Involvement of Can f 5 in a Case of Human Seminal Plasma Allergy

Abstract

Background: The existence of IgE binding to dog dander extract without IgE antibodies against the described dog allergens (Can f 1, 2, 3 and 4) implies the presence of other dog allergens yet to be identified. Recently, an IgE-binding protein was isolated from dog urine and identified as prostatic kallikrein; it has been named Can f 5. Cross-reactivity between a dog dander allergen and human prostate-specific antigen (PSA) has been described. The aim of this study was to identify the dog dander allergen that presents cross-reactivity with PSA and demonstrate its clinical relevance in our patient with human seminal plasma allergy. Methods: SDS-PAGE immunoblotting and inhibition tests were performed. Mass spectrometry was carried out to identify the protein involved in the allergy reactions. Results: SDS-PAGE immunoblotting-inhibition with an IgE-binding protein from dog prostatic secretion showed total IgE binding inhibition to a 28-kDa IgE-reactive band identified as PSA. The electroeluted protein from dog prostatic secretion was identified by mass spectrometry as Can f 5. IgE immunoblotting of human seminal plasma incubated with the serum of the patient revealed two IgE-binding bands (28 and 32.7 kDa). Both SDS-PAGE immunoblotting inhibition assays, with human seminal plasma or purified PSA in solid phase, showed complete IgE binding inhibition when the serum of the anaphylactic patient was preincubated with dog dander extract or recombinant Can f 5. Conclusions: The dog dander allergen that shows cross-reactivity with human PSA has been characterized and turns out to be the recently described Can f 5. We demonstrated the clinical relevance of this cross-reactivity in a patient.

World Allergy Organization Anaphylaxis Guidelines: 2013 Update of the Evidence Base

“…Cross-reactivity of this allergen with the newly identified dog dander allergen Can f 5 appears to be clinically relevant [41]. …”

What Could the Role of Can f 5 Allergen Be in Dog- Sensitized Patients in “Real Life”?

“…Some studies have highlighted the increasing importance of allergic sensitization to Can f 5 (a kallikrein), which is an androgen-regulated protein expressed in the prostate and detectable only in male dogs (small amounts might also be present in dog epithelia). In addition, Can f 5 may be involved in human seminal plasma allergy [7]. Schoos et al [8] recently suggested that patients monosensitized to Can f 5 seem to tolerate female dogs.…”

Seminal Plasma Allergy : A Literature Review

“…8 Moreover, few dog dander allergens demonstrate cross-reactivity with an allergic protein in human seminal plasma. 9,10 Furthermore, it has been hypothesized that an infection by microorganisms that introduce cross-reacting antigens may also result in the production of anti-sperm antibodies. 11 Levine et al have revealed that the causative antigen, which is a small protein, seems ubiquitous in the human prostatic secretion.…”