Neutrophil gelatinase-associated lipocalin and end-stage renal disease: it is not all about the kidneys!

Urine neutrophil gelatinase-associated lipocalin as a biomarker of acute kidney injury and prognosis in decompensated chronic liver disease: A prospective study

BACKGROUND

Acute kidney injury (AKI) heralds deterioration in patients with decompensated chronic liver disease (DCLD). Serum creatinine (sCr), a component of the model for end-stage liver disease-sodium (MELD-Na) prognostic score, has limitations in patients with DCLD. We evaluated the prognostic role of urine neutrophil gelatinase-associated lipocalin (NGAL) in DCLD and its ability to sub-type AKI.

METHODS

Total 147 consecutive patients hospitalized between June 2018 and June 2020 for complications of DCLD were evaluated. Urine NGAL was estimated and demographic, clinical and biochemical parameters recorded at baseline. Participants were followed up till the end of study period or mortality, whichever came earlier. Primary outcomes included all-cause mortality and time to death after index hospitalization. Secondary outcomes included the presence and type of AKI, need for intensive care unit (ICU) stay, length of ICU/hospital stay, in-hospital mortality, development of new-onset/recurrent AKI and recurrent hospitalization after index admission.

RESULTS

Urine NGAL was highest in acute tubular necrosis (ATN), lowest in pre-renal azotemia (PRA) and intermediate in hepatorenal syndrome (HRS-AKI). Urine NGAL (p = 0.0208) was superior to sCr (p = 0.0388) and inferior to fractionated excretion of sodium (FENa) (p = 0.0013) in stratifying AKI. A cut-off of 203.9 ng/mL discriminated between HRS and PRA with sensitivity 77.8% and specificity 68.7%. Urine NGAL correlated with MELD-Na score, need for ICU stay, in-hospital mortality and mortality at three and six months. Two-year survival was significantly lower in patients with urine NGAL > 205 ng/mL. Addition of log-urine-NGAL score did not improve predictive performance of MELD-Na.

CONCLUSION

Urine NGAL could identify AKI sub-types and correlated with short-term clinical outcomes, including mortality.

Association of plasma neutrophil gelatinase-associated lipocalin and thoracic aorta calcification in maintenance hemodialysis patients with and without diabetes

Background

Neutrophil gelatinase-associated lipocalin (NGAL) is not only a bone-derived factor involved in metabolism, but also a biomarker of kidney disease and cardiovascular pathophysiology. We conducted this cross-sectional observational study to explore relationships between plasma NGAL and thoracic aorta calcification (TAC) in maintenance hemodialysis (MHD) patients with and without diabetes.

Methods

Plasma NGAL was measured by ELISA, TAC was evaluated via computed tomography scan using a 3D quantification method or chest radiography aortic arch calcification score. Spearman correlation, Logistic regression and Partial correlation analysis were used to describe the correlations between NGAL and TAC.

Results

Plasma NGAL levels were lower in MHD patients with diabetes compared to those without diabetes (49.33(42.37, 55.48) vs 56.78(44.37, 674.13) ng/mL, P = 0.026). In MHD patients without diabetes, lg (NGAL) was positively correlated with ARC value(R = 0.612, P = 0.003) analyzed by Spearman correlation; for partial correlation analysis, lg (NGAL) was positively correlated with ARC value, after adjusting for age and sex (R = 0.550, P = 0.015), adjusting for age, sex and CHD (R = 0.565, P = 0.015), adjusting for age, sex, CHD and Alb (R = 0.536, P = 0.027), or adjusting for age, sex, CHD, Alb, and dialyzer membrane (polysulfone) (R = 0.590, P = 0.016); however, when adjusting for age, sex, CHD, Alb and Ca, the correlation between lg (NGAL) and ARC value disappeared. Positive correlation were found between NGAL and Ca (R = 0.644, P < 0.001), Ca and ACR (R = 0.534, P = 0.013) in Spearman coefficient analysis.

Conclusion

There were positive correlations among plasma NGAL, serum Ca and ARC in MHD patients without diabetes; which suggests that NGAL is possibly a participant in cardiovascular calcification, in non-diabetic MHD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02773-z.

Association of plasma neutrophil gelatinase-associated lipocalin with parameters of CKD-MBD in maintenance hemodialysis patients

INTRODUCTION

Neutrophil gelatinase-associated lipocalin (NGAL) is not only a biomarker of kidney injury but also a bone-derived factor involved in metabolism. We aimed to explore relationships between plasma NGAL and chronic kidney disease-mineral bone disorder (CKD-MBD) parameters in maintenance hemodialysis (MHD) patients.

MATERIALS AND METHODS

First, a cross sectional observational study, including 105 MHD patients, was conducted to explore relationships between plasma NGAL levels and CKD-MBD parameters. Second, impact of parathyroidectomy and auto-transplantation (PTX + AT) on plasma NGAL was investigated in 12 MHD patients with severe secondary hyperparathyroidism (SHPT).

RESULTS

According to Spearman correlation analysis, plasma NGAL levels were positively correlated with female (r = 0.243, P = 0.012), vintage (r = 0.290, P = 0.003), Klotho (r = 0.234, P = 0.016), calcium(Ca) (r = 0.332, P = 0.001), alkaline phosphatase (ALP) (r = 0.401, P < 0.001) and intact parathyroid hormone (iPTH) (r = 0.256, P = 0.008); while inversely correlated with albumin(Alb) (r = - 0.201, P = 0.039). After adjusting for age, sex, vintage, Alb and all parameters of CKD-MBD(Ca, P, lg(ALP), lg(iPTH), Klotho and fibroblast growth factor 23(FGF23)), lg(NGAL) were positively correlated with Ca (r = 0.481, P < 0.001), P (r = 0.336, P = 0.037), lg(ALP) (r = 0.646, P < 0.001) in Partial correlation analysis; further multiple linear regression analysis showed same positive associations between lg(NGAL) and Ca (β = 0.330, P = 0.002), P (β = 0.218, P = 0.037), lg(ALP) (β = 0.671, P < 0.001). During the 4-7 days after PTX + AT, plasma NGAL decreased from 715.84 (578.73, 988.14) to 688.42 (660.00, 760.26) ng/mL (P = 0.071), Klotho increased from 496.45 (341.73, 848.30) to 1138.25 (593.87, 2009.27) pg/mL (P = 0.099).

CONCLUSION

Plasma NGAL levels were positively associated with ALP in MHD patients; and downtrends were shown after PTX + AT in patients with severe SHPT. These findings suggest that NGAL is a participant in CKD-MBD under MHD condition.

Methods for the evaluation of biomarkers in patients with kidney and liver diseases: multicentre research programme including ELUCIDATE RCT

Background

Protein biomarkers with associations with the activity and outcomes of diseases are being identified by modern proteomic technologies. They may be simple, accessible, cheap and safe tests that can inform diagnosis, prognosis, treatment selection, monitoring of disease activity and therapy and may substitute for complex, invasive and expensive tests. However, their potential is not yet being realised.

Design and methods

The study consisted of three workstreams to create a framework for research: workstream 1, methodology – to define current practice and explore methodology innovations for biomarkers for monitoring disease; workstream 2, clinical translation – to create a framework of research practice, high-quality samples and related clinical data to evaluate the validity and clinical utility of protein biomarkers; and workstream 3, the ELF to Uncover Cirrhosis as an Indication for Diagnosis and Action for Treatable Event (ELUCIDATE) randomised controlled trial (RCT) – an exemplar RCT of an established test, the ADVIA Centaur® Enhanced Liver Fibrosis (ELF) test (Siemens Healthcare Diagnostics Ltd, Camberley, UK) [consisting of a panel of three markers – (1) serum hyaluronic acid, (2) amino-terminal propeptide of type III procollagen and (3) tissue inhibitor of metalloproteinase 1], for liver cirrhosis to determine its impact on diagnostic timing and the management of cirrhosis and the process of care and improving outcomes.

Results

The methodology workstream evaluated the quality of recommendations for using prostate-specific antigen to monitor patients, systematically reviewed RCTs of monitoring strategies and reviewed the monitoring biomarker literature and how monitoring can have an impact on outcomes. Simulation studies were conducted to evaluate monitoring and improve the merits of health care. The monitoring biomarker literature is modest and robust conclusions are infrequent. We recommend improvements in research practice. Patients strongly endorsed the need for robust and conclusive research in this area. The clinical translation workstream focused on analytical and clinical validity. Cohorts were established for renal cell carcinoma (RCC) and renal transplantation (RT), with samples and patient data from multiple centres, as a rapid-access resource to evaluate the validity of biomarkers. Candidate biomarkers for RCC and RT were identified from the literature and their quality was evaluated and selected biomarkers were prioritised. The duration of follow-up was a limitation but biomarkers were identified that may be taken forward for clinical utility. In the third workstream, the ELUCIDATE trial registered 1303 patients and randomised 878 patients out of a target of 1000. The trial started late and recruited slowly initially but ultimately recruited with good statistical power to answer the key questions. ELF monitoring altered the patient process of care and may show benefits from the early introduction of interventions with further follow-up. The ELUCIDATE trial was an ‘exemplar’ trial that has demonstrated the challenges of evaluating biomarker strategies in ‘end-to-end’ RCTs and will inform future study designs.

Conclusions

The limitations in the programme were principally that, during the collection and curation of the cohorts of patients with RCC and RT, the pace of discovery of new biomarkers in commercial and non-commercial research was slower than anticipated and so conclusive evaluations using the cohorts are few; however, access to the cohorts will be sustained for future new biomarkers. The ELUCIDATE trial was slow to start and recruit to, with a late surge of recruitment, and so final conclusions about the impact of the ELF test on long-term outcomes await further follow-up. The findings from the three workstreams were used to synthesise a strategy and framework for future biomarker evaluations incorporating innovations in study design, health economics and health informatics.

Trial registration

Current Controlled Trials ISRCTN74815110, UKCRN ID 9954 and UKCRN ID 11930.

Funding

This project was funded by the NIHR Programme Grants for Applied Research programme and will be published in full inProgramme Grants for Applied Research; Vol. 6, No. 3. See the NIHR Journals Library website for further project information.

Urinary NGAL for the diagnosis of the renal injury from multiple myeloma

OBJECTIVES

Neutrophil gelatinase-associated lipocalin (NGAL) has been proved as a sensitive biomarker in acute and chronic renal injury. Renal impairment is a common complication of multiple myeloma (MM). We attempt to assess the value of NGAL for the early and accurate diagnosis of renal injury in MM patients.

METHODOLOGY

Forty-five MM patients with CKD stage I to V(MM-renal group), 20 MM patients with normal kidney function (MM-non-renal group), and 37 healthy volunteers (healthy control) were compared for serum and urinary NGAL and other renal injury biomarkers (Creatinine[CRE]; Cystatin-C [CysC]; N-acetyl-beta-D-glucosaminidase [NAG]). Other biomarkers reflect the inflammation and tumor burden like high-sensitivity C-reactive protein(hs-CRP) and urine free light chain were also detected.

RESULTS

Among the biomarkers of renal injury, the assessment of serum CysC, CRE and NGAL was a reliable tool to distinguish MM-renal from MM-non-renal. Both serum and urinary NGAL levels were higher in MM-renal patients than in MM-non-renal or healthy controls (187.10 (45.60-699.60) vs 136.70 (47.70-216.50) vs 117.7 (69.3-192.3), P< 0.01; 37.50 (6.30-412.10) vs 18.00 (0.50-66.50) vs 11.2 (0.9-69.1), P< 0.01). Univariate analysis showed that both serum (Odds Ratio = 1.009; 95%CI 1.002-1.017; P= 0.018) and urinary NGAL (Odds Ratio = 1.038; 95%CI 1.003-1.073; P= 0.031) as well as serum CysC (Odds Ratio = 9.875; 95%CI 1.685-57.882; P= 0.011) were strong predictors for the risk of renal injury in MM patients. Moreover, the urinary NGAL level was negatively correlated with estimated glomerular filtration rate (eGFR) (r= -0.586, P= 0.00003) and has a tendency towards positive correlation with urine free light chain (r = 0.235, P = 0.124) and hs-CRP (r = 0.379, P = 0.074).

CONCLUSIONS

The present study demonstrated that urinary NGAL was not superior to serum NGAL in distinguishing MM-renal group from MM-non-renal group. And it could be considered an independent predictor of renal injury from multiple myeloma reflecting active kidney damage, tumor burden, and inflammation.

Neutrophil Gelatinase-Associated Lipocalin, but Not Kidney Injury Marker 1, Correlates with Duration of Delayed Graft Function

BACKGROUND

No specific early biomarker is available to measure kidney injury after kidney transplantation (KT). Both neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury marker 1 (KIM-1) increase after oxidative injury. Their potential as early biomarkers was evaluated in this one-arm pilot study.

MATERIALS AND METHODS

Twenty consecutive KT patients receiving a kidney from a donation after circulatory death donor were included. Graft perfusate was collected, as well as serum samples before transplantation, at the end of surgery, and 1, 4, and 7 days after transplantation. NGAL and KIM-1 were measured using ELISA. Kidney function and delayed graft function (DGF) were monitored.

RESULTS

In this cohort, 85% of the KT patients developed DGF. Perfusate NGAL correlated with donor age (r2 = 0.094, p = 0.01) and serum creatinine (r2 = 0.243, p = 0.05). A cardiac cause of death was associated with higher NGAL in the perfusate (p = 0.03). Serum NGAL at day 1 was significantly higher in patients with DGF (730 ng/ml, range 490-1,655, vs. 417 ng/ml, range 232-481; p = 0.01). Serum NGAL levels at day 1, 4, and 7 correlated with the duration of DGF. KIM-1 was not detectable in the perfusate or in the serum until postoperative day 4 in 80% of patients.

CONCLUSIONS

NGAL in the perfusate correlates with known donor risk factors for DGF. For the first time, we describe that serum NGAL at day 1 can discriminate between DGF and immediate graft function. Also, serum NGAL levels at day 1, 4, and 7 correlate with the duration of DGF. No association with KIM-1 was found. These data suggest that NGAL may be used as an early biomarker to detect DGF and warrants further study.

Type of Renal Replacement Therapy (Hemodialysis versus Peritoneal Dialysis) Does Not Affect Cytokine Gene Expression or Clinical Parameters of Renal Transplant Candidates

Patients with renal failure suffer from immune disturbances, caused by uremic toxins and influenced by dialysis treatment. The aim of the present study was to reveal whether type of dialysis modality (hemodialysis, HD, versus peritoneal dialysis, PD) differentially affects the immunocompetence, particularly the expression of genes involved in the immune response. Material. 87 renal transplant candidates (66 HD, 21 PD) were included in the study. Methods. The peripheral blood RNA samples were obtained with the PAXgene Blood system just before transplantation. The gene expression of CASP3, FAS, TP53, FOXP3, IFNG, IL2, IL6, IL8, IL10, IL17, IL18, LCN2, TGFB1, and TNF was assessed with real-time PCR on custom-designed low density arrays (TaqMan). Gene expression data were analyzed in relation to pretransplant clinical parameters. Results. The mean expression of examined genes showed no significant differences between PD and HD with the exception of FAS, expression of which was 30% higher in PD patients compared to the HD group. There was nonsignificantly higher expression of proinflammatory cytokines in the PD group. The clinical inflammatory parameters (CRP, albumin, cholesterol, and hemoglobin levels) did not differ between the groups. Conclusion. Type of renal replacement therapy exerts no differential effect on cytokine gene expression or inflammatory clinical parameters.

Proteomic urinary biomarker approach in renal disease: from discovery to implementation

Biomarkers hold the promise of significantly improving health care by enabling prognosis and diagnosis with improved accuracy, and at earlier points in time. Previous results have indicated that single biomarkers are not suitable to describe complex diseases such as kidney disease. Here we provide an update on the progress of urinary proteomics-based studies and strategies to develop biomarker-based classifiers that tolerate instability and inconsistency of individual biomarkers. The examples focus on two major fields in nephrology: chronic kidney disease in the adult population and obstructive nephropathies in the pediatric population. When employed adequately, urinary proteomics demonstrates a clear value in kidney disease, indicating that the current status quo ruling for decades now could be changed by applying modern "omics" approaches. However, while research is able to deliver these useful tools for patient management, the issues associated with implementation are not yet solved. Active engagement of the relevant clinical professional societies, as well as patient's organizations, might help to implement these omics approaches that have shown a clear benefit for the patient.

Plasma neutrophil gelatinase-associated lipocalinin in the general population: association with inflammation and prognosis

OBJECTIVE

Neutrophil gelatinase-associated lipocalin (NGAL) is a glycoprotein stored in granules of neutrophil leukocytes participating in inflammatory and atherosclerotic processes and possibly plaque rupture. Despite the putative role of NGAL in atherosclerosis and acute myocardial infarction, human studies of plasma NGAL are still limited.

APPROACH AND RESULTS

We prospectively followed 5599 randomly selected men and women from the community in the fourth Copenhagen Heart Study. Plasma NGAL was measured at study entry. Participants were followed for 10 years. During follow-up, 20% died (n=1120) and 15% (n=884) developed a major adverse cardiovascular event. Plasma NGAL associated strongly with all inflammatory markers (high-sensitivity C-reactive protein, total leukocyte count, neutrophil count) and inversely with estimated glomerular filtration rate (all, P<0.001). Multivariate analysis identified neutrophil leukocyte count as the main determinant of plasma NGAL. During follow-up, participants with increasing NGAL had increased risk of all-cause mortality and major adverse cardiovascular event (both, P<0.001). Even after adjustment for confounding risk factors by Cox regression analysis, NGAL remained an independent predictor of both all-cause mortality and major adverse cardiovascular event. When added to the Framingham risk score, NGAL improved c-statistics and correctly reclassified ≈15% into more appropriate risk groups. In comparison with high-sensitivity C-reactive protein, when both markers were added to the Framingham risk score, NGAL conferred 3× to 4× the risk.

CONCLUSIONS

Plasma NGAL is strongly associated with inflammation in the general population. NGAL independently associated with 10-year outcome, and when added to the Framingham risk score, NGAL both improves c-statistics and correctly reclassifies participants into more accurate risk categories.