Reproducibility of synovial fluid analyses. A study among four laboratories

Abstract

Aliquots from 30 synovial fluids were submitted to 4 laboratories for comparison of leukocyte counts and differential cell counts, and to 3 laboratories for a search for and identification of crystals. Leukocyte counts showed only fair correlation (coefficients of 0.76-0.80) with the reference laboratory. In synovial fluid from 4 patients, there was sufficient difference in leukocyte counts to cause the fluids to be erroneously classified as either "inflammatory" or "noninflammatory." In 12 of 24 fluid specimens examined, percentages of neutrophils fell outside the 95% confidence limits of the value determined by the reference laboratory. In 7 of the 11 patients with crystals reported, discrepancies were

The value of synovial fluid assays in the diagnosis of joint disease: a literature survey

“…24 In the Schumacher study results from three different hospital laboratories were compared with those recorded by an expert "reference" laboratory. 25 Reproducibility of results within the reference laboratory was also checked ("blind" assessments by two experienced operatives). This constitutes an intralaboratory study and tables 2 and 3 show the results.…”

“…Four studies involved a number of hospital laboratories assessing the same SF samples for crystal content. [24][25][26][27] In the fifth, six observers of variable experience within the same hospital laboratory, examined "blind", a range of synthetic crystal preparations. 28 A sixth study gave figures for sensitivity and specificity, and compared results for Gram stained versus "wet" slide preparations of SF containing MSUM.…”

Methods for detection of crystals in the joints: Status praesens. Part I

“…Однако многие авторы считают этот метод недостаточно чувстви-тельным и конкретным, чтобы квалифициро-вать его как стандарт для постановки диагно-за [11][12][13][14][15]. Это связано, во-первых, с тем, что разные кристаллы обладают различной степе-нью оптической анизотропии.…”

Update on identification of pathogenic crystals in joint fluid

“…Because it has been reported for some years that errors occur in crystal identification [3], thought has gone into the possibility of identifying some new technique perhaps more easily performed by clinical laboratories. No such breakthrough can be reported; thus, the authors review the few small developments in the past several years that may be of value.…”