Alpha-defensins(Auburn University)

Nosocomial ventriculitis is a difficult infectious condition to diagnose given that typical cerebral spinal fluid (CSF) parameters, commonly used in the diagnosis of meningitis, lack sensitivity and specificity in nosocomial ventriculitis. Consequently, novel diagnostics are needed to aid in diagnosing this condition. Herein a pilot study using alpha-defensins (α-defensins) to diagnose ventriculitis is discussed.

From May 01, 2022, to December 30, 2022, ten patients with culture-proven external ventricular drain (EVD)-associated ventriculitis and ten patients without EVD-associated ventriculitis had CSF preserved. Levels of α-defensins were compared between the two cohorts with enzyme-linked immunosorbent assay.

There was a statistically significant (P ˂0.0001) higher level of CSF α-defensins in the ventriculitis cohort compared to the non-ventriculitis cohort. The levels of α-defensins were not affected by blood in CSF or bacterial virulence. Patients with other infectious conditions had increased levels of α-defensins but these levels were still statistically significantly (P ˂0.001) less than those seen in the ventriculitis cohort.

This pilot study shows that α-defensins have promise as a biomarker to aid in the diagnosis of ventriculitis. If larger studies support the findings here, this biomarker can help improve diagnostic accuracy and decrease unwarranted empirical broad-spectrum antibiotic use in suspected EVD-associated ventriculitis.

Background: Leukocyte esterase (LE) and α-defensin (AD) are two synovial biomarkers that are used for the diagnosis of periprosthetic joint infection (PJI), however, the superiority of one over the other remains unknown. We aimed to compare their diagnostic value.Methods: In this retrospective study, we evaluated patients who underwent revision total hip and knee arthroplasty at a single institution between 2013 and 2019 for whom both LE and AD were available. PJI was defined by the 2018 International Consensus Meeting criteria. The diagnostic performance of AD and LE was compared.Results: Overall, 122 patients (28 PJI and 94 aseptic revisions) were included. The area under the curve was 0.905 (95% confidence interval[CI]:0.820-0.991) and 0.913 [95%CI:0.834-0.992] for LE and AD, respectively. Positive and negative predictive values were 95.8% (95%CI:76.5%-99.4%) and 94.9% (95%CI:89.4%-97.6%) for LE and 89.0% (95%CI:72.2%-96.1%) and 96.0% (95%CI:90.5%-98.3%) for AD. While both tests were useful in 18 cases that were inconclusive based on preoperative findings, AD had no benefit over LE.Conclusion: Both LE and AD are valuable markers in patients with suspected PJI. Since LE is very inexpensive and readily available point-of-care test, we believe it offers more value in the work up of suspected PJI.