RESUMEN
There is not a suitable marker in dilution method in analysis of biomarker in joint fluid. In past, dye dilution method was used for joint fluid, but there were some errors. The aim of this work is the use of rate change lactate level in serum and synovial fluid of patients with arthritis by application of dilution method and direct aspiration as a biomarker. In this cross-sectional study synovial fluid were obtained from 30 arthritis patients by direct aspiration. Also, serum sample were obtained from these patients. Serum and synovial fluid lactate level was measured by standard biochemical methods. For analysis results Students t-test was used and P was less than 0.05. lactate concentration increases in synovial fluid [14.1 +/- 2.3 mg/dl] in compare with serum [12.9 +/- 2.1 mg/dl], but the differences were not significant [p>0.05]. The difference between lactate concentration in synovial fluid and serum is not significant. The rate change of lactate concentrations in synovial fluid and serum was stable