Evaluation of the Phadiatop® test in an epidemiological study

Sera from 204 adult patients with chronic airways obstruction were analysed with the Phadiatop, a new allergosorbent test with a paper disc containing the most relevant inhalant allergens, the PRIST for total IgE determinations, and a panel of seven RAST tests with the common inhalant allergens in The Netherlands as reference. The aim was to evaluate the Phadiatop as screening test in the in vitro diagnostic procedures in an epidemiological setting. The Phadiatop was classified positive or negative according to percentage binding, total IgE was considered elevated at values greater than 100 kU/l and the RAST panel positive when at least one RAST result was class greater than 1. The prevalence of inhalant atopy came to 27.9%. The predictive value of the Phadiatop for a positive RAST panel was 96.4%, and for a negative RAST panel 97.3%. For the PRIST these values were 51.9% and 87.2% respectively. The correlation between the log percentages binding of the Phadiatop and the RAST panel was 0.93. It is concluded that the Phadiatop is a valuable test for the screening of inhalant atopy, and as the percentage binding of the Phadiatop may reflect the degree of sensitization it could also be applied as a quantitative measure especially for epidemiological purposes.     

Current allergic asthma and rhinitis: diagnostic efficiency of three commonly used atopic markers (IgE, skin prick tests, and Phadiatop®)

Total serum IgE, Phadiatop®, and the skin prick test (SPT) are commonly used to diagnose atopic diseases. However, no large study has ever been done to test their diagnostic efficiency. We studied the diagnostic value of these three atopic markers in 8329 well-randomized adults from the Swiss Population Registry. The prevalence of current allergic asthma (CAA) was 1.8% and of current allergic rhinitis (CAR) 16.3%. The prevalences of positive Phadiatop, positive SPT (at least, one out of eight SPT to common aeroallergens with a wheal of >3 mm), and positive total IgE (IgE >100 kU/1) were 29, 23, and 23%, respectively. To diagnose CAA and CAR. the sensitivity of Phadiatop was significantly higher than that of SPT (72.5% vs 65.4%, 77.1% vs 68.4% respectively; P<0.01 and <0.001) and IgE (72.5% VA- 56.9%, 77.1% vs 43.9%, respectively; both p<0.001). The sensitivity of SPT was significantly higher (68.4% vs 43.9% P<0.001) than that of IgE to diagnose CAR. When CAA and CAR were excluded, the SPT specificity was significantly higher than that of Phadiatop (77.8% vs 71.9% and 85.9% vs 80.5%, respectively; both P<0.001): when CAR was excluded, SPT was significantly higher than IgE (85.9 vs 81.4%; P<0.001). SPT had significantly the best positive predictive value for CAA (5.2% for SPT vs 4.6% for both IgE and Phadiatop; both P<0.001) and CAR (48.7% for SPT vs 43.5% for Phadiatop and 31.6% for IgE; both P<0.001). The three markers of atopy had roughly the same negative predictive value (NPV) for CAA, but IgE had a significantly lower NPV for CAR than SPT and Phadiatop (88.1% vs 93.3% and 94.7%, respectively; both P<0.001). The diagnostic efficiency of SPT was significantly higher than that of Phadiatop (83.1% vs 79.9% and 77.6 vs 71.9%, respectively; both F<0.001) to diagnose CAR and CAA. IgE and SPT had equal efficiency (77.6%), which was significantly higher than that of Phadiatop, to diagnose CAA (71.9%; both P<0.001). In conclusion, SPT have the best positive predictive value and the best efficiency to diagnose respiratory atopic diseases. Furthermore, SPT give information on sensitivity to individual allergens and should therefore be used primarily by clinicians to assess respiratory allergic diseases. Moreover, they are cheaper and provide immediate, educational information for both patient and physician.     

The Phadiatop® test compared with RAST, with the CAP system; proposal for a third Phadiatop outcome: "inconclusive"

In 19 general practices, blood samples were obtained from 361 patients aged 12 years or older with chronic nasal symptoms. The Phadiatop test and a panel of RASTs to common inhalant allergens were performed on all sera with the recently introduced Pharmacia CAP system. The RAST panel was accepted as the standard. The sensitivity of the Phadiatop was 94% (95% confidence interval (CI): 89–97%), the specificity 98% (95% CI: 95–99%), the positive predictive value 97% (95% CI: 94–99%), and the negative predictive value 95% (95% CI: 91–98%). It is noteworthy that these values are very similar to those found in hospital outpatient departments. It was possible to reduce further the small percentage of false outcomes by replacing the cutoff point of the Phadiatop ratio of 1.00 by the two cutoff points 0.75 and 1.15. This resulted in three possible outcomes: a highly predictive positive outcome, a highly predictive negative outcome, and an "inconclusive" outcome. Alternatively, the cutoff point of 1.00 may be maintained while attaching the annotation "borderline" to all positive or negative Phadiatop outcomes where the Phadiatop ratio is between 0.75 and 1.15. By this simple method, physicians are alerted to the possibility of a false outcome; on the basis of the case history and other clinical findings, they can then decide whether further testing should be done.     

In vitro diagnosis of farmers' IgE-mediated allergy by Phadiatop® and three new multiallergen RAST analyses

Identification of persons with atopic allergy in a population is difficult if the pattern of sensitizing allergens is unique. Three new multiallergen tests, Professional Allergy Mixes (PAX) 1–3 (Pharmacia Diagnostics, Uppsala, Sweden), have recently been inttoduced to screen IgE-mediated allergy among farmers. PAX 1 contains animal danders and feathers, PAX 2 mites and insects, and PAX 3 pollens and molds. The value of these new tests for the determination of IgE-mediated allergy among fanners was compared with that of Phadiatop®, a test for general atopy. Of 440 farmers, 91 were positive to Phadiatop and 97 to any of PAX 1–3. None of the farmers were positive in all tests. Only 70/97 sera positive in RAST to PAX 1–3 had a positive Phadiatop, whereas of 91 sera positive in Phadiatop, 70 had specific IgE antibodies to PAX 1–3. The value of using either Phadiatop or PAX 1–3 is limited (sensitivity 74–79%), but, together, these four tests will detect almost all (95.9%) farmers with IgE-mediated sensitization and all (100%) with symptoms. We have also shown that the grain weevil Sitophilus grcmarius and the botfly Gaslerophihts intestinalis are important sources of allergens in rural environments.     

The use of Phadiatop® in mass-screening programmes of inhalant allergies: advantages and limitations

The validity of Phadiatop as a tool in the mass screening for inhalant allergies was investigated. Seventy-nine out of 600 recruits (13.2%) were classified as allergic to inhalant allergens (68 oculorhinitis; 11 asthma) on the basis of positive history, confirmed by skin testing and/or RAST for the seven most common aero-allergens in Italy. Another 74 subjects had positive RAST and/or skin tests, yet had never experienced allergic symptoms. Phadiatop was positive in 145/600: in 78 out of 79 allergics and in 67 RAST-positive non-allergics. Correlation between Phadiatop and RAST was statistically significant, though higher for grass pollens (r = 0.85, P less than 0.001) than for Dermatophagoides pteronyssinus (r = 0.68, P less than 0.01). PRIST (cut-off 220 IU/ml) identified 36/79 allergics (45.6% sensitivity, whereas that of Phadiatop was 98.7%). As the high percentage of cases in the unselected population had specific serum IgE against inhalant allergens and no allergic symptomatology, the Phadiatop-positive predictive value falls to 53.7%, thus creating the need for Phadiatop-positive subjects to undergo further investigation for an appropriate diagnosis. Given this limitation, Phadiatop appears to be an important step forward in the field of mass-screening programmes for inhalant allergies.     

Evaluation of new system for the detection of IgE antibodies (CAP) in atopic diseases

An evaluation of a newly developed IgE antibody assay system (CAP) was carried out. There was a clear correlation between IgE antibody titers measured by CAP single and RAST (= 0.642 to 0.979). It turned out that CAP single is more sensitive than RAST and non-specific adsorption of IgE immunoglobulin to the solid phase was assumed to be less in CAP than in RAST. Pathogenic allergens diagnosed either clinically or by in vitro assay systems were compared. The sensitivity and specificity of the CAP system were 94.2% and 87.3%, respectively. CAP multi which binds groups of multiple allergens on the solid phase, was examined for the screening of hypersensitivity to categories of allergens. Statistical sensitivities of CAP multi resided between 63.9% to 86.2%, while the specificities were 98% to 100%, indicating that CAP multi is useful for the exploration of causative allergens. Phadiatop, which fixes multiple inhalant allergens, showed a sensitivity of 89.6%. The specificity of phadiatop was 93.9%, when examined for intrinsic bronchial asthma patients, and 91.2% for normal subjects indicating that phadiatop is more useful than total IgE measurement for the screening of atopic trait.     

Screening of atopic allergy in 5-year-old children – a comparison of the diagnostic properties of Phadiatop Paediatric and Phadiatop

The ability of Phadiatop Paediatric (PP), Phadiatop (P), mixed-food RAST (MF), and the combination of P and MF to identify children with atopic allergy was evaluated among 193 children who had a family history of atopic disease, and who had an average age of 5 years. If atopy is defined as the presence of at least one positive skin prick test ( 2 +) to common food and/or inhalant allergens, P had a sensitivity of 86%, a specificity of 94%, and an efficacy of 92%. These figures were somewhat better than the results with PP. However, when P was combined with MF, the sensitivity increased to 89%, but at the expense of lowered specificity (83%) and efficacy (84%). If the tests were related only to clinical signs/symptoms of atopic disease, the sensitivity and efficacy were, at maximum, 63% and 81%, respectively. There was a discrepancy between the results of P and PP in 9% of the children. One explanation of this discrepancy may be that PP seems to be incapable of detecting children with respiratory allergies induced by pollens from birch and related trees. The results indicate that in 5–6-year-old children P should be preferred to PP and to the combination of P and MF for atopy screening, at least in places where birch pollen is a common allergen.     

In vitro screening for inhalant allergy with multi SX 1 RAST® (Phadiatop®)

A new in vitro screening test for inhalant allergy (Phadiatop, Pharmacia Uppsala, Sweden) was evaluated for its effectiveness in identifying allergic patients. The test is based on the radio-allergo-sorbent-test (RAST). Specific IgE antibodies to different inhalant allergens are detected simultaneously. Serum samples from 300 patients and controls were run with Phadiatop. 96% of 150 patients with proved allergic disease were correctly identified by Phadiatop. 92% of 150 individuals without clinically relevant allergic hypersensitivity were found correctly to be negative. Allergic disease was proved or excluded by case history, skin prick test, RAST and, in some cases, additionally by provocation challenge.     

Diagnosis of allergy in different age groups of children: use of mixed allergen RAST discs, Phadiatop and Paediatric Mix

Childhood asthma often begins in children under 3 years of age. Allergy contributes to the severity and persistence of childhood asthma so we examined the application of mixed allergen RAST discs (Paediatric Mix, a mixture of food antigens and Phadiatop, a mixture of inhalants) to the diagnosis of allergy. One hundred and nine children with a median age of 3 years, 71.6% of whom had asthma, were first assessed by one allergist who recorded their atopic status as positive, negative or questionable, on clinical grounds. Serum from each of these patients was used to determine a total IgE and 13 RAST assays. A laboratory definition of atopy was defined as a serum IgE > 1 standard deviation from normal, plus one or more positive RAST assays. The laboratory results influenced the assessment of atopy in 41% of cases. The use of just two mixed allergen discs (Paediatric Mix and Phadiatop) correctly assigned the presence or absence of atopy with a sensitivity of 98% and specificity of 98%, compared with the full laboratory evaluation. Very young infants were often just positive to food allergens but the Phadiatop disc could be used to suggest the onset of immunological sensitivity to inhalant antigens. Thus the application of mixed allergen RAST discs facilitated the diagnosis of atopy in young children.     

Phadiatop—a novel IgE antibody screening test

The Phadiatop® test, which is based on a multi-allergen allergosorbent, proved to be a test that is simple to perform in the laboratory and produces reliable results. When compared with the more conventional RAST atopy screening test for grass, mite and IgE antibodies it produced similar results, except in those rare instances of patients who were RAST-positive only for moulds where the Phadiatop test was decidedly superior. The Phadiatop test disc contains only inhalant allergens and so it could not be used for screening infants and very young children whose IgE response, if any, is probably limited to foods.     

Reliability of respiratory symptoms to diagnose atopy

As reliance of responses to epidemiological questionnaires on atopic symptoms is doubtful, we studied the predictive value of these questions relative to atopy, defined by the presence of serum specific IgE, taking into account some extraneous variables such as age and sex. The study population included 2067 adults, 20-60 years old. The protocol consisted of a standardized questionnaire and an evaluation of serum specific IgE using the Phadiatop (Pharmacia Diagnostics, Uppsala, Sweden) test. The predictive value of each symptom suggestive of atopy was quite low, but was much dependent on age and sex. Women more often than men reported atopic symptoms in the absence of atopy. Similarly, the predictive value of each symptom decreased with age. Thus atopic symptoms do not have the same value as predictors of atopy. These findings have both clinical and epidemiological important implications.     

Is there a role for immunoblots in the diagnosis of latex allergy? Intermethod comparison of in vitro and in vivo IgE assays in spina bifida patients

BACKGROUND: The best diagnostic method for latex allergy is still controversial. This investigation was designed to evaluate the diagnostic efficiency of immunoblotting in comparison with established in vitro and in vivo test systems. METHODS: A total of 108 spina bifida patients were investigated by questionnaire and skin prick test (SPT). Specific serum IgE to latex was analyzed by the Pharmacia CAP FEIA immunoassay, DPC AlaSTAT microplate immunoassay, and DPC AlaBLOT immunoblot. Patients were regarded as latex allergic if they reacted positively to challenge by the latex glove wearing test. RESULTS: Thirty-four patients reacted positively to challenge. The sensitivity rates were 97% (SPT), 94% (immunoblot, CAP), 74% (AlaSTAT), and 35% (clinical history). The specificity rates were 92% (clinical history), 88% (AlaSTAT), 77% (SPT), 76% (CAP), and 69% (immunoblot). If two methods were combined, efficiency rates were highest for SPT combined with CAP (sensitivity 94%, specificity 82%), with AlaSTAT (sensitivity 74%, specificity 92%), or with immunoblot (sensitivity 91%, specificity 84%). The sera of challenge-positive patients recognized more immunoblot bands than challenge-negative patients, and the severity of symptoms correlated with the number of recognized bands. CONCLUSIONS The diagnostic efficiency of immunoblotting is not superior to that of SPT. However, immunoblotting may serve as an additional tool to increase slightly the specificity of SPT and specific serum IgE tests.     

Evaluation of a dipstick test (Allergodip-Latex) for in vitro diagnosis of natural rubber latex allergy.

BACKGROUND: IgE-mediated hypersensitivity to latex has been recognized as an increasing health problem with far-reaching consequences for patients, regarding both their occupational situation and safety in medical care. Therefore, a correct diagnosis of natural rubber latex (NRL) allergy is essential. The purpose of the study was to evaluate sensitivity and specificity of several established diagnostic methods for NRL allergy (in vitro assays and skin prick test) in relation to a new semiquantitative dipstick test (Allergodip-Latex, Allergopharma) as a screening test for NRL allergy. METHODS: Data obtained with quantitative assays including Pharmacia CAP System(FEIA), DPC-AlaSTAT and Magic Lite were compared with the dipstick test results in latex-sensitized (n = 151) and nonsensitized persons (n = 232). In addition these in vitro findings were related to clinical symptoms after exposure to latex and skin prick test results with a panel of different latex allergen extracts. RESULTS: When comparing sensitivity and specificity of all in vitro assays relative to skin prick test results the Pharmacia CAP System (FEIA) had the highest sensitivity in the range of 90%. Sensitivity of the other in vitro assays was in the range of 73.7-74.9%, specificity varied from 85.3 to 89.8%. A diagnostic standard was defined in terms of at least three corresponding test results out of all diagnostic methods (in vitro assays and skin prick test). The sensitivity and specificity of each diagnostic test were determined relative to this diagnostic standard. Hereby the Allergodip test results showed a sensitivity of 91% and a specificity of 93%. CONCLUSION: The dipstick test results are in line with the data of the other in vitro assays. In contrast to other in vitro assays the dipstick test requires no further laboratory equipment and is easy to perform.     

Prevalence of muscle relaxant sensitivity in a general population: implications for a preoperative screening.

BACKGROUND: Muscle relaxants (MR) are responsible for 59% of peroperative anaphylactic reactions. A major issue would be to determine whether a systematic preoperative screening in the general population should be recommended. OBJECTIVE: The purpose of the study was to evaluate the prevalence of muscle relaxant sensitivity in a sample of the general population and to assess the role of possible risk factors. METHODS: Two hundred and fifty-eight subjects, aged 20-40 years, visiting a health care centre for a check-up were evaluated. Protocol included a questionnaire (occupation, symptoms of atopy, previous surgery, history of drug allergy), skin-prick tests to four commercial muscle relaxants and measurement of specific IgE against quaternary ammonium ions. Atopy was evaluated by skin-prick tests to common inhalant allergens and by a Phadiatop test. RESULTS: Of the study group, 9.3% had either a positive skin test to one or more muscle relaxant or a presence of specific IgE to quaternary ammonium ions. No risk factor was identified in the studied group. CONCLUSION: Since the rate of MR sensitivity is much higher than the anticipated rate of peroperative reactions due to allergy, a systematic preoperative screening for MR allergy should not be recommended for adults in a general population.     

Allergy to complex salts of platinum in refinery workers: prospective evaluations of IgE and Phadiatop® status

BACKGROUND: Experience has shown some variation in the associations between IgE, atopy, and sensitization to platinum salts. Clarification of these associations, and the value of the parameters in predicting and diagnosing sensitization of workers at risk, required prospective investigation. OBJECTIVES: Evaluation of total IgE and Phadiatop(R) status to establish baseline values, and changes during employment, predictive or associated with subsequent platinum salt sensitization. METHODS: A 24-month prospective study, in a South African primary platinum refinery, of a cohort of 78 healthy recruits without evidence of atopy (tested negative to skin prick test with common allergens). Subsequently they were categorized as 22 sensitized (positive skin prick test to platinum salts), 46 not sensitized (negative skin prick test and symptom free), and 10 symptomatic subjects not included in either category. RESULTS: (1) Pre-employment: four (18%) of the subsequently sensitized subjects and eight (17%) not sensitized were Phadiatop(R) positive. Levels of total IgE > 100 kU/L, present in 16 subjects were associated with positive Phadiatop(R) status and race. (2) During employment: Phadiatop(R) status converted from negative to positive in more sensitized (12/18) than unsensitized (6/38) subjects (P 相似文献   

Flow cytometric basophil activation test by detection of CD63 expression in patients with immediate‐type reactions to betalactam antibiotics

BACKGROUND: In this study, we used flow cytometry to determine the percentage of activated basophils that expressed the CD63 marker after in vitro stimulation by different betalactam antibiotics. The diagnostic reliability of the technique was assessed, as well as its correlation with specific IgE. METHODS: Fifty-eight patients with clinical allergy to betalactam antibiotics and presenting positive skin tests to at least one of the allergens (minor determinant mixture (MDM), benzylpenicilloyl-polylysine (PPL), penicillin, ampicillin, amoxicillin, cephalosporins) were tested. Thirty subjects non-allergic to betalactams were also studied as controls. The flow assay stimulation test (FAST) uses flow cytometry to determine the percentage of basophils that express CD63 as an activation marker after in vitro stimulation with allergen. Double labelling with monoclonal antibodies anti-CD63-PE and anti-IgE FITC was used. RESULTS: The allergic patients show a statistically greater number of activated basophils than the control subjects, after the incubation of cells with all the betalactams at various concentrations. The sensitivity of the technique is 50%, the specificity 93.3%, the likelihood ratio for a positive value 7.46 and the likelihood ratio for a negative value 0.54. In spite of having a greater sensitivity (37.9%) and specificity (86.7%) than CAP, differences between sensitivity and specificities of both techniques (CAP and FAST) do not reach statistical significance. CONCLUSION: The basophil activation test is a particularly useful technique in the diagnosis of patients with IgE-mediated allergy to betalactams and allows the identification of 50% of patients. Used in conjunction with CAP, it allows the identification of 65.5% of such patients.     

The search of latex sensitization in spina bifida: diagnostic approach

BACKGROUND: Sensitization to latex has become a major problem in children with spina bifida. Life-threatening reactions may occur in these patients, therefore the search of latex sensitization must be an active task in all of these children. OBJECTIVE: To design an approach for the diagnosis of latex sensitization in children with spina bifida. METHODS: We studied 100 consecutive unselected patients. Skin prick tests with a commercial latex extract were performed, latex-specific serum immunoglobulin (Ig) E was determined by CAP test, and risk factors were studied. Originally, patients with an area of latex skin test > 50% of the area of histamine and/or CAP class > or = 3 were considered sensitized to latex. Diagnostic tests were also performed in a control group of 51 atopic and nonatopic children. RESULTS: After performing a receiver-operating characteristics curve for both tests we recommend skin tests > 25% of the area of histamine (sensitivity - SEN = 79%, specificity - SPE = 100%, positive predictive value - PPV = 100%, negative predictive value - NPV = 90%), or CAP class > or = 2 (SEN = 88%, SPE = 100%, PPV = 100%, NPV = 94%) as diagnostic cut-off points. The anamnesis had a SEN of 44% for diagnosis, and a SPE of 100%. Latex sensitization was associated with more than 5 operations (OR = 8, 95% CI = 3-21.3), a personal history of atopy (OR = 11.5, 95% CI = 2.3-57.1), and serum total IgE > or = 2 z-units (OR = 4, 95% CI = 1. 6-10). CONCLUSION: For the routine evaluation of children with spina bifida, we propose a diagnostic algorithm with skin prick tests as a first step and CAP second.     

Comparison between RAST and Pharmacia CAP system: a new automated specific IgE assay

RAST represents the standard technique to titrate serum-specific IgE and was found to have a higher efficiency in the diagnosis of IgE-mediated allergy than other in vitro tests. Pharmacia CAP system (CAP) is a new solid-phase immunoassay, fully automated, used for the titration of specific IgE antibodies. Results are listed in kilounits per liter, equilibrated against the World Health Organization standard for IgE. RAST and CAP were compared in 106 unselected patients (6 to 59 years) characterized by a detailed clinical history and skin prick tests with standardized allergen extracts. IgE to cat, Dermatophagoides pteronyssinus, Alternaria, orchard grass, olive, and Parietaria pollen were tested; 470 tests were run. The specificity, sensitivity, and efficiency of both in vitro tests ranged from 85.5% to 100% except for olive pollen, in which the sensitivity of both in vitro tests was low (68.2% for the new test and 63.6% for RAST). Except for orchard-grass pollen, the sensitivity and specificity of CAP were better than that of RAST. There was a highly significant correlation between both tests (r range, between 0.864 to 0.987). CAP competes favorably with RAST and has the advantage of being automated and eliciting results in kilounits per liter.     

Prepandemic viral community-acquired pneumonia: Diagnostic sensitivity and specificity of nasopharyngeal swabs and performance of clinical severity scores

The objectives of this work were to assess the diagnostic sensitivity and specificity of nasopharyngeal (NP) swabs for viral community-acquired pneumonia (CAP) and the performance of pneumonia severity index (PSI) and CURB-65 severity scores in the viral CAP in adults. A prospective observational cohort study of consecutive 341 hospitalized adults with CAP was performed between January 2018 and March 2020. Demographics, comorbidities, symptoms/signs, analytical data, severity scores, antimicrobials, and outcomes were recorded. Blood, NP swabs, sputum, and urine samples were collected at admission and assayed by multiplex real time-PCR, bacterial cultures, and Streptococcus pneumoniae and Legionella pneumophila antigens detection, to determine the etiologies and quantify the viral load. The etiology was identified in 174 (51.0%) patients, and in 85 (24.9%) it was viral, the most frequent rhinovirus and influenza virus. The sensitivity of viral detection in sputum (50.7%) was higher than in NP swabs (20.9%). Compared with sputum, the positive predictive value and specificity of NP swabs for viral diagnosis were 95.8% and 96.9%, respectively. Performance of PSI and CURB-65 scores in all CAP with etiologic diagnosis were as expected, with mortality associated with higher values, but they were not associated with mortality in patients with viral pneumonia. NP swabs have lower sensitivity but high specificity for the diagnosis of viral CAP in adults compared with sputum, reinforcing the use NP swabs for the diagnostic etiology work-up. The PSI and CURB-65 scores did not predict mortality in the viral CAP, suggesting that they need to be updated scores based on the identification of the etiological agent.     

Analysis of available diagnostic tests for latex sensitization in an at-risk population

BackgroundLack of a Food and Drug Administration (FDA)–approved skin testing reagent for latex allergy in the United States requires reliance on patient history and serologic assays for diagnosis.ObjectiveTo determine the diagnostic sensitivity, specificity, and predictive values of an FDA-cleared antilatex IgE serology test and an enzyme-linked immunosorbent assay (ELISA) with various sources of latex protein antigens in an at-risk but unselected population of health care workers.MethodsHealth care workers underwent duplicate latex and serologic testing for latex specific IgE with the CAP assay and ELISA from June 1, 1998, through December 31, 2002. Logistic regression with receiver operating characteristic curve analysis determined the values, resulting in 98% and 99% specificity for the CAP assay and ELISA, respectively.ResultsResults of paired skin and serologic tests were available for 792 participants. Forty duplicate skin test results (5%) were positive. For the CAP assay, sensitivity was 35%; specificity, 98%; positive predictive value, 48.3%; and negative predictive value, 96.6%. ELISA demonstrated similar results. Multivariable logistic regression yielding a 98% or 99% specificity for the various ELISAs demonstrated that the adjusted odds of a positive skin test result significantly increased with positive CAP assay and ELISA results using a powdered glove extract.ConclusionsThe performance of the FDA-cleared antilatex IgE serologic test for latex allergy has much lower sensitivity than previously reported. This finding confirms that this serologic test should be used only for patients with a history of latex allergy and not for screening the population with a low prevalence of latex sensitization.