Disease resolution of 10.3 per 100 patient-years. A, Twice, faster resolution in patients with positive basophil activation test (BAT) results was observed in our cohort (P = .02). CD63 level higher than 1.8% represents a positive basophil activation test result, whereas CD63 level of 1.8% or lower is negative. B, Absence of basophils (negative BAT result) was associated with faster resolution of disease (HR, 0.40 [95% CI, 0.20-0,99]; P = .047).