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Title:Rekombinantne alergenske determinante in test aktivacije bazofilcev kot metodi odkrivanja klinično pomembne alergije pri bolnikih senzibiliziranih za arašide
Authors:ID Homšak, Matjaž (Author)
ID Korošec, Peter (Mentor) More about this mentor... New window
ID Mičetić Turk, Dušanka (Comentor)
Files:.pdf DOK_Homsak_Matjaz_2015.pdf (2,73 MB)
MD5: 72ECE3CD02BEF82CD70F256C7C560FB1
 
Language:Slovenian
Work type:Doctoral dissertation
Organization:MF - Faculty of Medicine
Abstract:Alergija na arašide je ena izmed pogostejših alergij na hrano. Pri sumu, da gre za alergijo na arašide, naredimo test s celotnim alergenom arašida. Osebe s pozitivnimi testi na celotni alergen arašida so pogosto le senzibilizirane in nimajo težav pri uživanju arašidov. Z opisanimi alergološkimi testi oseb z alergijo na arašide ne ločimo od ljudi z le pozitivnim testom (senzibilizirani). Z uporabo novejših diagnostičnih metod, določanjem rekombinantnih alergenov arašida in testom aktivacije bazofilcev (BAT), lahko bolj zanesljivo dokažemo alergijo na arašide. V preiskavo smo vključili šestinšestdeset otrok iz severovzhodne Slovenije s pozitivnimi testi na arašid z določanjem sIgE na arašid in/ali kožnim vbodnim testom. Otroke smo razdelili v 3 skupine: skupino z anafilaksijo (AN), skupino s simptomi, kot sta OAS in/ali urtikarija (OASU), ter skupino brez simptomov (SZ). Pri vseh smo določili sIgE na celotni arašid, na rekombinantne alergene arašida (rAra h 1, rAra h 2, rAra h 3, rAra h 8 in rAra h 9). Dodatno smo pri sedemindvajsetih otrocih izpeljali še analizo izražanja s CD63 aktiviranih bazofilcev (test BAT) po stimulaciji z arašidi, izračunali občutljivost bazofilcev (CD-sens). Vrednosti koncentracij sIgE na celotni alergen arašida nimajo povezave z alergijo na arašide. Drugače je pri sIgE za rekombinantne alergene. Otroci z anafilaksijo imajo izrazito višje vrednosti sIgE na rAra h 2 (mediana 34,6 KE/L) kot skupina otrok z OASU (mediana 0,46 KE/L), p = 0,006; pri skupini SZ je mediana 0,1 KE/L. sIgE na rAra h 1 so pomembno višji za skupino AN (mediana 3,1 KE/L) OASU (mediana 0,1 KE/L), skupina SZ (mediana 0,1 KE/L). Skupini OASU in SZ se ne razlikujeta. Rezultati sIgE na rAra h 3 nakazujejo pomembno nižje vrednosti pri SZ (mediana 0,1 KE/L), skupino AN (mediana 0,79 KE/L) in OASU (mediana 0,1 KE/L). Pri sIgE na rAra h 8 ugotavljamo obrnjen vzorec senzibilizacije: najvišje vrednosti so pri skupini OASU (mediana 0,5 KE/L), sIgE na rAra h 8 so najnižji pri AN (mediana 0,1 KE/L), saj je p = 0,04. V analizi ROC je pomembna povezanost sIgE na rAra h 2 s AUC 0,85 (prag 0,17 KE/L) pri vseh otrocih s simptomi, pri tistih z anafilaksijo pa celo 0,91 (prag 0,47 KE/L) z občutljivostjo 100 % in specifičnostjo 79 %. Za druge komponente so rezultati primerljivi s testi določitve sIgE celotnega alergena arašida. Pri testu aktivacije bazofilcev so razultati še povednejši: pri 11 otrocih z anafilakso je prisoten izredno visok odgovor v izražanju CD63 na bazofilcih pri submaksimalnih koncentracijah alergena iz surovih arašidov (PA; konc. 0,03 ng/ml, mediana 69 vs. 9 %) in komercialnega pripravka (CA; konc. 30 ng/ml, mediana 82 vs. 5 %; p < 0,0001 do 0,03) za razliko od 16 otrok z blagimi simptomi. Pri izračunu CD-sens znaša za otroke z AN mediana 3000-krat več kot pri otrocih z OASU ob stimulaciji s surovimi arašidi (mediana 1667 vs. 0,5) in 10-krat več po stimulaciji s komercialnim pripravkom (mediana 10 vs. 0; obakrat p < 0,0001). sIgE na rAra h 2 nakazuje izrazito alergogenost. Verjetnost alergije na arašide se povečuje z višanjem vrednosti sIgE na rAra h 2, posebej anafilaksije pri dodatno prisotnih arašidnih sIgE na rekombinantne alergene rAra h 1 in rAra h 3. sIgE na rAra h 9 v naši populaciji ni potrdila alergogenosti. sIgE na rAra h 8 je povezan z alergijo na brezo zaradi homologije z rBet v 1. Vrednosti sIgE na rAra h 2 nad 0,47 KE/L nakazujejo možnost anafilaksije na arašide. Še izraziteje to velja za visok BAT CD-sens. Visoka občutljivost bazofilcev v testu BAT je neposredno povezana z anafilaktično reakcijo pri arašidih. Z nizkimi vrednostmi senzitivnosti (CD-sens) lahko z veliko verjetnostjo izključimo možnost anafilaksije in tudi verjetnost alergije na arašide.
Keywords:alergija na arašide, rekombinantni alergeni, test aktivacije bazofilcev, otroci
Place of publishing:Maribor
Year of publishing:2015
PID:20.500.12556/DKUM-47966 New window
COBISS.SI-ID:512499768  New window
NUK URN:URN:SI:UM:DK:3A4S9NU4
Publication date in DKUM:01.06.2015
Views:2794
Downloads:321
Metadata:XML DC-XML DC-RDF
Categories:MF
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Secondary language

Language:English
Title:Recombinant allergen determinants and basophil activation test as methods of detection of clinicaly relevant allergy in patients sensitized to peanut
Abstract:Peanut allergy is one of the most common food allergies. Routine allergic tests cannot distinguish between subjects with true allergy or simple sensitisation. In our study we would like to explore the clinical relevance of novel diagnostic tests in peanut allergy. Recombinant allergen determination to peanut and basophil activation test (BAT) can accurately confirm whether a person is truly allergic to peanut, Sixtysix children from northeast Slovenia with positive tests to whole peanut eather with sIgE to peanut or skin prick test were included. We divided children in 3 groups: anaphylaxis group (AN), group with mild symptoms like OAS and/or urticaria (OASU) and sensitized patients group (SZ). They all underwent determination of whole peanut sIgE as well as recombinant allergens with rAra h 1, rAra h 2, rAra h 3, rAra h 8 and rAra h 9. Additionaly BAT testing with peanut stimulation was performed in 27 of them, after which we calculated basophil sensitivity testing (CD-sens) and set recombinant sIgE to grasses and birch (rPhl p 1-5 and 7, rBet v 1). Whole peanut sIgE levels did not correlate with clinical picture of peanut allergy (p=NS). When recombinant allergens were considered in children with anaphylaxis they expressed higher sIgE rAra h 2 levels (median 34.6 KU/L) vs. OASU (median 0.46 KU/L), in SZ group median concentration was 0.1 KE/L. For sIgE rAra h 1 in AN group there was a higher concentration (3.1 kU/L, p=0.03) when compared to OASU and SZ. There was no difference between OASU and SZ group for sIgE rAra h 1. In sIgE rAra h 3 there was a significant difference between SZ (median 0.0 KU/L) compared to AN (median 0.79 KU/L) and OASU group (median 0.1 KU/L). Sensitization in rAra h 8 showed a different picture where we confirmed the highest concentration of sIgE rAra h 8 in OASU group and SZ group with no statistical difference. For AN group significantly lower concentrations of rAra h 8 were detected (p=0.04). No differences were detected for rAra h 9. ROC analysis showed important influence of rAra h 2 (AUC 0.85, treshold at 0.17 KE/L) in children with symptoms, especially with anaphylaxis (AUC 0.91, treshold 0.47 KE/L). Sensitivity was 100 % and specificity 79 %. For the rest of recombinant allergens ROC analysis confirmed similar results as for whole peanut allergen tests (f13). The importance of our study was additionaly confirmed in BAT testing. Children in anaphylaxis group showed extremly high CD63 response at submaximal allergen concentrations in stimulation with raw peanuts (conc. 0.03 ng/ml median 69 vs. 9 %) and commercial extract (conc. 30 ng/ml median 82 vs. 5 %;p < 0,0001) compared to children with minor symptoms. CD-sens calculations was 3000-time higher in AN group vs. OASU group (median 1667 vs. 0,5) at stimulation with raw peanut allergen and 10-time higher for stimulation with commercial extract (median 10 vs 0;p < 0.0001). ROC curve analysis in CD-sens shows AUC 0.96 – 0.98 at sensitivity between 88-94 %. Peanut recombinant allergens are important in peanut allergy. Especially rAra h 2 express important allergenicity and is related with major clinical symptoms. Higher levels of sIgE to rAra h 2 and additional to peanut recombinant allergens rAra h1 and h 3 increase the likelihood of peanut allergy. rAra h 9 showed no allergenicity in our population. Homologus allergens Ara h 8 and Bet v 1 are important in birch allergy. If rAra h 2 concentration was > 0.47 KE/L peanut allergy is very likely (especially anaphylaxis). In case of additionaly elevated concentrations of rAra h 1 and h 3 we can avoid additional peanut chalenge test in 85 %, what can be very usefull in our diagnostic approach. This applies even stronger for high BAT CD-sens. High basophil sensitivity in BAT test is directly correlated with anaphylaxis. Low CD-sens levels probably exclude posibility of anaphylaxis or even peanut allergy.
Keywords:peanut allergy, recombinant allergens, basophil activation test, children


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