AAAAI Report (2002)
The following Article originally appeared in The ALERT, Spring 2002, Vol. 8, No. 1
Report from the AAAAI
The American Academy of Allergy, Asthma and Immunology (AAAAI) held its 58th Annual Meeting in New York City, March 1-6, 2002. The following are some of the research abstracts related to natural rubber latex (NRL) allergy that were presented.
Behavioral Modifications in Response to Latex Glove-Induced Symptoms
BACKGROUND: The prevalence of sensitivity to natural rubber latex (NRL) has been studied in many different populations. While studies have addressed the prevalence, diagnosis and financial consequences, to our knowledge, none has focused on behavioral responses.
OBJECTIVE: We conducted a questionnaire-based cross sectional survey of Mount Sinai Hospital personnel about the prevalence of symptoms and behavioral response to the usage of latex gloves. Medical and surgical specialties, obstetrics/gynecology, psychiatry and pediatric staff including medical students, housestaff and attendings, laboratory and nursing staff were surveyed. 1480 questionnaires were distributed and 414 were returned (28%). Symptoms were classified as localized (dermatitis) or allergic (IgE-mediated). Localized skin symptoms included itching, chapping, cracking, rash, swollen hands, hives or blisters while reactions were deemed IgE-mediated if ocular, nasal, palatal, chest or constitutional.
RESULTS: Overall glove usage in this sample of healthcare workers (HCW) was 88.6% largely due to the inclusion of psychiatrists who had minimal glove usage. 116 of 414 (28.0%) respondents experienced at least one symptom to latex gloves. 112 of the 116 symptomatic subjects had localized cutaneous symptoms while 39 (39.4%) subjects had likely IgE-mediated symptomatology. Thus the overall incidence of Type I NRL symptoms of 9.4% is compatible with results of other studies. We then measured the behavioral response to symptoms in latex glove wearers. Modifications included seeing a physician, taking medications to suppress symptoms, taking time off work, modifying the daily schedule or avoiding glove use altogether to avoid NRL exposure. Of 116 symptomatic HCWs, only 18 (15.5%) had seen a physician regarding their reactions to NRL. However, 44/116 (37.9%) had modified their activities of who 40/44 (90.9%) were effective in reducing latex glove related symptoms. 4 (3.4% of those symptomatic) persons had missed work while 27/116 (23.3%) took medications to suppress symptoms. 35/116 (30.2%) subjects had avoided using any gloves to reduce glove-related symptoms and subsequently 11/35 (31.4%) were exposed to body fluids or blood products. 5 of 84 housestaff (6.0%) were exposed to blood/body fluids, which is an incidence almost 4 times higher than other hospital staff (6/328; 1.8%) responding to the questionnaire.
CONCLUSION: Personal avoidance behavior of latex, in the absence of an available substitute, may lead to exposure to infectious body fluids. Medical staff, especially overworked housestaff, should be routinely evaluated and treated for LA and glove-induced symptoms. Alternatives to latex gloves should be readily available.
Interventions of Latex Allergen Inhaled by Health Care Workers Through Use of Breathing Masks or Non-Powdered Gloves
Allergy to powdered latex gloves is a well-characterized phenomenon, particularly amongst health care workers. Despite this, many hospitals still provide staff with powdered latex gloves. Aims: (1) To measure the dose of allergenic latex particles inhaled by hospital health care workers wearing standard latex gloves, provided by the hospital, while performing routine activities in a bronchoscopy suite. (2) To measure the extent to which exposure was reduced by the use of protective masks or by replacing powdered gloves with non-powered latex gloves. 20 health care workers wore nasal air samplers (NAS) and IOM filter pumps (IOM) on the lapel for 4 x 20-minute sampling periods. Each subject wore powdered gloves, non-powdered gloves and no gloves during three of the sampling periods. In the fourth sampling period, each subject applied a face-mask while wearing the powdered gloves. Half the subjects used an aerosol barrier mask and the others wore a particulate mask (N95). All samples were stained for particles bearing Hev b 5 allergen by the Halogen assay. Haloed particles were counted and conditions were compared by paired sample T-tests. All subjects inhaled Hev b 5 bearing particles in all sampling periods. On average, the IOM sampler collected particles at 70% of the rate of the NAS. The number of particles inhaled while wearing standard, powdered gloves was 23.8 fold higher than when not wearing gloves and 9.7 fold higher than when wearing non-powdered latex gloves (P < .0001). The effectiveness of the masks was assessed by comparing the NAS to IOM ratio with and without a mask, to correct for between-sampling period variation in actual exposure. Wearing a mask reduced the NAS to IOM ratio by 7.5 fold (P = 0.01). There was no significant difference between the two types of masks examined (P = 0.2). The use of non-powdered gloves is the most effective method of reducing occupational exposure to latex arising from gloves. However, secondary protection using aerosol or articulate masks is an acceptable alternative.
FDA-Cleared Immunoassays for Latex-Specific IgE Are Missing Allergenic Epitopes From Multiple Hevb Allergens
BACKGROUND: In the absence of an FDA-approved latex skin testing reagent, serological tests for latex-specific IgE have become essential confirmatory diagnostic tests. Two independent studies (JACI 103:925-30, 1999; Annals AAI 84:193-6, 2000) have shown diagnostic sensitivity of the most widely used blood tests (Pharmacia CAP System, DPC AlaSTAT) at 73-80% in comparison to puncture skin tests (PST), indicating a 20-27% false negative rate.
OBJECTIVE: To identify missing latex allergen specificities in the CAP and AlaSTAT reagents to target assay reagent improvement.
METHOD: Serum from 60 healthcare workers with a positive latex allergy history and positive PST using non-ammoniated latex [NAL] (JACI. 98:872-83, 1996) were analyzed for IgE specific for latex (CAP, AlaSTAT) and purified native Hevea brasiliensis [Hevb] allergens 1, 2, 3, 4, 6.01, 7b, 7c and recombinant Hevb 5. The 8 Hevb-specific IgE immunoassays (EIA) were performed with purified allergen adsorbed onto microtiter plates. Each assay was calibrated with a human IgE anti-NP chimeric antibody dose-response curve and bound IgE was detected with biotin-monoclonal anti-human IgE Fc (clone HP6061) and peroxidase-strepavidin. Analytical sensitivity of all 8 IgE anti-Hevb EIAs was 0.5 ng/ml.
RESULTS: The diagnostic sensitivity displayed by the CAP (49%; 28+/57) and AlaSTAT (67%; 40+/60) for latex-specific IgE in serum as compared to PST was lower than previously reported. Of the 57 sera from Hx and PST positive subjects tested by EIA for Hevb-specific IgE, 12 CAP negative sera (21%) and 9 AlaSTAT negative sera (15%) contained no detectable IgE antibody to any of the 8 individual Hevb allergens. Of these, interestingly, 11/12 (CAP) and 9/9 (AlaSTAT) specimens were from subjects who had positive PSTs to one or more of the 8 Hevb proteins, indicating the greater sensitivity of the PST. The remaining 17 CAP and 11 AlaSTAT negative sera (all from NAL PST positive subjects) fell into 3 positive IgE anti-Hevb patterns: Hevb 2-4-7b (n=9 CAP; n=7 AlaSTAT), Hevb 5 (n=6 CAP; n=2 AlaSTAT), Hevb 6 (n=2 CAP, n=2 AlaSTAT). CAP and AlaSTAT positive sera displayed heterogeneous IgE anti-Hevb patterns, with Hevb 5, 7b > 2, 4, 6 > 7c, 1, 3 being the IgE specificities in order of greatest frequency.
CONCLUSION: The suboptimal diagnostic sensitivity of two widely used commercial IgE anti-latex serology tests (CAP, AlaSTAT) has been confirmed with a new set of patients. Latex reagents in both assays appear to be missing immunoreactive allergenic epitopes from multiple latex allergens (Hevb 2, 4, 5, 6, 7b). Whether the absence of a complete Hev b allergen presentation in commercial diagnostic latex reagents results from poor handling of source latex or differences in the treatment of latex during reagent and glove manufacturing needs further investigation.
Hair Glue Anaphylaxis: A Hidden Latex Allergy
Increasingly popular cosmetic hair bonds and extensions employ latex (NRL)-containing bonding glue. T.C., a 37 year-old janitorial worker with a PMH of inhalant allergy, had recurrent exposure to NRL condoms and had 9 OB/GYN procedures. By age 34 she reported acute localized dermal pruritis after NRL contact. Later that year hair glue was used to apply braids to her undamaged scalp during 2 hair bonds, a month apart. Within minutes of the 2nd procedure localized scalp then generalized pruritis occurred followed by diffuse urticaria, angioedema, rhinoconjunctivitis and palpitations. T.C. removed the glue, took Benadryl and improved. The bonding glue involved in T.C.'s reaction contained 1262 µg/ml of total protein by modified Lowry analysis. It contained high concentrations of NRL antigens—880 µg/ml by LEAP assay and 231 µg/ml by inhibition ELISA. Immunoblot revealed an antigen pattern similar to ammoniated latex. Serial dilution (Dermapik) skin tests with the glue were positive at 1:10:000 on T.C. and were negative at 1:10 on 2 atopic controls. T.C.'s RAST was class III (HYCOR) and class II (AlaSTAT). Her sera also revealed IgE reactivity to non-ammoniated latex by Western blot and weak reactivity to NRL allergens Hev b 3,5,6 and 8. As in Pumphrey's report of fatal anaphylaxis in a British fashion designer during a hair alteration (JACI 107:558,2001), anaphylaxis occurred in our patient without mucosal contact and began with localized itching at the glue bonding site on her scalp. This glue contained levels of soluble NRL allergens higher than previously reported from NRL gloves and dipped products. Repeated exposure to bonding glues during hair alterations may potentially sensitize consumers to NRL. Physicians, cosmetologists and NRL-allergic patients should be aware of bonding glue-induced IgE-mediated NRL reactions and anaphylaxis associated with hair alterations.