FDA-Authorized Alpha-Defensin Lateral Flow Test Highly Accurate
Test demonstrates good performance for rapid diagnosis of periprosthetic joint infection around joint implants
MONDAY, Nov. 23, 2020 (HealthDay News) -- The alpha-defensin lateral flow test shows solid diagnostic performance for the diagnosis of periprosthetic joint infection (PJI), according to a study published online Nov. 5 in the Journal of Bone & Joint Surgery.
Carl Deirmengian, M.D., from the Mayo Clinic in Rochester, Minnesota, and colleagues evaluated the performance of the lateral flow test for synovial fluid alpha defensin by using the methods of a formal diagnostic accuracy study and to compare its performance with that of the laboratory-based alpha defensin test for PJI. The analysis included a prospective multicenter cohort of outpatients with a failed hip or knee arthroplasty (57 patients with PJI and 248 patients without PJI) and a supplemental control cohort of fresh synovial fluid specimens submitted by physicians for diagnostic PJI testing (65 samples from patients with PJI and 397 without).
The researchers found that in the overall prospective patient cohort, the sensitivity and specificity of the alpha defensin lateral flow test were 89.5 and 94.8 percent, respectively. When excluding 17 patients with grossly bloody aspirates (>1 million red blood cells/µL), the sensitivity increased to 94.3 percent. In the supplemental control group, the sensitivity and specificity of the alpha defensin lateral flow test were 98.5 and 98.2 percent, respectively. In the combined cohort, the sensitivity and specificity of the alpha defensin lateral flow test versus the alpha defensin enzyme-linked immunosorbent assay did not show a significant difference in sensitivity (94.3 versus 93.0 percent) or specificity (96.9 versus 97.8 percent).
"The results of this study demonstrate the solid diagnostic performance of the alpha defensin test and have resulted in the U.S. Food and Drug Administration authorization of the lateral flow test with an intended use as an aid in the clinical diagnosis of PJI," the authors write.
Several authors disclosed financial ties to Zimmer Biomet, manufacturer of the test and sponsor of the study.