CLINICOPATHOLOGICAL CORRELATION OF HYPOCOMPLEMENTEMIC AND NORMOCOMPLEMENTEMIC URTICARIAL VASCULITIS

Background: Urticarial vasculitis is characterized by persistent urtic arial lesions with histologic evidence of leukocytoclastic vasculitis. Hypocomplementemic urticarial vasculitis (HUV) is a distinct clinical entity in a subset of patients;with urticarial vasculitis. Objective: We examined presentation of urticarial vasculitis and factors predict ive of connective tissue disease. Methods: The clinical, histologic, a nd immunologic characteristics of 132 patients with urticarial vasculi tis seen at the Mayo Clinic were examined, and features of the hypocom plementemic patients were compared with those of the normocomplementem ic patients. Results: Twenty-four patients (18%) had hypocomplementemi a; all were female. Interstitial dermal neutrophilia was seen in 19 bi opsy specimens (83%). On direct immunofluorescence (DIF) testing of le sional skin, 23 patients (96%) had a continuous strong granular deposi tion of immunoreactants along the basement membrane zone compatible wi th lupus erythematosus in addition to vascular fluorescence. Systemic lupus erythematosus (SLE) was present or occurred in 13 (54%). One hun dred eight patients (82%) had normocomplementemia; 65 (60%) were femal e. Interstitial dermal neutrophilia was seen in 11 of 26 (42%) randoml y selected biopsy specimens. On DIE one patient (1%) had the lupus ban d. SLE occurred in three patients (3%). Conclusion: Patients with HUV were more likely to be female, to have diffuse neutrophilia on biopsy specimens stained with hematoxylin and eosin, to have continuous stron g granular deposition of immunoreactants along the basement membrane z one on DIF, and to have SLE than normocomplementemic patients. We subm it that HUV represents a subset of SLE with shared clinical, laborator y, and immunologic features.