Short-chain fatty acids induce tissue plasminogen activator in airway epithelial cells via GPR41&43

BACKGROUND

Chronic rhinosinusitis (CRS) is a heterogeneous chronic inflammatory disease generally divided based on the presence or absence of nasal polyps (NPs). One of the features of NPs is excessive fibrin deposition, which is associated with down-regulation of tissue plasminogen activator (t-PA) in NPs. As t-PA is expressed in epithelial cells, and epithelium is readily accessible to topical therapies, identifying compounds that can mediate the induction of t-PA would be a potential new strategy for the treatment of NPs.

OBJECTIVE

The objective of this study was to determine whether short-chain fatty acids (SCFAs) can induce t-PA in airway epithelial cells via their known receptors GPR41 and GPR43.

METHODS

We performed immunohistochemistry (IHC) to determine whether receptors for SCFAs, known as G protein-coupled receptor 41/free fatty acid receptor 3 (GPR41/FFAR3) and GPR43/FFAR2, are expressed in nasal tissue. Primary normal human bronchial epithelial (NHBE) cells were stimulated with different concentrations of SCFAs to test induction of t-PA, which was analysed by expression of mRNA and protein. Mediation of responses by SCFA receptors was evaluated by specific receptor gene silencing with siRNA.

RESULTS

Immunohistochemistry study revealed that airway epithelial cells expressed GPR41 and GPR43. Acetic acid, propionic acid, butyric acid and valeric acid significantly induced t-PA expression from two- to tenfolds. The strongest inducer of t-PA from NHBE cells was propionic acid; cells stimulated with propionic acid released t-PA into the supernatant in its active form. Gene silencing of GPR41 and GPR43 revealed that induction of t-PA by SCFAs was dependent upon both GPR41 and GPR43.

CONCLUSIONS AND CLINICAL RELEVANCE

Short-chain fatty acids were shown to induce airway epithelial cell expression of t-PA via GPR41 and GPR43. Topical delivery of potent compounds that activate these receptors may have value by reducing fibrin deposition and shrinking nasal polyp growth.

Chronic airway inflammation provides a unique environment for B cell activation and antibody production

BACKGROUND

B cells play many roles in health and disease. However, little is known about the mechanisms that drive B cell responses in the airways, especially in humans. Chronic rhinosinusitis (CRS) is an inflammatory disease of the upper airways that affects 10% of Europeans and Americans. A subset of CRS patients develop nasal polyps (NPs), which are characterized by type 2 inflammation, eosinophils and group 2 innate lymphoid cells (ILC2s). We have reported that NP contain elevated levels of B cells and antibodies, making NP an ideal system for studying B cells in the airways.

OBJECTIVE

We sought to determine the mechanisms that drive B cell activation and antibody production during chronic airway inflammation.

METHODS

We analysed B cells from NP or tonsil, or after ILC2 coculture, by flow cytometry. Antibody production from tissue was measured using Luminex assays and the frequency of antibody-secreting cells by ELISpot. Formation of B cell clusters was assessed using immunohistochemistry. Expression of genes associated with B cell activation and class switch recombination was measured by qRT-PCR.

RESULTS

NP contained significantly elevated frequencies of plasmablasts, especially those that expressed the extrafollicular marker Epstein-Barr virus-induced protein 2 (EBI2), but significantly fewer germinal centre (GC) B cells compared with tonsil. Antibody production and the frequency of antibody-secreting cells were significantly elevated in NP, and there was evidence for local class switch recombination in NP. Finally, ILC2s directly induced EBI2 expression on B cells in vitro.

CONCLUSIONS AND CLINICAL RELEVANCE

Our data suggest there is a unique B cell activation environment within NP that is distinct from classic GC-mediated mechanisms. We show for the first time that ILC2s directly induce EBI2 expression on B cells, indicating that ILC2s may play an important role in B cell responses. B cell-targeted therapies may provide new treatment options for CRSwNP.

Elevated presence of myeloid dendritic cells in nasal polyps of patients with chronic rhinosinusitis

BACKGROUND

Although chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by Th2 inflammation, the mechanism underlying the onset and amplification of this inflammation has not been fully elucidated. Dendritic cells (DCs) are major antigen-presenting cells, central inducers of adaptive immunity and critical regulators of many inflammatory diseases. However, the presence of DCs in CRS, especially in nasal polyps (NPs), has not been extensively studied.

OBJECTIVE

The objective of this study was to characterize DC subsets in CRS.

METHODS

We used real-time PCR to assess the expression of mRNA for markers of myeloid DCs (mDCs; CD1c), plasmacytoid DCs (pDCs; CD303) and Langerhans cells (LCs; CD1a, CD207) in uncinate tissue (UT) from controls and patients with CRS as well as in NP. We assayed the presence of DCs by immunohistochemistry and flow cytometry.

RESULTS

Compared to UT from control subjects (n = 15) and patients with CRS without NP (CRSsNP) (n = 16) and CRSwNP (n = 17), mRNAs for CD1a and CD1c were significantly elevated in NPs (n = 29). In contrast, CD207 mRNA was not elevated in NPs. Immunohistochemistry showed that CD1c(+) cells but not CD303(+) cells were significantly elevated in NPs compared to control subjects or patients with CRSsNP. Flow cytometric analysis showed that CD1a(+) cells in NPs might be a subset of mDC1s and that CD45(+) CD19(-) CD1c(+) CD11c(+) CD141(-) CD303(-) HLA-DR(+) mDC1s and CD45(+) CD19(-) CD11c(+) CD1c(-) CD141(high) HLA-DR(+) mDC2s were significantly elevated in NPs compared to UT from controls and CRSsNP, but CD45(+) CD11c(-) CD303(+) HLA-DR(+) pDCs were only elevated in NPs compared to control UT.

CONCLUSION AND CLINICAL RELEVANCE

Myeloid DCs are elevated in CRSwNP, especially in NPs. Myeloid DCs thus may indirectly contribute to the inflammation observed in CRSwNP.

Reduced expression of antimicrobial PLUNC proteins in nasal polyp tissues of patients with chronic rhinosinusitis

BACKGROUND

Chronic rhinosinusitis (CRS) is a disease characterized by inflammation of the nasal mucosa and paranasal sinuses. This inflammation may result in part from decreased epithelial barrier and innate immune responses, leading to frequent bacterial and fungal colonization. The objectives of this study were to investigate the expression of innate immune proteins of the palate lung and nasal epithelium clone (PLUNC) family in patients with CRS.

METHODS

Nasal tissue samples were collected from control subjects and CRS patients with and without nasal polyps. Expression of the members of the PLUNC family was analyzed by real-time PCR. Expression of SPLUNC1 and LPLUNC2 proteins was analyzed by ELISA, immunoblot, and immunohistochemical analysis.

RESULTS

Levels of mRNA for most of the members of the PLUNC family were profoundly reduced in nasal polyps (NPs) compared to uncinate tissue from control subjects or patients with CRS. LPLUNC2 and SPLUNC1 proteins were decreased in NPs of patients with CRS compared to uncinate tissue from control subjects. Immunohistochemical data revealed that within submucosal glands of sinonasal tissues, SPLUNC1 and LPLUNC2 were differentially expressed, in serous and mucous cells, respectively. The decrease in the expression of these molecules is probably explained by a decrease in the number of glands in NPs as revealed by correlations with levels of the glandular marker lactoferrin.

CONCLUSIONS

Decreased SPLUNC1 and LPLUNC2 in NPs reflect a profound decrease in the number of submucosal glands. Decreased glands may lead to a localized defect in the production and release of glandular innate defense molecules.

Using test dose challenges to restore essential therapy in patients with idiopathic anaphylaxis and pharmacophobia: report of a patient with idiopathic anaphylaxis and statin phobia

Idiopathic anaphylaxis (IA) is a well-documented condition in which anaphylaxis occurs in the absence of an identifiable precipitant. However, many patients with IA find it difficult to accept this diagnosis and continue to search for an external cause. It is not uncommon for these highly anxious patients to discontinue essential medications that they feel are responsible for the reaction despite reassurance from their physicians to the contrary. In extreme cases, these patients may develop an actual phobia to preexisting medications and avoid them despite adverse consequences to their health. To illustrate this concept, we report a case involving a female patient with familial hypercholesterolemia who experienced a single episode of IA and developed a "statin phobia," falsely implicating her medication (lovastatin) for the reaction. After 5 years of failed therapy with other antihyperlipidemic agents, the patient finally agreed to undergo test dosing to a similar statin agent atorvastatin. On successful completion of the test, she resumed therapy with atorvastatin and her low-density lipoprotein (LDL) levels were reduced by 50% over 5 months. We conclude that patients with a confirmed diagnosis of IA who manifest phobic responses to beneficial medications should be reassured of the diagnosis promptly by their physician. When reassurance fails and the medication is essential to the patient's health, test dose challenges may be conducted to reintroduce the drug to the patient's regimen.

Multicenter, double-blind, placebo-controlled, multiple-challenge evaluation of reported reactions to monosodium glutamate

BACKGROUND

The frequency of reactions reported to occur after the consumption of monosodium glutamate (MSG) is the subject of controversy.

OBJECTIVE

We conducted a multicenter, multiphase, double-blind, placebo-controlled study with a crossover design to evaluate reactions reportedly caused by MSG.

METHODS

In 3 of 4 protocols (A, B, and C), MSG was administered without food. A positive response was scored if the subject reported 2 or more symptoms from a list of 10 symptoms reported to occur after ingestion of MSG-containing foods within 2 hours. In protocol A 130 self-selected reportedly MSG-reactive volunteers were challenged with 5 g of MSG and with placebo on separate days (days 1 and 2). Of the 86 subjects who reacted to MSG, placebo, or both in protocol A, 69 completed protocol B to determine whether the response was consistent and dose dependent. To further examine the consistency and reproducibility of reactions to MSG, 12 of the 19 subjects who responded to 5 g of MSG but not to placebo in both protocols A and B were given, in protocol C, 2 challenges, each consisting of 5 g of MSG versus placebo.

RESULTS

Of 130 subjects in protocol A, 50 (38. 5%) responded to MSG only, 17 (13.1%) responded to placebo only (P <. 05), and 19 (14.6%) responded to both. Challenge with increasing doses of MSG in protocol B was associated with increased response rates. Only half (n = 19) of 37 subjects who reacted to 5 g of MSG but not placebo in protocol A reacted similarly in protocol B, suggesting inconsistency in the response. Two of the 19 subjects responded in both challenges to MSG but not placebo in protocol C; however, their symptoms were not reproducible in protocols A through C. These 2 subjects were challenged in protocol D 3 times with placebo and 3 times with 5 g of MSG in the presence of food. Both responded to only one of the MSG challenges in protocol D.

CONCLUSION

The results suggest that large doses of MSG given without food may elicit more symptoms than a placebo in individuals who believe that they react adversely to MSG. However, neither persistent nor serious effects from MSG ingestion are observed, and the responses were not consistent on retesting.

Lymphocyte subsets and activation markers in patients with acute episodes of idiopathic anaphylaxis

BACKGROUND

Idiopathic anaphylaxis (IA), a type of anaphylaxis in which no external allergen can be identified, is a corticosteroid-responsive disease, that suggests that it may have an immunologic pathogenesis.

OBJECTIVE

The objective of this study is to compare patients with acute episodes of IA with normals, patients with chronic idiopathic urticaria, and patients with IA in remission relative to lymphocyte subsets and activation markers.

METHODS

This is a prospective cohort study of 38 adults: 5 normals, 4 idiopathic urticaria, 11 IA patients in remission, 9 IA patients with acute attacks who had not yet received prednisone, and 9 IA patients who had received prednisone. The main outcome measures were lymphocyte subset and activation markers determined by two and three color flow cytometry (CD2, CD3, CD4, CD5, CD8, CD16, CD19, CD23, CD25, CD56, and HLA-DR).

RESULTS

Comparing patients with acute IA with those in remission, the only significant difference was that the acute IA patients had a significantly higher percentage of CD3+HLA-DR+ cells. Normals had a significantly lower percentage of CD3+ HLA-DR+ cells than all other groups. Patients with acute IA on prednisone as well as IA patients in remission had a significantly higher percentage of CD 19+ CD23+ cells than normals.

CONCLUSIONS

These results suggest that there are more activated T cells in patients with acute episodes of IA than in patients in remission. Perhaps, these activated T cells have a role in the pathogenesis of IA.

Idiopathic anaphylaxis: variants as diagnostic and therapeutic problems

Idiopathic anaphylaxis presents a problem requiring rapid diagnosis and initiation of therapy. Some cases are complex and difficult to assess. We present four cases of unusual complexity to illustrate diagnostic and therapeutic problems. Two cases were found not to be idiopathic anaphylaxis, one being undifferentiated somatoform idiopathic anaphylaxis and the other very severe urticaria. Various conditions can be or mimic idiopathic anaphylaxis, and patience and observation can result in reasonable outcomes.

Review of alleged reaction to monosodium glutamate and outcome of a multicenter double-blind placebo-controlled study

Monosodium glutamate (MSG) has a long history of use in foods as a flavor enhancer. In the United States, the Food and Drug Administration has classified MSG as generally recognized as safe (GRAS). Nevertheless, there is an ongoing debate exists concerning whether MSG causes any of the alleged reactions. A complex of symptoms after ingestion of a Chinese meal was first described in 1968. MSG was suggested to trigger these symptoms, which were referred to collectively as Chinese Restaurant Syndrome. Numerous reports, most of them anecdotal, were published after the original observation. Since then, clinical studies have been performed by many groups, with varying degrees of rigor in experimental design ranging from uncontrolled open challenges to double-blind, placebo controlled (DBPC) studies. Challenges in subjects who reported adverse reactions to MSG have included relatively few subjects and have failed to show significant reactions to MSG. Results of surveys and of clinical challenges with MSG in the general population reveal no evidence of untoward effects. We recently conducted a multicenter DBPC challenge study in 130 subjects (the largest to date) to analyze the response of subjects who report symptoms from ingesting MSG. The results suggest that large doses of MSG given without food may elicit more symptoms than a placebo in individuals who believe that they react adversely to MSG. However, the frequency of the responses was low and the responses reported were inconsistent and were not reproducible. The responses were not observed when MSG was given with food.

Hypersensitivity pneumonitis resulting from community exposure to Canada goose droppings: when an external environmental antigen becomes an indoor environmental antigen

BACKGROUND

In the past, hypersensitivity pneumonitis has been attributed to occupational, agricultural, or home environmental exposure.

OBJECTIVE

This report describes the first case of hypersensitivity pneumonitis due to community exposure to droppings from Canada geese migrating through a suburban environment.

METHOD

Clinical and serologic information was used in making the diagnosis of hypersensitivity pneumonitis.

RESULTS

Serologic analysis demonstrated precipitating antibodies against goose droppings and against an extract made from washings from a filter taken from the patient's office. These studies also showed that the antigens in the office filter were goose dropping antigens.

CONCLUSION

Hypersensitivity pneumonitis can result from exposure to goose dropping antigens in the community that enter buildings through ventilation systems. This represents a new form of an old disease.

Combination therapy with tirofiban and enoxaparin in acute coronary syndromes

BACKGROUND

Tirofiban, an intravenous glycoprotein IIb/IIIa antagonist, and enoxaparin, a low molecular weight heparin, have each been shown to be effective at reducing cardiac ischemic events compared to unfractionated heparin alone in separate trials of patients with unstable angina and non-Q-wave myocardial infarction. The combination of these agents may offer further therapeutic benefit.

MATERIALS AND METHODS

Fifty-five patients with non-Q-wave myocardial infarction were randomized to receive double-blind treatment with tirofiban (0.1 microgram/kg/min i.v.) for 48-108 h coadministered with either enoxaparin (1 mg/kg sc q 12 h) (n=26) or unfractionated heparin (i.v. adjusted to activated partial-thromboplastin time) (n=27) to evaluate pharmacokinetics, pharmacodynamics, and safety. The primary objective of the study was to investigate the effect of unfractionated heparin versus enoxaparin on the plasma clearance of tirofiban.

RESULTS

Coadministration of tirofiban and enoxaparin was generally well tolerated. Plasma clearance of tirofiban was 176.7+/-59.8 and 187.5+/-81.8 ml/min, respectively, for enoxaparin and unfractionated heparin-treated patients (P=NS). The mean difference was well within the prespecified criterion for comparability. Administration of tirofiban with enoxaparin vs. unfractionated heparin resulted in lesser variability and a trend towards greater inhibition of platelet aggregation using 5 microM adenosine phosphate agonist. More patients achieved target inhibition of platelet aggregation >70% in the tirofiban and enoxaparin group (84% vs. 65%, P=0.19). Median bleeding time was 21 min for tirofiban and enoxaparin vs. > or =30 min for tirofiban and unfractionated heparin (P=NS). For a given level of inhibition of platelet aggregation, bleeding time was less prolonged with tirofiban and enoxaparin than tirofiban and unfractionated heparin (adjusted mean bleeding time 19.6 vs. 24.9 min, P=0.02). Tirofiban plasma concentration and clearance were comparable whether coadministered with enoxaparin or unfractionated heparin. There were no major or minor bleeding events in either group by the TIMI criteria.

INTERPRETATION

The more consistent inhibition of platelet aggregation and lower adjusted bleeding time of tirofiban and enoxaparin vs. tirofiban and unfractionated heparin support the therapeutic potential of combining these two agents. These data from the first clinical report of coadministration of a glycoprotein IIb/IIIa receptor antagonist and a low molecular weight heparin are consistent with prior data which show differential pharmacodynamic effects of enoxaparin and unfractionated heparin on platelet aggregation.

Idiopathic anaphylaxis

Anaphylaxis is an acute, life threatening event that can progress extremely rapidly. External allergens as causations have been identified over the last century. The most recently identified type of anaphylaxis is not caused by any external allergen and has been termed Idiopathic Anaphylaxis (IA). Two major types are Generalized or Angioedema with airway obstruction. IA is also classified by frequency of episodes and response to therapy. Therapy consists of acute emergency therapy and induction of remissions using prednisone, beta agonists, and H1 blockers. Control and remission are usually induced. IA occurs at all ages, and pediatric and geriatric IA are often special problems, as is a psychogenic form where no true reactions occur. Although appropriate management of IA, in general, has a good prognosis, several problems exist. Among these are failure to accept IA as an entity or in an individual case by physicians and patients. A different problem occurs when the recommended treatment is used and there is control of IA, but only with persisting high doses of prednisone. This is corticosteroid dependent IA. The lack of defined mechanisms that will lead to improved therapies and wider acceptance of IA as an entity remains a major problem. Undifferentiated Somatoform IA is a serious management problem for physicians.

Rush immunotherapy in a dog with severe ragweed and grass pollen allergy

BACKGROUND

Forty years of study of naturally occurring IgE-mediated allergy in animals is briefly reviewed. These studies provided models for study of bioactive mediators and innovative pharmacologic therapies for IgE-mediated asthma.

OBJECTIVE

Based on our experience with canine allergy we evaluated and treated a dog with severe grass and ragweed allergy whose allergic dermatitis was uncontrolled by H1 blockers and topical corticosteroids. The dog was miserable during the Chicago grass and ragweed pollen seasons.

METHODS

Rush immunotherapy was initiated during the ragweed season of 1997.

RESULTS

Dramatic improvement was seen which persisted through the grass and ragweed seasons of 1998 after maintenance immunotherapy.

CONCLUSION

The case is presented not as a model for canine immunotherapy but as an example of how animal research can be of value to both animals and humans.

Changing patterns in academic allergy-immunology

In evaluation of the current Allergy-Immunology (AI) Program of the Department of Medicine at Northwestern University Medical School and in planning for the future, it appeared that our assessment of changes in the AI program since its inception might be of value to other AI academic programs. Further, we might receive suggestions from other academic AI programs, and we request such advice.

Concurrent administration of inactivated hepatitis A vaccine with immune globulin in healthy adults

301 healthy adult volunteers were randomized to one of three treatment groups: inactivated hepatitis A vaccine alone; inactivated hepatitis A vaccine with immune globulin (Ig) concurrently; or Ig alone. The first two treatment groups received a second dose of hepatitis A vaccine at week 24. Anti-HAV was measured 4, 8, 12, 24 and 28 weeks after the primary immunization. When comparing subjects receiving inactivated hepatitis A vaccine alone to those receiving vaccine and Ig, the seropositivity rates were not significantly different at 4, 8, 12 and 28 weeks, but at week 24 the seropositivity rate was lower in the group receiving both vaccine and Ig compared to the group receiving vaccine alone (92.0% compared to 97.0%). At weeks 8, 12 and 24 the geometric mean titers (GMTs) were significantly lower for subjects receiving both vaccine and Ig. The GMTs were not significantly different after the second dose of vaccine. At all time points, the lower serum antibody concentrations observed in subjects receiving both inactivated hepatitis A vaccine and Ig were nevertheless substantially higher than the cutoff for assay seropositivity and much higher than after Ig alone; these differences are therefore clinically insignificant.

Immunoglobulin E antibody against environmental allergens in subjects with trimellitic anhydride-induced asthma

The purpose of this study was to assess the relationship between atopy and the development of occupational asthma as a consequence of exposure to trimellitic anhydride (TMA). A case-control study was performed, which comprised 16 employees identified as having TMA-induced asthma and 44 similarly exposed controls. Specific immunoglobulin E measurements in response to cat, dust mite, ryegrass, and ragweed antigens were performed. Fifty-six percent of cases and 29% of controls were found to be atopic (P = 0.098). We demonstrated that there was a trend toward employees with TMA asthma being more atopic than those without TMA asthma. Atopy as an assessment of risk for the development of TMA asthma is unlikely to be useful, although further investigation may be warranted.

Potential effect of the administration of substance P and allergen therapy on immunoglobulin E-mediated allergic reactions in human subjects

Previously we observed and reported that immunoglobulin E-mediated (IgE-mediated) allergy in rhesus monkeys was decreased by the administration of substance P (SP) and an allergen. We extended these studies to human subjects, giving SP and 1 allergen to subjects with reactivity to more than 1 allergen, using reactivity to a second allergen as a control. SP and an allergen were initially given by aerosol delivery but subsequently were given by injection. The administration of SP and 1 allergen by aerosol delivery or injection resulted in decreased IgE-mediated reactivity to the allergen administered and also to the control allergen. This result occurred in 7 of 8 human subjects. The 2 initial subjects receiving 8 SP and allergen injections had a sharp reduction in their symptoms of ragweed hay fever lasting for 3 years to date. No significant reactions to the injection of SP occurred. Further controlled human research is necessary on the administration of SP and allergen and the mechanisms of action. Unexpected and serendipitous results first observed in rhesus monkeys and reproduced in allergic human subjects provide a new and potential mechanism for control and perhaps obliteration of common IgE-mediated allergies and even more-serious allergic problems.

Hypersensitivity pneumonitis due to humidifier disease: seek and ye shall find

STUDY OBJECTIVES

This study reports a classic case of hypersensitivity pneumonitis (HP) with classic histologic changes in lung tissue and the research used to identify the causative antigens.

DESIGN

A patient with clinical, radiographic, pulmonary function abnormalities and a lung biopsy consistent with HP had no identifiable antigen exposure.

SETTING

Evaluation of the patient's activities provided no suggestion of antigen exposure. Her home was evaluated. It was found that her humidifier ran continually without being cleaned but water was added periodically.

MEASUREMENTS

Serologic analysis demonstrated precipitating antibodies against her humidifier water and ten antigens in the hypersensitivity lung disease serologic panel.

CONCLUSION

Removal of the humidifier, cleaning of the house, and a course of prednisone resulted in the return of the patient to a normal state.

Six-month angiographic and clinical follow-up of patients prospectively randomized to receive either tirofiban or placebo during angioplasty in the RESTORE trial. Randomized Efficacy Study of Tirofiban for Outcomes and Restenosis

OBJECTIVES

This study sought to investigate the effects of tirofiban versus placebo on the incidence of adverse cardiac outcomes and coronary artery restenosis at 6 months.

BACKGROUND

Tirofiban is a highly selective, short-acting inhibitor of fibrinogen binding to platelet glycoprotein IIb/IIIa. In a recent clinical study, tirofiban reduced the incidence of adverse cardiovascular events at both 2 and 7 days after coronary angioplasty or directional coronary atherectomy. This reduction persisted but was no longer statistically significant at 30 days.

METHODS

The Randomized Efficacy Study of Tirofiban for Outcomes and Restenosis (RESTORE) trial was a randomized, double-blind, placebo-controlled trial of tirofiban in patients undergoing balloon angioplasty or directional atherectomy within 72 h of presentation with either unstable angina pectoris or acute myocardial infarction. All patients received an initial bolus (10 microg/kg body weight over 3 min), followed by a 36-h infusion (0.15 microg/kg per min) of either tirofiban or placebo.

RESULTS

At 6 months the composite end point (either death from any cause, new myocardial infarction, bypass surgery for angioplasty failure or recurrent ischemia, repeat target vessel angioplasty or stent insertion for actual or threatened abrupt closure) occurred in 1,070 placebo group patients (27.1%) and 1,071 tirofiban group patients (24.1%, p = 0.11). Analysis of 6-month coronary arteriograms by means of quantitative coronary arteriography showed no significant difference between placebo- and tirofiban-treated patients in either the incidence of a > or =50% diameter stenosis (57% vs. 51%, p = NS), a loss of > or =50% of lumen diameter gained (50% vs. 50%, p = NS) or a loss of > or =0.72 mm of lumen diameter (44% vs. 42%, p = NS).

CONCLUSIONS

The 3% absolute reduction in the incidence of the composite end point at 6 months (27.1% placebo vs. 24.1% tirofiban) was similar to that previously reported at 2 days (8.7% vs. 5.4%, p < 0.005), and there does not appear to be any late effect of tirofiban on clinical end points between day 2 and 6 months. Tirofiban did not reduce the incidence of restenosis at 6 months when defined in a number of ways.

Malignant and corticosteroid-dependent idiopathic anaphylaxis: successful responses to ketotifen

BACKGROUND

Malignant idiopathic anaphylaxis refers to the most severe form of idiopathic anaphylaxis where defined episodes of idiopathic anaphylaxis are not controlled when the prednisone is reduced below at least 60 mg every other day or 20 mg daily. Corticosteroid-dependent idiopathic anaphylaxis refers to patients with idiopathic anaphylaxis who require continuous daily or alternate day prednisone at threshold doses for control of idiopathic anaphylaxis. Ketotifen has been reported to help induce remission in some patients with idiopathic anaphylaxis and has steroid sparing effects in other patients with idiopathic anaphylaxis.

METHODS

We present five patients, two with malignant idiopathic anaphylaxis and three with corticosteroid-dependent idiopathic anaphylaxis, who responded to the administration of ketotifen.

RESULTS

All five patients, while receiving ketotifen, had a reduction or resolution of their episodes of idiopathic anaphylaxis and prednisone was tapered and discontinued.

CONCLUSION

Ketotifen is shown to be successful in inducing remission in two patients with malignant idiopathic anaphylaxis and in three additional patients with corticosteroid-dependent idiopathic anaphylaxis. An additional patient with malignant idiopathic anaphylaxis had prednisone stopped after elective hip surgery.

A bradykinin antagonist inhibits both bradykinin- and the allergen-induced airway response in primates

Bradykinin is a mediator of bronchoconstriction and may play a role in the development of the asthmatic response after antigen challenge. Our objective was to study the effectiveness of NPC 17731 as a specific bradykinin beta 2-receptor antagonist and as an antagonist of the allergen-induced early phase of asthma. A primate model was used for all studies. Intracutaneous end-point titrations were performed with bradykinin. A shift of the bradykinin end-point titer was seen when NPC 17731 was injected by the intradermal route prior to performing the end-point titration. Using an aerosolized bradykinin or Ascaris suum antigen airway threshold challenge system, inhibition of the bradykinin or Ascaris airway response was evaluated after pretreatment with aerosolized NPC 17731. NPC 17731 proved to be a safe, effective specific bradykinin receptor antagonist in both cutaneous and airway challenges. NPC 17731 was able to inhibit the antigen-induced airway response in the primate. Bradykinin may play a larger role in mediating the early phase of the antigen-induced asthmatic response than previously was appreciated.

Idiopathic anaphylaxis: a series of 335 cases

BACKGROUND

Idiopathic anaphylaxis is anaphylaxis with no definable etiology and no trigger by exogenous allergens. Initially described in 1978, idiopathic anaphylaxis has been subsequently characterized and treatment protocols have been established.

OBJECTIVE

The demographics and course of 335 patients (225 previously reported) treated with prednisone, hydroxyzine, and albuterol are now reported.

RESULTS

Ages ranged from 5 to 83 years. There were nine new pediatric patients in this series totaling 14 (4.2%). Atopy was common (48%) with 34 new patients with asthma. The duration of symptoms prior to presentation ranged from three days to 27 years. One hundred thirty-two patients with idiopathic anaphylaxis were available for follow-up. Twenty of these are currently receiving prednisone for control of idiopathic anaphylaxis, seven of them as part of their initial therapy, and ten for control of recurrence of symptoms. Three patients required continuous alternate day prednisone for control of symptoms (corticosteroid-dependent idiopathic anaphylaxis). Of the 335 patients, there were no longer any patients with the diagnosis of malignant idiopathic anaphylaxis defined as requiring prednisone, 20 mg daily, or 60 mg every other day, for control of idiopathic anaphylaxis. Of the six patients previously diagnosed with malignant idiopathic anaphylaxis, five no longer required prednisone and one has a decreased prednisone requirement of 20 mg on alternate days. Hospital visits were significantly reduced by the management regimens. There were no fatalities from idiopathic anaphylaxis in this series.

CONCLUSIONS

The incidence of idiopathic anaphylaxis is increasing in our practice with more patients being evaluated each year. During 1104 patient years of observation (the longest period of single patient observation being 24 years), no inciting agent has been found responsible for the anaphylactic symptoms. Prognosis continues to remain good with the majority of patients achieving remission with pharmacotherapy.

Idiopathic anaphylaxis: long-term follow-up, cost, and outlook

To determine the efficacy of oral corticosteroids, antihistamines, and sympathomimetics in treating patients with idiopathic anaphylaxis, the charts of 225 patients diagnosed with idiopathic anaphylaxis from 1971 to 1990 treated at a single center were reviewed. Sixty-one patients (34 females and 27 males) were available for long-term follow-up. Ages ranged from 10 to 68 years with an average of 39 years. Patients with frequent episodes were treated with a protocol of oral corticosteroids, antihistamines, and sympathomimetics. Patients with infrequent episodes were treated for acute episodes only. The number of emergency room visits, hospitalizations, intensive care unit admissions, and length of time in remission were recorded. Sixty-five percent of patients with infrequent episodes and 91% of patients with frequent episodes of idiopathic anaphylaxis went into remission. Significant decreases in emergency room visits occurred for the idiopathic anaphylaxis-generalized-frequent group (P < 0.016), the idiopathic-anaphylaxis-generalized-infrequent group (P < 0.0001), and the idiopathic anaphylaxis-angioedema-infrequent group (P < 0.039). Significant decreases in the number of hospitalizations (P < 0.022) and intensive care unit admissions (P < 0.009) occurred for the idiopathic anaphylaxis-generalized-infrequent and frequent groups, respectively. Overall, an estimated $184 740 was saved with the treatment program, for 546 patient-years. Idiopathic anaphylaxis can be controlled and remission induced in most patients. An estimated $11 million per year can be saved for patients in the USA on the basis of the estimated prevalence in this country.

Total serum IgE in trimellitic anhydride-induced asthma

The objective of this study was to determine whether total serum IgE levels are elevated in workers with trimellitic anhydride-induced asthma as compared with anhydride-exposed workers without an occupational immunologic syndrome. Sera from 12 highly exposed workers with trimellitic anhydride-induced asthma, and from 31 similarly exposed workers without occupational immunologic disease, were assayed for total immunoglobulin E (IgE) levels by Total IgE II FAST analysis. The mean total IgE levels were 176.74 ng/mL and 34.55 ng/mL respectively. The difference between the two groups was statistically significant, but considerable overlap of IgE levels between groups was seen. In conclusion, although mean total IgE levels are significantly different between TMA-exposed workers with or without occupational asthma, the significant amount of overlap and poor sensitivity of the test preclude the use of this assay in the individual evaluation of these workers.

Undifferentiated somatoform idiopathic anaphylaxis: nonorganic symptoms mimicking idiopathic anaphylaxis

BACKGROUND

Northwestern University's Division of Allergy and Immunology has had experience with the diagnosis and treatment of more than 350 patients with idiopathic anaphylaxis (IA). In 1992 we reported a group of patients with IA whose presentations mimicked IA, but IA and other organic causes were later excluded. Psychologic factors were suspected as the underlying problem. These patients were classified as IA-variant. Management of these cases was extremely difficult. There was significant morbidity and high and unnecessary costs.

OBJECTIVE

We aim to distinguish the nature of this disease and to highlight the evaluation and treatment of this group of patients.

METHODS

Their cases are reviewed and reported.

RESULTS

Common features included (1) presenting symptoms mimicking IA, (2) no objective findings that correlated with 1, (3) no response to the therapeutic regimen for IA, (4) meeting the Diagnostic and Statistical Manual of Mental Disorders criteria for undifferentiated somatoform disorder, and (5) significant wasted health care expenditure.

CONCLUSIONS

This group of patients were better defined as having undifferentiated somatoform-IA. An algorithm was proposed to expedite the diagnosis of the disease so that with early recognition of the disease, unwarranted repetitive consultations, tests, and inappropriate therapy can be avoided.

Fatal and near fatal idiopathic anaphylaxis

OBJECTIVE

To document that idiopathic anaphylaxis may have a fatal or near fatal outcome.

DESIGN

Review of selected cases seen personally by authors during the past 16 years.

SETTING

University faculty practice and private practices.

PATIENTS

All cases of idiopathic anaphylaxis seen by the authors are not presented, but 10 cases were selected to demonstrate two fatalities and eight cases of near fatalities.

RESULTS

Two fatal cases had expired before emergency service therapy. Eight near fatal cases responded to acute therapy and subsequently were controlled. Remission of idiopathic anaphylaxis was then induced. Idiopathic anaphylaxis may be fatal or potentially fatal and must be treated to prevent a fatal outcome.

CONCLUSIONS

The documentation of fatalities and near fatalities should help patients and their physicians accept intense management of idiopathic anaphylaxis that will result in control and induction of a remission in idiopathic anaphylaxis.

Idiopathic anaphylaxis. An attempt to estimate the incidence in the United States

BACKGROUND

Idiopathic anaphylaxis has been described and classified, and increasing numbers of cases are being seen in the United States and abroad. Treatment regimens have been shown to be effective in prophylactic management. There is no available information about the number of cases in the United States.

METHODS

We attempted to determine the number of cases of idiopathic anaphylaxis in the United States by mailing a questionnaire to all graduates (for the last 31 years) of the Northwestern University Allergy-Immunology Fellowship training program.

RESULTS

Response to the questionnaire was 100%, and 633 cases were reported by this survey of 75 allergists. The current total number of identified cases of idiopathic anaphylaxis from all reports of cases in the United States is 1020.

CONCLUSIONS

By extrapolation of the cases of idiopathic anaphylaxis reported by the allergists surveyed to the approximately 4000 allergists in the United States, the estimated number of cases in the United States is between 20,592 and 47,024. Idiopathic anaphylaxis is potentially fatal, represents a source of major medical health care costs, causes anxiety to patients and families, occurs in pediatric and adult populations, and is controlled by appropriate regimens. The estimated number of cases emphasizes the need for careful attention to idiopathic anaphylaxis by physicians.

Evolution of patient care, education, and research in asthma by one academic team of investigators over 35 years: the Northwestern University Medical School Division of Allergy-Immunology experience (Part Two)

This report reviews approximately 35 years of patient care, teaching, and research an asthma in one academic unit at Northwestern University Medical School. Historical perspectives are summarized on the delivery of care for asthma, therapeutic regimens for asthma we believed in (and were wrong), and diagnosis and management in the last decade of this century. Particular problems, such as potentially fatal asthma and assessment and management of such problems, are discussed. Finally, certain aspects of our basic research programs and their relevance to asthma are briefly reviewed. Part One of this article appeared in the May-June issue of this journal.

A naturally occurring model of immunoglobulin E antibody-mediated hypersensitivity in laboratory animals

A naturally occurring model of immunoglobulin E (IgE) antibody-mediated hypersensitivity in canine and rhesus monkey species to environmental allergens is described. Cutaneous responses to a dust mite mix (Dermatophagoides farinae/pteronyssinus) and to four storage mite extracts (Aleuroglyphus ovatus, Blomia tropicalis, Chortoglyphus sp., Lepidoglyphus destructor) occurred in the canine species. Rhesus monkeys had IgE antibody-mediated hypersensitivity to dust mite on cutaneous challenge, but to a lesser degree than the canine species. Biologic relevance was verified by eliciting positive airway challenges in both species. The IgE antibody-mediated basis of these responses was confirmed by passive transfer technique. Demonstration of dust mite allergy provides a naturally occurring model of IgE antibody-mediated hypersensitivity in the canine and rhesus monkey species. Storage mite IgE antibody-mediated hypersensitivity exists in the canine species.

Immunologic cross-reactivity of acid anhydrides with immunoglobulin E against trimellityl-human serum albumin

The purpose of this study was to determine whether workers sensitized by one acid anhydride, trimellitic anhydride (TMA), would possibly react immunologically to two other acid anhydrides, phthalic anhydride (PA) or maleic anhydride (MA). We studied serum samples from four workers with TMA asthma and immunoglobin E (IgE) against TMA conjugated to human serum albumin (TM-HSA). In enzyme-linked immunosorbent assay (ELISA) cross-inhibition studies, TM-HSA inhibited IgE binding to TM-HSA, but when 100 times more P-HSA or M-HSA was used, no significant inhibition occurred. However, in ELISA studies of P-HSA and M-HSA, we saw binding of specific serum IgE. Finally, in passive transfer studies in rhesus monkeys with serum from an individual with antibodies to all three acid anhydrides, the following titers were obtained: TM-HSA (1:32), P-HSA (1:8), M-HSA (negative). We conclude that cross-inhibition studies may not be the best method for determining whether an individual sensitized to one antigen will react to a related antigen. The determination of biologic reactivity in a rhesus monkey model of passive cutaneous transfer makes it likely that biologic reactivity would also occur in a human sensitized to TMA and then exposed to another anhydride such as PA.

Evolution of patient care, education, and research in asthma by one academic team of investigators over 35 years. The Northwestern University Medical School Division of Allergy-Immunology Experience: Part One

This report reviews approximately 35 years of patient care, teaching, and research on asthma in one academic unit at Northwestern University Medical School. Historical perspectives are summarized on the delivery of care for asthma, therapeutic regimens for asthma we believed in (and were wrong), and diagnosis and management in the last decade of this century. Particular problems, such as potentially fatal asthma and assessment and management of such problems, are discussed. Finally, certain aspects of our basic research programs and their relevance to asthma are briefly reviewed. An outline of contents is shown in Table I.

Passive transfer of IgE-mediated cutaneous reactivity in heterologous species

The transfer of cutaneous hypersensitivity was performed in humans, monkeys, and dogs, using the Prausnitz-Küstner (PK) reaction. Quantitative endpoint titrations were used to study reactions resulting from sera from allergic humans, monkeys, and canines. IgE antibody from dogs sensitized human and rhesus monkey skin. IgE antibody from humans and rhesus monkeys did not sensitize canine skin. The Fc receptors on primate mast cells must have broader stoichiometric adaptation for IgE Fc receptors than the analogous Fc receptors on canine mast cells.

Algorithms for the diagnosis and management of idiopathic anaphylaxis

A major approach to the prevention of anaphylaxis due to exposure to an allergen is avoidance of the allergens. In cases of idiopathic anaphylaxis (IA), the method of management must first be pharmacologic control of the acute episode of IA and then the prevention of recurrent episodes. The appropriate management requires diagnosis, classification, and immediate initiation of a treatment regimen that will control and then induce a remission in patients with IA of the frequent (F) type. The classification and management of IA are reviewed and algorithms are presented for initial and long-term management of patients with IA.

Evaluation of a worker with possible formaldehyde-induced asthma

BACKGROUND

We describe the evaluation of a worker with clinical symptoms compatible with bronchospasm caused by formaldehyde exposure.

METHODS

The worker was evaluated by means of enzyme-linked immunosorbent assay, cutaneous tests, and methacholine and formaldehyde inhalation challenges. The worker's serum was injected intradermally into the skin of a normal rhesus monkey to determine whether hypersensitivity could be transferred from human to primate.

RESULTS

An enzyme-linked immunosorbent assay showed that the worker had positive IgE and IgG titers to formaldehyde-human serum albumin. The worker had a positive cutaneous test for formaldehyde-human serum albumin, and this cutaneous reactivity was transferred to a rhesus monkey through the worker's serum. The worker had a negative methacholine challenge at 25 mg/ml and negative formaldehyde inhalation challenges at 0.3, 1, 3, and 5 ppm for 20 minutes. It is possible that the worker would have had a positive result if a higher concentration of F were used for the challenge, but it is more probable that the worker's symptoms were not caused by immunologically mediated asthma. We have studied individuals exposed to formaldehyde, their clinical syndromes, and serologic results for a decade. This worker is the one subject with the most compatible history and immunology, but the worker had a negative challenge.

CONCLUSION

Immunologically mediated asthma caused by formaldehyde is extremely rare, if it exists at all.

Substance P and IgE-mediated allergy. II. Reduction of rhesus IgE antibody after aerosol exposure to substance P and allergen

Experiments were designed to evaluate the effect of aerosolized Substance P (SP) and ascaris antigen (A) on airway responses of rhesus monkeys that had IgE antibody against A. During the course of these experiments, a totally unplanned and unexpected observation was made: this was a decline in IgE antibody, as determined by quantitative end-point dilution titers, in the group of animals that had received aerosolized SP and A. Our experience with this species of primate over 2 decades had shown that IgE-mediated cutaneous reactivity persists in the monkeys (as in man) for years with little change. The decline in IgE antibody titers in monkeys occurred over a few weeks to months, was related to the aerosol exposure to SP and A, and has persisted with minimal to moderate rise in IgE antibody. Although these results had to be analyzed retrospectively, the changes were significant by statistical analysis. This serendipitous observation suggests a possible means of reducing IgE antibodies therapeutically in primates. A theory of why primates may develop IgE antibody to antigens absorbed through mucosal surfaces is proposed.

Substance P and IgE-mediated allergy. I. Transient increase in airway responsiveness to allergen in primates

Studies of IgE-mediated asthma in rhesus monkeys have shown that the animals have individual characteristics analogous to the individuality of human asthmatic patients. In the current study we evaluated the effect of aerosolized substance P (SP) and an allergen, ascaris antigen (A), on monkeys that had cutaneous and/or airway reactivity to A. When SP and A were aerosolized sequentially in the same experiment in two monkeys that had had IgE-mediated airway responses that had disappeared with time and in one monkey that had only had cutaneous reactivity to A, an airway response to A occurred. Furthermore, on subsequent challenges, the airway response persisted in the absence of SP exposure. In two other monkeys, SP and A given sequentially in the same experiment induced airway responses to A using a concentration of A that was too dilute to give a reaction in either monkey in previous experiments. The airway response to dilute A then persisted for months in the absence of further SP exposure. We conclude that bronchial challenge of SP in combination with allergen induces an immediate response that would not occur with allergen alone and that this heightened airway response to allergen persists for months as a result of interaction of the neurokinin SP and an IgE-mediated immunologic reaction in the airway.

Emergency medical recognition and management of idiopathic anaphylaxis

Idiopathic anaphylaxis (IA) is a diagnosis of exclusion that is made when no identifiable causative factors can be found for an episode of anaphylaxis. IA is a potentially life-threatening disease that is the result of a nonimmunologic mast cell activation syndrome. Acute presentation and treatment of these patients is most often in the emergency department and is clinically the same as anaphylaxis from allergens. Since these episodes are unpredictable and often recurrent, these patients are at risk of death if not identified on acute presentation and managed appropriately. As an increasing number of patients are being diagnosed with IA, they will be presenting to emergency departments with initial and recurrent episodes of IA. Therefore, increased awareness of IA and coordinated care is needed so that the morbidity and mortality of this potentially fatal disease can be kept at a minimum.

Malignant idiopathic anaphylaxis: three additional cases and extended evaluation

Northwestern University's Division of Allergy and Immunology (NUAI) has evaluated and treated 225 patients with idiopathic anaphylaxis (IA) over a period of 16 years. Four patients have been identified with malignant IA. The term "malignant" is used to identify those patients with the most severe form of IA that is resistant to standard therapy. The diagnosis of malignant IA is made in patients with IA whose controlling oral corticosteroid dose was not able to be reduced below 60 mg of prednisone (or its equivalent) every other day or 20 mg of prednisone (or its equivalent) every day without an exacerbation of IA. Presented here is the long-term evaluation of one patient as well as three additional patients with malignant IA managed by our service. At the time of this report we have had no deaths due to IA in patients treated with pharmacologic regimen.

A cross-sectional survey of 46 employees exposed to trimellitic anhydride

This is a report of 46 employees exposed to trimellitic anhydride (TMA). The evaluation consisted primarily of periodic serum antibody studies and a questionnaire that identified symptoms compatible with allergic asthma and/or rhinitis, late respiratory systemic syndrome (LRSS), or pulmonary disease anemia (PDA) syndrome. Industrial hygiene data from the plant in 1989 reported exposures that were lower than levels in 1979. Seven employees had positive IgE antibody against trimellityl-human serum albumin (TM-HSA); one had TMA rhinitis, and another possibly had TMA asthma/rhinitis. Fourteen employees had positive IgG antibody against TM-HSA of whom only three had titers high enough to cause disease, and none of them had symptoms compatible with LRSS or PDA. At most, two workers had asthma or rhinitis during the 1990 evaluation. In summary, in this employee population with low level TMA exposure there is a low incidence of immunologically mediated disease due to TMA.

IgE-mediated rhesus monkey asthma: natural history and individual animal variation

This report reviews the 20 years of experience with naturally occurring allergy in dogs and allergic rhesus monkeys. The primate model of allergy is characterized by IgE-mediated cutaneous and respiratory responses to Ascaris antigen. Individual assessments of these monkeys have been carried out over several years and separate populations which are analogous to human IgE-mediated allergic populations defined. These populations are as follows: (1) monkeys which have persistent and consistent IgE-mediated cutaneous and asthmatic responses to Ascaris antigen; (2) monkeys which have cutaneous and airway reactivity to Ascaris antigen but in which the airway reactivity subsides and disappears analogous to a spontaneous remission human asthma, and (3) finally, there is a group of animals with cutaneous reactivity but no asthma analogous to humans with a similar absence of asthma. Within these groups the animals, like humans, have individual variations of severity.