Distribution of urinary N-acetyl-beta-D-glucosaminidase and the establishment of reference intervals in healthy adults

Evaluation of N-acetyl-β-D-glucosaminidase as a prognostic marker for diabetic nephropathy in type 2 diabetics: systematic review and meta-analysis

OBJECTIVE

This review aimed to assess the utility of urinary N-acetyl-β-D-glucosaminidase (uNAG) as a prognostic biomarker for nephropathy in patients with type 2 diabetes mellitus.

METHODS

The search for relevant studies was conducted across multiple databases, including PubMed (Medline), EMBASE, LILACS, CENTRAL, IBECS, and gray literature. We employed a random effects model to calculate the standardized mean difference and 95% confidence interval. Furthermore, we assessed heterogeneity using Cochrane's Q test and Higgins' I2 statistics.

RESULTS

This review included a total of 16 articles involving 1669 patients, with 13 being case-control studies and three being cohorts. The meta-analysis conducted across all studies revealed significant heterogeneity. However, subgroup analysis of four studies indicated that an increase in uNAG among normoalbuminuric patients was associated with the development of macroalbuminuria (DMP = - 1.47; 95% CI = - 1.98 to 0.95; p < 0.00001; I2 = 45%). Conversely, it did not demonstrate effectiveness in predicting the development of microalbuminuria (DMP = 0.26; 95% CI = - 0.08 to 0.60; p = 0.13; I2 = 17%).

CONCLUSIONS

Elevated uNAG levels in normoalbuminuric patients may indicate an increased risk for the development of macroalbuminuria, but not microalbuminuria. However, the high heterogeneity observed among the studies highlights the necessity for further research to validate these findings.

Nephrotoxic Biomarkers with Specific Indications for Metallic Pollutants: Implications for Environmental Health

Environmental and occupational exposure to heavy metals and metalloids is a major global health risk. The kidney is often a site of early damage. Nephrotoxicity is both a major consequence of heavy metal exposure and potentially an early warning of greater damage. A paradigm shift occurred at the beginning of the 21st century in the field of renal medicine. The medical model of kidney failure and treatment began to give way to a social model of risk factors and prevention with important implications for environmental health. This development threw into focus the need for better biomarkers: markers of exposure to known nephrotoxins; markers of early damage for diagnosis and prevention; markers of disease development for intervention and choice of therapy. Constituents of electronic waste, e-waste or e-pollution, such as cadmium (Cd), lead (Pb), mercury (HG), arsenic (As) and silica (SiO₂) are all potential nephrotoxins; they target the renal proximal tubules through distinct pathways. Different nephrotoxic biomarkers offer the possibility of identifying exposure to individual pollutants. In this review, a selection of prominent urinary markers of tubule damage is considered as potential tools for identifying environmental exposure to some key metallic pollutants.

Reference interval for urinary neutrophil gelatinase-associated lipocalin in healthy adults in Jiangsu region in Eastern China: a multicenter study

Aim: We explored the concentrations of urinary neutrophil gelatinase-associated lipocalin (NGAL) in healthy adults in the Jiangsu region in Eastern China and established a reference interval using latex-enhanced immunoturbidimetry to provide important guidelines for the interpretation and application of urinary NGAL in clinical practice. Methods: In total, 1970 eligible subjects from four regions were included in this study. The urinary NGAL levels were measured using an AU5800 automatic biochemical analyzer with its matched reagents. The urinary NGAL reference interval was established using the one-sided percentile method (95th percentile). Results: The urinary NGAL data were non-normally distributed. The urinary NGAL levels were not significantly different by sex or age. Therefore, the urinary NGAL reference interval in healthy adults in the Jiangsu region in Eastern China was <87.5 ng/ml (95th percentile of the upper limit). Conclusion: Urinary NGAL reference interval will play an important role in promoting the clinical value of urinary NGAL.

Electrochemical N-Acetyl-β-D-glucosaminidase Urinalysis: Toward Sensor Chip-Based Diagnostics of Kidney Malfunction

N-Acetyl-β-D-glucosaminidase (GlcNAcase) is a valuable biomarker for kidney health, as an increased urinary level of the enzyme indicates cell damage within the renal tubular filtration system from acute or chronic organ injury or exposure to nephrotoxic compounds. Effective renal function is vital for physiological homeostasis, and early detection of acute or chronic renal malfunction is critically important for timely treatment decisions. Here, we introduce a novel option for electrochemical urinalysis of GlcNAcase, based on anodic differential pulse voltammetry at boron-doped diamond disk sensors of the oxidizable product 4-nitrophenol (4NP), which is released by the action of GlcNAcase on the synthetic substrate 4NP-N-acetyl-β-D-glucosaminide (GlcNAc-4NP), added to the test solution as a reporter molecule. The proposed voltammetric enzyme activity screen accurately distinguishes urine samples of normal, slightly elevated and critically high urinary GlcNAcase content without interference from other urinary constituents. Moreover, this practice has the potential to be adapted for use in a hand-held device for application in clinical laboratories by physicians or in personal home health care. Evidence is also presented for the effective management of the procedure with mass-producible screen-printed sensor chip platforms.