Periprosthetic Joint Infection (PJI) is one of the most common complications following total joint arthroplasty, accounting for 25% of total knee arthroplasty failures and 16% of total hip arthroplasty failures.1
What is Alpha Defensin?
Alpha Defensin is an antimicrobial peptide released into the body through activated neutrophils in response to an infection. In cases of PJI, a patient will have elevated levels of alpha defensin in their synovial fluid.
Clinical findings show that alpha Defensin test results are not influenced by:
- Prior antibiotic administration2,3
- Comorbidities related to inflammation2
- Type
and/or virulence of the organism2,4
Since discovery, alpha defensin has aided in the diagnosis of PJI following total joint replacement. In 2018, alpha defensing biomarker was included as a minor criteria for diagnosing PJI by the International Consensus Meeting (ICM) on Joint Infection.5
Synovasure® Alpha Defensin ELISA Test*
First and only laboratory test specifically designed and validated to aid in the diagnosis of PJI. The ELISA test identifies elevated levels of Alpha Defensin, a critical protein in the innate immune response to infection.
Proprietary Test for Synovial Fluid
Alpha Defensin ELISA
Laboratory testing is only available from CD Laboratories.
Unparalleled accuracy
95% sensitive and 97% specific using the 2013 MSIS criteria for diagnosing PJI. 2, 6-11
Study | N | Sensitivity | Specificity |
Rothman Institute2 | 149 | 97% (36/37) | 96% (107/112) |
Mayo Clinic6 |
61 | 100% (19/19) | 95% (40/42) |
Cleveland Clinic7 | 78 | 100% (24/24) | 98% (53/54) |
Endo Klinik8 |
156 | 97% (28/29) | 97% (123/127) |
Cleveland Florida9 | 70 | 97% (34/35) | 97% (34/35) |
Charite – Universitatsmedizin Berlin10 | 71 | 85% (11/13)** | 98% (57/58) |
Multi-center Study11*** | 369 | 93% (113/122) | 98% (241/247) |
Combined | 954 | 95% (265/279) | 97% (655/675) |
**Includes patients with a draining sinus
***Mayo Clinic, Cleveland Clinic – Florida, Sinai Hospital of Baltimore
Performance backed by data
- Prior antibiotic administration2,3
- Comorbidities related to inflammation2
- Type and/or virulence of the organism2,4