Urinary N-Acetyl-Beta-D-Glucosaminidase levels predict immunoglobulin a nephropathy remission status.

BACKGROUND: Tubulointerstitial lesions play a pivotal role in the progression of IgA nephropathy (IgAN). Elevated N-acetyl-beta-D-glucosaminidase (NAG) in urine is released from damaged proximal tubular epithelial cells (PTEC) and may serve as a biomarker of renal progression in diseases with tubulointerstitial involvement. METHODS: We evaluated the predictive value of urinary NAG (uNAG) for disease progression in 213 biopsy-proven primary IgAN patients from January 2018 to December 2019 at Zhongshan Hospital, Fudan University. We compared the results with those of serum cystatin C (sCysC). RESULTS: Increased uNAG and sCysC levels were associated with worse clinical and histological manifestations. Only uNAG level was independently associated with remission status after adjustment. Patients with high uNAG levels (> 22.32 U/g Cr) had a 4.32-fold greater risk of disease progression. The combination of baseline uNAG and clinical data may achieve satisfactory risk prediction in IgAN patients with relatively preserved renal function (eGFR ≥ 60 ml/min/1.73 m2, area under the curve [AUC] 0.760). CONCLUSION: Our results suggest that uNAG is a promising biomarker for predicting IgAN remission status.

Social Isolation Is Associated With Rapid Kidney Function Decline and the Development of Chronic Kidney Diseases in Middle-Aged and Elderly Adults: Findings From the China Health and Retirement Longitudinal Study (CHARLS).

Background: There is limited evidence on the relationship between social isolation and renal outcomes. To address this gap, this study estimated the prospective relationship of social isolation with rapid kidney function decline and the development of chronic kidney disease (CKD) in middle-aged and elderly Chinese with normal kidney function. Methods: We analyzed data from 3,031 participants aged ≥ 45 years with baseline estimated glomerular filtration rates (eGFR) ≥ 60 ml/min/1.73 m2. All data were obtained from the 2011 and 2015 waves of the Chinese Longitudinal Study of Health and Retirement (CHARLS). eGFR was estimated based on a combination of serum creatinine and cystatin C. The primary outcome was rapid decline in renal function, as defined by an eGFR decrease of > 5 ml/min/1.73 m2 per year, while the secondary outcome was the development of CKD, as defined by an eGFR decrease to a level < 60 ml/min/1.73 m2. Results: During the follow-up of 4 years, 258 (8.5%) participants experienced a rapid decline in renal function, while 87 (2.9%) developed CKD. In the fully adjusted model, high social isolation was significantly related to an increased risk of experiencing a rapid decline in renal function (OR 1.805, 95% CI 1.310-2.487) and CKD onset (OR 1.842, 95% CI 1.084-3.129). Among the five components of social isolation, being unmarried, not participating in social activities, and living alone independently predicted declined renal function. Conclusions: Social isolation is significantly associated with the risk of rapid eGFR decline and CKD onset in middle-aged and older adults with normal kidney function in China.

Urinary Soluble CD163 Levels Predict IgA Nephropathy Remission Status.

Noninvasive biomarkers of disease activity are needed to predict disease remission status in patients with IgA nephropathy (IgAN). Soluble CD163 (sCD163), shed by monocytes and macrophages, is a potential biomarker in diseases associated with excessive macrophage activation. We investigated the association of urinary sCD163 (u-sCD163) with histopathological activity and clinical manifestations in 349 patients with biopsy-diagnosed IgAN. U-sCD163 was measured via enzyme-linked immunosorbent assay. In patients with IgAN, higher u-sCD163 levels were associated with histological lesions of greater severity, as well as more proteinuria and poorer renal function. Additionally, u-sCD163 was correlated with infiltration of tubulointerstitial CD163+ macrophages. High u-sCD163 levels (>3.57 ng/mg Cr) were associated with a 2.66-fold greater risk for IgAN remission failure in adjusted analyses. Adding u-sCD163 levels to the model containing clinical data at biopsy and MEST-C score significantly improved the risk prediction of IgAN remission status (AUC 0.788). Together, our results suggest that u-sCD163 may be a useful noninvasive biomarker to evaluate disease severity and remission status of IgAN.

The Predictive Value of NT-Pro-Brain Natriuretic Peptide for Risk of Pneumonia in Patients on Maintenance Hemodialysis.

BACKGROUND/AIMS: Pneumonia is a common type of infection in maintenance hemodialysis (MHD) patients, while the treatment and prevention progress still keep limited. N-terminal-pro-brain natriuretic peptide (NT-proBNP) is an important marker in reflecting cardiac failure which also is a risk factor for pneumonia. This study aimed to determine the possible predictive value of NT-proBNP for pneumonia in MHD patients. METHODS: In this prospective study, the basic information of 276 MHD patients was collected in Fudan university Zhongshan hospital, followed up for 1 year. The primary endpoint was the first pneumonia event during follow-up. The value of NT-proBNP in patients with pneumonia and without pneumonia was analyzed, to elucidate the predictive value of the NT-proBNP in hemodialysis patients with pneumonia. RESULTS: Two hundred and seventy-six patients were finally enrolled in this prospective study, including 170 men. The mean age was 59.7 ± 14.0 years old. The average duration of hemodialysis is 56 (30-82.8) months. Enrolled patients were followed up for 1 year. During follow-up, 38 patients got pneumonia. After adjustment for other confounding factors, age (hazard ratio [HR] 1.031, 95% CI 1.003-1.060, p = 0.028), log NT-proBNP (HR 2.512, 95% CI 1.124-5.612, p = 0.025), history of smoking (HR 6.326, 95% CI 2.505-15.974, p < 0.001), ß2-microglobin (HR 1.042, 95% CI 1.007-1.079, p = 0.019), and history of cerebrovascular disease (HR 2.303, 95% CI 1.107-4.719, p = 0.026) were independent predictors of pneumonia. Receiver operating characteristic curves of log NT-proBNP to predict 1 year pneumonia cases, log NT-proBNP had an area under the curve of 0.647 (95% CI [0.564-0.729], p < 0.01). CONCLUSIONS: NT-proBNP is a predictive factor of pneumonia in hemodialysis patients.