Radioallergosorbent Test Method Research Articles

Correlations between Alder Specific IgE and Alder-related Tree Pollen Specific IgE by RAST Method

Wild birch trees grow in limited areas in Japan and are not a common aero-allergen. However, many patients who do not live in the area show positive birch pollen Radioallergosorbent Test (RAST). Therefore, being sensitized by another tree pollen which is closely related to birch may result in showing a specific IgE antibody to birch. Alder is a one of these trees and in the past it grew widely in Japan. However, there is no available RAST data as to the correlations between alder and alder-related trees. We measured the alder specific IgE (CAP-RAST, Phadea) in stored sera which was positive in birch RAST (228 samples), beech RAST (36 samples), oak RAST (152 samples) and cedar RAST (411 samples) and examined correlations between the RAST of alder and other trees. The correlation coefficient value of birch was very high (0.971). The other coefficient values of beech and oak were high (0.884 in beech and 0.895 in oak) but were slightly lower than that of the birch. This means that in terms of allergenicities, birch pollen is almost the same as alder and beech and oak are partly different from the alder. The Japanese respond to alder pollen just same as they do to birch pollen in forming specific IgE antibody. In clinical practice, positive alder RAST has the same meaning as positive birch RAST.

鼻アレルギー診断におけるＣＡＰシステム ＲＡＳＴ法との比較検討

The value of the radio allergosorbent test (RAST) in the detection of specific IgE antibody has been investigated by many researches.However, the clinical usefullness of the CAP-fluoro enzyme immuno assay (CAP-FEIA) method recently introduced for the same purpose as the RAST method is still not clear. The authors used both the RAST and the CAP-FEIA methods to test the same patients with nasal allergy and compared the results.It was found that the CAP-FEIA method was more sensitive than the RAST method in the detection of specific IgE antibodies to single or multiple antigens in patients with nasal allergy, except for house dust antigens. Further investigation showed that the lower sensitivity to house dust antigen was due to the impurities in the house dust extract.Reexamination with a new standard house dust extract showed as high sensitivity as to the other antigens. The CAP-FEIA method showed a better correlation with the results of skin tests than did the RAST method.It is concluded that CAP-FEIA is an excellent method for the diagnosis of nasal allergy.

Allergic reactions to enzymes used in plant cloning experiments

We report a case of rhinitis and asthma resulting from exposure to enzymes used in an experimental plant pathology laboratory. Immediate skin-test responses were elicited to both “Cellulase” and “Macerozyme” products, and a large late onset skin reaction occurred at the Cellulase site beginning in 6 hr. Special radioallergosorbent test (RAST) substrates were prepared that showed a strong positive response to Cellulase. By the RAST method other laboratory workers were screened and another symptomatic individual was found who also showed evidence of type 1 hypersensitivity to both enzymes. Skin biopsy and immunodiffusion data are presented. We conclude that enzymes used to digest cell wall structures of plants are capable of eliciting both immediate and late onset skin-test reactions and positive RAST responses in susceptible persons. These reactions are thought to be mediated by IgE antibodies and can be associated with symptoms of rhinitis and asthma.

IgE and IgG antibodies to bee venom as measured by a modification of the RAST method

The radioallergosorbent test (RAST) has been widely used in studying allergy to hymenoptera stings, but with variable results. We report here a modification of the RAST method which in a total of 157 bee keepers and family members, gave a close correlation between a positive RAST, and a history of generalized (100%) or localized (95%) allergic reactions. There was no positive RAST among forty-nine non-atopic control subjects but a striking finding was that 58% of non-allergic bee keepers had significant, but usually low, levels of IgE antibody to bee venom. IgG antibodies to bee venom have also been measured by a paper disc RAST which is quick and convenient. Levels were highest in non-allergic bee keepers. In the presence of high levels of IgG antibody, IgE antibody levels may be underestimated.

Enzymatic hydrolysis of allergens and assessment of the remaining allergenic activities by the paper disc radioallergosorbent method.

Birch-pollen and dog-epithelium allergenic extracts were hydrolyzed by the proteolytic enzyme pronase. The remaining allergenic activity in the hydrolyzed extract was then tested with various sera from allergen-sensitive patients, using the paper disc radioallergosorbent test method. The effect of enzymatic hydrolysis on dose-response curves was established. The isoelectrofocusing patterns of hydrolyzed and non-hydrolyzed allergen extracts were also compared.