Investigation of the protective effect of chitosan against arsenic-induced nephrotoxicity and oxidative damage in rat kidney tissue.

Arsenic is an important metalloid that can cause poisoning in humans and domestic animals. Exposure to arsenic causes cell damage, increasing the production of reactive oxygen species. Chitosan is a biopolymer obtained by deacetylation of chitin with antioxidant and metal ion chelating properties. In this study, the protective effect of chitosan on arsenic-induced nephrotoxicity and oxidative damage was investigated. 32 male Wistar-albino rats were divided into 4 groups of 8 rats each as control group (C), chitosan group (CS group), arsenic group (AS group), and arsenic+chitosan group (AS+CS group). The C group was given distilled water by oral gavage, the AS group was given 100 ppm/day Na-arsenite ad libitum with drinking water, the CS group was given 200 mg/kg/day chitosan dissolved in saline by oral gavage, the AS+CS group was given 100 ppm/day Na-arsenite ad libitum with drinking water and 200 mg/kg/day chitosan dissolved in saline by oral gavage for 30 days. At the end of the 30-day experimental period, 90 mg/kg ketamine was administered intraperitoneally to all rats, and blood samples and kidney tissues were collected. Urea, uric acid, creatinine, P, Mg, K, Ca, Na, Cystatin C (CYS-C), Neutrophil Gelatinase Associated Lipocalin (NGAL) and Kidney Injury Molecule 1 (KIM-1) levels were measured in serum samples. Malondialdehyde (MDA), Glutathione (GSH), Catalase (CAT) and Superoxide dismutase (SOD) levels in the supernatant obtained from kidney tissue were analyzed by ELISA method. Compared with AS group, uric acid and creatinine levels of the AS+CS group were significantly decreased (p<0.001), urea, KIM-1, CYS-C, NGAL, and MDA levels were numerically decreased and CAT, GSH, and SOD levels were numerically increased (p>0.05). In conclusion, based on both biochemical and histopathological-immunohistochemical- immunofluorescence findings, it can be concluded that chitosan attenuates kidney injury and protects the kidney.

Neutrophil Gelatinase-Associated Lipocalin for the Differentiation of Mucinous Pancreatic Cystic Lesions.

Undetermined pancreatic cystic lesion (PCL) differentiation benefits from endoscopic ultrasound (EUS) based on morphology and cyst fluid analysis, but room for new biomarkers exists. Our aim was to assess the intracystic and serum diagnostic value of neutrophil gelatinase-associated lipocalin (Ngal) and interleukin 1 beta (IL-1ß) for differentiation of PCLs. This prospective study included patients from one tertiary hospital, evaluated between April 2018 and May 2020. EUS fine-needle aspiration or pancreatic pseudocysts drainage was the source of PCL intracystic liquid. The final diagnosis was based on surgery or EUS results (morphology, cytology, glucose, and CEA-carcinoembryogenic antigen). The intracystic samples were tested for Ngal, IL-1ß, glucose, and CEA, and serum for Ngal and IL-1ß. We evaluated 63 cysts, 33 pseudocysts, and 30 non-inflammatory cysts. The diagnostic sensitivity and specificity for mucinous PCL was 70.8% and 92.3% for intracystic Ngal (cut-off: 500-800 ng/dL), without correlation with serum Ngal, no matter the inclusion of infected pseudocysts. After exclusion of infected pseudocysts, the sensitivity and specificity for glucose were 87% and 75%, respectively, and for CEA, they were 87.1%, and 96.8%, respectively. Intracystic Ngal shows promise in differentiating mucinous PCLs, but researchers need to conduct further studies to confirm its effectiveness. Intracystic IL-1ß and serum Ngal made no diagnostic contribution.

Associations of multiple air pollutants with kidney function in normal-weight and obese adults and effect modification by free fatty acids.

Increasing studies have linked air pollution to kidney dysfunction, however, the associations between the mixture of air pollutants and kidney function and potential effect modifiers remain unclear. We aimed to investigate whether obese adults were more susceptible than normal-weight ones to the joint effects of multiple air pollutants on kidney function and further to explore effect modification by free fatty acids (FFAs). Forty obese and 49 normal-weight adults were recruited from a panel study (252 follow-up visits). Individual exposure levels of air pollutants (PM2.5, PM10, O3, NO2, SO2 and CO) were estimated. Glomerular function (cystatin C (CysC) and estimated glomerular filtration rate (eGFR)) and tubular function (neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1) were evaluated. Plasma levels of FFAs including trans fatty acids (TFAs) and essential fatty acids (EFAs) were quantified using targeted metabolomics. Bayesian kernel machine regression model was applied to estimate the associations between the mixture of air pollutants and kidney function. The results showed significant joint effects of air pollutants on kidney function indicators. In the normal-weight group, the mixture of air pollutants was significantly associated with CysC and eGFRcr-cys when the mixture was at or above its 70 percentile compared with the median, where O3 was identified as the key pollutant. In the obese group, a significantly positive association between the pollutant mixture and NGAL was observed in addition to trends in CysC and eGFRcr-cys, mainly driven by SO2. Interaction analysis suggested that the associations of air pollutants with kidney function were augmented by TFAs in both groups and weakened by EFAs in the normal-weight group. This study highlighted the renal adverse effects of air pollutants and modification of FFAs, which has implications for target prevention for kidney dysfunction associated with air pollution, especially among vulnerable populations.

Rapid and quantitative detection of neutrophil gelatinase-associated lipocalin in synovial fluid using fluorescence immunochromatographic test strips for diagnosing prosthetic joint infections.

OBJECTIVES: We developed a rapid and highly sensitive method for quantitatively analyzing neutrophil gelatinase-associated lipocalin (NGAL) levels in synovial fluid and assessed its diagnostic performance for prosthetic joint infection (PJI). DESIGNS OR METHODS: We conducted a preliminary analysis of the performance of the developed test strips utilizing clinical specimens to verify their sensitivity, precision, specificity and accuracy. RESULTS: The standard curve of the test strip NGAL values was linear. The detection limit and the limit of quantification (LOQ) were 12.37 and 29.49 ng/mL, respectively, and the approximate detection range was 12.37 to 1250 ng/mL. The interbatch and intrabatch precision of the test strips were each less than 10%, and the cross-reaction rate with competitors' systems was less than 1%. CONCLUSIONS: The test strips can be used for the determination of synovial fluid NGAL levels; the test strips are highly sensitive, precise, specific, and stable. Furthermore, they demonstrated good performance in clinical verification.

L-FABP and NGAL are novel biomarkers for detection of abdominal injury and hemorrhagic shock.

INTRODUCTION: Delayed diagnosis of abdominal injuries and hemorrhagic shock leads to secondary complications and high late mortality in severely traumatized patients. The liver fatty acid-binding protein (L-FABP) is expressed in intestine, liver and kidney; the neutrophil gelatinase-associated lipocalin (NGAL) in colon and kidney. We hypothesized that l-FABP is an early biomarker for abdominal injury and hemorrhagic shock and that l-FABP and NGAL are specific markers for detection of liver and/or kidney injuries. PATIENTS AND METHODS: Traumatized patients with an age ≥18 years and an abdominal injury (AISabd≥2), independently from Injury Severity Score (ISS), were prospectively included from 04/2018 to 05/2021. 68 patients had an abdominal injury ("Abd") and 10 patients had an abdominal injury with hemorrhagic shock ("HS Abd"). 41 patients without abdominal injury and hemorrhagic shock but with an ISS ≥ 25 ("noAbd") were included as control group. Four abdominal subgroups with isolated organ injuries were defined. Plasma l-FABP and NGAL levels were measured at admission (ER) and up to two days post-trauma. RESULTS: All patient groups had a median ISS≥25. In ER, median l-FABP levels were significantly higher in "HS Abd" group (1209.2 ng/ml [IQR=575.2-1780.3]) compared to "noAbd" group (36.4 ng/ml [IQR=14.8-88.5]), and to "Abd" group (41.4 ng/ml [IQR=18.0-235.5]), p<0.001. In matched-pair-analysis l-FABP levels in the group "Abd" were significantly higher (108.3 ng/ml [IQR=31.4-540.9]) compared to "noAbd" (26.4 ng/ml [IQR=15.5-88.8]), p = 0.0016. l-FABP correlated significantly with clinical parameters of hemorrhagic shock; the optimal cut-off level of l-FABP for detection was 334.3 ng/ml (sensitivity: 90%, specificity: 78%). Median l-FABP-levels were significantly higher in patients with isolated liver or kidney injuries and correlated significantly with AST, ALT and creatinine value. Median NGAL levels in the ER were significantly higher in "HS Abd" group (115.9 ng/ml [IQR=90.6-163.8]) compared to "noAbd" group (58.5 ng/ml [IQR=41.0-89.6],p<0.001) and "Abd" group (70.5 ng/ml [IQR=53.3-115.5], p<0.05). The group "Abd" showed significant higher median NGAL levels compared to "noAbd", p = 0.019. NGAL levels correlated significantly with clinical parameters of hemorrhagic shock. CONCLUSION: L-FABP and NGAL are novel biomarkers for detection of abdominal trauma and hemorrhagic shock. l-FABP may be a useful and promising parameter in diagnosis of liver and kidney injuries, NGAL failed to achieve the same.

Galectin-3, Acute Kidney Injury and Myocardial Damage in Patients With Acute Heart Failure.

BACKGROUND: Galectin-3, a biomarker of inflammation and fibrosis, can be associated with renal and myocardial damage and dysfunction in patients with acute heart failure (AHF). METHODS AND RESULTS: We retrospectively analyzed 790 patients with AHF who were enrolled in the AKINESIS study. During hospitalization, patients with galectin-3 elevation (> 25.9 ng/mL) on admission more commonly had acute kidney injury (assessed by KDIGO criteria), renal tubular damage (peak urine neutrophil gelatinase-associated lipocalin [uNGAL] > 150 ng/dL) and myocardial injury (≥ 20% increase in the peak high-sensitivity cardiac troponin I [hs-cTnI] values compared to admission). They less commonly had ≥ 30% reduction in B-type natriuretic peptide from admission to last measured value. In multivariable linear regression analysis, galectin-3 was negatively associated with estimated glomerular filtration rate and positively associated with uNGAL and hs-cTnI. Higher galectin-3 was associated with renal replacement therapy, inotrope use and mortality during hospitalization. In univariable Cox regression analysis, higher galectin-3 was associated with increased risk for the composite of death or rehospitalization due to HF and death alone at 1 year. After multivariable adjustment, higher galectin-3 levels were associated only with death. CONCLUSIONS: In patients with AHF, higher galectin-3 values were associated with renal dysfunction, renal tubular damage and myocardial injury, and they predicted worse outcomes.

Sputum Neutrophil Gelatinase-Associated Lipocalin as a Biomarker in Asthma-COPD Overlap.

BACKGROUND: Asthma COPD overlap (ACO) is a consensus-based phenotype having characteristics of both COPD and asthma. Distinguishing ACO from other diseases is even more important as it is related to low health-related quality of life, augmented exacerbation rate and hospital admission, a rapid deterioration in lung function, and increased morbidity and mortality. But it cannot be diagnosed explicitly based on spirometry tests, patient demographics, radiology, or by-sputum cytology. There is an unmet need to develop biomarkers. OBJECTIVES: To assess the role of sputum neutrophil gelatinase-associated lipocalin (NGAL) as a biomarker of ACO. To find the correlation between sputum NGAL levels with forced expiratory volume 1 (FEV1) and exacerbation rate in ACO. To find the correlation between sputum NGAL level with sputum neutrophils and eosinophils in ACO. MATERIALS AND METHODS: In this comparative correlational study, 180 subjects were enrolled into four groups with 45 patients each with asthma, COPD, ACO, and healthy nonsmokers respectively, respectively. After taking detailed history and demographics, sputum was analyzed for the differential count and NGAL. RESULTS: Asthma COPD overlap (ACO) cases had high sputum NGAL levels; the second was the COPD group, and the last in the case asthma group. Nonsmokers had notably lower readings than the diseased. Out of three, receiver operating characteristic (ROC) figures, the validity of NGAL was best in selecting patients of ACO than COPD and asthma. The area under curve (AUC) was highest for ACO and less than the acceptable limit for the remaining two. NGAL cut-off value of 2473 pg/mL had 80% sensitivity and 50% specificity for ACO. CONCLUSION: The present study investigated the sputum NGAL levels as a biomarker in ACO identified by the syndromic approach. Sputum NGAL, a biomarker associated with airway inflammation in airway diseases, was supportive of clinically differentiating ACO from asthma to COPD. How to cite this article: Babu A, Narayanswamy H, Baburao A. Sputum Neutrophil Gelatinase-Associated Lipocalin as a Biomarker in Asthma-COPD Overlap. J Assoc Physicians India 2023;71(9):34-38.

Diagnostic value of ROC curve evaluation of serum markers in acute cholecystitis with bacterial infection.

OBJECTIVE: To explore correlation of serum markers human neutrophil lipocalin and C-reactive protein with acute cholecystitis associated with bacterial infection, and to evaluate the diagnostic value of the markers. METHODS: The cross-sectional study was conducted from January 2018 to April 2020 at the Beijing Luhe Hospital, Capital Medical University, Beijing, China, and comprised acute cholecystitis patients who were divided into bacterial infection group A and non-bacterial infection group B. Serum human neutrophil lipocalin and C-reactive protein were measured for both the groups. Receiver operating characteristic curve was used to evaluate the diagnostic value of the two markers in acute cholecystitis associated with bacterial infection. Data was analysed using SPSS 25. RESULTS: Of the 145 patients, 65(45%) were in group A; 36(55.38%) males and 29(44.62%) females with a mean age of 45.79±2.50 years. In group B there were 80(55%) subjects; 45(56.25%) males and 35(43.75%) females with a mean age of 46.16±2.52 years (p>0.05). In group A, there were 60(92.31%) cases of acute calculous cholecystitis, and 5(7.69%) had acute acalculous cholecystitis compared to 73(91.25%) and 7(8.75%), respectively, in group B (p>0.05). Serum human neutrophil lipocalin and C-reactive protein levels in group A were higher than group B (p<0.001). Serum human neutrophil lipocalin showed a high positive correlation with C-reactive protein in group A (r=0.800, p<0.001), and a moderate positive correlation in group B (r=0.683, p<0.001). Area under the curve of serum human neutrophil lipocalin associated with C-reactive protein was 0.901 (95% confidence interval: 0.850-0.953), which was higher than that of serum human neutrophil lipocalin and C-reactive protein alone, with sensitivity 95.40% and specificity 80%. CONCLUSIONS: The combined use of serum human neutrophil lipocalin and C-reactive protein may be used as an effective indicator for early diagnosis, identification and monitoring of acute cholecystitis with bacterial infection.

Clinical assessment of neutrophil gelatinase-associated lipocalin as a potential diagnostic marker for neonatal sepsis: a prospective cohort study.

Sepsis is a life-threatening condition associated with high morbidity and mortality rates among neonates. Clinical diagnosis is limited due to the neonates' unspecific signs and symptoms as well as the long time required to obtain the blood culture results. Consequently, there is an urgent need for new biomarkers to early diagnose neonatal sepsis. We aimed to evaluate Neutrophil Gelatinase-Associated Lipocalin (NGAL) diagnostic performance to detect neonatal sepsis. We enrolled 30 neonates with sepsis admitted to the neonatal intensive care units and 30 age- and sex-matched healthy neonates recruited from the neonatal outpatient clinic during their routine follow-up visits. We measured NGAL levels by sandwich enzyme-linked immunosorbent assay, the C-reactive protein (CRP) with nephelometry technique using BN II nephelometer, and the complete blood count by Mindray BC-6800 analysers. NGAL, CRP, TLC, haemoglobin, and platelet levels showed significant differences between cases and control (all p < .001). Of the 30 neonates with sepsis, 17 neonates (56.7%) survived. At 0 h, the NGAL level showed no statistically significant difference between the non-survivors and survivors' groups; however, after 96 h, NGAL was significantly higher in the non-survivors group (p ˂ .001). Our diagnostic analysis showed that NGAL levels have strong discrimination power to early differentiate neonates with sepsis; at the 475.00 pg/ml cut-off value, NGAL showed both sensitivity and specificity of 100% with an area under curve of 100%. Conclusion: Our study suggests that NGAL could be a promising biomarker for neonatal sepsis detection. Further studies with larger sample sizes and survival analysis are warranted to confirm this finding and to clarify the efficacy of NGAL in survival prediction. Key findingsNGAL level was high in neonates with sepsisNGAL level was high in non-survived neonatesNGAL could be a promising diagnostic marker for sepsis.

[Glucose, Lactate, NGAL and Coefficient of Energy Balance in Synovial Fluid in Patients with Hip and Knee Prosthetic Joint Infection]. / Stanovení hladiny glukózy, laktátu, NGAL a KEB ve výpotku u infekcí TEP kolen a kyclí.

PURPOSE OF THE STUDY Laboratory methods are central to prosthetic joint infection (PJI) diagnosis. Most research teams focus on detection of specific inflammatory markers, causative pathogens, or on assessment of the tissue response. This study sought to determine the optimal cut-off values and diagnostic performance of selected synovial markers in relation to the diagnosis of hip or knee PJI. The studied markers were synovial level of glucose, lactate, coefficient of energy balance (CEB) and NGAL (neutrophil gelatinase-associated lipocalin). MATERIAL AND METHODS This prospective study includes 89 patients who underwent revision total knee or hip arthroplasty for septic or aseptic reasons in the period from 2014 to 2017. Among these 89 patients, there are 2 cases of prosthetic hip infection, 22 cases of prosthetic knee infection, 31 aseptic revision total hip arthroplasties and 34 aseptic revision total knee arthroplasties. The diagnostic characteristics of the studied methods were set in relation to the reference standard, the 2013 MSIS (Musculoskeletal Infection Society) criteria. The cut-off values were calculated using the ROC (receiver operating characteristic curve) analysis. RESULTS The synovial glucose test is considered positive if the glucose level drops below 2.65 mmol/L. The area under the curve is 0.813, sensitivity 75.0%, specificity 83.1%. The synovial lactate test is considered positive if lactate level rises above 8.87 mmol/L. The area under the curve is 0.882, sensitivity 70.8%, specificity 95.4%. Synovial NGAL is considered positive if its level exceeds 998 µg/L. The area under the curve is 1.000, sensitivity 100.0%, specificity 100.0%. CEB is considered positive if its value is lower than +4.665. The area under the curve is 0.883, sensitivity 91.7% and specificity 69.8%. Combining of these tests with other synovial markers does not improve the diagnostic performance of the studied tests. CONCLUSIONS The glucose and lactate levels and CEB undoubtedly reflect the presence of an inflammatory process in a prosthetic joint. However, the diagnostic characteristics of these tests are not better than those of other modern diagnostic techniques. As opposed to these tests, synovial NGAL shows excellent diagnostic performance. Nonetheless, the potential of this method shall be verified on larger cohorts of patients. Key words: prosthetic joint infection, periprosthetic infection, total knee arthroplasty, total hip arthroplasty, diagnosis, glucose, lactate, CEB, NGAL.

Association between Neutrophil Gelatinase-Associated Lipocalin and Fetal Hemoglobin Levels in Patients with Type 2 Diabetes Mellitus.

The effect of neutrophil gelatinase-associated lipocalin (NGAL) on fetal hemoglobin (HbF) levels in diabetic patients is rarely investigated. This study is aimed at investigating the possible association between NGAL and HbF levels in type 2 diabetes mellitus (T2DM). A total of 160 patients with T2DM and 61 healthy individuals were evaluated. NGAL, HbF, tumor necrosis factor-α (TNF-α), interleukin-5 (IL-5), glycated hemoglobin (HbA1c), fasting plasma glucose (FPG), and urine albumin levels were measured. HbF levels were significantly higher in patients with elevated NGAL than in those without elevated NGAL (1.44% versus 0.94%, P = 0.001). High HbF was 2.3 times more prevalent in patients with elevated NGAL than in those without elevated NGAL. In addition, NGAL, TNF-α, and IL-5 levels were significantly higher in patients with high HbF than in those with low HbF; however, there was no significant difference in HbA1c and FPG levels between the two groups. HbF was positively correlated with NGAL (r = 0.275, P < 0.001), TNF-α (r = 0.256, P < 0.001), and IL-5 (r = 0.212, P < 0.001), but not with HbA1c and FPG. An elevated NGAL level led to a 1.27-fold increase in the prevalence of high HbF (odds ratio: 1.27, 95% CI: 1.03-2.51, and P < 0.001). The diagnostic efficacy of NGAL to identify an elevated HbF level was superior to that of HbA1c (area under the curve: 0.697, 95% CI: 0.609-0.786 versus 0.584, 95% CI: 0.488-0.681, and P = 0.022). In conclusion, enhanced NGAL production may be closely linked to elevated HbF in conjunction with proinflammatory cytokines in patients with T2DM.

Analysis of the Relationship between the Expression Levels of Neutrophil Gelatinase-Associated Lipocalin and Cytokine Genes in Bone Marrow.

Background: Recently, various associations of NGAL with several hematological cancers have been reported. However, given that the regulation of NGAL gene expression by cytokines is tissue-specific, NGAL expression in relation to those of cytokine genes has not been analyzed in bone marrow (BM) tissue. The purpose of this study was to analyze the association between NGAL and 48 cytokine gene expression levels in mononuclear cells (MNCs) of BM at the time of diagnosis of hematological malignancy and to explore the expression pattern of NGAL and related cytokine genes in patients with hematological malignancies and controls. Methods: BM MNCs were isolated from 48 patients, who were classified as patients presenting myeloproliferative neoplasm, acute myeloid leukemia, myelodysplastic syndrome, and as controls. NGAL and cytokine genes were analyzed using NanoString. Data on hematological parameters were collected from medical records. Single and multiple regression analyses were performed to analyze relationships. Results: Normalized counts of 26 cytokine genes were related to NGAL normalized counts, while STAT3 and TLR4 normalized counts had the highest explanatory power. The following multiple regression model was developed: NGAL normalized counts=4316.825 + 9.056 × STAT3 normalized counts + 844.226 × IL5 normalized counts + 17.540 × TLR1 normalized counts - 28.206 × TLR2 normalized counts - 42.524 × IRAK4 normalized counts. In the multiple regression analysis, STAT3 and TLR4 normalized counts showed multicollinearity. NGAL, STAT3, IL5, and TLR4 normalized counts showed similar intergroup patterns. Conclusions: NGAL normalized counts was predicted by a multiple regression model, while they showed similar intergroup patterns to STAT3, IL5, and TLR4 normalized counts.

Mucosal and faecal neutrophil gelatinase-associated lipocalin as potential biomarkers for collagenous colitis.

BACKGROUND: Collagenous colitis (CC) is an inflammatory bowel disease where chronic diarrhoea is the main symptom. Diagnostic markers distinguishing between CC and other causes of chronic diarrhoea remain elusive. This study explores neutrophil gelatinase-associated lipocalin (NGAL) and its mRNA lipocalin2 (LCN2) as histological and faecal disease markers in CC. METHODS: NGAL/LCN2 were studied in colonic biopsies from CC patients before and during budesonide treatment using RNA sequencing (n = 9/group), in situ hybridization (ISH) (n = 13-22/group) and immunohistochemistry (IHC) (n = 14-25/group). Faecal samples from CC (n = 3-28/group), irritable bowel syndrome diarrhoea (IBS-D) (n = 14) and healthy controls (HC) (n = 15) were assayed for NGAL and calprotectin. RESULTS: NGAL/LCN2 protein and mRNA expression were upregulated in active CC vs HC, and vs paired samples of treated CC in clinical remission. IHC and ISH localized increased NGAL/LCN2 mainly to epithelium of active CC, compared to almost absence in HC and treated CC. In contrast, calprotectin was solely expressed in immune cells. Despite great individual differences, faecal NGAL was significantly increased in active CC compared to HC, IBS-D and treated CC and had high test sensitivity. Faecal calprotectin levels were variably increased in active CC, but the values remained below usual clinical cut-offs. CONCLUSION: NGAL/LCN2 is upregulated in the epithelium of active CC and reduced during budesonide-induced clinical remission to the level of HC and IBD-S. This was reflected in NGAL faecal concentrations. We propose NGAL as an IHC marker for disease activity in CC and a potential faecal biomarker discriminating CC from HC and IBS-D.

Can remote ischemic preconditioning counteract the renal functional deterioration attributable to partial nephrectomy under warm ischemia? Results of an animal study.

BACKGROUND: To investigate if remote ischemic preconditioning (RIPC) can offer any renoprotective value by counteracting the deleterious effect of partial nephrectomy (PN) under warm ischemia on renal function. METHODS: Four groups, each with 5 Wistar albino rats, were constructed; RIPC + PN, PN, RIPC and sham. Right nephrectomy was performed to constitute a solitary kidney model. RIPC denoted sequential clamping/declamping of the femoral artery/vein complex. PN was performed under warm-ischemia following RIPC. Blood samples were collected on multiple occasions until euthanasia on day 7. Immunoassays were conducted to measure the serum and tissues levels of kidney injury markers. Kidneys were examined histologically and morphometric analyzes were performed using digital scanning. RESULTS: IL-33 levels did not differ significantly between the groups. Serum levels of KIM-1, NGAL, and aldose reductase in RIPC + PN, PN and RIPC groups were significantly lower than that of sham group. Tissue biomarker levels were similar across groups. The observed trend in mean necrosis area of PN group was higher than that of RIPC + PN group (p > 0.05). The transitional zone between necrosis and healthy tissue showed a trend towards increasing width in the rats subjected to RIPC before PN vs. those who underwent PN without RIPC (p > 0.05). CONCLUSION: RIPC failed to counteract the renal functional consequences of PN under warm ischemia in a solitary kidney animal model. The supportive but marginal histological findings in favor of RIPC's renoprotective potential were not supplemented with the changes in serum and tissue biomarker levels.

Functions and potential of lipocalin-2 as fecal biomarker for acute gastrointestinal infections (review of literature).

Despite the visible progress in reducing morbidity and mortality from intestinal infections and acute diarrhea associated with them, especially in childhood, the problem of their diagnosis and treatment remains relevant. The article discusses the structure, function and application of lipocalin-2 in infectious diseases as a non-invasive biomarker of bacterial inflammation in the intestine.

Immunofibrotic drivers of impaired lung function in postacute sequelae of SARS-CoV-2 infection.

BACKGROUNDIndividuals recovering from COVID-19 frequently experience persistent respiratory ailments, which are key elements of postacute sequelae of SARS-CoV-2 infection (PASC); however, little is known about the underlying biological factors that may direct lung recovery and the extent to which these are affected by COVID-19 severity.METHODSWe performed a prospective cohort study of individuals with persistent symptoms after acute COVID-19, collecting clinical data, pulmonary function tests, and plasma samples used for multiplex profiling of inflammatory, metabolic, angiogenic, and fibrotic factors.RESULTSSixty-one participants were enrolled across 2 academic medical centers at a median of 9 weeks (interquartile range, 6-10 weeks) after COVID-19 illness: n = 13 participants (21%) had mild COVID-19 and were not hospitalized, n = 30 participants (49%) were hospitalized but were considered noncritical, and n = 18 participants (30%) were hospitalized and in the intensive care unit (ICU). Fifty-three participants (85%) had lingering symptoms, most commonly dyspnea (69%) and cough (58%). Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), and diffusing capacity for carbon monoxide (DLCO) declined as COVID-19 severity increased (P < 0.05) but these values did not correlate with respiratory symptoms. Partial least-squares discriminant analysis of plasma biomarker profiles clustered participants by past COVID-19 severity. Lipocalin-2 (LCN2), MMP-7, and HGF identified by our analysis were significantly higher in the ICU group (P < 0.05), inversely correlated with FVC and DLCO (P < 0.05), and were confirmed in a separate validation cohort (n = 53).CONCLUSIONSubjective respiratory symptoms are common after acute COVID-19 illness but do not correlate with COVID-19 severity or pulmonary function. Host response profiles reflecting neutrophil activation (LCN2), fibrosis signaling (MMP-7), and alveolar repair (HGF) track with lung impairment and may be novel therapeutic or prognostic targets.FundingNational Heart, Lung, and Blood Institute (K08HL130557 and R01HL142818), American Heart Association (Transformational Project Award), the DeLuca Foundation Award, a donation from Jack Levin to the Benign Hematology Program at Yale University, and Duke University.

Novel predictive biomarkers for acute injury superimposed on chronic kidney disease / Novedosos biomarcadores predictivos para lesiones agudas superpuestas a una enfermedad renal crónica

INTRODUCTION AND OBJECTIVES: Chronic kidney disease (CKD) is a risk factor for the development of acute kidney injury (AKI). Recent studies have revealed numerous biomarkers eligible for AKI prediction. However, the expression and performance of AKI biomarkers in acute injury superimposed on preexisting CKD (AonC) remain elusive. The aim of this study was to evaluate whether biomarkers which robustly expressed in acute kidney injury could predict acute injury based on CKD. MATERIALS AND METHODS: Mice were classified into cohorts: AKI, CKD, AonC and sham. The AonC model mice were subjected to renal bilateral ischemia/reperfusion (I/R) injury fourteen days after intraperitoneally administrated with 20 mg/kg aristolochic acid. Severity of acute ischemic injury was stratified by clamping the dissected bilateral renal arteries with non-traumatic microvascular clips for 20 or 35 min. The AKI mice were induced with renal bilateral I/R injury and CKD mice were crafted with 20mg/kg aristolochic acid administrated intraperitoneally. Histology, genetic and protein expression of biomarkers were measured in three cohorts. RESULTS: We found that serum creatinine dramatically increased in severe (sAonC) but not in moderate (mAonC) injury mice. Upregulation of Kidney injury molecule-1 (KIM-1) mRNA, tissue inhibitor of metalloproteinase-2 (TIMP-2), Syndecan-1 (SDC-1) mRNA and insulin-like growth factor binding protein-7 (IGFBP7) protein indicated the onset of mAonC. An increase in neutrophil gelatinase-associated lipocalin (NGAL), rhomboid-like protein 2 (RHBDL2), Syndecan-1 (SDC-1) mRNA and protein, and a decrease in IGFBP7 protein were associated with sAonC. CONCLUSIONS: Our study revealed the variational expression of AKI biomarkers in AonC kidneys, and uncovered IGFBP7 protein can be used as a sensitive biomarker to predict and differentiate AonC severity. The performance of RHBDL2 and SDC-1 in predicting severe AonC was promising, providing new biomarkers for predicting AonC

INTRODUCCIÓN Y OBJETIVOS: La enfermedad renal crónica (ERC) es un factor de riesgo para el desarrollo de una lesión renal aguda (LRA). Estudios recientes han revelado numerosos biomarcadores para la predicción de LRA. No obstante, la expresión y el rendimiento de los biomarcadores de LRA en lesiones agudas superpuestas a una ERC preexistente (AonC, en inglés) siguen siendo imprecisos. El objetivo de este estudio fue evaluar si los biomarcadores que se encuentran muy expresados en la lesión renal aguda podrían predecir una lesión aguda superpuesta a una ERC. MATERIALES Y MÉTODOS: Se dividieron ratones en cohortes (LRA, ERC, AonC y grupo de referencia). A los ratones del modelo de AonC se les indujo una lesión renal bilateral por isquemia/reperfusión (I/R) 14 días después de la administración intraperitoneal de 20 mg/kg de ácido artistolóquico. La gravedad de la lesión isquémica aguda se estratificó pinzando las arterias renales bilaterales diseccionadas con horquillas microvasculares no traumáticas durante 20 o 35 min. A los ratones de LRA se les indujo una lesión renal bilateral por I/R y a los ratones de ERC se les administraron 20mg/kg de ácido artistolóquico por vía intraperitoneal. Se determinaron la histología, la genética y la expresión de proteínas en las tres cohortes. RESULTADOS: Observamos que la creatinina sérica aumentaba drásticamente en los ratones con lesiones graves (AonCg) pero no en aquellos con lesiones moderadas (AonCm) El aumento del ARNm de la molécula1 de lesión renal (KIM-1), del inhibidor tisular de metaloproteinasas 2 (TIMP-2), del ARNm de sindecán 1 (SDC-1) y de la proteína de unión al factor de crecimiento insulinoide 7 (IGFBP7) fue indicativo de aparición de AonCm. El incremento de la lipocalina asociada a la gelatinasa de neutrófilos (NGAL), la proteína romboidal 2 (RHBDL2) y el ARNm y la proteína de sindecán 1 (SDC-1), así como la reducción de la proteína IGFBP7, se asociaron a una AonCg. CONCLUSIONES: Nuestro estudio mostró la variación de la expresión de los biomarcadores de LRA en riñones con AonC y descubrió que la proteína IGFBP7 puede emplearse como biomarcador sensible para la predicción y la diferenciación de la gravedad de la AonC. El rendimiento de RHBDL2 y SDC-1 en la predicción de AonC graves resultó prometedor, lo que ofrece nuevos biomarcadores para la predicción de AonC

Effects of pneumoperitoneum on kidney injury biomarkers: A randomized clinical trial.

BACKGROUND: Increased intra-abdominal pressure causes hemodynamic changes that may affect renal biomarkers. METHODS: This randomized, single-blind, single-center clinical trial recruited patients undergoing laparoscopic cholecystectomy at a tertiary care center in Brazil. They were randomly allocated to a standard intra-abdominal pressure group (P10-12, 10-12 mm Hg) and a low intra-abdominal pressure group (P6-8, 6-8 mm Hg). The primary outcome was the change in neutrophil gelatinase-associated lipocalin (NGAL) and cystatin C levels measured at the beginning of the procedure (T0), at the end of the procedure (T1), and 24 hours after the procedure (T2). P-values < 0.05 were considered statistically significant. RESULTS: In total, 64 patients completed the study-33 were given standard pressure and 31 were given low pressure. There was no significant difference in the biomarker between the groups (P = 0.580), but there was a significant difference between the time points with elevation at T1 (P < 0.001). Similar to NGAL, cystatin C had an elevation at T1 in both groups (P = 0.021), but no difference was found when comparing the groups. CONCLUSIONS: In laparoscopic cholecystectomy, pneumoperitoneum increases NGAL and cystatin C levels intraoperatively, and the use of low-pressure pneumoperitoneum does not change the course of these biomarkers.

Neutrophil gelatinase-associated lipocalin for urinary tract infection and pyelonephritis: a systematic review.

BACKGROUND: The sensitivity and specificity of the leukocyte esterase test are relatively low for a screening test for urinary tract infection (UTI). More accurate tests could reduce both overtreatment and missed cases. This study aimed to determine whether neutrophil gelatinase-associated lipocalin (NGAL) can replace leukocyte esterase in the diagnosis of UTI and/or whether NGAL accurately identifies children with acute pyelonephritis. METHODS: Data sources-MEDLINE and EMBASE. We only considered published studies that evaluated the results of an index test (NGAL) against the results of urine culture (for UTI) or against the results of dimercaptosuccinic acid (for acute pyelonephritis) in children aged 0 to 18 years. Two authors independently applied the selection criteria to all citations and independently extracted the data. RESULTS: A total of 12 studies met our inclusion criteria. Four studies (920 children) included data on NGAL for UTI; eight studies (580 children) included data on NGAL for pyelonephritis. We did not pool accuracy values because the included studies used different cutoff values. For the diagnosis of UTI, urinary NGAL appeared to have better accuracy than the leukocyte esterase test in all included studies. For the diagnosis of pyelonephritis, neither plasma NGAL nor urinary NGAL had high sensitivity and/or specificity. The number of studies was the main limitation of this systematic review. CONCLUSIONS: Urinary NGAL appears promising for the diagnosis of UTI; however, larger studies are needed to validate this marker as a replacement for leukocyte esterase. The use of NGAL for diagnosing acute pyelonephritis requires further study.

Faecal Biomarkers in Inflammatory Bowel Diseases: Calprotectin Versus Lipocalin-2-a Comparative Study.

BACKGROUND AND AIMS: Faecal biomarkers, particularly calprotectin [FCAL], have become important diagnostic and monitoring tools in inflammatory bowel diseases [IBD]. As FCAL is mainly produced by neutrophils, we hypothesised that faecal lipocalin-2 [FLCN2], also expressed by intestinal epithelial cells [IEC], could be beneficial in specific clinical situations. METHODS: We compared clinical and endoscopic activity-related correlations between FCAL and FLCN2, assayed from the same sample, in a cohort of 132 patients (72 Crohn's disease [CD]) and 40 controls. A detailed analysis of cellular origins was done by confocal microscopy and flow cytometry. To evaluate the potential to detect low-grade inflammation, we studied faecal and tissue concentrations in a cohort with clinical, endoscopic, and histological remission. RESULTS: There was an excellent correlation between FCAL and FLCN2 [rS = 0.87, p <0.001] and comparable sensitivity and specificity to predict clinical and endoscopic disease activity, with optimal thresholds for endoscopic activity of 73.4 and 1.98 µg/g in ulcerative colitis [UC] and 78.4 and 0.56 µg/g in Crohn's disease for FCAL and FLCN2, respectively. Strong co-expression of both proteins was observed in granulocytes and macrophages. IECs expressed LCN2 but not CAL. In our IBD cohort in deep remission neither FCAL nor FLCN2 was different from controls; yet mucosal LCN2 but not CAL expressions remained elevated in the rectum of UC and the ileum of CD patients. CONCLUSIONS: This study corroborates the diagnostic equivalence of FLCN2 and FCAL in IBD. In remission, persistent mucosal overexpression renders LCN2 an attractive candidate for molecular inflammation warranting further investigation.