Immunocytochemical and biochemical characterization of the connective tissue component of fibrous papular lesions of oral mucosa

In an attempt to define the fibroblastic components of fibrous papular lesions of oral mucosa. 21 cases representing these lesions were selected for study. Paraffin or frozen sections of the lesions were stained, using the immunoperoxidase technique, with antibodies to: alpha-l-antitrypsin. alpha-l-antichymotrypsin. lysozyme. fibro-nectin. act in. myosin, and for Clq binding Three of these cases were biochemically analyzed for collagen Types 1. III. and V. This study demonstrated the presence of cytochemical markers in fibrous papules that were similar to those observed for the compartment of circumvascular fibroblasts in control normal mucosa. Analysis of the collagens present indicated that in addition to histologic similarities, the gene products of these extracellular matrices were similar to those reported for angiofibromas and Shagreen patches in tuberous sclerosis. The cells in these lesions appear to be distinct from myofibroblasts and the high affinity complement binding fibroblasts characterized by Bordin et al. (1).