IL-6 serum an ineffective diagnostic tool for postoperative shoulder infection
Measured levels of serum interleukin-6 were not effective as a diagnostic tool for infection following shoulder arthroplasty, according to recently published data.
Researchers prospectively studied 69 patients who underwent revision shoulder arthroplasty at a single institution between 2010 and 2013. In addition to standard measures to check for infection both pre- and intraoperatively, preoperative serum interleukin-6 (IL-6) measurements were taken in all patients.
Patients were categorized into groups based on their likelihood of infection (group 1: certain; group 2: probable; group 3: possible; group 4: none).
No infection was observed in 32 patients. Among the 24 patients classified as groups 1 or 2, IL-6 levels were not found to be a significant marker of infection based on sensitivity or specificity, according to the researchers.
The majority of patients in groups 1 or 2 (83%) were found to have the organism Propionibacterium acnes; however, the researchers found IL-6 was not a sensitive marker of infection in these patients. In fact, sensitivity of IL-6 was found to be lower than that of erythrocyte sedimentation rate and C-reactive protein levels.
In cases not involving P. acnes — one involving Staphylococcus aureus, one involving Enterobacter cloacae and two involving coagulase-negative Staphylococcus species — IL-6 sensitivity was 25%, according to the researchers.
Disclosure: The authors have no relevant financial disclosures.