Loren W. Hunt

An epidemic of occupational allergy to latex involving health care workers.

IgE-mediated sensitivity to natural rubber latex is being recognized more frequently among health care workers. Between January 1990 and June 1993, we evaluated 342 consecutive Mayo Medical Center employees who reported symptoms suggestive of latex allergy. All were interviewed and underwent puncture skin testing with extracts of rubber gloves. In some cases, latex-specific IgE antibodies were measured by immunoassay. One hundred four of the 342 employees evaluated (30%) were latex-allergic. Risk factors for sensitization included frequent use of disposable gloves, presence of prior a topic disease, and prior or current hand dermatitis. The peak onset of symptoms occurred in late 1989 and early 1990 and did not correlate with a peak in glove usage at our medical center, which continued to rise. Most sensitized employees (78%) reported contact urticaria from rubber gloves, and over two thirds also experienced allergic rhinitis, conjunctivitis, or asthma when working in areas where large numbers of gloves were being used. Sixteen episodes of rubber-induced anaphylaxis were documented in 12 employees; six episodes occurred after latex skin testing and were easily reversed with appropriate therapy. Our findings substantiate a local epidemic of latex allergy among medical center employees. Epidemiologic studies are needed to assess the effects of various interventions to reduce occupational exposure to latex allergens. Although prick skin testing with concentrated latex glove extracts presents some risk of systemic reaction, pending availability of commercial diagnostic extracts, such testing is generally safe when performed by skilled laboratory personnel. Skin testing is warranted to investigate health care workers suspected of being latex-sensitive.

Allergic Reactions to Latex Among Health-Care Workers

With the emergence of the acquired immunodeficiency syndrome (AIDS) epidemic and the practice of protecting health-care workers from all body fluids, the use of rubber gloves has increased, as has occupational allergy to latex among health-care workers. During 1991, 49 Mayo Medical Center employees sought assessment and treatment of rhinitis, conjunctivitis, contact urticaria, contact dermatitis, asthma, or eczema thought to be related to exposure to latex. Most of these persons had a history of atopy and worked in areas where rubber gloves were used and changed frequently. Of the 49 subjects, 34 had positive results of skin tests to latex products, and the sera from 19 of 35 persons tested contained increased latex-specific IgE antibodies. Employees with sensitivity to latex (and co-workers in the immediate areas) should use vinyl gloves and should notify their own health-care providers of their sensitization. Changes in job assignment may be necessary for some persons.

Effect of Nebulized Lidocaine on Severe Glucocorticoid-Dependent Asthma

OBJECTIVE To determine whether nebulized lidocaine is a useful therapy in patients with severe glucocorticoid-dependent asthma. DESIGN We prospectively conducted an open study of the effects of administration of nebulized lidocaine four times daily in 20 patients with asthma who had side effects of exogenous hypercortisolism. MATERIAL AND METHODS The 18 women and 2 men, who were 19 to 71 years of age, all had severe asthma that necessitated both topical and systemic administration of glucocorticoids to control symptoms of airflow obstruction. Treatment consisted of nebulized lidocaine, 40 to 160 mg four times daily. Initially, all topical and systemic glucocorticoid regimens were maintained; if peak flow rates remained stable and symptoms of asthma were well controlled, orally administered glucocorticoid regimens were slowly reduced. RESULTS Thirteen patients were able to discontinue oral use of glucocorticoids entirely, despite prolonged glucocorticoid dependence (mean 6.6 years and median 3 years for the 20 patients); 4 achieved reduction in their daily glucocorticoid requirement while maintaining control of symptoms of asthma (duration of glucocorticoid dependence for responders, mean 6.2 years and median 3.2 years). Three patients had no apparent response, as determined by their continued severe asthma symptoms and inability to reduce oral glucocorticoid requirements. CONCLUSION These results suggest that nebulized lidocaine is a useful therapy for chronic asthma, allowing reduction or elimination of oral glucocorticoid therapy.

Purification of tryptase from a human mast cell line.

The neutral protease tryptase has been isolated from a human mast cell line, HMC‐1. The HMC‐1 line was established from the peripheral blood of a patient with mast cell leukemia and maintained as continuously proliferating clones in vitro and as solid mast cell tumors in nude mice. HMC‐1‐derived tryptase was purified by sequential chromatography on Dowex 1, DEAE 5 PW, and heparin‐agarose. Purified tryptase has an apparent molecular weight of 150,000, as determined by molecular sieve HPLC, but migrates as a doublet of bands of 32/35,000 on SDS‐PAGE gels. Maximal enzymatic activity was observed at pH 8.5. Cleavage of tosyl‐L‐arginine methyl ester by purified tryptase was inhibited by dansyl‐L‐glutamyl‐glycyl‐L‐arginine chloromethyl ketone 2 HCI, HgCI2, tosyl‐L‐lysine chloromethyl ketone, leupeptin, and PMSF but not by benzamidine, aprotinin, tosyl‐L‐phenylalanine chloromethyl ketone, soybean trypsin inhibitor, human plasma, ovomucoid inhibitor, or lima bean trypsin inhibitor. Microsequencing of purified tryptase yielded an amino terminal sequence that was identical to that previously reported for human pituitary‐derived tryptase.

Eosinophil recruitment is associated with IL-5, but not with RANTES, twenty-four hours after allergen challenge

Several lines of evidence suggest that the chemokine RANTES may play a role in eosinophilia observed during allergic inflammation. To test this hypothesis, six patients with allergic asthma were studied. After performing bronchoalveolar lavage in a lung segment (baseline), segmental bronchoprovocation was performed with saline solution in another segment and with ragweed in a third segment. Bronchoalveolar lavage was performed 24 hours later in the saline-challenged (sham) and ragweed-challenged lung segments. The bronchoalveolar lavage fluids from the baseline, sham, and ragweed segments were analyzed for cell counts and for the levels of IL-5, RANTES, and eosinophil-derived neurotoxin. IL-5 levels were elevated in the ragweed (984 +/- 588 pg/ml) compared with sham segments (2.8 +/- 0.2 pg/ml, p = 0.02). Likewise, RANTES levels were elevated in the ragweed (12.93 +/- 3.4 pg/ml) compared with the sham segments (3.05 +/- 1.19 pg/ml, p = 0.006). The IL-5 levels correlated with both eosinophil numbers (r = 0.90, p < 0.02) and eosinophil-derived neurotoxin levels (r = 0.89, p < 0.02). In contrast, RANTES levels did not correlate with either eosinophil numbers or eosinophil-derived neurotoxin levels. These results indicate that although both IL-5 and RANTES are elevated 24 hours after allergen challenge, only IL-5 correlates with eosinophil recruitment and degranulation.

Immunofluorescent staining for mast cells in idiopathic pulmonary fibrosis: quantification and evidence for extracellular release of mast cell tryptase

In many diseases, retrospective analysis for determining the presence of mast cells has been difficult because of their loss of metachromatic staining properties once tissue has undergone formalin fixation. We quantified mast cells in peribronchiolar tissue of idiopathic pulmonary fibrosis (IPF) and in normal human lung by using rabbit antiserum to human mast cell tryptase. In lung biopsy specimens from 15 patients with IPF, the mean number of mast cells per high-power field in connective tissue directly adjacent to the lumen of small airways (0.5 to 2 mm in diameter) and other fibrotic foci was 29.9 +/- 10.8 in comparison with 13.7 +/- 3.5 in 16 normal controls (P < 0.001). In addition, mast cells in cases of IPF had an altered appearance--irregularity of the plasma membrane and release of extracellular tryptase. We conclude that the number of mast cells is increased in IPF and that the altered appearance of the mast cells suggests that they are activated and undergoing degranulation.

A medical-center-wide, multidisciplinary approach to the problem of natural rubber latex allergy

Latex is a common cause of occupational allergy in health care workers; latex-sensitized patients are at increased risk of allergic reactions in medical environments. Skin test reagents and latex-specific immunoglobulin E immunoassays were established for diagnosis of latex allergy. Inhibition immunoassays were developed for measuring latex aeroallergens and latex allergens in rubber products. A registry of latex-sensitive employees was established. High-allergen gloves were removed from the medical center inventory; latex aeroallergen levels subsequently declined. Despite an increasing number of gloves used annually, expenditures for gloves in 1994 were lower than in previous years. Latex-sensitive individuals can be identified using skin tests or immunoassays. Latex aeroallergen levels in medical environments can be reduced substantially at lower cost by using powder-free rubber gloves with lower allergen content.

Prevalence, pathophysiology, and treatment of patients with asthma and gastroesophageal reflux disease

About one third of the US adult population experiences symptoms of gastroesophageal reflux on a monthly basis. Asthma is present in about 5% of the same population. This article reviews and summarizes the literature in the following areas: (1) prevalence of gastroesophageal reflux disease (GERD) in asthmatic patients based on clinical symptoms, endoscopic esophagitis, and 24-hour ambulatory esophageal pH recordings; (2) proposed pathophysiologic mechanisms linking the 2 diseases; and (3) medical and surgical treatment trial results of antireflux therapy for asthmatic patients. Asthmatic patients appear to have an increased prevalence of GERD symptoms and 24-hour esophageal acid exposure. The clinical management of these patients remains controversial. Common management approaches to GERD in asthmatic patients include medical therapy with a proton pump inhibitor and/or antireflux surgery, which improve asthma symptoms in many patients but minimally affect pulmonary function.

Severe Asthma Complicated by Bilateral Diaphragmatic Paralysis Attributed to Parsonage-Turner Syndrome

Progressive dyspnea that developed in a 52-year-old woman with a lifelong history of asthma did not respond to high-dose orally administered glucocorticoids. Initially, a diagnosis of allergic bronchopulmonary aspergillosis or hypersensitivity pneumonia was suggested as the cause of the worsening dyspnea. Pulmonary function tests demonstrated severe airway obstruction; substantial improvement was noted after bronchodilator therapy. Maximal inspiratory pressure was decreased, and the diffusing capacity of the lungs was abnormal. Computed tomography of the chest showed no parenchymal or mediastinal abnormalities. During a sniff test, fluoroscopy of her diaphragm disclosed paradoxical motion of both hemidiaphragms during inspiration, consistent with bilateral hemidiaphragmatic paralysis. Parsonage-Turner syndrome was diagnosed. The dose of glucocorticoids was tapered. Follow-up of the patient by telephone contact in March 1994 (9 months after her initial examination at our clinic) revealed that the dyspnea was still severe.

Removal of bronchoalveolar cells augments the late eosinophilic response to segmental allergen challenge

Background In patients with quiescent asthma, macrophages are the most prevalent cells recovered by bronchoalveolar lavage (BAL). Through activation via their FcεRII receptors or by acting as antigen‐presenting cells, macrophages could, in theory, promote the late airway response to allergen.