Cell-to-cell contacts between lymphoreticular cells in rheumatoid synovial membrane.

Nodular type and diffuse perivascular lymphoid cell infiltrates in rheumatoid synovial membranes from 72 patients were examined under the electron microscope. Attempts were made to describe the ultrastructural relations of the cells examined and to classify the different types of cell-to-cell contracts between them. Members of a complex series, composed of gradually differentiating forms of cell contacts beginning from simple membrane adherences and interdigitations and gap junctions; minute filamentous intercellular bridges: subsurface confronting cisternae and desmosome-like structures, are described and suggested as function-dependent morphological representatives of sites of cellular interactions.