PATTERNS OF REACTIVITY WITH ANTI-GLYCOLIPID ANTIBODIES IN HUMAN PRIMARY BRAIN-TUMORS

Antibodies against carbohydrates of three glycolipids were used to det ermine patterns of immunohistochemical reactivity of histologically id entifiable cell subpopulations in 101 human primary brain tumors. For all tumor types fibrillary cells, polar cells, and gemistocytes (commo nly seen in astrocytomas and ependymomas) stained more frequently for galactosylcerebroside with mAbO1 than small tumor cells and macrophage s. Frequency of staining for sulfatide with mAbO4 was fibrillary > pol ar > small cells = macrophages. Gemistocytes stained more frequently w ith mAbO4 than polar cells in all tumors except low grade astrocytomas . These data indicate that tumors classified on histological grounds a s astrocytic are often stained with antibodies that recognize oligoden drocytes and their progenitors. Thus, anti-glycolipid antibodies used in the study of developmental lineage may offer useful tools for class ification of human brain tumors. Staining of fibrillary cells, polar c ells, and gemistocytes for paragloboside directly with mAb F1H11 was m uch less common than with mAbO1, but this increased by pretreatment of the tissues with neuraminidase (F1H11 + N). Of particular note was th e finding that small tumor cells frequently stained with F1H11 + N. Ev idence that these were not macrophages was obtained using double immun ostaining with F1H11 + N and anti-macrophage antibodies. In astrocytom as the frequency of small tumor cells imnunostained with F1H11 + N was high grade > anaplastic > low grade, demonstrating a correlation of t his tumor cell population with more aggressive astrocytomas. Thus, imm unostaining with F1H11 + N may be of value in identifying small, anapl astic tumor cells, especially in small biopsies or tissue taken adjace nt to the main tumor mass. (C) 1994 Wiley-Liss, Inc.