title: Clinicopathologic correlation of 282 leukocytoclastic vasculitis cases in a tertiary hospital: a focus on direct immunofluorescence findings at the blood vessel wall.
abstract: This is the largest direct immunofluorescence (DIF) analysis of patients with histology-proven cutaneous leukocytoclastic vasculitis (LCV). To establish the correlation of deposition of immune complexes at the blood vessel walls with underlying causes and prognosis of LCV, we performed a retrospective study from January 2007 to December 2014. The patients are followed at the Department of Dermatology, Hospital Das Clínicas da Faculdade de Medicina da Universidade de São Paulo, a tertiary hospital at São Paulo, Brazil. We reviewed the data of 282 biopsy-proven LCV cases with DIF performed. For the statistical analysis, we included only patients with positive DIF exclusively in vessel walls (235/282 patients). We planned to find a correlation between the DIF profiles of LCV patients and the epidemiology data, underlying causes and prognosis. Ages ranged from five to 87 years old (yo), median age of 45 and 191/282 (67.73 %) were female individuals. DIF analysis showed positivity in 70.21 % of the samples, and C3 was the most frequent immunoreactant. Immunoglobulin A (IgA) deposition at the blood vessel wall was related to age and absence of autoimmune/inflammatory diseases. Immunoglobulin M (IgM) deposition at the blood vessel wall was related to females, autoimmune/inflammatory disorders, C3 and C4 consumption and antinuclear antibody and anti-SSA/anti-SSB positivity. Immunoglobulin G (IgG) deposition at the blood vessel wall was associated with age and positive ANCA; finally, C3 deposition at the blood vessel wall was associated with hematuria and renal involvement. Systemic involvement was present in 12.5 % cases of LCV patients. C3 deposits, the most frequent finding of this study, were related to renal involvement; IgA deposits to absence of autoimmune or inflammatory diseases; IgM deposition to the presence of autoimmune or inflammatory diseases and IgG deposits were associated with positive ANCA. DIF seems to be an important method to establish the prognosis and underlying etiology of LCV. Characterization of the immune complex at the blood vessel wall by DIF is relevant to determine underlying conditions related to LCV.
authors.affiliation: Department of Dermatology, Hospital das Clínicas, University of São Paulo Medical School, Av. Dr. Enéas de Carvalho Aguiar, 255, São Paulo, SP, 05403-000, Brazil.
authors.forename: Caroline Maris
authors.initials: CM
authors.lastname: Takatu
authors.affiliation: Department of Dermatology, Hospital das Clínicas, University of São Paulo Medical School, Av. Dr. Enéas de Carvalho Aguiar, 255, São Paulo, SP, 05403-000, Brazil. heringer@gmail.com.
authors.forename: Antonio Pedro Ribeiro
authors.initials: APR
authors.lastname: Heringer
authors.affiliation: Department of Dermatology, Hospital das Clínicas, University of São Paulo Medical School, Av. Dr. Enéas de Carvalho Aguiar, 255, São Paulo, SP, 05403-000, Brazil.
authors.forename: Valéria
authors.initials: V
authors.lastname: Aoki
authors.affiliation: Department of Dermatology, Hospital das Clínicas, University of São Paulo Medical School, Av. Dr. Enéas de Carvalho Aguiar, 255, São Paulo, SP, 05403-000, Brazil.
authors.forename: Neusa Yuriko Sakai
authors.initials: NYS
authors.lastname: Valente
authors.affiliation: Department of Dermatology, Hospital das Clínicas, University of São Paulo Medical School, Av. Dr. Enéas de Carvalho Aguiar, 255, São Paulo, SP, 05403-000, Brazil.
authors.forename: Paula Cristina
authors.initials: PC
authors.lastname: de Faria Sanchez
authors.affiliation: Health Science Institute, Federal University of Bahia, Salvador, Bahia, Brazil.
authors.forename: Jozélio Freire
authors.initials: JF
authors.lastname: de Carvalho
authors.affiliation: Department of Dermatology, Hospital das Clínicas, University of São Paulo Medical School, Av. Dr. Enéas de Carvalho Aguiar, 255, São Paulo, SP, 05403-000, Brazil.
authors.forename: Paulo Ricardo
authors.initials: PR
authors.lastname: Criado
mesh_terms: D000328:Adult; D001808:Blood Vessels / Q000276:immunology* / Q000473:pathology; D003176:Complement C3 / Q000276:immunology; D005260:Female; D019085:Fluorescent Antibody Technique, Direct; D006801:Humans; D007136:Immunoglobulins / Q000276:immunology; D008297:Male; D012867:Skin / Q000276:immunology / Q000473:pathology; D062606:Tertiary Care Centers; D018366:Vasculitis, Leukocytoclastic, Cutaneous / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology
chemical_list: D003176:Complement C3; D007136:Immunoglobulins
keywords: Cutaneous leukocytoclastic vasculitis; Cutaneous small vessel vasculitis; Cutaneous vasculitis; Direct immunofluorescence