Urine NGAL as an early biomarker for diabetic kidney disease: accumulated evidence from observational studies

Urinary biomarkers NG AL and beta-2 microglobulin in children with type 1 diabetes mellitus

OBJECTIVES

To study the urinary neutrophil gelatinase-associated lipocalin (NGAL) and beta-2-microglobulin (β2M) levels as markers of tubular damage in children with type 1 diabetes (T1DM).

METHODS

Forty T1DM children and 40 age-matched controls were enrolled. Subjects with coexisting kidney disorder, intake of oral glucose lowering drugs and syndromic diabetes mellitus were excluded. Fasting plasma glucose, glycated hemoglobin (HbA1c), kidney function, urinary albumin-creatinine ratio (UACR), NGAL and β2M were measured and compared in cases and controls.

RESULTS

The median (IQR) age of cases and controls was 10.6 (8, 14.2) and 10.7 (8.4, 13.7) years, respectively. Cases had disease duration of 4 (3, 6.8) years and HbA1c 10.9 (9, 13.1) %. Microalbuminuria was seen in 14 (35 %). Median (IQR) levels of UACR were higher in cases than controls [19.38 (10.27, 35.26) and 6.49 (3.10, 11.65) µg/mg; p<0.001], similarly NGAL/creatinine [352.21 (191.49, 572.45) and 190.54 (125.91, 322.83) ng/mg; p=0.006], unlike β2M/creatinine [1.7 (0.43, 6.02) and 2.12 (1.05, 4.47) µg/mg; p=0.637]. Children with higher HbA1c (≥10 %) had higher urinary ACR and tubular biomarkers than HbA1c<10 % (p>0.05). Urinary ACR showed positive correlation with NGAL/creatinine (r=0.38, p=0.019) and β2M/creatinine (r=0.42, p=0.009).

CONCLUSIONS

Urinary biomarkers NGAL and β2M were elevated in the presence of normal urinary microalbumin levels suggestive of early tubular damage in T1DM.

Urinary Biomarkers NGAL and Beta-2 Microglobulin for Detection of Diabetic Nephropathy in Type 1 Diabetes Mellitus.. [DOI: 10.21203/rs.3.rs-3417003/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Objectives: Urinary neutrophil gelatinase-associated lipocalin (NGAL) and beta-2 microglobulin(β2M) have been evaluated as markers of tubular damage in type 2 diabetes mellitus. There is limited data on their performance to screen nephropathy in type 1 diabetes mellitus (T1DM). Methods: This case-control study enrolled 40 children with T1DM and 40 age-matched controls age 2-18 years. Subjects with coexisting renal disorder and syndromic diabetes mellitus were excluded. Fasting plasma glucose, glycated hemoglobin (HbA1c), and renal function were measured. Urinary levels of urine albumin-creatinine ratio (ACR), neutrophil gelatinase-associated lipocalin (NGAL) and beta-2 microglobulin (β2M) were measured for an associated with disease duration, glycemic control and microalbuminuria. Correlation (r) was measured for statistical association between biochemical markers and area-under-curve (AUC) calculated to predict nephropathy. Results: The median (IQR) age of cases and controls was 10.6(8,14.2) and 10.7 (8.4,13.7) years, respectively, disease duration 4 (3,6.8) years and HbA1c 10.9(9.,13.1)% in cases. Microalbuminuria was seen in 14(35%) but none had macroalbuminuria.The urinary ACR and NGAL were significantly higher in cases than controls [19.38 (10.27,35.26) and 6.49 (3.10,11.65) µg/mg; p<0.001] and [352.21(191.49,572.45) and 190.54 (125.91,322.83) ng/mg; p=0.006], respectively, unlike β2M [1.7 (0.43,6.02) and 2.12 (1.05,4.47) µg/mg; p=0.637]. Children with higher HbA1C (>10%) had higher urinary ACR, NGAL and β2M levels than those with HbA1C<10%. Urinary ACR showed positive correlation with NGAL/creatinine (r= 0.38, p value=0.019) and β2M/ creatinine (r=0.48, p value= 0.004) in cases. The AUC was 0.57 (95% CI 0.36,0.78); p value= 0.48 for NGAL/creatinine, and 0.62 (95%CI 0.43,0.81); p value=0.21 for β2M /creatinine to predict microalbuminuria (ACR >30mg/g). Conclusion: Urinary biomarkers NGAL and β2M showed a good correlation with ACR suggesting their role in screening of diabetic tubulopathy before overt glomerular damage in T1DM.

Early renal structural changes and potential biomarkers in diabetic nephropathy

Diabetic nephropathy is one of the most serious microvascular complications of diabetes mellitus, with increasing prevalence and mortality. Currently, renal function is assessed clinically using albumin excretion rate and glomerular filtration rate. But before the appearance of micro-albumin, the glomerular structure has been severely damaged. Glomerular filtration rate based on serum creatinine is a certain underestimate of renal status. Early diagnosis of diabetic nephropathy has an important role in improving kidney function and delaying disease progression with drugs. There is an urgent need for biomarkers that can characterize the structural changes associated with the kidney. In this review, we focus on the early glomerular and tubular structural alterations, with a detailed description of the glomerular injury markers SMAD1 and Podocalyxin, and the tubular injury markers NGAL, Netrin-1, and L-FABP in the context of diabetic nephropathy. We have summarized the currently studied protein markers and performed bioprocess analysis. Also, a brief review of proteomic and scRNA-seq method in the search of diabetic nephropathy.

Usefulness of urinary tubule injury markers for predicting progression of renal dysfunction in patients with type 2 diabetes and albuminuria: The Fukuoka Diabetes Registry

AIMS

We prospectively investigated the association of urinary tubule injury markers with estimated glomerular filtration rate (eGFR) decline in Japanese patients with type 2 diabetes.

METHODS

Urinary kidney injury molecule 1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), liver-type fatty-acid-binding protein (L-FABP), and urinary albumin-to creatinine ratio (UACR) were measured in 2,685 participants with type 2 diabetes. Renal outcomes were ≥ 30% decline in eGFR from the baseline and annual eGFR decline for 5 years.

RESULTS

In normoalbuminuric participants, no tubular markers were associated with ≥ 30% decline in eGFR or annual eGFR changes. In those with UACR ≥ 30 mg/gCr, hazard ratios for ≥ 30% eGFR decline were 1.37 (95% confident interval (CI) 1.07-1.75) for urinary KIM-1 (>1.5 µg/gCr), 1.46 (95% CI 1.13-1.66) for urinary NGAL (>16.4 µg/gCr), and 1.26 (95% CI 0.94-1.66) for urinary L-FABP (>12.5 µg/gCr), 2.61 (95% CI 1.64-4.17) for the combination of 3 tubular markers above the cutoff after multivariable adjustments including UACR and eGFR.

CONCLUSIONS

The current study demonstrated that urinary tubule injury markers and their combination were significant predictors for the future eGFR decline in those with type 2 diabetes and albuminuria independently of UACR and eGFR. Urinary tubular markers may be useful to identify high-risk patients with albuminuria.

Association of Acute Kidney Injury During Diabetic Ketoacidosis With Risk of Microalbuminuria in Children With Type 1 Diabetes

IMPORTANCE

Diabetic kidney disease is among the most important causes of end-stage kidney disease worldwide. Risk factors for diabetic kidney disease remain incompletely defined. Recent studies document a high frequency of acute kidney injury (AKI) during diabetic ketoacidosis (DKA) in children, raising the question of whether these AKI episodes might contribute to future risk of diabetic kidney disease.

OBJECTIVE

To determine whether episodes of AKI occurring during DKA in children are associated with increased risk of development of microalbuminuria.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective review of medical records included children with type 1 diabetes with 1 or more urine albumin levels measured during routine diabetes care from 2 university-affiliated urban tertiary children's hospitals in the United States from January 2006 to December 2019. Age at diagnosis of diabetes, hemoglobin A1c levels, episodes of DKA, pH and creatinine levels during DKA, and urine albumin and creatinine measurements were analyzed. Cox proportional hazards regression models were used to identify variables affecting the hazard rate for microalbuminuria development. Analyses began January 2021 and ended May 2021.

EXPOSURES

Episodes of DKA and episodes of AKI occurring during DKA.

MAIN OUTCOMES AND MEASURES

AKI occurrence and AKI stage were determined from serum creatinine measurements during DKA using Kidney Disease: Improving Global Outcomes criteria. Microalbuminuria was defined as urine albumin-to-creatinine ratio of 30 mg/g or more or excretion of 30 mg or more of albumin in 24 hours.

RESULTS

Of 2345 children, the mean (SD) age at diagnosis was 9.4 (4.4) years. One or more episodes of DKA occurred in 963 children (41%), and AKI occurred during DKA in 560 episodes (47%). In multivariable models adjusting for the associations of age at diagnosis and mean hemoglobin A1c level since diagnosis, each episode of AKI during DKA was associated with a hazard ratio of 1.56 (95% CI, 1.3-1.87) for development of microalbuminuria. Four or more episodes increased the hazard rate by more than 5-fold. DKA episodes without AKI did not significantly increase the hazard rate for microalbuminuria development after adjusting for other covariates.

CONCLUSIONS AND RELEVANCE

These data demonstrate that episodes of AKI occurring during DKA in children with type 1 diabetes are significantly associated with risk of developing microalbuminuria. Greater efforts are necessary to reduce the frequency of DKA.

The Perspectives of Biomarkers in Predicting the Survival of the Renal Graft

Kidney transplantation (KT) is currently the elective approach for patients with end-stage renal disease. Although it is a safe choice for these patients, the early complications can lead to graft dysfunction. One of the most redoubtable complications is delayed graft function (DGF), having no specific treatment. The effects of DGF on the graft survival are large enough to justify the formulation of specific biological protocols. Therefore, discovering biomarkers of acute impairment in renal transplanted patients is required. Creatinine is a poor marker to establish the kidney injury. Estimated glomerular filtration rate together with creatinine is ready to approximately measure the kidney function. Different serum and urine proteins are being studied as possible predictive biomarkers for delayed graft function. This review will concentrate on recent and existing research which provide insight concerning the contribution of some molecules for the estimation and evaluation of graft function after kidney transplantation. Further studies examining various aspects of DGF after KT are urgently needed to address a hitherto less-known clinical question.

Acute Kidney Injury in Pediatric Diabetic Kidney Disease

Diabetic kidney disease (DKD) is a common complication of type 1 and 2 diabetes and often presents during adolescence and young adulthood. Given the growing incidence of both type 1 and type 2 diabetes in children and adolescents, DKD represents a significant public health problem. Acute kidney injury (AKI) in youth with diabetes is strongly associated with risk of DKD development. This review will summarize the epidemiology and pathophysiology of AKI in children with diabetes, the relationship between AKI and DKD, and the potential therapeutic interventions. Finally, we will appraise the impact of the recent COVID-19 infection pandemic on AKI in children with diabetes.

Urinary podocyte mRNAs precede microalbuminuria as a progression risk marker in human type 2 diabetic nephropathy

Earlier detection of progression risk in diabetic nephropathy will allow earlier intervention to reduce progression. The hypothesis that urinary pellet podocyte mRNA is a more sensitive progression risk marker than microalbuminuria was tested. A cross sectional cohort of 165 type 2 diabetics and 41 age and sex-matched controls were enrolled. Podocyte stress (Urinary pellet podocin:nephrin mRNA ratio), podocyte detachment (Urinary pellet podocin mRNA:creatinine ratio: UPPod:CR) and a tubular marker (Urinary pellet aquaporin 2:creatinine ratio) were measured in macro-albuminuric, micro-albuminuric and norm-albuminuric groups. eGFR was reassessed after 4 years in 124 available diabetic subjects. Urinary pellet podocyte and tubular mRNA markers were increased in all diabetic groups in cross-sectional analysis. After 4 years of follow-up univariable and multivariate model analysis showed that the only urinary markers significantly related to eGFR slope were UPPod:CR (P < 0.01) and albuminuria (P < 0.01). AUC analysis using K-fold cross validation to predict eGFR loss of ≥ 3 ml/min/1.73m²/year showed that UPPod:CR and albuminuria each improved the AUC similarly such that combined with clinical variables they gave an AUC = 0.70. Podocyte markers and albuminuria had overlapping AUC contributions, as expected if podocyte depletion causes albuminuria. In the norm-albuminuria cohort (n = 75) baseline UPPod:CR was associated with development of albuminuria (P = 0.007) and, in the tertile with both normal kidney function (eGFR 84 ± 11.7 ml/min/1.73m²) and norm-albuminuria at baseline, UPPod:CR was associated with eGFR loss rate (P = 0.003). In type 2 diabetics with micro- or macro-albuminuria UPPod:CR and albuminuria were equally good at predicting eGFR loss. For norm-albuminuric type 2 diabetics UPPod:CR predicted both albuminuria and eGFR loss.

Assessment of urinary NGAL for differential diagnosis and progression of diabetic kidney disease

OBJECTIVE

Chronic kidney disease (CKD) related to diabetes has become more common than glomerulonephritis in recent years. Given the inefficient and difficult identification of diabetic kidney disease (DKD) from non-diabetic kidney disease (NDKD) as well as a result of emerging evidence supporting a role for tubular involvement in DKD, we aimed to investigate the utility of urinary neutrophil gelatinase-associated lipocalin (uNGAL) in the differential diagnosis and predictive value of DKD from NDKD.

METHODS

Data for 100 type 2 diabetic patients with CKD at our center from June 2016 to August 2019 were reviewed. All the patients were categorized into 2 groups by the renal biopsy results: DKD and NDKD. Urinary NGAL levels were normalized by urinary creatinine and calculated as uNGAL/creatinine ratios (uNCR). The independent factors of the occurrence of DKD and the diagnostic implications of uNCR were explored by logistic regression and receiver-operating characteristic (ROC) curve analysis. In addition, we analyzed the relationship between uNCR and proteinuria in patients with DKD by Pearson test and linear regression. Kaplan-Meier survival analysis was performed to assess the prospective association of uNCR with the renal outcome.

RESULTS

Significantly higher levels of uNCR were observed in patients with DKD when compared to those with NDKD (28.65 ng/mg vs 27.47 ng/mg, p< .001). uNCR was identified as an independent risk factor for the occurrence of DKD in diabetic patients with CKD (odds ratio [OR] = 1.020; 95%CI = [1.001-1.399], p = .042). The optimal cutoff value of uNCR for predicting DKD was 60.685 ng/mg with high specificity (90.5%) but relatively low sensitivity (55.7%). In Pearson test, uNCR was positively correlated with proteinuria, serum creatine, blood urea nitrogen, duration of diabetes, interstitial inflammation score and global sclerosis, whereas it was inversely correlated with eGFR, hemoglobin, serum albumin and 25-hydroxy vitamin D. Furthermore, in a fully adjusted model including eGFR, serum albumin and total cholesterol, the group with uNCR>60.685 ng/mg was associated with 7.595 times higher likelihood of nephrotic-range proteinuria compared to the group with uNCR≤60.685 ng/mg. In the Kaplan-Meier survival analysis, the event-free survival probability in patients with uNCR>60.685 ng/mg was significantly lower than those with uNCR≤60.685 ng/mg (p = .048).

CONCLUSIONS

uNCR might serve as a potential tool for identifying cases in which there was a high clinical suspicion of DKD and that in whom confirmatory biopsy could be considered, and the best predictive cutoff value of normalized uNCR for DKD diagnosis was 60.685 ng/mg. Type 2 diabetic patients with increased level of uNCR had higher risk to nephrotic-range proteinuria and worse renal outcome.

Prediction Value of Serum NGAL in the Diagnosis and Prognosis of Experimental Acute and Chronic Kidney Injuries

Sensitive and accurate serum biomarkers for monitoring acute and chronic kidney disease progression are more convenient and can better evaluate drug efficiency in pharmacological research. Neutrophil Gelatinase-associated Lipocalin (NGAL) is considered a hopeful early biomarker of acute kidney injury (AKI), but its utility in early prediction and prognosis of diabetic nephropathy (DN) and immune-mediated glomerulonephritis is still not clear. Moreover, detailed prognosis studies of NGAL in AKI are lacking, and most studies use a urine source. In the current study, through two experimental AKI and two chronic kidney injury animal models, serum NGAL (sNGAL) prediction values on diagnosis and prognosis of kidney injuries in animal disease models have been investigated thoroughly. Four experimental kidney disease models include cisplatin-induced and lipopolysaccharide (LPS)-induced AKI, streptozocin-induced diabetic nephropathy (DN), and cationized-bovine serum albumin (c-BSA)-induced membranous nephropathy (MN), respectively. The sNGAL concentration was measured at different stages of kidney injury (KI) in each experimental model, and receiver operating characteristic (ROC) analyses were performed to investigate the diagnosis efficiency of sNGAL for KI. Western blot and immunohistochemistry were used to measure the protein levels in the kidneys, and pathological analysis was used as the gold standard to confirm KI. Results suggest that sNGAL can predict early diagnosis of cisplatin-induced AKI accurately but is less powerful in later stages compared to blood urea nitrogen (BUN) and serum creatinine (Scr). sNGAL is sensitive but lacks specificity to evaluate early kidney injury for LPS-induced AKI under low-dosage LPS challenge. sNGAL is not an efficient biomarker for early diagnosis of STZ-induced DN, but sNGAL is an efficient predictor for the early diagnosis and prognosis of immune-mediated MN. In conclusion, application of sNGAL as a kidney injury biomarker to determine the diagnosis and prognosis in pharmacological studies is dependent on experimental animal models.

The Lipocalin2 Gene is Regulated in Mammary Epithelial Cells by NFκB and C/EBP In Response to Mycoplasma

Lcn2 gene expression increases in response to cell stress signals, particularly in cells involved in the innate immune response. Human Lcn2 (NGAL) is increased in the blood and tissues in response to many stressors including microbial infection and in response to LPS in myeloid and epithelial cells. Here we extend the microbial activators of Lcn2 to mycoplasma and describe studies in which the mechanism of Lcn2 gene regulation by MALP-2 and mycoplasma infection was investigated in mouse mammary epithelial cells. As for the LPS response of myeloid cells, Lcn2 expression in epithelial cells is preceded by increased TNFα, IL-6 and IκBζ expression and selective reduction of IκBζ reduces Lcn2 promoter activity. Lcn2 promoter activation remains elevated well beyond the period of exposure to MALP-2 and is persistently elevated in mycoplasma infected cells. Activation of either the human or the mouse Lcn2 promoter requires both NFκB and C/EBP for activation. Thus, Lcn2 is strongly and enduringly activated by mycoplasma components that stimulate the innate immune response with the same basic regulatory mechanism for the human and mouse genes.

Neutrophil Gelatinase-Associated Lipocalin and Retinol-Binding Protein-4 as Biomarkers for Diabetic Kidney Disease

AIMS

This study was designed to evaluate the conflicting association between 2 tubular protein markers including neutrophil gelatinase-associated lipocalin (NGAL) and retinol-binding protein-4 (RBP-4) with albuminuria and glomerular filtration rate (GFR) and calculate the accuracy of the role of NGAL and RBP-4 in diagnosis of diabetic nephropathy (DN) in patients with type2 diabetes.

METHODS

This is a cross-sectional study that included 133 patients with type 2 diabetes. There were 3 diabetic study groups with normoalbuminuria, moderately increased albuminuria, severely increased albuminuria, and non-diabetic control group without any renal disease. We analyzed the difference of urinary NGAL (uNGAL) and RBP-4 between nondiabetics and diabetics, as well as within the diabetic group. We also assessed the association between albuminuria and NGAL and RBP-4.

RESULTS

The urinary levels of NGAL and RBP-4 were higher in patients with type 2 diabetes compared to nondiabetics as well as in albuminuric diabetics compared to nonalbuminuric patients with diabetes (p value <0.001). These 2 proteins were higher in patients with severely increased albuminuria compared to patients with moderately increased albuminuria, even after adjustment for other metabolic factors (all p < 0.01). Moreover, areas under the curve of NGAL and RBP-4 for the diagnosis of chronic kidney disease were 80.6 and 74.6%, respectively.

CONCLUSION

uNGAL and RBP-4 are potential markers of tubular damage that may increase before the onset of glomerular markers such as albuminuria and GFR in patients with type 2 diabetes. Therefore, these markers can be used as complementary measurements to albuminuria and GFR in the earlier diagnosis of DN.

Diabetic kidney diseases revisited: A new perspective for a new era

BACKGROUND

Globally, diabetic kidney disease (DKD) is the leading cause of end-stage renal disease. As the most common microvascular complication of diabetes, DKD is a thorny, clinical problem in terms of its diagnosis and management. Intensive glucose control in DKD could slow down but not significantly halt disease progression. Revisiting the tremendous advances that have occurred in the field would enhance recognition of DKD pathogenesis as well as improve our understanding of translational science in DKD in this new era.

SCOPE OF REVIEW

In this review, we summarize advances in the understanding of the local microenvironmental changes in diabetic kidneys and discuss the involvement of genetic and epigenetic factors in the pathogenesis of DKD. We also review DKD prevalence changes and analyze the challenges in optimizing the diagnostic approaches and management strategies for DKD in the clinic. As we enter the era of 'big data', we also explore the possibility of linking systems biology with translational medicine in DKD in the current healthcare system.

MAJOR CONCLUSION

Newer understanding of the structural changes of diabetic kidneys and mechanisms of DKD pathogenesis, as well as emergent research technologies will shed light on new methods of dealing with the existing clinical challenges of DKD.