INTRODUCTION: Septic arthritis is a common and serious problem. Early detection and prompt treatment improve outcomes. OBJECTIVE: To evaluate serum procalcitonin for diagnosis of acute bacterial septic arthritis and to compare its diagnostic utility with synovial white blood cells (WBC), erythrocyte sedimentation rate (ESR) and high-sensitivity C-reactive protein (hs-CRP). METHOD: A prospective cross-sectional study was performed in 78 Thai patients with acute arthritis. Patients with concomitant infections were excluded. Twenty-eight patients were diagnosed with acute bacterial septic arthritis and 50 patients were diagnosed with acute inflammatory arthritis. Blood samples were collected for complete blood count, ESR, hs-CRP, procalcitonin and hemoculture. Synovial fluid was sent for cell count, Gram stain, crystals identification and culture. The diagnostic accuracy by area under receiver operating characteristic (ROC) curve was calculated. RESULT: Patients with acute bacterial septic arthritis had higher procalcitonin levels than in acute inflammatory arthritis (mean ± SD = 1.48 ± 2.30 vs. 0.44 ± 0.92 ng/mL, P = 0.032). The cut-off level of procalcitonin was 0.5 ng/mL for which sensitivity, specificity and accuracy for diagnosis of bacterial septic arthritis were 59.3%, 86% and 75.3%, respectively. The ROC curve analysis showed that procalcitonin had a good diagnostic performance (area under the curve = 0.78, 95% CI 0.69-0.89). The area under the curve of hs-CRP and synovial fluid WBC were 0.67 (95% CI 0.55-0.79) and 0.821 (95% CI 0.720-0.923), respectively. Combining procalcitonin with other markers did not provide better sensitivity or specificity than procalcitonin alone. CONCLUSION: Serum procalcitonin has a potential role in diagnosing acute bacterial septic arthritis, especially if arthrocenthesis cannot be performed.
INTRODUCTION:Septic arthritis is a common and serious problem. Early detection and prompt treatment improve outcomes. OBJECTIVE: To evaluate serum procalcitonin for diagnosis of acute bacterial septic arthritis and to compare its diagnostic utility with synovial white blood cells (WBC), erythrocyte sedimentation rate (ESR) and high-sensitivity C-reactive protein (hs-CRP). METHOD: A prospective cross-sectional study was performed in 78 Thai patients with acute arthritis. Patients with concomitant infections were excluded. Twenty-eight patients were diagnosed with acute bacterial septic arthritis and 50 patients were diagnosed with acute inflammatory arthritis. Blood samples were collected for complete blood count, ESR, hs-CRP, procalcitonin and hemoculture. Synovial fluid was sent for cell count, Gram stain, crystals identification and culture. The diagnostic accuracy by area under receiver operating characteristic (ROC) curve was calculated. RESULT: Patients with acute bacterial septic arthritis had higher procalcitonin levels than in acute inflammatory arthritis (mean ± SD = 1.48 ± 2.30 vs. 0.44 ± 0.92 ng/mL, P = 0.032). The cut-off level of procalcitonin was 0.5 ng/mL for which sensitivity, specificity and accuracy for diagnosis of bacterial septic arthritis were 59.3%, 86% and 75.3%, respectively. The ROC curve analysis showed that procalcitonin had a good diagnostic performance (area under the curve = 0.78, 95% CI 0.69-0.89). The area under the curve of hs-CRP and synovial fluid WBC were 0.67 (95% CI 0.55-0.79) and 0.821 (95% CI 0.720-0.923), respectively. Combining procalcitonin with other markers did not provide better sensitivity or specificity than procalcitonin alone. CONCLUSION: Serum procalcitonin has a potential role in diagnosing acute bacterial septic arthritis, especially if arthrocenthesis cannot be performed.