Abstract: Objective  To investigate the relationship between intestinal barrier and the ratio of peripheral neutrophil to lymphocyte (NLR) in peritoneal dialysis (PD) patients.  Methods  The PD patients treated and regularly followed up in the Department of Nephrology, the Second Hospital of Anhui Medical University during September 2016 to August 2020 were enrolled in this study as the PD group. The chronic kidney disease patients at the stage 3～5 without dialysis and regularly followed up in our outpatient clinic during the same period were recruited as the CKD group. Clinical data, gastrointestinal symptoms and laboratory indices were collected. Intestinal barrier function was evaluated by serum diamine oxidase (DAO), d-lactic acid and bacterial endotoxin assays. Multivariate linear regression model was used to analyze the relationship between NLR and serum levels of DAO, d-lactic acid and bacterial endotoxin in the two groups.  Results  There were 121 cases in PD group and 69 cases in CKD group. At least one gastrointestinal symptom was present in 73 patients (60.3%) in PD group and 37 patients (53.6%) in CKD group. The NLR was significantly higher in PD group than in CKD group (Z=2.223, P=0.026). Serum d-lactic acid and bacterial endotoxin were significantly higher in PD group than in CKD group (Z=2.323 and 5.519 respectively, P=0.020 and＜0.001 respectively). Multivariate regression analysis showed that NLR in PD group was positively correlated with bacterial endotoxin (β=0.308, P=0.003), but not with DAO (β=-0.154, P=0.108), d-lactic acid (β=0.173, P=0.068) and age (β=-0.177, P=0.058); while NLR in CKD group was positively correlated with age (β=0.311, P=0.012) but not statistically correlated with serum d-lactic acid (β=0.162, P=0.197), bacterial endotoxin (β=0.234,           P=0.072) and DAO (β=-0.160, P=0.224).  Conclusion  Gastrointestinal symptoms were present in most PD patients. Serum d-lactic acid and bacterial endotoxin were higher in PD patients than in non-dialysis CKD patients, and bacterial endotoxin was positively correlated with NLR in PD patients, suggesting that intestinal barrier function may affect the inflammatory responses in PD patients.

Key words: Neutrophil to lymphocyte ratio, Gut barrier function, Peritoneal dialysis