Streptococcal infection in the pathogenesis of Behcet's disease and clinical effects of minocycline on the disease symptoms

Although the precise pathoetiology of Behcet's disease (BD) remains obscure, patients with BD have a high incidence of chronic infectious foci, indicating an enhanced susceptibility to chronic tonsillitis, and dental caries. Sometimes, clinical symptoms appear after treatment of these foci in BD patients. It is believed that BD might be related to an allergic reaction to a bacterial infection in view of the many clinical symptoms, especially the presence of aphthous and genital ulcerations. An attempt to obtain cutaneous responses to bacterial antigens has been carried out using various vaccines developed from bacteria isolated from the ulcerative lesions and oral cavities of BD patients. BD patients often show intense hypersensitivity to various strains of streptococci, not only by their cutaneous reactions but also by in vitro testing. In this report, we describe our previous studies on the correlation between streptococcal antigens and the pathogenesis of BD and also discuss the recent reports of other authors. The intense hypersensitivity to streptococcal antigens acquired after streptococcal infection is thought to play an important role in the appearance of symptoms in BD patients since the production of pro-inflammatory cytokines by peripheral blood mononuclear cells (PBMC) was enhanced when stimulated with streptococcal antigen in a culture system. Minocycline, an antibiotic to which certain strains of streptococci are sensitive, reduced the frequency of clinical symptoms in BD patients as well as the production of pro-inflammatory cytokines by BD-PBMC stimulated with streptococcal antigen.

Effects of Prostaglandin E_1 on Cell Proliferation and Cytokine Production in Human Keratinocytes and Dermal Fibroblasts / 中华皮肤科杂志

Prostaglandin E_1 (PGE_1) has been proven to be effective in the treatment of chronic skin ulcers and wounds.To elucidate the possible mechanism involved,normal human keratinocytes and der- mal fibroblasts were cultured with PGE_1.Cell proliferation was measured by MTT assay and cytokine production by enzyme-linked immunosobent assay (ELISA).The results revealed that keratinocytes produced IL-1?,IL-8,TGF? and PDGF,while dermal fihroblasts produced IL-6 and IL-8,suggesting dif- ferent kinds of cytokine production between keratinocytes and dermal fibroblasts.PGE_1 promoted IL-6 and IL-8 production in dermal fibroblasts but not in keratinocytes.Moreover,PGE_1 promoted cell prolif- eration in dermal fibroblasts but not in keratinocytes,suggesting that dermal fibroblasts are more sensi- tive than keratinocytes to PGE_1 and that the therapeutic effects of topical PGE_1 on skin ulcer or wound may mainly be mediated by its effects on dermal fibroblasts.