II. Mechanism: Assays
- RadioAllergoSorbent Test (RAST)
- Older methodology
- ImmunoCAP has largely replaced the older RAST methodology
- Enzyme-linked Immunosorbent Assay (ELISA, most common)
- Fluorescent Enzyme Immunoassay (FIA)
- Chemiluminescent Immunoassay
III. Efficacy
- Lower Test Sensitivity than allergy Skin Testing
- Highly specific for allergens
- Standardized testing to 95% Positive Predictive Value for reactivity within the testing population
- Contrast with Skin Testing extracts which are not standardized
- Positive Result Precautions
- Positive tests do not absolutely indicate allergy
- Level of specific IgE does not correlate with severity of allergy
- Negative Result Precautions
- Negative results may indicate lack of prior exposure (and not lack of allergy risk)
IV. Indications
- Not recommended for food, venom, or drug allergies unless high risk for Anaphylaxis
- Alternative to Skin Testing in certain cases
- Age <3 years
- Skin Testing contraindicated
- High risk for Anaphylaxis
- Uncontrolled Asthma or other medical conditions
- Essential medications that require continuation (e.g. Beta Blockers, Antihistamines)
- Skin conditions that interfere with Skin Testing (e.g. Eczema)
-
Allergy Testing for common allergens
- Pet dander
- Dust mites
- Pollen
- Mold spores
V. Approach: Screen Contents
- June Grass and cross reacting grasses
- Rye
- Sweet Vernal
- Timothy
- Brome
- Oak Tree
- Short ragweed
- Alternaria mold
- Dust mite
- Cat
VI. Technique
VII. Interpretation: RAST Scoring
- Class 0: 200-750 (No significant allergy)
- Class 1: 750-1600 (Mild allergy)
- Class 2: 1600-3600 (Moderate allergy)
- Class 3: 3601-8000
- Class 4: 8001-18000
- Class 5: 18001-40000 (Most allergic)
VIII. References
Images: Related links to external sites (from Bing)
Related Studies
| Definition (NCI) | A type of blood test used to test for allergies. |
| Definition (MSH) | An in vitro allergen radioimmunoassay in which allergens are coupled to an immunosorbent. The coupled allergens bind the IgE in the sera of patients which in turn binds radioisotope-labeled anti-IMMUNOGLOBULIN E antibodies. |
| Concepts | Laboratory Procedure (T059) |
| MSH | D011852 |
| SnomedCT | 69214006, 143398009, 166022006, 397587005 |
| LNC | LP6477-6 |
| English | Allergens Radioimmunosorbent Assay, Allergens Radioimmunosorbent Assays, Radioallergosorbent Test, Radioimmunosorbent Assay of Allergens, Test, Radioallergosorbent, Tests, Radioallergosorbent, Radioallergosorbent Tests, EAST test, RAST-Radio-allergosorbent test, radioallergosorbent test, rast test, east test, radioallergosorbent testing, rasts, Test;RAST, rast testing, rast tests, rast, Radioallergosorbent test, RAST - Radio-allergosorbent test, Radio-allergosorbent test, RAST test, Radioallergosorbent test (procedure), Radioallergosorbent test, NOS, RAST test, NOS, RAST |
| Italian | Test di radioallergoadsorbimento, RAST, Prova di radioallergoassorbimento |
| Portuguese | Prova radialergabsorvente, Teste de Radioalergoadsorção, Testes de Radioimunoensaio para Alérgenos, RAST, Teste radioalergoabsorvente |
| Spanish | PRAA, Prueba de Radioalergoadsorción, Prueba de Radioinmunoadsorción de Alérgenos, prueba RAST, Test de Radioalergoadsorción, Ensayos de Alérgenos Radioinmunoadsorbente, RAST, prueba radioalergosorbente (procedimiento), prueba radioalergosorbente, Prueba de radioalergoabsorbente |
| Japanese | ＲＡＳＴ, 放射性アレルゲン吸着検査, RAST, ﾎｳｼｬｾｲｱﾚﾙｹﾞﾝｷｭｳﾁｬｸｹﾝｻ, 放射性アレルゲン吸着試験, アレルゲン放射性免疫吸着分析, ラジオアレルゴソルベントテスト, 放射性アレルギー吸着試験, 放射線アレルギー吸着検査法 |
| Swedish | Radioallergosorbent-test |
| Czech | radioalergosorpční test, RAST, Radioalergosorbentní test |
| Finnish | Radioallergosorbenttitesti |
| French | RAST (RadioAllergoSorbent Test), Test RAST, Test radioallergosorbent, Test radioimmunosorbent d'allergènes, Test radioallergosorbant, RAST |
| Russian | RADIOALLERGOSORBENTNYI TEST, RADIOIMMUNOSORBENTNYI ANALIZ ALLERGENOV, РАДИОАЛЛЕРГОСОРБЕНТНЫЙ ТЕСТ, РАДИОИММУНОСОРБЕНТНЫЙ АНАЛИЗ АЛЛЕРГЕНОВ |
| Polish | Próba radioalergosorbentowa |
| Hungarian | Radioallergosorbent vizsgálat, RAST (radioallergosorbent teszt) |
| Norwegian | RAST, Radioallergosorbent test |
| Dutch | radioallergosorbent test, RAST, Radio-allergo-sorbent-test, Test, radio-allergo-sorbent- |
| German | RAST, Radio-Allergo-Sorbent-Test, Radioimmunosorbent Assay auf Allergene |
Ontology: Allergen specific IgE antibody measurement (C1306725)
| Concepts | Laboratory Procedure (T059) |
| SnomedCT | 69214006, 104381000 |
| English | IgE - Specific IgE test, IgE - Specific immunoglobulin E test, Specific immunoglobulin E test, Allergen specific immunoglobulin E antibody measurement (procedure), Allergen specific IgE antibody measurement (procedure), Allergen specific immunoglobulin E antibody measurement, Allergen specific IgE antibody measurement |
| Spanish | medición de anticuerpo IgE específico de alérgeno, medición de anticuerpo IgE alergoespecíficos (procedimiento), medición de anticuerpo IgE alergoespecíficos, medición de anticuerpo IgE específico de alérgeno (procedimiento), medición de anticuerpo IgE específico de alérgenos |
