Analytical Evaluation of a Vancomycin Immunoassay in Synovial Fluid

In clinical laboratories performing routine activities, the need to answer the burning clinical question in emerging field may be limited by lack of technology support or assays accessibility. Commercially available methods, although originally validated for specific biological matrices, may be employed for other matrices, following appropriate guidelines such as Clinical and Laboratory Standards Institute (CLSI) EP 19. We investigated the use of a vancomycin assay with synovial fluid samples, in view of a possible employment in vancomycin release study. The standard of care of periprosthetic joint infection is a two- stage revision surgery with antibiotic-loaded bone cement implantation. Vancomycin, for its activity against gram-positive bacteria even multidrug-resistant staphylococci, is the most widely used antibiotic. Despite the widespread use of such devices, little is known about the in vivo elution in the joint space. Clinical laboratories equipped with a validated, affordable method to quantify vancomycin in synovial fluid, may support clinical research, and give an important contribution to the study of the pharmacokinetics of antibiotic release from bone cement matrix.