Supravital staining of synovial fluid with testsimplets

Abstract

We explored the use of Testsimplet (TS) After the history and physical examination, synovial fluid (SF) analysis ranks as the most simple diagnostic procedure for the evaluation ofjoint diseases. In many patients with septic arthritis and crystal-associated arthritis, a few drops of SF often yield a rapid and definitive diagnosis. In other rheumatic diseases, SF analysis provides useful information about the intensity of the inflammatory process and helps to narrow the differential diagnosis to conditions associated with either "inflammatory" or "noninflammatory" fluids.Differentiation of inflammatory cells is usually performed in air-fixed Wright-stained preparations and oc- casionally with the Papanicolaou stain. Wright stains of "noninflammatory" SF preparations are difficult to read when few cells are present or when the fluid is very viscous. Early reports suggested that supravital staining of fresh synovial fluid preparations using neutral red and Janus green were helpful in differentiating mononuclear cells in noninflammatory fluids. 6,7 We and others have been unable to corroborate these findings. 3,8 Supravital staining with cresyl violet and methylene blue is performed easily with precoated, dry glass slides containing these dyes (Testsimplet TM, Boehringer, Mannhein, Germany). 9-11 We report our experience with Testsimplet (TS) in the synovial fluid analysis of 159 patients with various rheumatic diseases. TS provided a rapid and reproducible method of SF supravital staining and allowed better visualization of Reiter cells, synovial cells, cartilage fragments, fat droplets, fibrin, monosodium urate, and calcium pyrophosphate dihydrate crystals than fixed, dried Wright-stained preparations. Calcium pyrophosphate and monosodium urate crystals were well preserved for simultaneous examination under compensated polarized light. Materials and MethodsTS was performed by placing a drop of SF on the center of the commercially available glass slide already containing the dried stains. The slide was covered with a glass cover slip and examined after 10-15 min9-l2 The differential cell count and the search for crystals under compensated polarized light with TS staining were compared with simultaneous same-patient control samples obtained with dry-fixed Wright-stained preparations and unstained synovial fluid fresh preparations, respectively.Routine SF analysis included a fresh preparation observed under regular and compensated polarized light, total cell count, and differential cell count in a dried, fixed Wright-stained preparation. These studies were performed on SF from 159 patients between 1988 and 1990 0

Processing of noninflammatory synovial fluids with hyaluronidase for cytospin preparations improves the accuracy of differential counts

“…[2][3][4][5][6] Wright's stained smears have proved useful when adequate numbers of cells are present, but this technique seems to have several shortcomings with NISF, i.e., 1) viscous fluids make for thick smears that make examination difficult, 2) because of the few cells it is often necessary to evaluate several smears to count 100 cells, and 3) an important percentage of cells, mostly mononuclears, appear to be damaged and difficult to identify. 3,4 Although supravital staining has proved to be useful in NISF, 5,6 it has the disadvantages that the prepared slides were, until recently, not readily available in the USA; staining without such special slides may be time-consuming; additional investigative procedures cannot be done on such specimens; and stained specimens cannot be saved for more than a few hours.…”

Intracellular and extracellular CPPD crystals are a regular feature in synovial fluid from uninflamed joints of patients with CPPD related arthropathy

“…Differential cell counts were done using pre-stained slides (Testsimplets, Boehringer Mannheim, Germany). 21 CPPD crystals were searched for in every cell and the percentage of cells with intracellular crystals was noted, as supravital staining with Testsimplets does not modify the morphology and optic characteristics of the crystals. …”