The preservation method and timing on accuracy of manual leukocytes counts in synovial fluid

Abstract

Objectives: To compare the efficacy of heparin and EDTA and determine the impact of time delays in stabilizing leukocyte counts in synovial fluid. Material and Method: 33 specimens were collected in heparin-preserved and EDTA-preserved containers. Total cell count was performed manually at 1 hour and 24 hours. Correlation between cell counts from both preservatives and the leukocyte number at 1 hour and 24 hours were analyzed by means of agreement measurement. Results: There were good correlations between the leukocyte numbers from the specimens preserved by heparin and EDTA (ICC = 0.889, r = 0.879, P < 0.0001 at 1 hour and ICC = 0.822, r = 0.693, p < 0.0001 at 24 hour ). At 24 hours, total cell counts from EDTA-preserved samples were comparable to those obtained at 1 hour ( ICC = 0.985, r = 0.986, p < 0.0001) and were not different from those of the heparinized samples (ICC = 0.833, r = 0.751, p < 0.0001) but the ICC value was higher. Conclusion: EDTA was as effective as heparin for preservation of synovial fluid. Therefore, it can be used routinely as a preservative of synovial fluid.