Objective      To investigate the relationship between renal tissue expression of NALP3 and renal tubulointerstitial inflammation in patients with diabetic kidney disease (DKD).       Methods      Thirty patients with DKD were enrolled (patient group)

and the pathologically confirmed normal renal tissues adjacent to the renal angiomyolipoma or kidney transplants were assigned as a control group. Immunohistochemistry and confocal laser scanning microscopy were performed to detect the expressions of NALP3 and IL-1β in renal tubular epithelial cells and their relationship. The levels of urine IL-1β

serum total cholesterol

low density lipoprotein (LDL)

serum creatinine (SCr) and 24 h urine protein were measured by ELISA. The estimated glomerular filtration rate (eGFR) was calculated and the correlations between the indicators and renal tubulointerstitial inflammation were analyzed.       Results      The level of IL-1β in the urine of the patient group was significantly higher than that of the control group. The expression of NALP3 and IL-1β in renal tubular epithelial cells both increased significantly in the patient group compared with those in the control group (P0.05)

and their expression was positively correlated with renal tubulointerstitial injury (r=0.66

r=0.55

P0.001). The confocal laser scanning microscopy showed that the NALP3 expression upregulated accompanied by the increase of IL-1β expression in the DKD patients. The proportion of NALP3 and IL-1β positive cells was significantly correlated with SCr

urine IL-1β and eGFR (P0.01)

but was not correlated with the age

body mass index (BMI)

diastolic pressure

LDL

24 h urine protein or serum total cholesterol.       Conclusion      NALP3 expression in renal tubular epithelial cells is closely related to the level of inflammatory cytokine IL-1β

renal tubulointerstitial injury and renal function changes in DKD patients

suggesting that NALP3 expression plays an important role in renal tubulointerstitial inflammation in DKD.