Utility of CD64 on Neutrophils in Orthopedic Infection

【Background】 Musculoskeletal infections are often seen in the daily practice of orthopedics. Several markers [white blood cell (WBC), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), procalcitonin (PCT)] have been used for diagnosing these infections. However, these markers may be elevated due to surgery or trauma, and may not be infection-related. These markers also show drug-dependent dynamics during infection that differ from its usual dynamics. Such situations make diagnosis of infections difficult, and Cluster of Differentiation 64 (CD64) has been brought to attention. This study aimed to clarify the utility of CD64 on neutrophils by comparing it with conventional infection markers (CRP, PCT) in musculoskeletal infection. 【Methods】 Forty-four patients who were suspected of having musculoskeletal infection between May 2010 and November 2013 in our hospital were enrolled in this study. Patients were divided into subgroups according to their culture results, antibiotics administration, measurement timing, and if they were immunocompromised. The measurements of the infection markers were compared between each group. In addition, the positive rates of each infection marker were compared between groups. 【Results】 There was no difference in the infection marker measurements between several groups. There was no statistically significant difference between groups for the positive rates of CD64, CRP, and PCT. 【Conclusion】 We evaluated the utility of CD64 on neutrophils in musculoskeletal infection. CD64 showed the utility that was equivalent to conventional infection markers in diagnoses of various musculoskeletal infections.