Immunoblot and radioallergosorbent test inhibition studies of allergenic cross-reactivity of the predatory mite Amblyseius cucumeris with the house dust mite Dermatophagoides pteronyssinus.
BACKGROUND
In 1999, an extensive study among bell pepper growers showed that a predatory mite, Amblyseius cucumeris, is a potentially relevant source of occupational allergens because 23% of the population had positive skin prick test reactions.


OBJECTIVE
To investigate whether cross-reactivity between A. cucumeris and Dermatophagoides pteronyssinus is responsible for the cosensitization to both mite species found in 58.7% of A. cucumeris-sensitized greenhouse workers.


METHODS
Fifteen serum samples from greenhouse workers with work-related inhalant allergy and a positive radioallergosorbent test (RAST) reaction to A. cucumeris or D. pteronyssinus were selected for immunoblot analysis using extracts of both mites. A subselection (n = 5) was used for RAST and immunoblot inhibition to investigate potential cross-reactivity.


RESULTS
On immunoblot, 2 distinct patterns were observed: one pattern showed common protein bands in A. cucumeris and D. pteronyssinus blots suggestive of cross-reactivity between A. cucumeris and D. pteronyssinus and the other pattern showed no shared protein bands. Dermatophagoides pteronyssinus RAST inhibition with A. cucumeris extract was low in 4 serum samples (<25% inhibition) and nearly absent in 1 serum sample; A. cucumeris RAST inhibition with D. pteronyssinus extract was high in 1 serum sample (75% inhibition), low in 2 serum samples (35% and <15% inhibition), and absent in 2 serum samples. These results were confirmed by immunoblot inhibition experiments.


CONCLUSIONS
Amblyseius cucumeris, a new occupational allergen, has species-specific antigens and common antigens that are cross-reactive with the house dust mite D. pteronyssinus.
Department of Allergology, Erasmus MC, Rotterdam, the Netherlands. n.w.dejong@erasmusmc.nl
Nicolette W
NW
de Jong
Giséle C M
GC
Groenewoud
Ronald
R
van Ree
Astrid
A
van Leeuwen
Ab M
AM
Vermeulen
Albert W
AW
van Toorenenbergen
Hans
H
de Groot
Roy Gerth
RG
van Wijk
D000328:Adult; D000382:Agricultural Workers' Diseases / Q000209:etiology / Q000276:immunology*; D000485:Allergens / Q000276:immunology* / Q000302:isolation & purification; D000818:Animals; D015153:Blotting, Western; D002212:Capsicum / Q000276:immunology / Q000469:parasitology; D002415:Cats; D015331:Cohort Studies; D003429:Cross Reactions; D040002:Dermatophagoides pteronyssinus / Q000276:immunology; D004285:Dogs; D005260:Female; D006197:Hair / Q000276:immunology; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000150:complications; D007073:Immunoglobulin E / Q000276:immunology; D008297:Male; D008875:Middle Aged; D008925:Mites / Q000276:immunology*; D009426:Netherlands; D006109:Poaceae / Q000276:immunology; D011058:Pollen / Q000276:immunology; D011852:Radioallergosorbent Test; D012130:Respiratory Hypersensitivity / Q000209:etiology / Q000276:immunology*; D012867:Skin / Q000276:immunology; D012882:Skin Tests; D014020:Tissue Extracts / Q000276:immunology; D014197:Trees / Q000276:immunology
D000485:Allergens; D014020:Tissue Extracts; D007073:Immunoglobulin E