SEPTIC ARTHRITIS
International Journal of
Molecular Sciences
Review
Neutrophils: Beneficial and Harmful Cells in Septic Arthritis
Daiane Boff 1,2, Helena Crijns 1,2, Mauro M. Teixeira 1, Flavio A. Amaral 1,† ID and Paul Proost 2,*,† ID
1 Imunofarmacologia, Department of Biochemistry and Immunology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Brazil; daiane.bff@hotmail.com (D.B.); helena.crijns@kuleuven.be (H.C.); mmtex@gmail.com (M.M.T.); dr.famaral@gmail.com (F.A.A.)
2 Laboratory of Molecular Immunology, Department of Microbiology and Immunology, Rega Institute for Medical Research, KU Leuven, B-3000 Leuven, Belgium
* Correspondence: paul.proost@kuleuven.be; Tel.: +32-16-322-471 † These authors contributed equally to this work.
Received: 31 December 2017; Accepted: 1 February 2018; Published: 5 February 2018
Abstract: Septic arthritis is an inflammatory joint disease that is induced by pathogens such as Staphylococcus aureus. Infection of the joint triggers an acute inflammatory response directed by inflammatory mediators including microbial danger signals and cytokines and is accompanied by an influx of leukocytes. The recruitment of these inflammatory cells depends on gradients of chemoattractants including formylated peptides from the infectious agent or dying cells, host-derived leukotrienes, complement proteins and chemokines. Neutrophils are of major importance and play a dual role in the pathogenesis of septic arthritis. On the one hand, these leukocytes are indispensable in the first-line defense to kill invading pathogens in the early stage of disease. However, on the other hand, neutrophils act as mediators of tissue destruction. Since the elimination of inflammatory neutrophils from the site of inflammation is a prerequisite for resolution of the acute inflammatory response, the prolonged stay of these leukocytes at the inflammatory site can lead to irreversible damage to the infected joint, which is known as an important complication in septic arthritis patients. Thus, timely reduction of the recruitment of inflammatory neutrophils to infected joints may be an efficient therapy to reduce tissue damage in septic arthritis.
