BACKGROUND: The carbohydrate epitope galactose-α 1,3-galactose (α-Gal) is abundantly expressed on nonprimate mammalian proteins. We have recently shown that α-Gal is responsible for the IgE binding to cat IgA, a newly identified cat allergen (Fel d 5). OBJECTIVE: We sought to investigate the diagnostic relevance of IgE antibodies to Fel d 5 and α-Gal among parasite-infected patients from central Africa without cat allergy compared with patients with cat allergy from the same region. METHODS: Sera from 47 parasite-infected patients and 31 patients with cat allergy were analyzed for total IgE and IgE antibodies against cat dander extract (CDE) by using the ImmunoCAP system. Inhibition assay was performed with α-Gal on solid phase-bound CDE. The presence of IgE specific for the major cat allergen Fel d 1, Fel d 5, and α-Gal was analyzed by means of ELISA. RESULTS: Among the 47 parasite-infected patients, 85% had IgE antibodies against α-Gal (OD; median, 0.175; range, 0.102-1.466) and 66% against Fel d 5 (OD; median, 0.13; range, 0.103-1.285). Twenty-four of the parasite-infected patients were sensitized to CDE, and 21 of them had IgE antibodies to Fel d 5 and α-Gal. There was no correlation between IgE levels to CDE and rFel d 1 among the parasite-infected patients but a strong correlation between CDE and Fel d 5 and α-Gal (P < .001). Among the group with cat allergy, only 5 patients had IgE to α-Gal, and nearly 75% (n = 23) had IgE to rFel d 1 (median, 7.07 kU(A)/L; range, 0.51-148.5 kU(A)/L). In contrast, among the patients with cat allergy, there was a correlation between IgE levels to CDE and rFel d 1 (P < .05) but no correlation between CDE and Fel d 5 and α-Gal. CONCLUSION: IgE to α-Gal causes impaired allergy diagnostics in parasite-infected patients. Screening for IgE to rFel d 1 and other allergens without carbohydrates might identify patients with true cat sensitization/allergy in parasite-infested areas.
BACKGROUND: The carbohydrate epitope galactose-α 1,3-galactose (α-Gal) is abundantly expressed on nonprimate mammalian proteins. We have recently shown that α-Gal is responsible for the IgE binding to cat IgA, a newly identified cat allergen (Fel d 5). OBJECTIVE: We sought to investigate the diagnostic relevance of IgE antibodies to Fel d 5 and α-Gal among parasite-infectedpatients from central Africa without cat allergy compared with patients with cat allergy from the same region. METHODS: Sera from 47 parasite-infectedpatients and 31 patients with cat allergy were analyzed for total IgE and IgE antibodies against cat dander extract (CDE) by using the ImmunoCAP system. Inhibition assay was performed with α-Gal on solid phase-bound CDE. The presence of IgE specific for the major cat allergen Fel d 1, Fel d 5, and α-Gal was analyzed by means of ELISA. RESULTS: Among the 47 parasite-infectedpatients, 85% had IgE antibodies against α-Gal (OD; median, 0.175; range, 0.102-1.466) and 66% against Fel d 5 (OD; median, 0.13; range, 0.103-1.285). Twenty-four of the parasite-infectedpatients were sensitized to CDE, and 21 of them had IgE antibodies to Fel d 5 and α-Gal. There was no correlation between IgE levels to CDE and rFel d 1 among the parasite-infectedpatients but a strong correlation between CDE and Fel d 5 and α-Gal (P < .001). Among the group with cat allergy, only 5 patients had IgE to α-Gal, and nearly 75% (n = 23) had IgE to rFel d 1 (median, 7.07 kU(A)/L; range, 0.51-148.5 kU(A)/L). In contrast, among the patients with cat allergy, there was a correlation between IgE levels to CDE and rFel d 1 (P < .05) but no correlation between CDE and Fel d 5 and α-Gal. CONCLUSION: IgE to α-Gal causes impaired allergy diagnostics in parasite-infectedpatients. Screening for IgE to rFel d 1 and other allergens without carbohydrates might identify patients with true cat sensitization/allergy in parasite-infested areas.
Authors: Scott P Commins; Libby A Kelly; Eva Rönmark; Hayley R James; Shawna L Pochan; Edward J Peters; Bo Lundbäck; Lucy W Nganga; Philip J Cooper; Janelle M Hoskins; Saju S Eapen; Luis A Matos; Dane C McBride; Peter W Heymann; Judith A Woodfolk; Matthew S Perzanowski; Thomas A E Platts-Mills Journal: Am J Respir Crit Care Med Date: 2012-01-26 Impact factor: 21.405
Authors: Thomas A E Platts-Mills; Alexander J Schuyler; Anubha Tripathi; Scott P Commins Journal: Immunol Allergy Clin North Am Date: 2015-03-06 Impact factor: 3.479
Authors: Michael Levin; Danijela Apostolovic; Tilo Biedermann; Scott P Commins; Onyinye I Iweala; Thomas A E Platts-Mills; Eleonora Savi; Marianne van Hage; Jeffrey M Wilson Journal: Ann Allergy Asthma Immunol Date: 2019-03-26 Impact factor: 6.347