The parallels between particle induced lung overload and particle induced periprosthetic osteolysis (PPOL)

List of Authors

  1. Paul J.A. Borm
Article Authors & roles Authors Peer review record Peer review Metrics
Cite

Abstract

Background: When particles deposit for instance in the lung after inhalation or in the hip joint after local release from a hip implant material they can initiate a defense response. Even though these particles originate from inert materials such as polyethylene (PE) or titanium, they may cause harm when reaching high local doses and overwhelming local defense mechanisms.

Main body: This paper describes the parallels between adverse outcome pathways (AOP) and particle properties in lung overload and periprosthetic osteolysis (PPOL). It is noted that in both outcomes in different organs, the macrophage and cytokine orchestrated persistent inflammation is the common driver of events, in the joint leading to loss of bone density and structure, and in the lung leading to fibrosis and cancer. Most evidence on lung overload and its AOP is derived from chronic inhalation studies in rats, and the relevance to man is questioned. In PPOL, the paradigms and metrics are based on human clinical data, with additional insights generated from in vitro and animal studies. In both organ pathologies the total volume of particle deposition has been used to set threshold values for the onset of pathological alterations. The estimated clinical threshold for PPOL of 130 mg/ml is much higher than the amount to cause lung overload in the rat (10 mg/ml). although the threshold in PPOL is not necessarily synonymous to particle overload.

Conclusions: The paradigms developed in two very different areas of particle response in the human body have major similarities in their AOP. Connecting the clinical evidence in PPOL to lung overload challenges current paradigms and relevance of rat inhalation studies to the human lung cancer hazard.

Corresponding author
Paul J.A. Borm
Grant information

This work was financially supported by the European Union’s Horizon 2020 research and innovation programme under the grant agreement No [814654] (MDOT).

The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Copyright
© 2022 Paul J.A. Borm (Corresponding Author) Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

First version published
Latest version published
Revised

Amendment

It has been made clear throughout the text that the role of overload is less apparent for PPOL than in the lung and that the threshold (in the joint) is not necessarily synonymous to particulate overload. Overload definition has been changed to be congruent to 6% of macrophage volume which was suggested by Morrow (1988). Figure 1 was amended to illustrate that particle accumulation is a consequence of clearance impairment. In addition in the text referring to Fig.1 it is mentioned that IL-10 and TGF-b are also strong pro-fibrotic molecules with reference to Huaux (2018) and that osteoclasts are derived from the monocyte/macrophage lineage by the action of macrophage colony stimulating factor (M-CSF) and receptor activator of nuclear factor-kB ligand (RANKL).  In the Discussion and conclusions the threshold values have been put in perspective since similar metrics for both endpoints are missing.

Comments

Authors & roles

Paul J.A. Borm

Nanoconsult, Meerssen, The Netherlands

University of Dusseldorf, Dusseldorf, 50224, Germany

Roles
Corresponding Author, Conceptualization, Data Curation, Formal Analysis, Investigation, Methodology, Resources, Validation, Writing – Original Draft Preparation, Writing – Review & Editing

Downloads over the last 12 months:

Cited by

via Crossref

View citing articles