Lipopolysaccharide in systemic circulation induces activation of inflammatory response and oxidative stress in cardiorenal syndrome type 1.

Background: Cardiorenal syndrome type 1 (CRS type 1) is characterized by a rapid worsening of cardiac function leading to acute kidney injury. In this study, we evaluate the role of lipopolysaccharide (LPS) and various inflammatory markers in the developing acute kidney injury (AKI) in acute heart failure (AHF) patients.

Methods: We enrolled 31 AHF patients and 20 CRS type 1 (the cause of AKI was presumed to be related to cardiac dysfunction) and 17 healthy volunteers without AHF, AKI or CKD, as control group (CTR). We assessed levels of LPS, proinflammatory cytokines (TNF-α, IL-6, IL-18), and oxidative stress marker (myeloperoxidase, MPO).

Results: We observed a significant increase in LPS, TNF-α, IL-6, IL-18 and MPO levels in CRS type 1 and AHF group compared to CTR. LPS levels resulted significantly higher in CRS type 1 patients compared with AHF (118.2 pg/mL, IQR 77.8-217.6 versus 13.5 pg/mL, IQR 12.0-17.0, p = 0.008). We found a cytokines and oxidative stress dysregulation in CRS type 1 patients compared with AHF. Furthermore, we observed a strong positive significant correlation between LPS levels and IL-6 (Spearman's rho = 0.79, p < 0.001), and IL-18 (Spearman's rho = 0.77, p < 0.001) and MPO (Spearman's rho = 0.80, p < 0.001), all confirm by simple linear regression analysis.

Conclusion: CRS type 1 patients presented an increased level of LPS, pro-inflammatory cytokines, and MPO. Furthermore, there is a direct correlation between LPS and pro-inflammatory cytokines and stress oxidative marker. LPS may play a role in the pathophysiology of CRS type 1 inducing inflammation, oxidative stress and finally kidney damage.