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.

Direct Immunofluorescence (Dif) Microscopy In Cutanous Small Vessel Vasculitis: A Single Institution Experiences

“…Daha önce bazı merkezlerde yapılan çalışmalarda, İD'lerden en az bir tanesinin bulunması pozitif kabul edildiğinde, kutanöz vaskülitlerde ve LKV'lerde değişken oranlarda (%20-%70,5) DİF pozitifliği bildirildi (6,8,(9)(10)(11)17). Tüm KV'ler için en düşük oran %20 ile Feasel ve arkadaşlarının geniş vaka serisi içeren (1318 vaka) çalışmasında tespit edilirken (6), en yüksek oran Guerraro ve arkadaşlarının 20 vaka analizinde %70 olarak tespit edilmiştir (17).…”

“…Literatür taramasında DİF bulgularının ağırlıklı olarak ya herhangi bir sınıflama yapılmadan KV başlığı altında ya da LKV ve HSP vasküliti olgularında değerlendirildiği görüldü (6,8,(9)(10)(11)17). Sınıflandırılmış bir şekilde KKV'lerin-de DİF çalışmalarının oldukça sınırlı sayıda olduğu tespit edildi (12,14).…”

“…Sınıflandırılmış bir şekilde KKV'lerin-de DİF çalışmalarının oldukça sınırlı sayıda olduğu tespit edildi (12,14). (6,8,(9)(10)(11)13,17). Çalışmalarda en çok depolanan immunglobülin IgA (%30.6, %34.5, %64.7), en çok depolanan İD C3 (%54.5, %80.4, %82.2) olarak bildirilmiştir (8,10,13).…”

“…Bu çalışmada KKV'lerinin büyük bir kısmında (%58.7) perivasküler alanda ya da bazal membranda en az bir İD'in varlığı tespit edildi. PV alanda en fazla depolanan İD C3 (% 53.7), en fazla depolanan immunglobülin IgA (%11.6) olup literatür verileri ile uyumluydu (8,(9)(10)(11)(12)(13)(14). Doku üzerinde immunglobülin ve kompleman İD'lerinin belirlenebilmesi bazı otoimmün ve inflamatuvar hastalıkların teşhisi açısından klinik öneme sahiptir (15,16).…”

Biomarkers and Pathogenic Mechanisms in Autoimmunity

“…Finally, 282 cases of biopsy-proven leukocytoclastic vasculitis were discussed with a focus on direct immunofluorescence detection of immunoglobulin and complement deposition at the blood vessel wall. Their findings support immune complex deposition in the blood vessel wall being relevant to determine underlying conditions related to this disease [18,19]. The meeting ended up with many clinical and basic issues being discussed and with a clear agreement that the 11th meeting on autoimmunity should be a wider platform for new issues to be raised, and move on toward further scientific achievements.…”