We use cookies to understand how you use our site and to improve your experience. This includes personalizing content and advertising. To learn more, click here. By continuing to use our site, you accept our use of cookies. Cookie Policy.

Features Partner Sites Information LinkXpress
Sign In
Advertise with Us
LGC Clinical Diagnostics

Download Mobile App


24 Feb 2024 - 28 Feb 2024
05 Mar 2024 - 07 Mar 2024

Synovial Fluid NGAL Accurately Diagnoses Prosthetic Joint Infection

By LabMedica International staff writers
Posted on 04 Oct 2022
Print article
Image: Neutrophil gelatinase-associated lipocalin (NGAL) Duo Set ELISA (Photo courtesy of R&D Systems)
Image: Neutrophil gelatinase-associated lipocalin (NGAL) Duo Set ELISA (Photo courtesy of R&D Systems)

Prosthetic joint infection (PJI) is a serious complication that is difficult to diagnose after joint arthroplasty and seriously affects the physical and mental health of patients. Current studies suggest that PJI is a relatively limited infectious disease, and the synovial fluid (SF) biomarkers more directly reflect the nature and extent of inflammation.

The previous use of antimicrobial therapies will significantly decrease the sensitivities of either serum or the synovial fluid (SF) biomarkers. Inaccurate diagnosis may lead to incorrect treatment options and poor prognosis. Neutrophil gelatinase-associated lipocalin (NGAL) has been used for the early identification of bacterial and viral infections in blood and cerebrospinal fluid.

Orthopaedic Surgeons at the Fujian Medical University (Fuzhou, China) included in a prospective study in a single osteoarticular infection referral center, in which consecutive patients who needed revision surgery after hip and knee arthroplasty due to PJI or aseptic prosthesis loosening from January 2017 to September 2018. A total of 78 patients who underwent hip or knee revision surgery were included in the study.

The scientists collected 0.5 mL of the SF for the white blood cell count (SF-WBC) and neutrophil classification. A total of 1 mL of the SF was frozen at -80 °C for NGAL determination. The remaining SF was used for microbiological culture. SF was injected into Bactec Plus/F aerobic or Bactec Peds Plus/F blood culture bottles and anaerobic blood culture bottles (Becton-Dickinson, Heidelberg Germany). The plates and bottles were incubated for 14 days in a Bactec 9050 automatic incubator.

The periprosthetic tissue was cut into pieces, added to the broth for grinding, and then cultured for aerobic and anaerobic bacteria on a blood plate for 14 days. The Vitek II system (bioMérieux, Durham, NC, USA) was used for microbial identification and antibiotic susceptibility testing. The SF samples were centrifuged and diluted appropriately before assaying. The team determined NGAL levels using the NGAL Duo Set ELISA Kits (R&D Systems, Minneapolis, MN, USA). The level of NGAL in the SF was measured in duplicate.

The investigators reported that a total of 50 of 78 included patients were diagnosed with PJI. A total of 40 cases were positively cultured. The most common pathogen was Staphylococcus aureus in 10 (25%) patients, followed by coagulase-negative staphylococci in seven patients, and gram-negative bacilli in seven patients (17.5%), and other pathogens in 16 patients. The median SF-NGAL level was 3,633 ng/mL (interquartile range [IQR], 1,332-10,737) in the PJI group and 26.8 ng/mL (IQR, 12.4-52.5) in the aseptic failure group. When the SF-NGAL threshold was 263 ng/mL, the area under the curve was 0.98, the sensitivity was 92.9%, and the specificity was 98%. The median level was 5,779 ng/mL (IQR, 1425-13,072) in the antibiotic group and 2,590 ng/mL (IQR, 932-8,970) in the non-antibiotic group.

The authors concluded that NGAL in the SF has both high sensitivity and specificity for the PJI diagnostics. The previous use of antibiotics does not affect the level of the SF-NGAL. The SF-NGAL can be used as a potential laboratory indicator for diagnosing PJI. The study was published on October 1, 2022 in the International Journal of Infectious Diseases.

Related Links:
Fujian Medical University 
R&D Systems 

Platinum Member
COVID-19 Rapid Test
OSOM COVID-19 Antigen Rapid Test
One Step HbA1c Measuring System
POCT Fluorescent Immunoassay Analyzer
Gold Member
Real-time PCR System
GentierX3 Series

Print article


Molecular Diagnostics

view channel
Image: Aptiva utilizes particle-based multi-analyte technology (PMAT) (Photo courtesy of Werfen)

Novel Immunoassays Enable Early Diagnosis of Antiphospholipid Syndrome

Antiphospholipid syndrome (APS) is an autoimmune disorder that typically presents as venous or arterial thrombosis and/or pregnancy loss. Diagnosing APS can be difficult as its symptoms often resemble... Read more


view channel
Image: The Gazelle Hb Variant Test (Photo courtesy of Hemex Health)

First Affordable and Rapid Test for Beta Thalassemia Demonstrates 99% Diagnostic Accuracy

Hemoglobin disorders rank as some of the most prevalent monogenic diseases globally. Among various hemoglobin disorders, beta thalassemia, a hereditary blood disorder, affects about 1.5% of the world's... Read more


view channel
Image: The photoacoustic spectral response sensing instrument is based on low-cost laser diodes (Photo courtesy of Khan et al., doi 10.1117/1.JBO.29.1.017002)

Compact Photoacoustic Sensing Instrument Enhances Biomedical Tissue Diagnosis

The pursuit of precise and efficient diagnostic methods is a top priority in the constantly evolving field of biomedical sciences. A promising development in this area is the photoacoustic (PA) technique.... Read more


view channel
Image: The companies will develop genetic testing systems based on capillary electrophoresis sequencers (Photo courtesy of 123RF)

Sysmex and Hitachi Collaborate on Development of New Genetic Testing Systems

Sysmex Corporation (Kobe, Japan) and Hitachi High-Tech Corporation (Tokyo, Japan) have entered into a collaboration for the development of genetic testing systems using capillary electrophoresis sequencers... Read more
Copyright © 2000-2024 Globetech Media. All rights reserved.