IgE Antibodies to Mouse Urinary Allergens in Sera from Urban Asthmatics: How do we tell if it is an Important Allergen?

Abstract

RATIONALE: Positive skin tests to mouse urinary allergens have been reported among patients with asthma. In addition, mouse allergen has been detected in a large number of inner city homes. However, very little data has been reported about the titer of IgE ab to mouse allergen and it is not yet clear how significant this allergen is. METHODS: 833 sera from clinics, cross sectional, and ER studies (including 40% patients from urban areas) were assayed for IgE ab to mouse urinary allergen (Pharmacia ImmunoCAP code e88) and also to recombinant Mus m 1 using the Streptavidin technique (JACI June 2005). RESULTS: Positive results were found in 55 sera but only 7 sera had an IgE ab titer ≥10 IU/ml. Results for rMus m 1 showed a strong quantitative correlation with IgE ab to mouse allergen, r = 0.96, p<0.001. Comparing IgE ab to mouse urine with total IgE, this specific ab did not represent 5% of the total in any serum. In only one serum was IgE ab to mouse the strongest IgE ab response. Asthmatics (20/219) were more likely than non-asthmatics (2/215) to have a positive response to mouse urine, p = 0.006. CONCLUSIONS: Although skin tests to mouse urinary allergen may be common in inner city patients with asthma, the IgE ab response is generally very low titer and not comparable to mite or cockroach IgE ab responses.