39 Evaluating Clinical Performance, Utility, and Impact of a PCR Panel for Diagnosis of Joint Infections

Abstract Background Joint infections can cause significant morbidity and long-term disability if not promptly diagnosed and treated. We evaluated the clinical utility and outcomes following a one-year implementation of the FDA-approved BioFire JI® PCR panel for joint infections in our hospital. Methods Patients who had a JI Panel ordered between January and December 2024 were included in this study. A retrospective clinical chart review was performed to collect patient demographics, laboratory results, and infection course. Results Samples from 30 patients were analyzed (55% male; median age: 54 years). The most common clinical histories included hardware infection (42%), septicemia (16%), gout (10%), and arthritis (10%). The overall positivity rate was 50% (17/34). The JI PCR Panel identified 32% (11/34) of cases, while cultures were positive in 47% (16/34). Using culture as the standard, the JI Panel demonstrated a sensitivity of 63% and a specificity of 94%. The JI Panel detected one Klebsiella pneumoniae case missed by culture but failed to identify Staphylococcus species (n = 4) and Pseudomonas aeruginosa (n = 1), which were detected in culture. Polymorphonuclear leukocytes were observed in 90% of specimens (100% in PCR-positive vs. 84% in PCR-negative cases). A positive Gram stain result was seen in 72% of PCR-positive specimens. Differences in cell counts and parameters were observed between PCR-positive versus PCR-negative samples (WBC: 205,342 vs. 104,831 cells/mm³; RBC: 188,500 vs. 118,463 cells/mm³; segmented neutrophils: 96% vs. 75%; lymphocytes: 1% vs. 8%; monocytes: 5% vs. 20%). The median time-to-result for the JI Panel was approximately 5.5 hours, significantly shorter than the 95 hours required for final culture results (p-value: 0.00001). Among PCR-positive patients, the rapid JI PCR result led to an escalation of therapy in 45% of cases and no change in 55%. Among PCR-negative patients, antibiotic therapy was discontinued in 26% of cases, while 73% continued antibiotic treatment. Conclusion The BioFire JI® Panel provides rapid pathogen identification; however, its sensitivity was lower than bacterial culture in our hospital, with minimal impact on clinical outcomes in PCR-positive patients. Ongoing studies evaluating the panel’s predictive value concerning joint fluid cell counts and patient symptoms will help optimize its use, ensuring maximal diagnostic utility and cost-effectiveness.