Cytocentrifuge Preparations 2. Synovial Fluid Cells

Abstract

A review of the literature would show, rightly, that neutrophils, lymphocytes and ‘mononuclear cells’ are the most commonly encountered cells in synovial fluid^1–4. Unfortunately, all too frequently, it would appear from published descriptions of synovial fluid cytoanalysis that they are the only cells within synovial fluid. There is a limit to the permutations possible with three cell types; it is scarcely surprising, therefore, that it is frequently concluded that synovial fluid cytoanalysis is of only limited diagnostic value. However, it is our experience that careful examination of cytocentrifuge preparations confirm the prediction (see Chapter 2) that it is possible to recognize a greater diversity of cell types than has been previously recorded. To fully appreciate this diversity, it is necessary to examine synovial fluid using a variety of techniques. Electron microscopy, immunocytochemistry and enzyme histochemistry reveal subgroups of cells that cannot be recognized morphologically. Unfortunately, these techniques cannot be employed as standard in most laboratories, and, although they will be used to supplement the data on the different cell types described in the next few chapters, much of the information presented will be derived from examination of cell morphology in standard Jenner—Giemsa-stained cytocentrifuge preparations.