PB0786 - The increased NETosis in plasma of patients with periprosthetic joint infection is aggravated by lower DNaseI activity: potential therapeutic intervention to eliminate the bacterial biofilm

Monday, June 26, 2023

18:30 – 19:30 ET

Room: Exhibition

Presenting Author(s)

Raquel Herranz, MSc (she/her/hers)

PhD Candidate
Hemostasis, Thrombosis, Arteriosclerosis and Vascular Biology Research Group, Medical Research Institute Hospital La Fe, Valencia, Spain
Valencia, Comunidad Valenciana, Spain

Co-Author(s)

Julia Oto

Postdoctoral Researcher
Hemostasis, Thrombosis, Arteriosclerosis and Vascular Biology Research Group, Medical Research Institute Hospital La Fe, Valencia, Spain
Valencia, Comunidad Valenciana, Spain
MF

Manuel Fuertes

Medical doctor
Orthopaedics and Traumatology Service. La Fe University and Polytechnic Hospital, Valencia, Spain
Valencia, Comunidad Valenciana, Spain
EP

Emma Plana

Postdoctoral Researcher
Haemostasis, Thrombosis, Arteriosclerosis and Vascular Biology Research Group, Medical Research Institute Hospital La Fe, Valencia, Spain; Angiology and Vascular Surgery Service, La Fe University and Polytechnic Hospital, Valencia, Spain
Valencia, Comunidad Valenciana, Spain
FC

Fernando Cana

Laboratory Technician
Hemostasis, Thrombosis, Arteriosclerosis and Vascular Biology Research Group, Medical Research Institute Hospital La Fe, Valencia, Spain
Valencia, Comunidad Valenciana, Spain
MC

Maria Castaño

Researcher
Hemostasis, Thrombosis, Arteriosclerosis and Vascular Biology Research Group, Medical Research Institute Hospital La Fe, Valencia, Spain
Valencia, Comunidad Valenciana, Spain
IA

Isabel Aleman-Cabrera

PhD Student
Haemostasis, Thrombosis, Arteriosclerosis and Vascular Biology Research Group, Medical Research Institute Hospital La Fe, Valencia, Spain
Valencia, Comunidad Valenciana, Spain
CD

Carolina De la Calva

Medical doctor
Orthopaedics and Traumatology Service. La Fe University and Polytechnic Hospital, Valencia, Spain
Valencia, Comunidad Valenciana, Spain
MA

Manuel Angulo

Medical doctor
Orthopaedics and Traumatology Service. La Fe University and Polytechnic Hospital, Valencia, Spain
Valencia, Comunidad Valenciana, Spain
IB

Ignacio Baixauli

Medical doctor
Orthopaedics and Traumatology Service. La Fe University and Polytechnic Hospital, Valencia, Spain
Valencia, Comunidad Valenciana, Spain
FB

Francisco Baixauli

Medical doctor
Orthopaedics and Traumatology Service. La Fe University and Polytechnic Hospital, Valencia, Spain
Valencia, Comunidad Valenciana, Spain
JA

Jose Vicente Amaya

Medical doctor
Haemostasis, Thrombosis, Arteriosclerosis and Vascular Biology Research Group, Medical Research Institute Hospital La Fe, Valencia, Spain; Orthopaedics and Traumatology Service. La Fe University and Polytechnic Hospital, Valencia, Spain
Valencia, Comunidad Valenciana, Spain
PM

Pilar Medina

PI
Hemostasis, Thrombosis, Arteriosclerosis and Vascular Biology Research Group, Medical Research Institute Hospital La Fe, Valencia, Spain
Valencia, Comunidad Valenciana, Spain

Background: Bacterial infection activates neutrophils through immunothrombosis, which release neutrophil extracellular traps (NETs) into bacterial biofilms of periprosthetic joint infections(PJI). We previously showed an increase in NETs markers in PJI plasma and that levels of cell-free DNA (cfDNA) could improve PJI diagnosis. In disorders like thrombotic microangiopathies, the increase in plasma cfDNA is mediated by decreased plasma DNaseI activity.

Aims: To evaluate the increase in NETosis in plasma of PJI patients, to ascertain if this process is mediated by plasma DNaseI and to correct in vitro the possible deficiency with rDNaseI.

Methods: We obtained citrated plasma from 94 prospective patients before prosthetic surgery, in 49 of whom PJI diagnosis was confirmed. We quantified NETs markers and interleukin-6 with specific assays, and DNaseI activity with the SRED. We analyzed the ability of plasma from patients to degrade PMA-generated NETs from a healthy donor. We incubated NETs for 6h with 5µl plasma from each participant and quantified the residual fluorescence after staining with SytoxGreen (Invitrogen). In parallel, we supplemented PJI plasma with Dornase Alfa (Pulmozyme®, Roche) to assess the ability of DNaseI to restore the DNaseI-deficiency of PJI plasma.

Results: Patients with PJI have increased plasma markers of NETs and IL-6 and lower DNaseI activity than patients without PJI (P < 0.001) (Figure 1). In addition, they have a lower ability to degrade NETs in vitro than patients without PJI (P < 0.001) (Figure 2). The addition of DNaseI restored the ability to degrade NETs to the level of controls (Figure 2D&F).

Conclusion(s): Patients with PJI have increased plasma NETosis in part mediated by reduced DNaseI activity. The in vitro addition of Pulmozyme®, an approved treatment for cystic fibrosis, restores the degradation of NETs in patients with PJI, so it could become a therapeutic tool to degrade the biofilm of periprosthetic infections. ISCIII-FEDER (PI20/00075, FI21/00171), GVA-CIACIF/2021/192, Zimmer Biomet.