Serologic methods in the laboratory diagnosis of latex rubber allergy: study of nonammoniated, ammoniated latex, and glove (end-product) extracts as allergen reagent sources.
In the absence of approved natural rubber latex skin testing reagents, serologic methods for the detection of latex-specific immunoglobulin E (IgE) antibody are useful in the definitive diagnosis of latex allergy. In this study we examined extracts from two nonammoniated latex (NAL), two ammoniated latex (AL), and three diverse latex rubber gloves as sources of allergen for their utility in solid phase radioimmunoassays (SPRIAs) for latex-specific IgE. Serum samples were collected from 46 healthcare workers (HCWs), one beautician, two clerks, and seven children with spina bifida who exhibited clinical evidence of latex-associated contact dermatitis (CD, n = 8), contact urticaria (CU) with or without CD (n = 15), or systemic reactions involving respiratory symptoms with or without anaphylaxis (n = 33) and from 10 latex-exposed HCW control subjects with no latex allergy symptoms. Serum samples were coded and analyzed in a blinded manner in two laboratories by three particulate and four nonparticulate SPRIAs with different latex extracts on the allergosorbent. Intraassay coefficient of variation as assessed with 44 split, randomized, blinded serum specimens was < 20%. Agreement within a source of latex (e.g., NAL, AL, or gloves) and between laboratories was > 90% concordant for Glove 1/Glove 2 and NAL1/2. Specific IgE antilatex was detected in one of 10 latex-exposed control serum samples by five of the seven SPRIAs, despite a lack of clinical evidence for latex allergy in this otherwise atopic individual. Latex-specific IgE was detected in the serum of 22% of subjects with CU with or without CD, suggesting that IgE antibody may not be the primary factor involved in the induction of these local reactions. Approximately two thirds of the systemic reactor group had detectable latex-specific IgE in their serum, with levels ranging from 0.7 to 338 ng/ml. The predictive characteristics of these assays will await future provocation testing. We conclude that glove extracts contain as complete a repertoire of allergens as the NAL and AL. Of the three source latex materials, NAL and glove extracts provided the most sensitive and greatest consistency of IgE antibody results between laboratories.
Hamilton
R G
RG
Division of Allergy and Clinical Immunology, Johns Hopkins Asthma and Allergy Center, Johns Hopkins University School of Medicine, Baltimore, MD 21224.
Charous
B L
BL
Adkinson
N F
NF
Yunginger
J W
JW
D000328:Adult; D000485:Allergens / Q000276:immunology*; D000641:Ammonia / Q000276:immunology*; D002648:Child; D017449:Dermatitis, Allergic Contact / Q000276:immunology*; D017575:Gloves, Protective / Q000009:adverse effects*; D006801:Humans; D007118:Immunoassay; D007073:Immunoglobulin E / Q000097:blood*; D009784:Occupational Diseases / Q000276:immunology; D011237:Predictive Value of Tests; D012408:Rubber / Q000009:adverse effects*; D016135:Spinal Dysraphism / Q000276:immunology
D000485:Allergens; D007073:Immunoglobulin E; D000641:Ammonia; D012408:Rubber