Immune stimulatory effects of neutrophil extracellular traps in granulomatosis with polyangiitis

Author information

CER9612
2017 Vol.35, N°1 ,Suppl.103
PI 0033, PF 0039
Aetiopathogenesis

Free to view
(click on article PDF icon to read the article)

PMID: 28281454 [PubMed]

Received: 26/05/2016
Accepted : 16/01/2017
In Press: 08/03/2017
Published: 19/04/2017

Abstract

OBJECTIVES:
The aim of this study was to analyse the role of netting neutrophils in the pathogenesis of granulomatosis with polyangiitis (GPA), especially their interplay with peripheral blood mononuclear cells (PBMCs).
METHODS:
The amount of cell-free DNA (cfDNA) was determined in sera from GPA patients (pairs active/inactive state of disease, n=18) and from healthy controls (HCs, n=10). Furthermore, we performed in vitro incubation experiments using PBMCs and NETs from patients and HCs for accessing the effect of NETs on PBMC behaviour. We determined proliferation of T- and B-cells (CSFE assay), B-cell maturation (CD38 staining and flow cytometry), production of IgG (ELISpot, ELISA), and secretion of the cytokines IFN-γ, IL-4, IL-10, IL-17A (ELISA).
RESULTS:
We detected a significant increase in serum cfDNA levels of GPA patients compared to HCs. The concentration of cfDNA was associated with disease activity. NETs of patients and HCs induced proliferation of CD4+ T- cells and CD19+ B-cells and maturation of B-cells. Furthermore, we detected an increase in IL-17A secretion after stimulating PBMCs with NETs. A significant difference between PBMCs from GPA patients and HCs was not detectable.
CONCLUSIONS:
NETs activate PBMCs of HCs and GPA patients. Our findings give supportive evidence that NETosis plays a role in the pathogenesis of GPA.