Proteoglycan alterations in rheumatoid arthritis—a light and electron microscopy study

We have previously studied the ultramorphology oh cells in rheumatoid arthritis using conventional staining techniques. We have recently reported a technique for the precipitation and fixation of proteoglycan using Toluidine Blue 0 or Safranin 0 which permits simultaneous localization of proteoglycan using either light or electron microscopy in sections cut from the same block. This paper reports a study of rheumatoid arthritic cartilage using this technique.Samples oh cartilage were removed from the femoral condyles of thirteen patients with classical rheumatoid arthritis who were having operations on the knee. Control samples were removed from the knees of eleven normal patients who were having surgery for recent trauma. In both Instances, the tissues were prepared with Toluidine Blue or Safranin 0 Introduced into the fixation process as will be described.When fixed and stained by conventional methods, articular cartilage has been traditionally reported to consist ofi chondrocytes lying in a matrix of collagen and proteoglycan though separated from this matrix by a pericellular clear space, “halo” or “lacuna” of varying dimensions. This pericellular space was thought to contain only small amounts of collagen.