Characterization of rapidly adhering amniotic fluid cells by combined immunofluorescence and phagocytosis assays.

Culture of human amniotic-fluid cells from cases of fetal neural tube defects produces a population of rapidly adhering cells that were initially thought to be macrophages and later interpreted to be of neural origin. In this study double and triple labeling systems for the simultaneous detection of glial and macrophage differentiation marker antigens have been used to demonstrate that rapidly adhering cells cannot be considered a homogeneous population but instead represent two distinct cell types. One of these cell populations is of glial origin and shows specific staining for glial fibrillary acidic protein, while the other population is monocyte-derived macrophages which express marker antigens recognized by Leu M3, KiM7, and Dako antimacrophage monoclonal antibodies.