Specific IgE recognition of pollen allergens from subtropic grasses in patients from the subtropics.
BACKGROUND
Pollens of subtropical grasses, Bahia (Paspalum notatum), Johnson (Sorghum halepense), and Bermuda (Cynodon dactylon), are common causes of respiratory allergies in subtropical regions worldwide.


OBJECTIVE
To evaluate IgE cross-reactivity of grass pollen (GP) found in subtropical and temperate areas.


METHODS
Case and control serum samples from 83 individuals from the subtropical region of Queensland were tested for IgE reactivity with GP extracts by enzyme-linked immunosorbent assay. A randomly sampled subset of 21 serum samples from patients with subtropical GP allergy were examined by ImmunoCAP and cross-inhibition assays.


RESULTS
Fifty-four patients with allergic rhinitis and GP allergy had higher IgE reactivity with P notatum and C dactylon than with a mixture of 5 temperate GPs. For 90% of 21 GP allergic serum samples, P notatum, S halepense, or C dactylon specific IgE concentrations were higher than temperate GP specific IgE, and GP specific IgE had higher correlations of subtropical GP (r = 0.771-0.950) than temperate GP (r = 0.317-0.677). In most patients (71%-100%), IgE with P notatum, S halepense, or C dactylon GPs was inhibited better by subtropical GP than temperate GP. When the temperate GP mixture achieved 50% inhibition of IgE with subtropical GP, there was a 39- to 67-fold difference in concentrations giving 50% inhibition and significant differences in maximum inhibition for S halepense and P notatum GP relative to temperate GP.


CONCLUSIONS
Patients living in a subtropical region had species specific IgE recognition of subtropical GP. Most GP allergic patients in Queensland would benefit from allergen specific immunotherapy with a standardized content of subtropical GP allergens.
Stallergenes, Antony, France. Electronic address: j.davies2@uq.edu.au.
Emmanuel
E
Nony
The University of Queensland, School of Medicine, Brisbane, Australia.
Victoria
V
Timbrell
Stallergenes, Antony, France.
Maud
M
Hrabina
Stallergenes, Antony, France.
Mélanie
M
Boutron
Watkins Medical Centre, Brisbane, Australia.
Graham
G
Solley
Stallergenes, Antony, France.
Philippe
P
Moingeon
The University of Queensland, School of Medicine, Brisbane, Australia.
Janet M
JM
Davies
D000328:Adult; D000485:Allergens / Q000276:immunology / Q000627:therapeutic use; D052179:Antigens, Plant / Q000276:immunology; D016022:Case-Control Studies; D003429:Cross Reactions / Q000276:immunology; D031744:Cynodon / Q000276:immunology*; D003888:Desensitization, Immunologic; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D031781:Paspalum / Q000276:immunology*; D010936:Plant Extracts / Q000276:immunology; D011058:Pollen / Q000276:immunology; D011897:Random Allocation; D006255:Rhinitis, Allergic, Seasonal / Q000276:immunology*; D045868:Sorghum / Q000276:immunology*
D000485:Allergens; D052179:Antigens, Plant; D010936:Plant Extracts; D007073:Immunoglobulin E