Leukocytoclastic vasculitis - Correlation between different histologic stages and direct immunofluorescence results

Background: Leukocytoclastic vasculitis is a well-known clinico- pathologic entity. A good correlation between clinical and direct immunofluorescence (DIF) findings has been shown only in the early stages of vasculitis. Our purpose was to determine the correlation between different stages of vasculitis, etiology of vasculitis, and DIF findings. Methods: Histologic and DIF studies were performed and evaluated from 40 patients with leukocytoclastic vasculitis. Results: Thirty-seven out of 40 patients (92%) showed positive DIF findings in the blood vessel walls. Eight patients were in the early stage of vasculitis and exhibited deposits mainly of fibrinogen, C3, and IgM. Seventeen patients were at the fully developed vasculitis stage and showed albumin, fibrinogen, and IgG deposits. Fifteen patients were in the late stage of vasculitis and showed deposits of mainly fibrinogen and C3 in the blood vessel walls. Conclusions: The present study demonstrates that DIF examination is a very sensitive test in the diagnosis of vasculitis, and can be used in all stages of vasculitis and not only in the early stages as has been shown in previous studies.