Dog dander is an important cause of respiratory allergy, but the spectrum of known dog allergens appears incomplete.
The 2 lipocalins, Can f 1 and Can f 2, and serum albumin, Can f 3, do not fully account for the IgE antibody-binding activity of dog dander extract.
The study authors focused on allergen activity of dog urine.
Dog urine was fractionated by size exclusion chromatography and examined for IgE antibody binding. One particular protein displaying IgE antibody-binding activity was identified by N-terminal sequencing and mass spectrometry.
This IgE antibody-binding protein isolated from dog urine was identified as prostatic kallikrein.
Prostatic kallikrein bound IgE antibodies from 70% of subjects with dog allergy, some of which reacted to none of Can f 1, Can f 2, or Can f 3.
The authors concluded that prostatic kallikrein was a new major dog allergen.
In addition, dog prostatic kallikrein cross-reacts with human prostate-specific antigen (PSA), a key culprit in IgE-mediated vaginal reactions to semen. Here is a case report that confirms this suspicion: Involvement of the dog allergen Can f 5 in a Case of Human Seminal Plasma Allergy http://goo.gl/cQSvj
Kallikreins are peptidases (enzymes that cleave peptide bonds in proteins), a subgroup of the serine protease family. There are at least 15 known kallikreins. Prostate specific antigen (PSA) is a kallikrein which liquefies the semen and allows sperm to swim freely.
Can f 6 and lipocalins may contribute to multisensitization in people allergic to mammals: dog, cat and horse (http://bit.ly/I03kmX).
Mind map: Indoor allergens
Mind map: Animal Dander Avoidance
See more Allergy and Immunology mind maps at AllergyCases.org.
Prostatic kallikrein: A new major dog allergen. Mattsson L, Lundgren T, Everberg H, Larsson H, Lidholm J. J Allergy Clin Immunol. 2009 Jan 7.
Prostate specific antigen, from Wikipedia, the free encyclopedia.
CNN: Allergic and wheezing, but still keeping pets
"You might think you’ve found the perfect dog or cat to suit your allergies, but experts say it doesn’t exist" http://goo.gl/9zUq3
From the Blogosphere: Barrack Obama's Daughter Has Asthma, Gets a Hypoallergenic Dog
Indoor Allergen Avoidance. Allergy Cases.
Children with a family history of allergies are less likely to develop eczema if they live with a dog starting in infancy http://goo.gl/gost
Image source: Yellow Labrador Retriever, Wikipedia, GNU Free Documentation License.