https://doi.org/10.1007/s00392-025-02625-4
1Uniklinik RWTH Aachen Institut für Molekulare Herz-Kreislaufforschung (IMCAR) Aachen, Deutschland; 2Uniklinik RWTH Aachen Med. Klinik I - Kardiologie, Angiologie und Internistische Intensivmedizin Aachen, Deutschland; 3Klinik für Nieren- und Hochdruckkrankheiten, rheumatologische und immunologische Erkrankungen (Med. Klinik II) 52074, Deutschland; 4Inselspital - Universitätsspital Bern Universitätsklinik für Angiologie Bern, Schweiz
Background:
Patients with chronic kidney disease (CKD) have a significantly increased risk of developing cardiovascular disease (CVD). Atherosclerotic lesions are more prevalent in CKD patients and progress faster, contributing to a higher risk of myocardial infarction. Neutrophils play a key role in the development and progression of these atherosclerotic lesions. Interestingly, CKD patients suffer from persistent low-grade inflammation. While neutrophil activation was shown to be increased in patients with kidney failure (CKD stage 5 on dialysis), the effect of CKD on neutrophils in early stages of CKD has been less investigated. Therefore, we analyzed activation and maturation makers of neutrophils in a CKD cohort of moderate to advanced chronic kidney disease (CKD stage 3 and 4).
Methods:
Blood samples were collected from CKD patients as well as from healthy volunteers. Patients were excluded if they had been treated with glucocorticoids, cortisone, or other immunosuppressive medications; had an active infectious or non-infectious inflammatory condition; had an autoimmune disorder; had a hematologic disease; had liver or intestinal disorders; or had a history of malignancy within the past five years. Neutrophil activation and maturation markers were analyzed in unstimulated, IL-8 stimulated, and PMA stimulated whole blood using flow cytometry. In addition, DNA release by isolated neutrophils (SYTOX assay) was measured as an indication for NET formation. Levels of myeloperoxidase, neutrophil elastase and inflammatory cytokines and chemokines were measured in plasma and lysates of isolated neutrophils.
Results & Conclusion:
Overall, 30 patients were included (20 patients with moderate CKD and 10 patients with advanced CKD) as well as 10 healthy controls. FACS analysis revealed a significant downregulation of the maturation marker CD10 in patients with moderate CKD compared to the healthy controls (p-value: 0.0267), which previously has been associated with a more pro-inflammatory neutrophil phenotype. In line, patients with moderate to advanced CKD showed signs of increased neutrophil degranulation in vivo (myeloperoxidase, neutrophil elastase). Also, Sytox analysis revealed a tendency of higher DNA release in unstimulated CKD neutrophils compared to healthy.
Overall, this study revealed a more immature and pro-inflammatory neutrophil phenotype. As neutrophils are associated with the progression of CVD, this altered phenotype may contribute to the increased risk of CVD in the CKD population. Understanding the changes in immune cell behavior like neutrophils is essential to find therapeutic approaches to ameliorate the life expectancies of this vulnerable patient cohort.