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.

The ratio of monocytes to lymphocytes multiplying platelet predicts incidence of pulmonary infection-related acute kidney injury.

BACKGROUND: Inflammation is a crucial factor in the pathogenesis and development of acute kidney injury (AKI). Macrophages, as an important innate immune cell, regulate immune response and play a pathophysiological role in AKI. This study aimed to evaluate the predictive capacity of peripheral blood monocytes for the incidence of pulmonary infection-related AKI. METHODS: We recruited 1038 hospitalized patients with pulmonary infections from January 1 to December 31, 2019, in Zhongshan Hospital, Fudan University. Patients were divided into derivation and validation cohorts. Data on demographic characteristics, disease history, and biochemical indexes were retrieved from the electronic medical system. The composite inflammatory indexes were calculated as monocyte/(lymphocyte × platelet ratio) (MLPR). We applied dose-response relationship analyses to delineate the nonlinear odds ratio (OR) in different MLPR levels and integrated it into a logistic model to predict the risk of AKI. RESULTS: The incidence of hospital-acquired AKI was 18.8% in the derivation cohort. Compared to non-AKI, the MLPR levels were significantly higher in AKI patients. Dose-response curve revealed that the increase of AKI risk was faster in the first half of MLPR and then tended to flatten. After classifying the MLPR levels into six groups, the AKI incidence increased from 4.5% to 55.3% with a peaking OR of 24.38. The AUC values of the AKI model only including MLPR were 0.740, and after gradually integrating other covariates, the area under the receiver operating characteristic (AUC) value reached 0.866, which was significantly higher than the AUC of full models without MLPR (0.822). Moreover, the better prediction ability of AKI was observed in the external validation, with an AUC of 0.899. CONCLUSION: MLPR has good predictive efficiency in AKI, which can be used as a simple and easy clinical composite index to effectively predict early pulmonary infection-related AKI.

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.

Short sleep duration increases the risk of hyperuricemia among Chinese adults: findings from the China Health and Nutrition Survey.

STUDY OBJECTIVES: Hyperuricemia is a growing public health problem with its increasing prevalence. Few studies have investigated the association between sleep duration and hyperuricemia. The objective of this study is to explore whether short sleep duration is an independent risk factor of hyperuricemia in Chinese adults. METHODS: The data we analyzed was extracted from the 2009 wave of the China Health and Nutrition Survey. The population we analyzed included 8289 participants aged 18 years or older with sleep of 5-10 h per 24 h. We categorized the population into three groups by sleep duration: 5-6 h (short sleeper),7-8 h (regular sleeper), and 9-10 h (long sleeper). Hyperuricemia was defined as serum uric acid ≥7 mg/dL in men and ≥6 mg/dL in women. RESULTS: Among the three groups, 9.8% were short sleepers, 68.4% were regular sleepers and 21.8% were long sleepers. The prevalences of hyperuricemia were 19.5%,15.2% and 15.5% respectively. The risks of hyperuricemia in regular and long sleep groups were lower than short sleep group, and the association remained after adjusting for indexes including age, gender, chronic kidney disease, hypertension, diabetes mellitus, high low-density lipoprotein cholesterol (LDL-c), and obesity. In subgroup analysis, we found the association was still observed in participants without hypertension, diabetes mellitus or obesity. CONCLUSIONS: Our findings suggest that short sleep duration is associated with higher risk of hyperuricemia independently of cardiometabolic risk factors, especially in individuals without traditional hyperuricemia risk factors.

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.

Decreased percentage of memory B cells is independently associated with increased susceptibility to infection in patients on maintenance hemodialysis.

PURPOSE: Infection is a common complication and cause of death in patients on maintenance hemodialysis (MHD). B lymphocytes, which are an important component of the immune system, play a significant role in defending against pathogen invasion. However, in patients on MHD, the connection between infection and B cell subsets remains largely unknown. Our study aims to clarify the potential role of the distribution of B cell subsets in the infection process in patients on MHD. METHODS: In this cross-sectional study, basic information was collected from 175 patients on MHD from July 2016 to July 2017 at Zhongshan Hospital, Fudan University. The distributions of the B cell subsets in patients with and without infection were analyzed using flow cytometry to determine the role of B lymphocyte subsets in the infection process in patients on MHD. RESULTS: Among the 175 patients, 45 suffered from infection. The respiratory tract was the most common infection site, accounting for 67.86% of all infections. After adjustment using multivariate logistic regression models, memory B cells [per 1% increase, odds ratio [95% confidence interval (CI)]: 0.949 (0.915, 0.984), P < 0.01], switched memory B cells [per 1% increase, odds ratio (95% CI): 0.939 (0.898, 0.982), P < 0.01], naïve B cells [per 1% increase, odds ratio (95% CI): 1.042 (1.009, 1.075), P < 0.05] and IgG titers [per 1 g/L increase, odds ratio (95% CI): 0.779 (0.630, 0.963), P < 0.05] were independent risk factors for infection in dialysis patients. CONCLUSION: A decrease in memory B cells is independently associated with an increased risk of infection in patients on dialysis.

[The prevalence and risk factors of kidney disease in type 2 diabetic patients in rural Shanghai].

OBJECTIVE: To identify the prevalence and etiology of kidney disease and the related risk factors in type 2 diabetic patients in rural Shanghai. METHODS: A cross-sectional study in type 2 diabetic patients was conducted in a community of Shanghai. Questionnaire, clinical examination and laboratory tests were completed to collect the information about sociodemographic and healthcare characteristics. RESULTS: A total of 1421 eligible patients with complete information were screened from 1487 type 2 diabetic patients between November 2008 and March 2009. Of them, 40.75% were men, 59.25% were women, aged 37 - 86 (61.33 ± 9.65) years old, with diabetic duration of 0.25 - 43.92 (7.85 ± 6.34) years. Among them, 43.42% had diabetic retinopathy, 21.18% had neuropathy; 69.95% met the screening definition for hypertension, 76.07% for hyperlipidemia, 15.55% for hyperuricemia and 23.65% for cardiovascular disease. The control rates of fasting blood glucose, glycosylated hemoglobin, blood pressure and serum cholesterol were 57.71%, 33.99%, 14.22% and 2.46%, respectively. The prevalence of kidney disease, diabetic nephropathy and non-diabetic renal disease was 41.31%, 18.51% and 13.44%, respectively; and 9.36% were diagnosed as renal insufficiency of unknown reasons. Age, diabetic duration, hyperuricemia, diabetic retinopathy and poor control of blood pressure were independently associated with kidney disease; age and poor control of blood pressure were independently associated with diabetic nephropathy; age and hyperuricemia were independent risk factors of renal insufficiency in patients with diabetic nephropathy. CONCLUSIONS: Although the diabetic duration of these subjects is relatively short, the prevalence of complications including diabetic nephropathy is high. The high prevalence of non-diabetic renal disease shows the importance of further screening and diagnoses for prevention. Strict control of blood glucose, blood pressure, serum cholesterol and serum uric acid are key points of cutting down the prevalence of diabetic nephropathy and chronic kidney disease.