Matrix remodelling and fibroblast phenotype in early lesions of human cutaneous leishmaniasis.

The connective matrix participates directly in early pathological events observed in the cutaneous lesion of leishmaniasis, due to Leishmania braziliensis guyanensis. A sample of 19 skin biopsies was examined by light and electron microscopy, in order to identify the matrix components (collagen isotypes I to IV, elastin and membrane associated proteins) of the dermal infiltrate, and the pattern of organization of the reparative connective matrix. An extensive remodelling process of apparently parasite-independent nature involves different fibroblast sub-populations. The original organization of this immune-mediated lesion offers a rare opportunity to study in situ the local inflammatory mediators inducing the activation of fibroblasts and macrophages.