Evaluation Of CCR3 As a Basophil Activation Marker

Background: Recent reports have provided conflicting evidence on the stability of CCR3 expression on the surface of basophils. Hence we wanted to independently evaluate the diagnostic usefulness of CCR3 as a surrogate marker of basophil activation and function.

Methods: We examined the correlative relationship between CCR3 expression on the surface of donor-basophils and histamine release after donor basophils were treated with agonistic antibodies directed against the high-affinity IgE-Fc receptor and serum samples from 80 individuals displaying symptoms of chronic urticaria (CU).

Results: We observed that CCR3 was significantly downregulated on donor-basophils treated with the agonistic antibody and CU-patient serum that demonstrated positive “histamine-releasing activity” (HRA scores >10). However, CCR3 downregulation was also observed on donor-basophils incubated with more than 40% of CU-patient serum samples with HRA scores less than 10.

Conclusions: Overall our data show that CCR3 demonstrates adequate sensitivity (83%) but weak specificity (59%) in its ability to reliably identify histamine-releasing activated basophils.