Soluble Pecam-1 As Biomarker In Periprosthetic Joint Infections (PJI)

Objectives PJI account for the majority of implant failure, occurring in 2-3 % of all primary total joint arthroplasties. To allow a sufficient prevention and therapy of implant-associated infections, a reliable diagnostic workup is critical for the therapeutic success. While infection treatment focuses mainly on diagnostics of germs, the endogenous immunological competence of patients has so far not been getting enough attention.

The immunologically reactive molecule Pecam-1 is shed from the T-cell surface upon activation of immune cells. We hypothesized that soluble Pecam-1 (sPecam-1) allows evaluating the local level of T-cell activation and reactivity of the adaptive immune response and can hence function as a potential biomarker to track infections.

Methods Freshly collected synovia from primary and revision knee surgery was used to establish a database on local sPecam-1 levels, correlated with the infection status of the patients. Synovia samples were taken in a standardized manner from patients undergoing knee replacement surgeries (3 patient cohorts; native knees prior to surgery, revision surgeries in septic and aseptic conditions). sPecam-1 quantities in synovia were measured via ELISA.

Results and Conclusion A significantly larger quantity of sPecam-1 is present under septic conditions (n = 38) compared to aseptic conditions (n = 54, p < 0,001) and a significantly larger quantity was observed in septic and aseptic revisions compared to native joints (n = 15, p < 0,001). When using the current standard classification criteria, statistical outliers from the aseptic group could be traced back to be of patients that either showed signs of PJI in a follow up treatment or were suffering from PJI in another location (marked in red). The ROC curve demonstrates a high specificity and sensitivity of sPecam-1 as a biomarker for periprosthetic joint infection.

There is a strong potential of sPecam-1 to be a reliable marker molecule for diagnosing PJI. Benchmarking it to the gold standard even showed a high predictive power of sPecam-1, upgrading its potential clinical value. While a clear role of sPecam-1 in infection and inflammation could be demonstrated in this pilot study, the underlying mechanism of the molecule’s natural function, specifically in septic conditions, is so far unknown and needs to be further unraveled.

Stichwörter periprosthetic joint infection, sPECAM, biomarker

Publication History

Article published online:
15 October 2020