[Clinical characteristics and related factors of acute tubular necrosis in patients with minimal change disease]

Objective: To investigate the clinical characteristics and related factors of acute tubular necrosis (ATN) in patients with minimal change disease (MCD). Methods: Patients from Chinese PLA General Hospital who were pathologically diagnosed with MCD and had clinical manifestations of nephrotic syndrome from January 1, 2013 to December 31, 2019 were included. The clinical and pathological data of patients were retrospectively analyzed. Meanwhile, the incidence and clinical characteristics of ATN in different age groups were compared. The risk factors for ATN were assessed using binary logistic regression. Results: A total of 525 patients were included, with a gender ratio of 1.56∶1 (male: female), aged 33 (21, 48) years old. ATN occurred in 49 (9.3%) of 525 patients, of which 34 were male and 15 were female. The incidence of ATN increased with age in MCD patients of different age groups (χ(2)=31.442, P<0.001). The incidence of ATN in groups of age≤20 years, 21-40 years, 41-60 years, and >60 years was 2.4% (3/123), 5.2% (10/192), 13.2% (20/152) and 27.6% (16/58), respectively. Elevations of alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyl transpeptidase (GGT) and serum IgE occurred in 92 patients (17.5%), 53 patients (10.1%), 99 patients (18.9%), and 303 patients (57.7%), respectively. There were significant differences in age, ALT, serum creatinine, serum urea nitrogen, history of diabetes and history of hypertension between non-ATN group and ATN group (all P<0.05). The results of logistic regression analysis showed that>40 years old (OR=6.283, 95% CI: 2.695-14.649, P<0.001) and serum albumin (OR=0.924, 95% CI: 0.857-0.997, P=0.040) was independently associated with ATN in MCD patients. Conclusion: Age>40 years is an independent risk factor and serum albumin is a protective factor for ATN in MCD patients.

[Diagnostic value of serum cystatin C for acute kidney injury in patients with liver cirrhosis]

Objective: To determine the diagnostic value of serum cystatin C (Cys C) for acute kidney injury (AKI) in patients with liver cirrhosis. Methods: Serum Cys C levels in 150 liver cirrhosis patients (88 AKI and 62 non-AKI patients) were measured by the Particle-Enhanced Nephelometric Immuno-Assay. The accuracy of serum Cys C for the diagnosis of AKI in liver cirrhosis was evaluated by the ROC curve. Results: Liver cirrhosis patients with AKI had significantly higher serum Cys C levels [2.37 (1.75-2.83) mg/L] than those without AKI [0.97 (0.85-1.09) g/L] (P <0.001). Serum Cys C level was highest in the acute tubular necrosis group [5.41 (2.77-6.19) mg/L], followed by the hepatorenal syndrome group [2.55 (2.28-3.59) mg/L] and prerenal azotemia group [2.07 (1.70-2.41) mg/L], and the serum Cys C level was significantly different between the three groups (P <0.001). In addition, patients with AKI were further divided into infection group and non-infection group. Serum Cys C level was significantly higher in the infection group than in the non-infection group (P <0.05). The area under the ROC curve of serum Cys C for the diagnosis of AKI in liver cirrhosis was 0.99 (0.98-1.00) at a cut-off value of 1.36 mg/L, and the sensitivity and specificity were 97% and 95%, respectively. Conclusion: Serum Cys C is a good marker for detecting AKI in liver cirrhosis, and the different levels of increase in Cys C may be useful in differentiating the different types of AKI.