P Ravaud1, C Hudry, B Giraudeau, B Weill, M Dougados. 1. Département d'Epidémiologie, Biostatistiques et Recherche clinique, Hôpital Bichat (AP-HP), Faculté Xavier Bichat, Paris, France.
Abstract
OBJECTIVE: To determine the usefulness of reagent test strips for screening inflammatory synovial fluid (SF). METHODS: Consecutive patients undergoing diagnostic arthrocentesis, attending the Department of Rheumatology of a large tertiary care hospital were evaluated. All SF specimens obtained were tested using two techniques: (i) white blood cell (WBC) count with the differential according to standard practice (which is considered the gold standard) (an inflammatory SF was defined as a WBC count > or =2000 cells/mm3); and (ii) reagent strips used to test urine (Multistix 8 SG, Bayer Diagnostics) for the presence of leucocytes (a positive test was defined as a strip showing more than a trace for leucocytes). Sensitivity, specificity, predictive values and likelihood ratio (LR) of the reagent strip in diagnosing inflammatory SF were determined. RESULTS: Two hundred and eight samples of SF were tested. The results of using the reagent strip were: sensitivity 76.9% (95% CI, 66.0-85.7%), specificity 86.9% (95% CI, 79.9-92.2%); positive LR, 5.88 (95% CI, 3.71-9.31) and negative LR, 0.27 (95% CI, 0.18-0.40). In 13 of the 19 false negative results, the differential cell count showed a predominance (> or =50%) of lymphocytes. CONCLUSION: This study suggests that, in daily practice, the evaluation of SF by reagent strips could be of use to discriminate between inflammatory and non-inflammatory SF.
OBJECTIVE: To determine the usefulness of reagent test strips for screening inflammatory synovial fluid (SF). METHODS: Consecutive patients undergoing diagnostic arthrocentesis, attending the Department of Rheumatology of a large tertiary care hospital were evaluated. All SF specimens obtained were tested using two techniques: (i) white blood cell (WBC) count with the differential according to standard practice (which is considered the gold standard) (an inflammatory SF was defined as a WBC count > or =2000 cells/mm3); and (ii) reagent strips used to test urine (Multistix 8 SG, Bayer Diagnostics) for the presence of leucocytes (a positive test was defined as a strip showing more than a trace for leucocytes). Sensitivity, specificity, predictive values and likelihood ratio (LR) of the reagent strip in diagnosing inflammatory SF were determined. RESULTS: Two hundred and eight samples of SF were tested. The results of using the reagent strip were: sensitivity 76.9% (95% CI, 66.0-85.7%), specificity 86.9% (95% CI, 79.9-92.2%); positive LR, 5.88 (95% CI, 3.71-9.31) and negative LR, 0.27 (95% CI, 0.18-0.40). In 13 of the 19 false negative results, the differential cell count showed a predominance (> or =50%) of lymphocytes. CONCLUSION: This study suggests that, in daily practice, the evaluation of SF by reagent strips could be of use to discriminate between inflammatory and non-inflammatory SF.
Authors: Louisa Kolbeck; Marco Haertlé; Tilman Graulich; Max Ettinger; Eduardo M Suero; Christian Krettek; Mohamed Omar Journal: In Vivo Date: 2021 May-Jun Impact factor: 2.155
Authors: Liza L Ramenzoni; Marc P Lehner; Manuela E Kaufmann; Daniel Wiedemeier; Thomas Attin; Patrick R Schmidlin Journal: Diagnostics (Basel) Date: 2021-03-22