Prospective Study
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Orthop. Aug 18, 2021; 12(8): 565-574
Published online Aug 18, 2021. doi: 10.5312/wjo.v12.i8.565
Performance of alpha-defensin lateral flow test after synovial fluid centrifugation for diagnosis of periprosthetic knee infection
Rodrigo Calil Teles Abdo, Riccardo Gomes Gobbi, Chilan Bou Ghosson Leite, Sandra Gofinet Pasoto, Elaine Pires Leon, Ana Lucia Lei Munhoz Lima, Eloisa Bonfa, José Ricardo Pécora, Marco Kawamura Demange
Rodrigo Calil Teles Abdo, Riccardo Gomes Gobbi, Chilan Bou Ghosson Leite, Ana Lucia Lei Munhoz Lima, José Ricardo Pécora, Marco Kawamura Demange, Instituto de Ortopedia e Traumatologia, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Sao Paulo 05403-010, Brazil
Sandra Gofinet Pasoto, Elaine Pires Leon, Eloisa Bonfa, Division of Rheumatology, Faculdade de Medicina da Universidade de São Paulo, Sao Paulo 01246-903, Brazil
Author contributions: Abdo RCT wrote the draft of the article, collected the samples and contributed to the data analysis, intellectual concept and design of the study; Gobbi RG reviewed the article and contributed to the intellectual concept and design of the study; Leite CBG wrote the article and contributed to the data analysis; Pasoto SG performed the laboratory tests and contributed to the strategy for alpha-defensin analysis according to its dilution; Leon EP conducted the laboratory tests; Lima ALLM contributed to data analysis, design and intellectual concept of the work; Bonfa E contributed to data analysis and intellectual concept of the work; Pécora JR and Demange MK contributed to the design and intellectual.
Supported by Fundação de Amparo à Pesquisa do Estado de São Paulo.
Institutional review board statement: The study was approved by the local Institutional Review Board (2179456).
Informed consent statement: All study participants, or their legal guardian, provided written consent prior to study enrollment.
Conflict-of-interest statement: The authors declare that there are no any conflicts of interest.
Data sharing statement: There is no additional data available.
CONSORT 2010 statement: The authors have read the CONSORT 2010 Statement, and the manuscript was prepared and revised according to the CONSORT 2010 Statement.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Chilan Bou Ghosson Leite, MD, Attending Doctor, Research Fellow, Instituto de Ortopedia e Traumatologia, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Ovídio Pires de Campos St, 333, 2nd Floor, Cerqueira César, Sao Paulo 05403-010, Brazil. chilan@usp.br
Received: April 24, 2021
Peer-review started: April 24, 2021
First decision: June 7, 2021
Revised: June 14, 2021
Accepted: July 9, 2021
Article in press: July 9, 2021
Published online: August 18, 2021
Processing time: 108 Days and 22.4 Hours
Abstract
BACKGROUND

The quantitative alpha-defensin enzyme-linked immunosorbent assay (ELISA) demands a prior synovial fluid centrifugation, whereas this processing is not routinely required prior to the alpha-defensin lateral flow test.

AIM

To evaluate whether a prior synovial fluid centrifugation could lead the lateral flow performance to achieve comparable results to ELISA during periprosthetic joint infection (PJI) diagnosis.

METHODS

Fifty-three cases were included in this study: 22 classified as PJI and 31 classified as aseptic cases, according to Musculoskeletal Infection Society 2013 criteria. Synovial fluid samples were submitted to centrifugation, and the supernatant was evaluated by ELISA and lateral flow tests. The sensitivity (SE), specificity (SP) and accuracy of each method were calculated as well as the agreement between those two methods.

RESULTS

In all of the 31 samples from aseptic patients, alpha-defensin ELISA and lateral flow tests showed negative results for infection. Regarding the 22 infected patients, the lateral flow test was positive in 19 cases (86.4%) and the ELISA was positive in 21 (95.5%). Sensibility, SP and accuracy were, respectively, 86.4% (95%CI: 65.1%-97.1%), 100% (95%CI: 88.8%-100%) and 93.2% (95%CI: 82.8%-98.3%) for the lateral flow test and 95.5% (95%CI: 77.2%-99.9%), 100% (95%CI: 88.8%-100%) and 98.1% (95%CI: 89.9%-100%) for ELISA. An agreement of 96.2% between those methods were observed. No statistical difference was found between them (P = 0.48).

CONCLUSION

Alpha-defensin lateral flow test showed high SE, SP and accuracy after a prior synovial fluid centrifugation, achieving comparable results to ELISA. Considering the lower complexity of the lateral flow and its equivalent performance obtained in this condition, a prior centrifugation might be added as a valuable step to enhance the PJI diagnosis.

Keywords: Alpha-defensin, Alpha-defensin lateral flow, Periprosthetic joint infection

Core Tip: This was a prospective study seeking to evaluate whether the synovial fluid centrifugation prior to the alpha-defensin lateral flow test leads to comparable results in relation to the alpha-defensin enzyme-linked immunosorbent assay (ELISA) during periprosthetic joint infection of the knee. Prior centrifugation of the synovial fluid showed to achieve high sensitivity, specificity and accuracy for the lateral flow test during periprosthetic joint infection diagnosis, leading to similar results in comparison to alpha-defensin ELISA.