Carboxylic activity of giant cells of human granuloma produced by Paracoccidioides brasiliensis.

The carboxilic activity of giant cells of human granuloma produced by P. brasiliensis was studied. The enzymatic activity was revealed by reddish-brown, purple red, and indigo-blue cytoplasmic precipitate, using the substrates alpha-naphthyl-acetate, naphthol-AS acetate and 5-bromo-4-chloro-indoxyl acetate respectively. The giant cells were intensely positive in all cases studied. We believe this esterasic activity is related to the lytic, lisosomic activity of the macrophages and giant cells in response to the activity by the P. brasiliensis in tissue.