Cutaneous inflammatory cell infiltrate in chronic idiopathic urticaria: Comparison of patients with and without anti-Fc epsilon RI or anti-IgE autoantibodies

Background: Previous studies defining the histopathologic features of patie nts with chronic idiopathic urticaria (CIU) were performed on wheals of unc ertain duration and before the identification of functional autoantibodies against Fc epsilon RI and/or IgE, now known to be present in approximately 30% of patients with CIU. Objective: We sought to determine the timing of the inflammatory infiltrate in the wheals of patients with CIU and to detect differences between patie nts with and without autoantibodies. Methods: Immunohistochemistry was used to identify neutrophils (neutrophil elastase), T lymphocytes (CD3), and activated eosinophils (EG2) in biopsy s pecimens from uninvolved skin and wheals present for less than 4 hours and greater than 12 hours in 22 patients with CIU,as wed as in biopsy specimens from the skin of 12 healthy control subjects. Patients were identified as having functional autoantibodies on the basis of their serum-evoked histami ne release in vitro from the basophils of 2 healthy donors Results: EG2(+), neutrophil elastase(+), and, to a lesser extent, CD3(+) ce lls were found in greater numbers in wheals undergoing biopsy at less than 4 and greater than IZ hours than in uninvolved skin (P < .05). Patients wit hout autoantibodies (n = 12) had significantly more EG2(+) cells in wheals of greater than 12 hours' duration than patients with autoantibodies (n = 1 0; P = .02). There was no other difference between patients with and withou t autoantibodies in the cutaneous cellular infiltrate. Conclusion: Neutrophil and eosinophil accumulation occurs early in the evol ution of a wheal in patients with CIU but eosinophil activation may occur l ater or be more persistent in patients without autoantibodies.