Comparison of Modified PhadezymRAST, ImmunoCAP, and serial dilution titration skin testing by receiver operating curve analysis

Is There An Association between Migraine and Allergic Rhinitis?

We conducted a prospective study to evaluate nasal signs and symptoms and to perform allergen-specific immunoglobulin E (IgE) testing to investigate the relationship between migraine and allergic rhinitis. Our study group consisted of 40 patients diagnosed with migraine—22 men and 18 women, aged 21 to 38 years (mean: 25.7). We compared their findings with a control group of 40 healthy adults—15 men and 25 women, aged 19 to 36 years (mean: 25.1). Allergen-specific IgE measurements were obtained with six groups of allergens: fungi, grass pollens, tree pollens, wild herbs, house dust mite 1, and house dust mite 2. We found no significant difference between the migraine patients and the controls in the incidence of nasal signs and symptoms (i.e., discharge, congestion, itching, and sneezing) or inferior turbinate signs (i.e., color and edema). According to the IgE assays, 14 migraine patients (35.0%) were sensitized to one or more allergens, compared with 11 of the controls (27.5%); the difference was not statistically significant. Sensitization was highest for the grass pollens panel in both groups. Even though we did not find an association between migraine and allergic rhinitis, the recent literature supports a correlation between migraine and atopy. The two conditions share common neural pathways and common mediators, and they can be linked statistically in patients and their families. A pathophysiologic association between the two conditions seems more likely than an etiologic association. In this regard, future efforts could be focused on the determination of atopy in migraine patients and the therapeutic implications of this diagnosis.

Tissue-specific immunoglobulin E in human nasal polyps

Allergy is generally believed to be an underlying cause of nasal polyps. The objective of this study was to define allergic nasal polyps. We investigated specific immunoglobulin E (sIgE) in polyp tissue. Thirty pieces of polyp tissue were taken from patients with positive allergic symptoms, and 30 from patients without allergic symptoms. Nasal polyp tissue homogenate and serum from these patients were prepared for detecting sIgE by a CAP method. For patients with allergic symptoms and/or positive serum CAP test results, the rates of positive tissue CAP tests were low: 36.7% and 35.7%, respectively. However, nearly all of the tissue CAP-positive subjects had allergic symptoms and positive serum CAP tests. We conclude that the local tissue sIgE profile reflects more specifically the allergic status of patients with nasal polyps than does the systemic serum test or the presentation of allergic symptoms. Thus, polyp tissue CAP tests might be performed in patients with positive allergic symptoms and positive serum CAP tests to define an allergy-induced polyp precisely. Then, specific antiallergic treatment could be administered to prevent polyp recurrence.

A Comparison of Skin Endpoint Titration and Skin-Prick Testing in the Diagnosis of Allergic Rhinitis

Among the many methods of allergy diagnosis are intradermal testing (IDT) and skin-prick testing (SPT). The usefulness of IDT has been called into question by some authors, while others believe that studies demonstrating that SPT was superior might have been subject to bias. We conducted a study to compare the validity of SPT and IDT—specifically, the skin endpoint titration (SET) type of IDT—in diagnosing allergic rhinitis. We performed nasal provocation testing on 62 patients to establish an unbiased screening criterion for study entry. Acoustic rhinometric measurements of the nasal responses revealed that 34 patients tested positive and 28 negative. All patients were subsequently tested by SET and SPT. We found that SPT was more sensitive (85.3 vs 79.4%) and more specific (78.6 vs 67.9%) than SET as a screening procedure. The positive predictive value of SPT was greater than that of SET (82.9 vs 75.0%), as was the negative predictive value (81.5 vs 73.0%). None of these differences was statistically significant; because of the relatively small sample size, our study was powered to show only equivalency. The results of our study suggest that the information obtained by the SET method of IDT is comparable to that obtained by SPT in terms of sensitivity, specificity, and overall performance and that both SET and SPT correlate well with nasal provocation testing for ragweed. Therefore, the decision as to which to use can be based on other factors, such as the practitioner's training, the desire for quantitative results, the desire for rapid results, and the type of treatment (i.e., immunotherapy or pharmacotherapy) that is likely to be chosen on the basis of test results.

ImmunoCAP and HY*TEC enzyme immunoassays in the detection of allergen-specific IgE compared with serial skin end-point titration by receiver operating characteristic analysis

OBJECTIVES

In this study, we compared 2 different immunoassays, HY*TEC enzyme immunoassay (Hycor Biomedical Inc, Garden Grove, CA) and Pharmacia Upjohn ImmunoCAP (Pharmacia and Upjohn, Kalamazoo, MI) using skin end-point titration as a gold standard by receiver operating characteristic analysis.

MATERIALS

One hundred patients were enrolled in this study and were tested with the above 3 modalities. The results were analyzed by receiver operating characteristic analysis, in which the curves give a decision criterion for any diagnostic test relative to its sensitivity and specificity against an accepted gold standard test. Only inhalant allergens (Dermatophagoides pteronyssinus, Dermatophagoides farina, cat dander, giant ragweed, English plantain weed, timothy grass, Alternaria tenuis, Aspergillus fumigatus, meadow fescue, oak tree, white ash tree, and lamb's-quarter weed) were studied.

RESULTS

The results obtained with both ImmunoCAP and HY*TEC showed a good correlation with skin end-point titration for D pteronyssinus, D farina, cat dander, giant ragweed, timothy grass, A tenuis, and meadow fescue, with sensitivities ranging from 71% to 88%. However, the sensitivity of both tests to English plantain weed, lamb's-quarter weed, oak tree, and white ash tree was lower (66% down to 39%). Additionally, HY*TEC results were not satisfactory for detecting specific IgE to A fumigatus (30% sensitivity). The overall sensitivity for each test was 65.67% for the HY*TEC and 71.25% for the ImmunoCAP.

CONCLUSION

The 2 in vitro testing systems are comparable for most of the allergens, except for A fumigatus, English plantain, lamb's-quarter, and white ash tree; ImmunoCAP and HY*TEC would benefit from improved technology for detecting these specific IgE antibodies. The HY*TEC assay did not give acceptable results for A fumigatus. The overall assay characteristics were good to excellent for each system tested.

Evidence of possible localized specific immunoglobulin E production in middle ear fluid as demonstrated by ELISA testing

To determine whether IgE in the middle ear represents a passive transudate from the serum or may be produced within the middle ear itself, paired effusion and serum from 18 atopic children with otitis media with effusion were tested by micro-ELISA for specific IgE to 12 allergens. Elevated effusion concentrations of specific IgE were present in 83.3% (15 of 18) of atopic patients, but only 30% (64 of 214) of the serum antibodies appeared in the effusion. The data show that in atopic children with otitis media with effusion, there is no relation between a patient's serum and effusion level of IgE for specific antibodies (P < 0.001), suggesting that IgE in middle ear effusion is not a transudate but more likely reflects an active localized process in atopic patients.

Comparison of mRAST and CAP with Skin end Point Titration for Altemaria Tenuis and Dermatophagoides Pteronyssinus

There has been a recent explosion of new in vitro tests for the diagnosis of allergies. At present there is no general agreement on which type of in vitro test is best. Recently our hospital switched in vitro testing from the modified radioallergosorbent system (mRAST) to the Pharmacia CAP system (CAP). While changing in vitro testing techniques, 47 patients were tested with both the mRAST and CAP tests. Comparisons were made between the mRAST and CAP results of Alternaria tenuis and Dermatophagoides pteronyssinus allergens. These results were then compared with the results of patients who also underwent intradermal skin testing based on end point titration techniques.