RESUMEN
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.