Immunopathogenic characterization of cutaneous inflammation in Behçet's disease

Behçet's disease (BD) is a recurrent multisystemic inflammatory disease characterized by recurrent oral aphthous and genital ulcers, ocular lesions and cutaneous lesions. Although many studies of cytokine levels in sera of BD patients have been conducted, there are only limited number of studies about the cytokine expression and cellular infiltration in the BD-related skin lesions.

To investigate the immunophenotypes and cytokine profiles of BD-related skin lesions.

Twenty patients who fulfilled the diagnostic criteria for BD with BD-related skin lesions were enrolled in this study. We assessed the histopathological features of BD-related skin lesions by immunohistochemical studies with anti-human CD4, CD8, CD68, FoxP3, CD-11b, IFN-γ and IL-4 antibodies.

Immunophenotyping of inflammatory infiltrating cells showed that CD68+ macrophages were the most common type of infiltrated cells in erythema nodosum-like lesions, erythema multiforme-like lesions and Sweet's syndrome-like lesions, whereas neutrophils were the main population of inflammatory infiltrating cells in papulopustular lesions. In all of the four types of BD-related skin lesions, the percentage of CD8+ T cells was higher than that of CD4+ T cells (P < 0.05), and IL-4 expression was stronger than IFN-γ expression (P < 0.05).

In this study, we assessed the infiltrating inflammatory cells and cytokine expression of acute cutaneous lesions in BD through immunohistochemical staining of BD-related skin lesions. Further studies about the disease activity and the molecular biology underlying the cutaneous inflammation are needed to understand the detailed pathogenesis of BD.