Detection of an allergen in dog dander that cross-reacts with the major cat allergen, Fel d 1.
BACKGROUND
A considerable proportion of animal-allergic patients are sensitized to both cat and dog allergens but knowledge about cross-reactive allergens in cat and dog dander is limited.


OBJECTIVE
To investigate whether dog dander contains an allergen that cross-reacts with the major cat allergen, Fel d 1.


METHODS
Recombinant Fel d 1 with the same immunological properties as natural Fel d 1 was used for quantitative (CAP) IgE competition experiments performed with sera obtained from cat-allergic patients (n=36). A Fel d 1 cross-reactive dog allergen was characterized by one- and two-dimensional immunoblotting using rFel d 1 for IgE inhibition experiments and with monospecific, polyclonal rabbit anti-recombinant Fel d 1 antibodies.


RESULTS
In 25% of Fel d 1-reactive cat-allergic patients, more than 50% inhibition of IgE reactivity to dog allergens was achieved with recombinant Fel d 1. An Fel d 1 cross-reactive 20 kDa allergen with a pI of approximately 3.4 was detected in dander extracts of several different dog breeds.


CONCLUSIONS
This is the first report demonstrating the presence of an Fel d 1-like allergen in dog dander extracts, which may be responsible for double positivity to cat and dog in serology. However, the clinical relevance of this cross-sensitization needs to be confirmed. These results are important for the diagnostic and therapeutic use of dog dander allergen extracts.
Reininger
R
R
Clinical Institute for Medical and Chemical Laboratory Diagnostics, Medical University of Vienna, Vienna, Austria.
Varga
E M
EM
Zach
M
M
Balic
N
N
Lindemeier
A D
AD
Swoboda
I
I
Grönlund
H
H
van Hage
M
M
Rumpold
H
H
Valenta
R
R
Spitzauer
S
S
D000328:Adult; D000485:Allergens / Q000276:immunology; D000818:Animals; D052179:Antigens, Plant; D002415:Cats; D002648:Child; D002675:Child, Preschool; D003429:Cross Reactions; D004285:Dogs; D004391:Dust; D015180:Electrophoresis, Gel, Two-Dimensional; D004787:Environmental Pollution; D005260:Female; D006023:Glycoproteins / Q000276:immunology*; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology*; D007106:Immune Sera / Q000276:immunology / Q000302:isolation & purification; D015151:Immunoblotting; D007073:Immunoglobulin E / Q000097:blood*; D008297:Male; D011817:Rabbits; D011994:Recombinant Proteins / Q000276:immunology; D012709:Serum Albumin / Q000276:immunology; D012882:Skin Tests
D000485:Allergens; D052179:Antigens, Plant; C522890:Can f 3 allergen, Canis familiaris; D004391:Dust; C522889:Fel d 2 allergen, Felis domesticus; D006023:Glycoproteins; D007106:Immune Sera; D011994:Recombinant Proteins; D012709:Serum Albumin; C091462:allergen Can f I; D007073:Immunoglobulin E; C059296:Fel d 1 protein, Felis domesticus