of the allergen used in each individual for inhalation were also used in skin-prick tests. Early cutaneous allergic response (ECAR) mean wheal diameters were obtained at 10 min and late cutaneous allergic response (LCAR) mean diameters at 6-8 hr. Early asthmatic response (EAR) subjects differed modestly from DAR subjects in the relationships between ECAR and LCAR; in the EAR group, a significantly larger wheal diameter (P less than 0.01) was required before an LCAR ensued, however there was some overlap. Once LCAR developed, there was no difference between EAR and DAR groups in the magnitude of the LCAR. There was a trend (not significant) towards a requirement for a higher antigen concentration in the EAR group to elicit an LCAR.(ABSTRACT TRUNCATED AT 250 WORDS)