Biomedical subjects

Robert G Hamilton

Publications and source records attributed to Robert G Hamilton.

At least 37 records · Page 2Linked to original sources

PubMed2004

Outcomes of allergy to insect stings in children, with and without venom immunotherapy.

BACKGROUND: Children are thought to "outgrow" the allergy to insect stings, but there are no reports documenting the natural history of this reaction. We studied the outcome of allergic reactions to insect stings in childhood 10 to 20 years afterward in patients who had not received venom immunotherapy and in those who had been treated. METHODS: Between 1978 and 1985, we diagnosed allergic reaction to insect stings in 1033 children, of whom 356 received venom immunotherapy. We conducted a survey of these patients by telephone and mail between January 1997 and January 2000, to determine the outcome of stings that occurred in the period from 1987 through 1999. RESULTS: Of the 1033 patients, 512 patients (50 percent) responded, with a mean follow-up period of 18 years, a mean duration of venom immunotherapy of 3.5 years in treated patients, and an incidence of stings of 43 percent. Systemic reactions occurred less frequently in patients who had received venom immunotherapy (2 of 64 patients, or 3 percent) than in untreated patients (19 of 111 patients, or 17 percent; P=0.007). Patients with a history of moderate-to-severe reactions had a higher rate of reaction if they had not been treated (7 of 22 patients, or 32 percent) than if they had received venom immunotherapy (2 of 43 patients, or 5 percent; P=0.007). In patients who had been treated and who had a history of mild (cutaneous) systemic reaction (i.e., one with only cutaneous manifestations), none of the 21 subjects who received stings had a systemic reaction. CONCLUSIONS: A clinically important number of children do not outgrow allergic reactions to insect stings. Venom immunotherapy in children leads to a significantly lower risk of systemic reaction to stings even 10 to 20 years after treatment is stopped, and this prolonged benefit is greater than the benefit seen in adults.

Animals↗

PubMed2004

Isolation and characterization of the early nodule-specific protein homologue (Hev b 13), an allergenic lipolytic esterase from Hevea brasiliensis latex.

Recurring reports of a highly allergenic 42-46-kDa protein in Hevea brasiliensis latex appeared to have been resolved with the discovery of a 43-kDa allergenic latex protein that was a homologue to patatin. However, the low to moderate prevalence of sensitization to the protein, designated Hev b 7, among latex-allergic patients could not adequately explain the frequent observations of the 42-46-kDa allergen. This led to the hypothesis that another, more allergenic protein of a similar molecular mass existed in Hevea latex. We report the isolation and purification of a 42.98-kDa latex glycoprotein showing homology to the early nodule-specific protein (ENSP) of the legumes Medicago sativa, Medicago truncatula, and Glycine max. The protein is allergenic, being recognized by immunoglobulin E (IgE) in sera from latex-allergic patients. The IgE epitope resides on the carbohydrate moiety of the protein, and the presence of a similar carbohydrate component on potato tuber patatin enables the latter to inhibit IgE binding to the ENSP homologue. The cDNA encoding the ENSP homologue was isolated by reverse transcription-PCR and cloned. The protein predicted from the cDNA sequence has 391 amino acids, the first 26 of which constitute a putative signal peptide. The deduced molecular mass of the mature protein is 40.40 kDa, while its isoelectric point is estimated at 5.0. The discrepancy between the predicted and observed molecular mass might be due to glycosylation, for which three N-sites on the protein are predicted. The purified protein showed lipase and esterase activities and may be involved in plant defense.

Allergens↗

PubMed2004

Different latex aeroallergen size distributions between powdered surgical and examination gloves: significance for environmental avoidance.

BACKGROUND: Proactive medical institutions implement latex allergen avoidance to protect workers and patients with latex allergy and to prevent latex sensitization in these groups by creating latex-safe environments that include replacement of natural rubber latex examination and surgical gloves, especially those that are powdered, with synthetic alternatives. We have hypothesized that an apparent decreasing trend in new latex allergy cases in hospitals using only synthetic examination gloves but the occasional powdered latex surgical glove might result from constitutive differences in allergen content (particle size distribution and quantity) between powdered surgical gloves and examination gloves. OBJECTIVE: Because aerodynamic particle size determines where inhaled airborne allergen deposits in the airway, the aim of this study was to investigate the differential particle size distribution of latex allergen released from powdered latex examination and surgical gloves. METHODS: Powdered and nonpowdered latex examination and surgical gloves were processed to create an aerosol in a glove box equipped with air sampling equipment capable of total particle number and mass measurements. Air particulate generated in the glove box was collected on impactors with less than 2.5-microm, 2.5- to 10-microm, and greater than 10-microm particle size limits (4 L/min for 4 hours). All filters were extracted, and latex allergen was quantified by using a latex-CAP inhibition assay with a human IgE anti-latex serum pool. RESULTS: Latex aeroallergen on powdered sterile surgical gloves resided primarily on particles greater than 10 microm in size (P <.006). In contrast, powdered examination gloves released the highest total latex aeroallergen content, with 68% of the particles sized in the respirable 2.5- to 10-microm range and carrying 56% of the airborne latex allergen. CONCLUSIONS: Significantly lower quantities and larger sizes of latex allergen-containing particles released from surgical gloves provides one potential explanation as to why an apparent decrease in new cases of latex allergy can occur in hospitals that successfully replace latex examination gloves with synthetic gloves but continue occasional use of powdered surgical gloves.

Allergens↗

PubMed2004

Hev b 5 and Hev b 13 as allergen markers to estimate the allergenic potency of latex gloves.

BACKGROUND: Sensitization to natural rubber latex has been linked to proteins from medical latex gloves. Various assays to estimate the amount of residual allergenic proteins extractable from latex gloves to assess their potential exposure hazard have inherent weaknesses. OBJECTIVE: This investigation was aimed at developing 2-site immunoenzymetric assays and identifying appropriate protein markers to assess the allergenic potential of latex gloves. METHODS: The presence of 6 latex allergens--Hev b 1, 2, 3, 5, 6, and 13--was measured in a cross-section of commercial latex medical gloves by using monoclonal and polyclonal antibody-based 2-site immunoenzymetric assays. The overall allergenic potential of these gloves was assessed by IgE-inhibition assay. Stepwise multiple regression analyses were performed to identify marker allergens that best explained the variation in latex glove allergenicity. RESULTS: All 6 latex allergens were detected in at least some of the glove samples. Hev b 5 and Hev b 13 were identified as the marker allergens that combined best to explain the variation in the glove allergenicity. The significant multiple correlation (R=0.855) between these 2 markers and glove allergenic potency forms the basis of an assay to gauge latex glove allergenicity. CONCLUSION: The overall allergenic potential of latex gloves can be estimated by using Hev b 5 and Hev b 13 as indicator allergens. The correlation between glove allergenicity and the level of these allergens was maintained for low-protein gloves (<200 microg/g). This estimation of glove allergenicity was superior to that obtained by using total protein readings.

Allergens↗

PubMed2004

In vitro assays for the diagnosis of IgE-mediated disorders.

Advances in technology have provided new laboratory tools for the quantitation of allergen-specific IgE antibodies in serum and on the surface of basophils. This review examines the evolution from qualitative IgE antibody assays of the late 1960s to the present-day, third-generation, automated and quantitative allergen-specific IgE assays. The latest technology trend is toward microarrays in which crude or purified native and recombinant allergens can be spotted in microdot arrays on silica chips to permit extensive panels of specific IgE measurements to be performed with small quantities of serum. Although these technologies hold promise, their diagnostic performance requires further assessment once their technical details have been optimized. Potential abuses of this newer IgE antibody technology include the use of allergosorbent specificities (eg, especially food and drugs) that lack validation, application of IgE antibody measurements in the diagnosis of non-IgE-dependent disorders (eg, aspirin sensitivity), and modification of IgE antibody assays to measure food-specific IgG antibody for which there is no clinical indication. Basophil mediator release assays have evolved to include flow cytometric methods that can quantitatively detect the presence of cell surface-bound allergen-specific IgE antibodies. Assays for histamine and leukotriene C 4 released after in vitro basophil activation are now more accurate and standardized. Current analytic methods for IgE antibodies provide more quantitative and reproducible measurements of IgE than ever before, although still with less sensitivity that traditional skin testing. The current challenge is to translate the quantitative IgE antibody results into a more accurate diagnosis of allergic disease.

Allergens↗

PubMed2004

Contamination of nebulizer equipment with cockroach allergen: there's a bug in the system!

BACKGROUND: Physicians often have anecdotal reports of patients describing increased asthma symptoms after the use of nebulizers; however, there are few published reports of nebulizer-associated exacerbations. OBJECTIVE: To present 2 cases of asthmatic children who experienced a life-threatening exacerbation of their symptoms after nebulizer use. METHODS: Case 2's nebulizer was tested for cockroach allergen by washing the medication reservoir with 2 mL of sterile filtered 1% phosphate-buffered saline, 0.05% bovine serum albumin, and Tween 20 overnight with rotation. The patient's sealed albuterol nebulizer medication was used as a control. The control albuterol and test solutions were analyzed for Blattella germanica 1 and 2 allergens using a monoclonal antibody-based immunoenzymetric assay. RESULTS: The reservoir from case 2 was found to have measurable levels of both Bla g 1 and Bla g 2. The control albuterol solution had no measurable cockroach allergen. An insect found in the nebulizer box of case 2 was identified as an infantile German cockroach. CONCLUSIONS: Nebulizer use provides an opportunity for antigen exposure directly to small airways, which may lead to severe allergic reactions in patients using contaminated equipment.

Adolescent↗

PubMed2004

Diagnostic methods for insect sting allergy.

PURPOSE OF REVIEW: This review overviews advances from mid-2002 to the present in the validation and performance methods used in the diagnosis of Hymenoptera venom-induced immediate-type hypersensitivity. RECENT FINDINGS: The general diagnostic algorithm for insect sting allergy is initially discussed with an examination of the AAAAI's 2003 revised practice parameter guidelines. Changes as a result of a greater recognition of skin test negative systemic reactors include repeat analysis of all testing and acceptance of serology as a complementary diagnostic test to the skin test. Original data examining concordance of venom-specific IgE results produced by the second-generation Pharmacia CAP System with the Johns Hopkins University radioallergosorbent test are presented. Diagnostic performance of honeybee venom-specific IgE assays used in clinical laboratories in North America is discussed using data from the Diagnostic Allergy Proficiency Survey conducted by the College of American Pathologists. Validity of venom-specific IgE antibody in postmortem blood specimens is demonstrated. The utility of alternative in-vivo (provocation) and in-vitro (basophil-based) diagnostic testing methods is critiqued. SUMMARY: This overview supports the following conclusions. Improved practice parameter guidelines include serology and skin test as complementary in supporting a positive clinical history during the diagnostic process. Data are provided which support the analytical performance of commercially available venom-specific IgE antibody serology-based assays. Intentional sting challenge in-vivo provocation, in-vitro basophil flow cytometry (CD63, CD203c) based assays, and in-vitro basophil histamine and sulfidoleukotriene release assays have their utility in the study of difficult diagnostic cases, but their use will remain as supplementary, secondary diagnostic tests.

Animals↗

PubMed2004

Recent studies on the characterization of Anaplasma marginale isolated from North American bison.

Anaplasma marginale (Rickettsiales: Anaplasmataceae), a tick-borne pathogen of cattle, is endemic in tropical and subtropical regions of the world. Many geographic isolates of A. marginale occur worldwide that have been identified by major surface protein (MSP) 1a, which varies in sequence and molecular weight owing to different numbers of tandem 28-29 amino acid repeats. Although serologic tests have identified American bison, Bison bison, as being infected with A. marginale, the present studies were undertaken to confirm A. marginale infection in bison, to characterize bison isolates, and to compare the phylogenetic relationship of the bison isolates with other A. marginale isolates from North America. Nine A. marginale isolates derived from Canadian bison possessed identical msp4 sequences with one characteristic silent nucleotide change. The sequence of MSP1a was determined for one Canadian and two U.S. bison isolates of A. marginale, and these isolates contained 4 and 5 tandem repeats, respectively. One U.S. bison isolate tested for infectivity proved to be infective for cattle and transmitted by Dermacentor variabilis ticks. the results of this study demonstrated that these A. marginale isolates obtained from bison were similar to ones derived from naturally infected cattle.

Anaplasma marginale↗

PubMed2003

Environmental allergens and asthma in urban elementary schools.

BACKGROUND: Asthma in school children is rising, and indoor allergens are very common triggers of asthma attacks; however, the risk of the school environment on asthma has not been well studied. OBJECTIVE: To determine the presence and the levels of common aeroallergens in schools, where asthma prevalence rates are high. METHODS: Settled dust samples were collected from 12 Baltimore City public elementary schools, and they were analyzed for the following allergens: cockroaches (Bla g 1/2), dust mites (Der f 1/p 1), dog (Can f 1), cat (Fel d 1), and mouse (Mus m 1). School asthma prevalence rates were correlated with allergen levels, and association between allergen levels and other risk factors present in the schools' environment was examined. RESULTS: The mean and range levels were 1.49 U/g (0 to 8) for Bla g 1/2; 0.38 microg/g (0 to 11.9) for the Der f 1/p 1; 1.44 microg/g (0.1 to 9.6) for Can f 1; 1.66 microg/g (0.2 to 12) for Fel d 1; and 6.24 microg/g (0.3 to 118.3) for Mus m 1. Dust mite, cat and dog allergens were significantly in rooms with carpet and/or area rugs, compared to rooms with bare floors (P < 0.05). Asthma prevalence rates varied from 11.8 to 20.8% between schools and positively correlation with the mean levels of Bla g 1/2 in the schools (P = 0.001). CONCLUSIONS: Common allergens that are known to trigger asthma were detected in all school environments, where asthma prevalence rates were high. However, the overall allergen levels were low, indicating that other factors, including exposures in the homes of asthmatic patients, may have more relevance to sensitization and symptoms than school exposures.

Air Pollutants↗

PubMed2003

How health care organizations can establish and conduct a program for a latex-safe environment.

BACKGROUND: The advent of universal precautions brought about a dramatic increase in the use of natural rubber latex gloves, and reports of rubber latex allergies began appearing in the literature. In 1997 the Johns Hopkins Hospital created the interdisciplinary Latex Task Force to address the issue of creating, implementing, and evaluating a latex-safe environment. CONVERSION TO NONLATEX PRODUCTS AND EXAMINATION GLOVES: When suitable alternatives were available, all medical products that contained latex were to be removed from the hospital and nonlatex alternatives substituted. Latex medical gloves, especially powdered latex examination gloves, which were used in all patient care areas, were replaced by vinyl gloves. Yet because of the ongoing concern about strike-through and the minimal level of acceptance of fit with the vinyl gloves, the search for alternatives to the vinyl gloves continued. The task force recommended switching to nitrile examination gloves throughout the hospital. To facilitate the transition to another examination glove, new educational pamphlets about the nitrile gloves were developed. POSTSCRIPT: The switch to nitrile examination gloves was successfully completed, but conversion to nonlatex surgical gloves was less successful, with costs being the overwhelming impediment. Monitoring of latex-containing products and ongoing evaluations of alternatives are crucial in ensuring patient and health care worker safety.

Advisory Committees↗

PubMed2003

Pneumococcal polysaccharide revaccination: immunoglobulin g seroconversion, persistence, and safety in frail, chronically ill older subjects.

OBJECTIVES: To determine the 1-month postpneumococcal polysaccharide-revaccination immunoglobulin G (IgG) antibody response, its persistence at 1 year, and tolerability of revaccination in frail, chronically ill older nursing facility residents. DESIGN: Prospective study conducted between December 1998 and July 2000. SETTING: Six skilled nursing facilities in the Minneapolis-St. Paul, Minnesota, metropolitan area. PARTICIPANTS: Sixty-seven subjects aged 65 and older having received primary vaccination with pneumococcal polysaccharide vaccine (PPV) at least 5 years before enrollment. INTERVENTION: Revaccination with one dose of 23-valent PPV. MEASUREMENTS: Adverse events and concentrations of seven individual pneumococcal polysaccharide type-specific IgG antibodies (against serotypes 4, 6B, 9V, 14, 18C, 19F, 23F) and their aggregate before and 1 and 12 months after revaccination. RESULTS: A significant increase in all individual and aggregate median antibody concentrations over baseline was observed 1 month after revaccination. However, after 1 year, the increase remained significant only for serotypes 6B and 18C and the aggregate parameter. One month after revaccination, the mean increase in antibody concentration over baseline was significantly greater than 1.4-fold for six of the seven serotypes and the aggregate. However, the increase was not significantly greater than 1.4 at 1 year for any of the serotypes or the aggregate. Minor, self-limited localized adverse reactions and systemic reactions occurred in 11.3% of the subjects. CONCLUSIONS: In frail, chronically ill older nursing facility residents, revaccination with 23-valent PPV at least 5 years after primary vaccination (whether primary vaccination occurred before or after age 65) is associated with a significant, albeit brief, immunological response for most of the serotypes tested. Revaccination was well tolerated.

Aged↗

PubMed2003

23. Clinical laboratory assessment of IgE-dependent hypersensitivity.

This chapter reviews clinical and laboratory analyses that aid in the diagnosis and management of human allergic (IgE-dependent) diseases. The diagnostic algorithm for immediate-type hypersensitivity begins with a thorough clinical history and physical examination. Once signs and symptoms compatible with an allergic disorder have been identified, a skin test and/or blood test for allergen-specific IgE antibodies may serve as primary confirmation to strengthen the diagnosis. Puncture and intradermal skin testing provide a biologically relevant immediate-type hypersensitivity response in the skin, with resultant wheal and flare reactions within 15 minutes of allergen application. Bleeding, dermatographism, and antihistamines may confound the quality of the skin test. Allergen-specific IgE antibody may also be detected in the blood using a radioallergosorbent test (RAST). Nonisotopic "second-generation" RAST-type assays have evolved to provide more quantitative, sensitive, precise IgE antibody results. In vivo provocation tests may serve as secondary confirmatory tests when the clinical history is discordant with a primary IgE antibody test result. The multiallergen screen is a qualitative RAST-type assay that detects specific IgE antibody to approximately 15 allergens that evoke a large majority of aeroallergen or food-related allergic disorders. Other useful serological assays performed in the diagnostic allergy laboratory include total serum IgE, Hymenoptera venom-specific IgG antibody, IgG precipitins for organic dusts, mast cell tryptases, and the venom RAST inhibition test. Above all, in vivo or laboratory confirmatory test results that are inconsistent with the clinical history should be repeated as for any laboratory assessment.

Algorithms↗

PubMed2003

Characterization of Anaplasma marginale isolated from North American bison.

Anaplasma marginale (Rickettsiales: Anaplasmataceae), a tick-borne pathogen of cattle, is endemic in tropical and subtropical regions of the world. Although serologic tests have identified American bison, Bison bison, as being infected with A. marginale, the present study was undertaken to confirm A. marginale infection and to characterize isolates obtained from naturally infected bison in the United States and Canada. Major surface protein (MSP1a and MSP4) sequences of bison isolates were characterized in comparison with New World cattle isolates. Blood from one U.S. bison was inoculated into a susceptible, splenectomized calf, which developed acute anaplasmosis, demonstrating infectivity of this A. marginale bison isolate for cattle. The results of this study showed that these A. marginale isolates obtained from bison were similar to ones from naturally infected cattle.

Amino Acid Sequence↗

PubMed2003

Clinical and laboratory investigation of allergy to genetically modified foods.

Technology has improved the food supply since the first cultivation of crops. Genetic engineering facilitates the transfer of genes among organisms. Generally, only minute amounts of a specific protein need to be expressed to obtain the desired trait. Food allergy affects only individuals with an abnormal immunologic response to food--6% of children and 1.5-2% of adults in the United States. Not all diseases caused by food allergy are mediated by IgE. A number of expert committees have advised the U.S. government and international organizations on risk assessment for allergenicity of food proteins. These committees have created decision trees largely based on assessment of IgE-mediated food allergenicity. Difficulties include the limited availability of allergen-specific IgE antisera from allergic persons as validated source material, the utility of specific IgE assays, limited characterization of food proteins, cross-reactivity between food and other allergens, and modifications of food proteins by processing. StarLink was a corn variety modified to produce a (Italic)Bacillus thuringiensis(/Italic) (Bt) endotoxin, Cry9C. The Centers for Disease Control and Prevention investigated 51 reports of possible adverse reactions to corn that occurred after the announcement that StarLink, allowed for animal feed, was found in the human food supply. Allergic reactions were not confirmed, but tools for postmarket assessment were limited. Workers in agricultural and food preparation facilities have potential inhalation exposure to plant dusts and flours. In 1999, researchers found that migrant health workers can become sensitized to certain Bt spore extracts after exposure to Bt spraying.

Animal Feed↗

PubMed2002

Immediate-type hypersensitivity and other clinical reactions in volunteers immunized with a synthetic multi-antigen peptide vaccine (PfCS-MAP1NYU) against Plasmodium falciparum sporozoites.

We tested the clinical reactions to a synthetic, Plasmodium falciparum, circumsporozoite multiple antigen peptide (MAP) vaccine in 39 volunteers immunized two to three times over 2-8 months using a dose escalation design. Immediate pain at the injection site was associated with the adjuvant QS-21 (P<0.001), and delayed local inflammatory reactions were associated with high-titered circulating IgG anti-MAP antibody (P=0.03). Because two volunteers developed acute, systemic urticaria after the third immunization associated with development of serum IgE MAP antibody, we employed immediate-type hypersensitivity skin tests (ITH-STs) using intradermal injections of diluted MAP vaccine to identify persons sensitized to the vaccine. ITH-STs were negative in seven volunteers tested 27 days after the first vaccination, but six of these individuals developed positive wheal and flare reactions when tested 14 or 83 days after the second vaccination; IgE MAP antibody was detected in only one of them. Another cohort of 16 volunteers, including the 2 allergic individuals, were ITH-ST negative when first tested late after their second or third vaccination at 6-7 months. Five of five non-immunized persons were also ITH-ST negative. ITH-STs may help identify individuals sensitized to malaria peptides and at potential risk of developing systemic allergic reactions after re-vaccination.

Adjuvants, Immunologic↗

PubMed2002

Delayed-type hypersensitivity in volunteers immunized with a synthetic multi-antigen peptide vaccine (PfCS-MAP1NYU) against Plasmodium falciparum sporozoites.

During the testing of the safety and immunogenicity of an adjuvanted, synthetic Plasmodium falciparum CS multiple antigen peptide (MAP) vaccine, we investigated the potential for using cutaneous delayed-type hypersensitivity (DTH) reactions as a correlate of immune response. We evaluated 27 of our volunteers for DTH reactions to intradermal inoculation (0.02 ml) of several concentrations of the MAP vaccine and adjuvant control solutions. Induration was measured 2 days after skin tests were applied. Nine of 14 vaccinees (64%) with serum, high-titered anti-MAP antibody developed positive DTH (>or=5mm induration), that first appeared by 29 days after immunization and persisted for at least 3-6 months after 1-2 more immunizations. In contrast, DTH responses were negative in eight of eight vaccinees with no or low antibody titers, and in five of five non-immunized volunteers. Biopsies of positive DTH skin test sites were histologically compatible with a DTH reaction. We conclude that the presence of T cell functional activity reflected by a positive DTH skin test response to the MAP antigen serves as another marker for vaccine immunogenicity.

Adjuvants, Immunologic↗

PubMed2002

Diagnosis of natural rubber latex allergy.

The accurate diagnosis of a latex-allergic individual begins with a comprehensive clinical history. Atopy, food allergies, hand dermatitis, and temporal relationships between allergic symptoms and natural rubber product exposure are risk factors that increase the suspicion of latex allergy. If symptoms are temporally delayed (hours-days) and confined to skin-latex product contact areas, Type IV hypersensitivity should be suspected and patch testing may be performed to identify activated T cells that are specific for selected rubber chemical additives. If ocular, upper and lower airway, and/or systemic allergic symptoms are observed with rapid onset (minutes) following a definable latex exposure, Type I hypersensitivity should be suspected. One or several confirmatory tests for latex-specific IgE antibody in the skin or blood may next be performed to verify a sensitized (IgE antibody positive) state. If the clinical history remains discordant with a skin test or blood test result, in vivo provocation tests may be cautiously considered for adjudication. Diagnostic methods for latex-specific IgE antibody detection in skin and blood are overviewed, with a focus on their performance, advantages, and limitations.

Humans↗

PubMed2002

A hospital-based screening program for natural rubber latex allergy.

BACKGROUND: Natural rubber latex (NRL) allergy has become an important occupational health problem for health care workers, of whom approximately 10% are reportedly sensitized. Some medical facilities have chosen to convert entirely to NRL-free gloves, but others have found this to be financially or logistically unfeasible. OBJECTIVES: The goals of this study were 1) to devise a NRL allergy screening program that could identify sensitized (at-risk) employees for the purpose of providing them with a safe working environment; and 2) to develop a glove conversion plan that would lead to the removal of all NRL gloves from the institution. METHODS: A multidisciplinary University of Maryland Medical System NRL risk team developed a mandatory NRL screening program for all newly hired employees and any existing employees transferring into or within patient care positions. Employees were screened with a clinical questionnaire and a serology for immunoglobulin (Ig)E anti-NRL. Some employees voluntarily received an experimental NRL skin test to evaluate their skin reactivity to NRL. Each employee reporting respiratory or systemic symptoms associated with NRL exposure was evaluated by an allergist. RESULTS: During the 15-month study period from April 1998 to July 1999, 1,795 employees were screened for NRL allergy. Of the whole group, 8% (144 of 1,795) were NRL-specific IgE antibody-positive by CAP radioallergosorbent test (Pharmacia-Upjohn Diagnostics, Kalamazoo, MI) and/or NRL skin test, 57.3% of whom reported symptoms with powdered NRL glove exposure. The NRL IgE-positive rates of nonpatient-care employees (who did not use NRL gloves on a regular basis) and direct patient-care employees was 5.9% and 8.6%, respectively. Most NRL-sensitized employees were successfully accommodated with the use of synthetic gloves and continued to work in the positions for which they were hired. CONCLUSIONS: The University of Maryland Medical System NRL screening program has been successful in identifying at-risk employees and ensuring them a safe working environment during a progressive conversion of the hospital to a NRL-safe environment.

Adolescent↗