The optimal diagnostic cut-off of WBC and PMN counts for joint aspiration in periprosthetic joint infection is 2479/µL and 67%, respectively : ICM criteria thresholds are too high

© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature..

BACKGROUND: Various organizations have published definitions for periprosthetic joint infection (PJI) with significant differences in the cut-offs of white blood cell (WBC) count and polymorphonuclear (PMN) leukocyte cells. Herein, we aim to analyze optimal cut-offs in patients which are planned to undergo a prosthesis revision and compare them with the actual published thresholds of the International Consensus Meeting (ICM) and European Bone and Joint Infection Society (EBJIS).

METHODS: A test kit was compiled in a monocentric prospective study, according to the ICM criteria (2018) and 2021 EBJIS criteria. The kit was implemented using: blood samples (including leukocyte count and C-reactive protein); samples for examining the synovial fluid (WBC count, PMN cell differentiation, microbiological culture for incubation over 14 days, alpha-defensin ELISA laboratory test, and leukocyte-esterase test). The cut-offs for WBC and PMN counts were investigated using ROC analyses and Youden index. The ICM 2018 criteria were applied, using alpha-defensin in all cases. Patients which have to undergo a prosthesis revision were included, a pre-operative joint aspiration had been performed, and the patients had been followed up prospectively.

RESULTS: 405 patients were examined with the compiled test kit; 100% had a complete dataset with respect to alpha-defensin; 383 patients, according to WBC count; and 256, according to PMN cell differentiation The cut-off of 2478.89 cells/µl in the WBC count (sensitivity: 87.70%; specificity: 88.10%) and the cut-off of 66.99% in PMN differentiation showed the best accuracy (sensitivity: 86.00%; specificity: 88.80%). Other published cut-offs for WBC were tested in this cohort and showed the following accuracy: 3000/µl (EBJIS/ICM; sensitivity: 82.10%; specificity: 91.00%), 2000/µl (sensitivity: 89.60%; specificity: 83.40%), and 1500/µl (sensitivity: 91.50%; specificity: 75.00%). The published cut-offs for PMN had the following accuracy in this cohort: 80% (ICM; sensitivity: 66.3%; specificity: 96.50%), 70% (sensitivity: 82.6%; specificity: 90%), and 65% (EBJIS, sensitivity: 86%; specificity: 88.8%).

CONCLUSIONS: This study aims to improve current cut-offs for PMN- and WB-Count, even though PJI diagnosis is based on the combination of all defined tests. The optimal diagnostic cut-off of WBC and PMN counts was found to be 2479/µL and 67%, respectively, whereas ICM cut-offs in this cohort seem too high, as they provide high specificity but very low sensitivity. On the other hand, a cut-off for WBC count of 1500/µl alone would be very low, leading to low specificity and very high suspicion of PJI. The current consensus guidelines could be actualized considering these results to significantly improve the diagnostic quality.

LEVEL OF EVIDENCE: II.

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:143

Enthalten in:

Archives of orthopaedic and trauma surgery - 143(2023), 8 vom: 20. Aug., Seite 5229-5238

Sprache:

Englisch

Beteiligte Personen:

Gramlich, Y [VerfasserIn]
Schnetz, M [VerfasserIn]
Ruckes, C [VerfasserIn]
Kemmerer, M [VerfasserIn]
Kremer, M [VerfasserIn]
Hoffmann, R [VerfasserIn]
Klug, A [VerfasserIn]

Links:

Volltext

Themen:

Alpha-Defensins
Alpha-defensin
Biomarkers
EBJIS criteria
ICM consensus criteria
Journal Article
PJI test kit
Periprosthetic joint infection
Polymorphonuclear cell
White blood cell count

Anmerkungen:

Date Completed 31.07.2023

Date Revised 31.07.2023

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1007/s00402-023-04822-0

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM354468588