190 likes | 476 Views
ISAC and Component-resolved Diagnosis. Douwe de Boer, Chris Nieuwhof, Judith Bons en Paul Menheere. allergen = mixture of allergen components. B. A. E. D. C. Ebo et al. , University of Antwerp. Allergy: clinical relevance “ in vitro ” testing. intra-allergenic heterogeneity.
E N D
ISAC and Component-resolved Diagnosis April 23, 2013 Douwe de Boer, Chris Nieuwhof, Judith Bons en Paul Menheere
CRD and ISAC | De Boer, Nieuwhof, Bons and Menheere | April 23, 2013 allergen = mixture of allergen components B A E D C Ebo et al., University of Antwerp Allergy: clinical relevance “in vitro” testing intra-allergenic heterogeneity Component-resolved Diagnosis (CRD)
CRD and ISAC | De Boer, Nieuwhof, Bons and Menheere | April 23, 2013 ImmunoCAP ISAC (16 spots per mm2) RAST Single-analyte assay:single analysis of specific IgE directed against single allergens, single allergen components or mixtures of allergens classical ImmunoCAP assay RAST1 40 µL ISAC (Immuno Solid-phase Allergy Chip) Multiplex assay:multiple analysis of specific IgE directed against allergen components in one single run 30 µL ISAC112
CRD and ISAC | De Boer, Nieuwhof, Bons and Menheere | April 23, 2013 Storage protein Storage protein Storage protein Storage protein Profilin Storage protein Storage protein Pathogenesis Related-10 protein non-specific Lipid Transfer Protein intra-allergenic heterogeneity Component-resolved Diagnosis (CRD)
CRD and ISAC | De Boer, Nieuwhof, Bons and Menheere | April 23, 2013 Complications Detecting specific IgEs - 1 intra-allergenic heterogeneity inter-allergenic homogeneity non-specific Lipid Transfer Proteins Ara h 9 Ara h 8 Pathogenesis Related-10 proteins Profilins Ara h 5 Pan-allergens
CRD and ISAC | De Boer, Nieuwhof, Bons and Menheere | April 23, 2013 Complications Detecting specific IgEs - 2 Component-resolved Diagnosis (CRD) intra-allergenic heterogeneity inter-allergenic homogeneity
CRD and ISAC | De Boer, Nieuwhof, Bons and Menheere | April 23, 2013 Cross-reactive Carbohydrate Determinants specific glycan epitope Pan-allergens – risks and severity initially CCD was considered to be important to explain cross-reactivity mainly “plant” derived pan-allergens
CRD and ISAC | De Boer, Nieuwhof, Bons and Menheere | April 23, 2013 Cytoskeleton proteins rMer a 1 rAra h 5 rBet v 2 rPhl p 12 rHev b 8 rMal d 4 rPru p 4 Profilins Highly conserved proteins True pan-allergen (high degree of cross-reactivity)
CRD and ISAC | De Boer, Nieuwhof, Bons and Menheere | April 23, 2013 Unknown function rCor a 1.01 rCor a 1.04 rGly m 4 rAra h 8 rBet v 1 rApi g 1 rDau c 1 rPru p 1 rPyr c 1 rMal d 1 rPru ar 1 rPru av 1 Pathogenesis Related-10 Protein (PR-10) Large family and conserved proteins Heat and acid labile proteins
CRD and ISAC | De Boer, Nieuwhof, Bons and Menheere | April 23, 2013 Shuttle protein of lipids rZea m 4 rCor a 8 rPru av 3 rPru p 3 rAra h 9 rMal d 3 non-specific Lipid Transfer Protein (LTP) Relatively conserved proteins Heat and acid stable protein
CRD and ISAC | De Boer, Nieuwhof, Bons and Menheere | April 23, 2013 “Voorraad of opslag eiwitten” rSes i 3 rBer e 1 rCor a 9 rAra h 1 rAra h 2 rAra h 3 rAra h 6 nGly m 5 nGly m 6 Storage Protein Proteins for storage of energy mainly in seeds Relatively less conserved proteins pseudo-Pan-allergen (low degree of cross-reactivity)
CRD and ISAC | De Boer, Nieuwhof, Bons and Menheere | April 23, 2013 Pan-allergen sensitization in Europe
CRD and ISAC | De Boer, Nieuwhof, Bons and Menheere | April 23, 2013 ISAC and Component-resolved Diagnosis Conclusions and remarks • Component-resolved Diagnosis can give insights in sensibilisations for separate allergen components intra-allergenic heterogeneity • Besides separate allergen components groups of pan- allergens can be distinguished inter-allergenic homogeneity Components and pan-allergens are being associated with risks ISAC is a multiplex assay (an extensive number of components) RAST is a single analyte assay (limited number of components)