Expression of transforming growth factor-beta 1 in chronic pancreatitis.

Transforming growth factor-beta 1 (TGF-beta 1) is a multifunctional cytokine which modifies tissue stromal matrix synthesis, cell proliferation and immune function. In the present study, we have used a mouse monoclonal antibody to the latent (intracytoplasmic) form of TGF-beta 1 to compare its expression in 144 cases of human chronic pancreatitis (both obstructive and chronic calcifying) with that of 10 control pancreatic specimens. In all the control specimens, and most of those with chronic pancreatitis, cytoplasmic immunoreactivity was identified in pancreatic duct and ductular epithelium, in islet cells and in vascular smooth muscle and endothelium. Two distinct patterns of ductular epithelial staining emerged: in morphologically normal tissues, only individual distal ductular/centroacinar cells stained but in chronic pancreatitis (whether chronic calcifying or chronic obstructive) the staining was panductular. Positive cytoplasmic immunostaining of acinar epithelial cells was found in 3% of pancreatitis specimens but in none of the normal controls. There was no staining of fibroblasts. Synthesis of TGF-beta 1 appears to be normally restricted to a population of epithelial cells located in terminal/centroacinar regions of the ductules (together with occasional ductal cells) whereas in chronic pancreatitis, TGF-beta 1 is expressed in most ductular and ductal epithelial cells.