Clinical evaluation of CAP System and RAST in the measurement of specific IgE.
We investigated the diagnostic value of a new in vitro test, Pharmacia CAP System (Pharmacia Diagnostics AB, Uppsala, Sweden), for the quantitative measurement of allergen-specific IgE antibodies by comparison with RAST in 2 groups of patients, 71 atopic and 48 non-atopic. In the last 20 years RAST has supplied a good diagnostic tool, but this test presents some problems, the main one being sensitivity. The new test has a solid phase able to bind even very small amounts of specific IgE and an anti-IgE tracer with very low cross-reactivity with other immunoglobulins, thus presenting more favourable conditions. From the analysis of our results, Pharmacia CAP System gave higher sensitivity (94% compared to 88% of RAST) with no loss of specificity (96% for both tests). The reliability of these results is ensured by the proper selection of patients who were all suffering from pollinosis and were clinically diagnosed as certainly hypersensitive to a single pollen. A positive trend was found between severity of asthma and levels of specific IgE for timothy. Pharmacia CAP System appears to identify a larger number of atopic patients than RAST.
Pastorello
E A
EA
1st Department of Internal Medicine, University of Milan, Italy.
Incorvaia
C
C
Pravettoni
V
V
Marelli
A
A
Farioli
L
L
Ghezzi
M
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D000485:Allergens; D000911:Antibodies, Monoclonal; D002214:Capsules; D002648:Child; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000175:diagnosis*; D007073:Immunoglobulin E / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D010944:Plants / Q000276:immunology; D011852:Radioallergosorbent Test; D012015:Reference Standards; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods*
D000485:Allergens; D000911:Antibodies, Monoclonal; D002214:Capsules; D007073:Immunoglobulin E