Factor XIIIa(+) dermal dendrocytes in erythema elevatum diutinum and ordinary cutaneous leukocytoclastic vasculitis lesions

Factor XIIIa(+) dermal dendrocytes belong to the dermal microvascular unit and are related to wound healing, angiogenic and fibrogenic processes. Eryt hema elevatum diutinum (EED) is a leukocytoclastic vasculitis followed by r epair and fibrosis, In order to verify the involvement of fXIIIa(+)DD in th e pathogenesis of EED and ordinary leukocytoclastic vasculitis (OLV) these cells were immune labeled with anti-factor XIIIa antibody and quantified in 15 biopsies of EED, 18 of OLV: and compared with 11 fragments of normal sk in (NS). The number of vessels was evaluated by endothelial cell staining w ith anti CD34 antibody, FXIIIa(+)DD appeared in both groups of vasculitis w ith hyperthophic dendrites, with no difference ill their number at any leve l of the dermis. The number of fXIIIa(+)DD in the superficial dermis was hi gher in OLV than in NS (p<0.001), The number of dermal vessels in the EED g roup was higher at all dermis depths evaluated when compared with NS (p<0.0 5) and in the middle and deep dermis when compared with OLV (p<0.05). The r esults suggest the participation of fXIIIa(+)DD in the immunopathological m echanisms of both groups of vasculitis studied. However, there was no corre lation between the number of fXIIIa(+)DD and angiogenesis and fibrogenesis in the EED lesions.