Reactivity of antibody YU-311 in formalin-fixed, paraffin-embedded specimens of normal organs, non-hematopoietic tumors, and mast cell tumors.

Abstract

YU-311 is a monoclonal antibody that reacts with a human leukemia cell line resistant for cytosine arabinoside and that identifies a 92 kDa membrane protein. The reactivity of YU-311 in normal organs, various non-hematopoietic tumors and in mast cell tumors in formalin-fixed, paraffin-embedded specimens was examined using immunohistochemical methods. In normal organs, YU-311 reacted with fundic glands of the stomach, the intercalated duct of the pancreas, the distal portion and the loop of Henle of renal tubules and tissue mast cells. Benign neoplasms of various organs showed no immunoreaction with YU-311, except for mast cell tumors. Some types of malignant neoplasms were occasionally positive against YU-311, suggesting neoplasms arising from or differentiating along normal YU-311-positive counterparts. Some other types of malignancies were rarely positive for YU-311, although their normal counterparts showed no immunoreactivity with YU-311. None of the non-epithelial tumors reacted with YU-311, except for one case of malignant melanoma. In contrast, normal tissue mast cells and their related tumors, such as urticaria pigmentosa or solitary mastocytoma, were constantly positive for YU-311. None of the non-hematopoietic human tumor cell lines examined in the present study was reactive with YU-311. These findings indicate that YU-311 is a good marker of some types of tumors and mast cell tumors and that an aberrant expression of YU-311 rarely occurs.