Relationship Between Arteriovenous Fistula Stenosis and Circulating Levels of Neutrophil Granule Proteins in Chronic Hemodialysis Patients

Abstract

Background: Arteriovenous fistula (AVF) stenosis leading to its failure is a major cause of morbidity in hemodialysis patients; however, detailed pathogenesis of AVF stenosis is still under investigation. To date, monocytes/macrophages have been considered pivotal players in chronic inflammation of vascular disease including atherosclerosis and AVF stenosis. However, recent evidence strongly suggests that neutrophils and neutrophil granule proteins are important contributors to vascular disease. The aim of the present study was to evaluate the relationship between AVF stenosis and neutrophil activation by measuring circulating levels of neutrophil elastase (NE) and lactoferrin, enzymes released on neutrophil activation, as well as other inflammation markers including neutrophil counts.

Methods: This was a single-center, prospective observational study conducted on 83 prevalent hemodialysis patients with AVF. Blood levels of biomarkers and sonography (US) measurement were assessed at baseline and 1 year after enrollment. Clinical follow-up continued for one more year (a total of 2 years for each patient) to observe any AVF events.

Results: Circulating levels of both NE and lactoferrin positively correlated with the degree of AVF stenosis. Patients with significant AVF stenosis had older AVFs, higher neutrophil-to-lymphocyte ratio (NLR), and higher circulating levels of NE and lactoferrin. On multivariate logistic regression analysis, both circulating levels of NE and NLR remained independent predictors of significant AVF stenosis.

Conclusions: Circulating levels of NE and the NLR were identified as independent predictors of at-risk AVF with significant stenosis. Our data suggest the potential role of neutrophil and innate immunity activation on the development of AVF stenosis.