Lawrence M. Lichtenstein

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.

A controlled trial of immunotherapy in insect hypersensitivity.

Insect hypersensitivity is currently treated by immunization using whole-body extracts. We compared this regimen with immunotherapy using insect venoms or placebo in groups of 20 patients matched for history and sensitivity, as judged by venom skin test, histamine release and IgE antibody to venom. After six to 10 weeks of immunization, systemic reactions to stings occurred in seven of 12, seven of 11, and one of 18 patients treated with placebo, whole-body extract, and venom, respectively. Placebo and whole-body extract gave similar results and were significantly less effective than venom immunotherapy (P less than 0.01). The 14 patients with failure of treatment with whole-body extract and placebo were subsequently provided with venom immunotherapy; one reacted to a subsequent sting. We conclude that venom immunotherapy is clinically superior to therapy on whole-body extract or placebo.

Cutaneous late-phase response to allergen. Mediator release and inflammatory cell infiltration.

To better define the inflammatory infiltrates and kinetics of mediator release during the cutaneous late-phase reaction (LPR), we examined skin biopsies at 8 h, and skin chamber cell counts and mediator release for 12 h after antigen challenge. Compared with the control sites, the antigen-stimulated biopsy sites contained 14 times as many basophils (P less than 0.01) and six times as many eosinophils (P less than 0.001) with one to two fold more mononuclear cells (P less than 0.03) and neutrophils (P less than or equal to 0.01). Similar changes were found in the skin chambers. Although there were neutrophils in the control chamber, they were only twice as numerous in the antigen challenged site (P less than 0.01). Eosinophils were 35-fold (P less than or equal to 0.03) more prevalent in the antigen chamber than the control chamber for hours 8-12 and basophils were noted starting in the eighth hour and were 20-fold (P less than or equal to 0.03) more concentrated in the antigen chamber during the next 4 h. The mononuclear cells were not significantly different between antigen and control blisters. With respect to inflammatory mediators, there was an initial peak of histamine (13.2 +/- 2.9 ng/ml) in the blister fluid at 1 h. The level then fell to approximately 2 ng/ml, followed by a secondary rise starting at the eighth hour and increasing to 9.8 +/- 2.8 ng/ml by the twelfth hour. This secondary increase in histamine correlated significantly (r = 0.81, P less than 0.05) with the observed influx of basophils. PGD2 in the blister fluid rose to 371+/-25 pg/ml during the first 4 h and then slowly decreased to half this level during the last 4 h. Thus, the cutaneous LPR has been shown to manifest a secondary increase in histamine levels and a markedly specific increase in eosinophils and basophils with mediator release apparently being derived from the latter cells.

Basophil influx occurs after nasal antigen challenge: Effects of topical corticosteroid pretreatment

Both the pattern of mediator release during the late-phase response (LPR) and the reduction of the LPR with corticosteroid pretreatment have suggested that basophils, not mast cells, represent the main source of histamine in the late response to nasal antigen challenge. We tested this hypothesis by examining alcian blue-stained cytospin slides of nasal washings obtained before and for 11 hours after nasal antigen challenge in 11 asymptomatic subjects with seasonal allergic rhinitis. In a double-blind manner, subjects received placebo or topical flunisolide (50 micrograms, each nostril, twice daily) for 1 week before antigen challenge. One month later, the challenge was repeated with the alternate pretreatment. On placebo-treatment days, a twelve-fold increase occurred in the number and a threefold increase in the percentage of alcian blue-stained positive cells in nasal washings in the LPR compared to baseline. At least 68% of these alcian blue-stained positive cells were basophils, as determined by light microscopic criteria. Alcian blue-stained cell influx correlated with increases in histamine levels in nasal washes (p less than 0.001). Topical steroid pretreatment blocked the influx of alcian blue-stained positive cells, as well as other inflammatory cells, including eosinophils, neutrophils, and mononuclear cells. Symptoms and mediator release were also blocked. These data demonstrate an influx of basophils and suggest that these cells are responsible for the histamine release observed in the LPR. Our findings indicate that pharmacologic control of basophil histamine release may represent a strategy for the treatment of a variety of chronic allergic diseases that are believed to resemble the LPR.

IgE receptors on human basophils. Relationship to serum IgE concentration

As reported previously, and confirmed here in 26 donors, the serum IgE level (2.6-5,500 ng/ml) correlates well (rs = 0.95, P less than 0.001) with the in vivo number of IgE molecules/basophil (6,000-600,000). The total number of IgE receptors/basophil was monitored by incubating them with an IgE-rich serum (15 microgram/ml), quantitatively stripping IgE from the cells at pH 3.7, and measuring eluted IgE by a direct radioimmunosorbent test. Saturation of receptors for each donor was achieved with 15 nM IgE (3 microgram/ml). The proportion of receptors occupied in vivo correlated with the serum IgE (rs = 0.84, P less than 0.001) whereas the average association constant of the receptors was independent of serum IgE and ranged from 7.1 X 10(8)/M to 2.8 X 10(10)/M, averaging 7.7 X 10(9)/M. Unexpectedly, the total number of IgE receptors/basophil was closely related to the serum IgE level. (rs = 0.92, P less than 0.001). Thus, either there is genetic association between serum IgE and the number of basophil IgE receptors, or, more likely, the receptor number is modulated by the serum IgE concentration.

Inhibition of mediator release in allergic rhinitis by pretreatment with topical glucocorticosteroids

Patients with allergic rhinitis often have immediate symptoms after antigen challenge (the early-phase response), followed several hours later by a recurrence of symptoms (the late-phase response). Systemic glucocorticosteroids are known to inhibit the late-phase but not the early-phase response. We studied the effect of one week of pretreatment with topical (rather than systemic) glucocorticosteroids on the response to nasal challenge with antigen in a double-blind, randomized, placebo-controlled crossover study of 13 allergic patients who had previously had a dual response to nasal challenge. The patients were challenged with three 10-fold increments of allergen, producing an early response, and were then followed for 11 hours, encompassing the late response, before they were rechallenged with the lowest dose of allergen. We monitored their responses by means of symptom scores and measurements of the levels of histamine, tosyl-L-arginine methyl ester (TAME)-esterase activity, and kinins in nasal lavages. Topical glucocorticosteroids significantly reduced both the symptoms and the levels of histamine, TAME-esterase activity, and kinins in the early, late, and rechallenge allergic reactions. The fact that, in contrast to treatment with systemic glucocorticosteroids, prolonged pretreatment with topical glucocorticosteroids inhibited the early-phase response to antigen suggests that the route and duration of administration affect the mechanisms of action of the steroids. We conclude that inhibition of the early-phase as well as the late-phase response by topical glucocorticosteroids may provide an advantage over treatment with systemic glucocorticosteroids in patients with allergic rhinitis.

Effect of cetirizine on mast cell-mediator release and cellular traffic during the cutaneous late-phase reaction.

A new H1 antihistamine, cetirizine, was studied to determine its effects on mediators and cellular infiltration during the cutaneous late-phase response (LPR). Ten ragweed-allergic subjects, who had previously demonstrated a cutaneous LPR, were examined in a double-blind, crossover study. Either cetirizine, 20 mg, or placebo was administered orally once daily for 2 days before and the morning of placement of a skin chamber overlying an unroofed heat/suction-induced blister to which was added antigen or buffer. Skin test erythema was significantly reduced by cetirizine at 15 minutes, 2 hours, and 4 hours by 56%, 40%, and 39%, respectively (all, p less than or equal to 0.01), but by 6 and at 8 hours, the cutaneous erythema was not significantly lessened. Histamine release was not altered by cetirizine treatment, but prostaglandin D2 (PGD2) production, which peaked at 3 to 5 hours, was clearly reduced by cetirizine treatment, being lower at all time points during the reaction; this was significant by analysis of variance (p less than or equal to 0.04). The inhibition was most marked during the fifth hour of the reaction when there was a 50% suppression of the PGD2 level by cetirizine (0.193 ng/ml to 0.075 ng/ml [p less than or equal to 0.03]). The most dramatic effect of cetirizine was attenuation of the inflammatory cell migration into the chamber. Eosinophil infiltration was decreased by about 75% during hours 6, 7, and 8 (p less than or equal to 0.04), whereas the number of neutrophils was reduced by the same magnitude at the same times (p less than or equal to 0.04).(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnostic tests in ragweed hay fever: A comparison of direct skin tests, IgE antibody measurements, and basophil histamine release☆

Abstract In 87 patients with both spring and fall hay fever symptoms the radioallergosorbent test (RAST) technique for specific IgE antibodies to ragweed was compared with basophil histamine release and direct intradermal skin testing by the threshold dilution technique. The three techniques gave good agreement except with the leastsensitive patients, some of whom had a positive skin test but undetectable histamine release or IgE antibodies. Twenty-one patients who were highly sensitive to ragweed as measured by all three techniques were followed without specific immunotherapy. There was significant agreement between the level of positivity of all three tests and the symptom index obtained during the ragweed season. In 14 of the 21 patients there was a significant correlation between daily ragweed pollen counts and daily symptom indexes during the season. On the other hand, among the 16 least-sensitive patients (as judged by histamine release) the correlation between daily ragweed pollen counts and symptom indexes was significant in only 3 patients. Other significant allergens could not be identified in the latter group, and the cause of their symptoms is not clearly identified but appears not to be ragweed. The RAST is a quantitative technique that gives diagnostically useful information in ragweed hay fever, although not significantly different from basophil histamine release or carefully performed skin testing. The convenience to the patient may, however, offer a noticeable advantage.

Insect allergy: the state of the art.

There has been significant recent progress in the diagnosis and treatment of patients with Hymenoptera sensitivity.‘-” Many problems remain, and, indeed, the introduction of new information has raised additional questions. Treatment is highly efficacious but expensive, of long duration, and has an unknown degree of long-term side effects. The question of whom to treat, therefore, becomes critical. With the commercial availability of venoms for immunotherapy, the practicing allergist will need to make a series of difficult decisions. With this in mind, it seems appropriate to present our clinical and laboratory experience during the last five years and to summarize our suggestions concerning the management of patients with an allergy to insect stings. Our recommendations are derived from experience with the evaluation of over 500 patients and the therapy, including inhospital sting, of over 300 adults and children. A degree of controversy persists in this field, and additional data must be gathered before a fully defined position can be established. We have tried to make what follows as precise a statement of what is and is not known as is currently possible. Whole body extract therapy In the first volume of the

Clinical relevance of the venom-specific immunoglobulin G antibody level during immunotherapy

Parameters associated with successful venom immunotherapy in insect allergy were sought by comparison of treatment failures with successes. Half-dose treatment was completely protective in 32 patients (successes) but was only partially effective in eight (failures). The outcome of treatment was not related to the severity of pretreatment sting reactions, to the degree of skin-test sensitivity, to an atopic personal history, or to age or gender. The mean yellow jacket venom-specific IgG antibody level (by the Staph-A solid-phase radioimmunoassay) was significantly less in the failures (3.9 +/- 0.6 microgram/ml) than in the successes (7.3 +/- 1.1 microgram/ml) (p less than 0.01). When the failures were successfully treated, their mean IgG level (6.1 +/- 1.3 microgram/ml) was significantly greater than that associated with treatment failure (p less than 0.025). Patients with an IgG antibody level above 5.0 microgram/ml were significantly more likely to be fully protected (p less than 0.02). Those whose IgG levels were less than 5 microgram/ml had a risk of reaction similar to that in untreated patients. We conclude that early in the maintenance phase of low-dose venom immunotherapy, the risk of a reaction to a challenge sting is significantly greater for those patients with low levels of venom-specific IgG antibodies.