THE INFLAMMATORY RESPONSE PROMOTES CUTANEOUS METASTASIS IN HAMSTERS INFECTED WITH LEISHMANIA (VIANNIA) PANAMENSIS

The influence of nonspecific and immunologically elicited inflammatory responses on the development of metastatic lesions was examined in th e hamster model of Leishmania (Viannia) panamensis infection. Delayed type hypersensitivity (DTH) responses were induced using the contact s ensitizing agent DNFB (2, 4-dinitro-1-fluorobenzene) and infection wit h L. panamensis followed by intradermal application of leishmanin. Non specific inflammatory response was achieved by the surgical excision o f toes. The inductive and eliciting procedures were performed on the e ars and fore and hind paws of the right side of experimental groups of hamsters that were inoculated in the snout with a highly metastatic s train of L. panamensis (MHOM/COL/84/1099). Skin metastases were detect ed by physical evaluation at 15-day intervals over a period of 7-8 mo. Suspected metastases were parasitologically confirmed by culture of t issue fluid aspirated from the lesion. The frequency of metastatic les ions was greater in hamsters subjected to inflammatory stimuli (14/38) than control animals (6/33; P = 0.035). Likewise, the frequency of me tastases at the site of induction and elicitation of inflammation (18/ 22 lesions) in the experimental groups was greater than that observed at the same site in control animals (5/11 lesions; P = 0.017). These f indings support a casual relationship between inflammatory response an d the development of lesions in this model of secondary disease caused by L. panamensis.