BACKGROUND: There is no consensus about dermal dendrocytes (DD) function on physiopathological events on psoriasis. Pentoxifylline (PTX) is a methylxanthine that inhibits many inflammatory mechanisms. OBJECTIVE: The aim was to evaluate PTX effect on DD proliferation of psoriasis through immunohistochemical techniques. MATERIAL AND METHODS: Thirty psoriatic skin specimens before and 8 weeks after 1200mg/day PTX were incubated with primary rabbit antibody anti-factor XIIIa and binding antibody conjugated with alkaline phosphatasis. RESULTS: Factor XIIIa+ DD were prominent with large cytoplasm and markedly dendritic morphology. They were present in a diffuse manner in the papillary dermis and around vessels. After PTX they became oval with scarce cytoplasm, showed no dendritic extensions, and were only present in some papillary bodies. CONCLUSION: PTX pharmacological action promotes vessel flow enhancement, endothelial cell adhesivity decrease, and mast cells and DD factor XIIIa+ increase. PTX has an inhibitory action on TNF alpha, which could imply in a decrease of DD receptor expression, as CCR7, and maintenance of the tissular stimulus to signalization and migration of precursors, since the etiopathogenic processes would not be affected by the drug.
Dendritic cells; Pentoxifylline; Psoriasis
