Urine neutrophil gelatinase-associated lipocalin in septic patients with and without acute kidney injury

Neutrophil gelatinase-associated lipocalin as predictor of acute kidney injury requiring renal replacement therapy: A systematic review and meta-analysis

Background

Patients with severe acute kidney injury (AKI) may require renal replacement therapy (RRT), such as hemodialysis and peritoneal dialysis. Neutrophil gelatinase-associated lipocalin (NGAL) is a sensitive indicator for early diagnosis and recognition of AKI; however, its predictive value of AKI-associated need for RRT needs further evaluation.

Methods

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, relevant articles were systematically searched and selected from seven databases. The random effects model was applied to evaluate the predictive performance of NGAL for AKI requiring RRT. The Newcastle–Ottawa Scale (NOS) was used to assess the quality of each included study.

Results

A total of 18 studies including 1,787 patients with AKI and having an average NOS score of 7.67 were included in the meta-analysis. For plasma/serum NGAL, the pooled sensitivity and specificity with corresponding 95% confidence interval (CI) were 0.75 (95% CI: 0.68–0.81) and 0.76 (95% CI: 0.70–0.81), respectively. The pooled positive likelihood ratio (PLR) was 2.9 (95% CI: 2.1–4.1), and the pooled negative likelihood ratio (NLR) was 0.34 (95% CI: 0.25–0.46). Subsequently, the pooled diagnostic odds ratio (DOR) was 9 (95% CI: 5–16) using a random effects model, and the area under the curve (AUC) of summary receiver operating characteristic to summarize predictive accuracy was 0.82 (95% CI: 0.79–0.85). For urine NGAL, the pooled sensitivity, specificity, PLR, NLR, DOR, and AUC values were 0.78 (95% CI: 0.61–0.90), 0.77 (95% CI: 0.65–0.85), 3.4 (95% CI: 2.4–4.8), 0.28 (95% CI: 0.15–0.52), 12 (95% CI: 6–24), and 0.84 (95% CI: 0.80–0.87), respectively.

Conclusion

Plasma/serum and urine NGAL levels performed comparably well in predicting AKI requiring RRT. Our findings suggested that NGAL is an effective predictive biomarker for the AKI-associated need for RRT. Nevertheless, more pieces of high-quality evidence and future trials with larger sample sizes are needed for further improvement of patient outcomes.

Systematic review registration

[https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022346595], identifier [CRD42022346595].

Meta-analysis of the diagnostic value of serum, plasma and urine neutrophil gelatinase-associated lipocalin for the detection of acute kidney injury in patients with sepsis

The objective of the present study was to assess the diagnostic value of urine, serum and plasma neutrophil gelatinase-associated lipocalin (NGAL) for the early diagnosis of acute kidney injury (AKI) among patients with suspected sepsis. Therefore, a meta-analysis was carried out to evaluate diagnostic accuracy data from the literature regarding the diagnosis of AKI in patients with sepsis. Electronic databases were systematically searched for relevant studies and quality assessment was conducted using the Quality Assessment for Diagnostic Accuracy Studies 2 tool. A summary receiver operating characteristic curve analysis was performed, and several parameters including sensitivity, specificity, diagnosis odds ratio (DOR) and area under the curve (AUC) were calculated to evaluate the diagnostic performance of urine, serum and plasma NGAL. Meta-regression, sensitivity and subgroup analysis were also conducted to identify the source of heterogeneity in the eligible studies. In total, 28 studies were included. The pooled sensitivities for urine, serum and plasma NGAL were 0.87, 0.83 and 0.80, respectively. Pooled specificity was 0.84, 0.79 and 0.74. The DORs were 35, 18 and 11, respectively. The AUC for urine, serum and plasma NGAL were 0.92, 0.87 and 0.84, respectively. Urine NGAL presented superior performance for the diagnosis of AKI with the highest AUC and other diagnostic accuracy values, compared with serum and plasma NGAL. Further studies are needed to clarify the controversial issue between the usefulness of serum and plasma NGAL.

Rates, predictors, and mortality of sepsis-associated acute kidney injury: a systematic review and meta-analysis

BACKGROUND

Due to the high incidence and mortality of sepsis-associated acute kidney injury, a significant number of studies have explored the causes of sepsis-associated acute kidney injury (AKI). However, the opinions on relevant predictive risk factors remain inconclusive. This study aimed to provide a systematic review and meta-analysis to determine the predisposing factors for sepsis-associated AKI.

METHOD

A systematic literature search was performed in the Medline, Embase, Cochrane Library, PubMed, and Web of Science, databases, with an end-date of 25th May 2019. Valid data were retrieved in compliance with specific inclusion and exclusion criteria.

RESULT

Forty-seven observational studies were included for analysis, achieving a cumulative patient number of 55,911. The highest incidence of AKI was caused by septic shock. Thirty-one potential risk factors were included in the meta-analysis. Analysis showed that 20 factors were statistically significant. The odds ratio (OR) and 95% confidence interval (CI), as well as the prevalence of the most frequently-seen predisposing factors for sepsis-associated AKI, were as follows: septic shock [2.88 (2.36-3.52), 60.47%], hypertension [1.43 (1.20-1.70), 38.39%], diabetes mellitus [1.59 (1.47-1.71), 27.57%], abdominal infection [1.44 (1.32-1.58), 30.87%], the administration of vasopressors [2.95 (1.67-5.22), 64.61%], the administration of vasoactive drugs [3.85 (1.89-7.87), 63.22%], mechanical ventilation [1.64 (1.24-2.16), 68.00%], positive results from blood culture [1.60 (1.35-1.89), 41.19%], and a history of smoking [1.60 (1.09-2.36), 43.09%]. Other risk factors included cardiovascular diseases, coronary artery diseases, liver diseases, unknown infections, the administration of diuretics and ACEI/ARB, the infection caused by gram-negative bacteria, and organ transplantation.

CONCLUSION

Risk factors of S-AKI arise from a wide range of sources, making it difficult to predict and prevent this condition. Comorbidities, and certain drugs, are the main risk factors for S-AKI. Our review can provide guidance on the application of interventions to reduce the risks associated with sepsis-associated acute kidney injury and can also be used to tailor patient-specific treatment plans and management strategies in clinical practice.

S-nitrosoglutathione protects lipopolysaccharide-induced acute kidney injury by inhibiting toll-like receptor 4-nuclear factor-κB signal pathway

OBJECTIVES

To investigate the therapeutic effects and mechanisms of S-nitrosoglutathione (SNG) on acute kidney injury (AKI) induced by lipopolysaccharide (LPS).

METHODS

We established an AKI model by intraperitoneal administration of LPS in mice and LPS-induced human kidney (HK-2) cells in vitro. We obtained the kidney tissues from mice for histopathological examination, examined inflammatory cytokines by enzyme-linked immunosorbent assay and measured the expression levels of toll-like receptor 4-nuclear factor-κB (TLR4-NF-κB) signal pathway-related proteins by Western blotting.

KEY FINDINGS

Pretreatment of SNG effectively improved the kidney function, reduced the pathological damage score of kidney in mice and decreased the expression levels of IL-1β, IL-6 and TNF-α in a dose-dependent manner in vivo and in vitro. Furthermore, pretreatment of SNG also repressed TLR4, phosphorylated NF-κB IκBα, IKKβ and p65 expression levels in HK-2 cells induced by LPS.

CONCLUSIONS

S-nitrosoglutathione attenuates the severity of LPS-induced AKI by inhibiting the TLR4-NF-κB signalling pathway and may act as a protective agent for septic AKI.

The future for diagnostic tests of acute kidney injury in critical care: evidence synthesis, care pathway analysis and research prioritisation

BACKGROUND

Acute kidney injury (AKI) is highly prevalent in hospital inpatient populations, leading to significant mortality and morbidity, reduced quality of life and high short- and long-term health-care costs for the NHS. New diagnostic tests may offer an earlier diagnosis or improved care, but evidence of benefit to patients and of value to the NHS is required before national adoption.

OBJECTIVES

To evaluate the potential for AKI in vitro diagnostic tests to enhance the NHS care of patients admitted to the intensive care unit (ICU) and identify an efficient supporting research strategy.

DATA SOURCES

We searched ClinicalTrials.gov, The Cochrane Library databases, Embase, Health Management Information Consortium, International Clinical Trials Registry Platform, MEDLINE, metaRegister of Current Controlled Trials, PubMed and Web of Science databases from their inception dates until September 2014 (review 1), November 2015 (review 2) and July 2015 (economic model). Details of databases used for each review and coverage dates are listed in the main report.

REVIEW METHODS

The AKI-Diagnostics project included horizon scanning, systematic reviewing, meta-analysis of sensitivity and specificity, appraisal of analytical validity, care pathway analysis, model-based lifetime economic evaluation from a UK NHS perspective and value of information (VOI) analysis.

RESULTS

The horizon-scanning search identified 152 potential tests and biomarkers. Three tests, Nephrocheck^® (Astute Medical, Inc., San Diego, CA, USA), NGAL and cystatin C, were subjected to detailed review. The meta-analysis was limited by variable reporting standards, study quality and heterogeneity, but sensitivity was between 0.54 and 0.92 and specificity was between 0.49 and 0.95 depending on the test. A bespoke critical appraisal framework demonstrated that analytical validity was also poorly reported in many instances. In the economic model the incremental cost-effectiveness ratios ranged from £11,476 to £19,324 per quality-adjusted life-year (QALY), with a probability of cost-effectiveness between 48% and 54% when tests were compared with current standard care.

LIMITATIONS

The major limitation in the evidence on tests was the heterogeneity between studies in the definitions of AKI and the timing of testing.

CONCLUSIONS

Diagnostic tests for AKI in the ICU offer the potential to improve patient care and add value to the NHS, but cost-effectiveness remains highly uncertain. Further research should focus on the mechanisms by which a new test might change current care processes in the ICU and the subsequent cost and QALY implications. The VOI analysis suggested that further observational research to better define the prevalence of AKI developing in the ICU would be worthwhile. A formal randomised controlled trial of biomarker use linked to a standardised AKI care pathway is necessary to provide definitive evidence on whether or not adoption of tests by the NHS would be of value.

STUDY REGISTRATION

The systematic review within this study is registered as PROSPERO CRD42014013919.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Health insurance status and risk factors of mortality in patients with septic acute kidney injury in Ningbo, China

OBJECTIVE

To investigate the relationship between health insurance status and outcomes of septic acute kidney injury (AKI) related hospitalizations in an intensive care unit (ICU) in Ningbo, China.

METHODS

For this retrospective study, information was extracted from patients notes and billing records for patients >18 years of age with a diagnosis of AKI admitted to the ICU department, Ningbo First Hospital from April 2013 to March 2018.

RESULTS

Of the 368 patients with sepsis admitted to ICU, 167 (45%) developed AKI; 95 patients were insured and 72 were uninsured. Compared with insured patients, uninsured patients were younger, had higher Acute Physiology and Chronic Health Evaluation II (APACHE II) and Sequential Organ Failure Assessment (SOFA) scores, but had less catheter interventions and received less renal replacement therapy (RRT). Results from a multivariate analysis showed that independent predictors of ICU mortality were age, APACHE II scores, MODS scores, use of RRT and lack of insurance.

CONCLUSIONS

Uninsured patients with septic AKI were younger, stayed a shorter time in ICU, had higher illness severity scores and a higher ICU mortality than insured patients. Importantly a major risk factor for ICU mortality in this group was lack of insurance.

Urinary neutrophil gelatinase-associated lipocalin, kidney injury molecule-1, N-acetyl-β-D-glucosaminidase levels and mortality risk in septic patients with acute kidney injury

INTRODUCTION

The aim of the study was to confirm whether higher levels of urinary neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1) and N-acetyl-β-D-glucosaminidase (NAG) are associated with mortality risk scores in severe septic patients with acute kidney injury (AKI).

MATERIAL AND METHODS

A prospective observational study was performed in an adult critical care unit. A total of 135 patients were included. The levels of urinary NGAL, KIM-1 and NAG were compared between patients with acute physiology and chronic health evaluation (APACHE II) score > 25 (group A, n = 31) and APACHE II score ≤ 25 (group B, n = 104).

RESULTS

Median level of NGAL was 105.1 ng/ml (77.6-132.5) in group A versus 40.0 ng/ml (18.6-60.5) in group B (p < 0.001), KIM-1 was 16.2 ng/ml (10.2-22.3) versus 3.3 ng/ml (1.8-4.6) (p < 0.001), and NAG was 32.0 U/l (17.5-46.4) versus 15.0 U/l (7.7-22.3) (p < 0.001). The area under the receiver operating characteristic curve for NGAL was 0.70 (95% CI: 0.60-0.79), KIM-1 was 0.75 (95% CI: 0.66-0.83), and NAG was 0.69 (95% CI: 0.60-0.79). A NGAL level > 102.5 ng/ml had 95% sensitivity and 76% specificity, KIM-1 > 7.3 ng/ml had 96% sensitivity and 61% specificity, and NAG > 15.4 U/l had 86% sensitivity and 74% specificity.

CONCLUSIONS

In severe septic AKI patients, high levels of NGAL, KIM-1 and NAG are associated with mortality risk scores. Urinary NGAL, KIM-1 and NAG concentrations higher than 102.5 ng/ml, 7.3 ng/ml and 15.4 U/l respectively may be used to predict increased of death risk scores.

Urinary calprotectin, kidney injury molecule-1, and neutrophil gelatinase-associated lipocalin for the prediction of adverse outcome in pediatric acute kidney injury

Early identification of patients with acute kidney injury (AKI) being at high risk for adverse outcome can influence medical treatment. This study compares urinary calprotectin, kidney injury molecule-1 (KIM-1), and neutrophil gelatinase-associated lipocalin (NGAL) for their performance in predicting mortality and need for renal replacement therapy (RRT) in pediatric AKI patients. Urinary biomarker concentrations were assessed prospectively in 141 subjects aged 0-18 years including 55 patients with established AKI according to pediatric Risk, Injury, Failure, Loss, and End-stage kidney disease (pRIFLE) criteria, 27 patients without AKI, and 59 healthy children. Within the AKI group, receiver operating characteristic (ROC) curve analysis revealed moderate to poor performance of calprotectin and KIM-1 in the prediction of 30-day mortality (calprotectin area under the curve (AUC) 0.55; KIM-1 AUC 0.55) and 3-month mortality (calprotectin AUC 0.61; KIM-1 AUC 0.60) and fair performance in the prediction of RRT requirement (calprotectin AUC 0.72; KIM-1 AUC 0.71). Urinary NGAL showed good performance in predicting 30-day (AUC 0.79) and 3-month (AUC 0.81) mortality and moderate performance in predicting RRT (AUC 0.61).

CONCLUSIONS

Whereas urinary calprotectin and KIM-1 can be useful for the prediction of RRT, urinary NGAL has a good diagnostic performance in predicting mortality in pediatric patients with AKI of heterogeneous etiology. What is known: • There is increasing evidence that urinary biomarkers like neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) are valuable for the prediction of adverse outcome in adult acute kidney injury (AKI), whereas data on pediatric AKI is scarce. What is new: • Urinary calprotectin and KIM-1 do not predict mortality in our heterogeneous pediatric AKI cohort, but they show moderate performance in the prediction of dialysis. • Urinary NGAL is a good predictor of mortality performing better than pRIFLE stage, eGFR, or creatinine, but it shows moderate performance in the prediction of dialysis.

Predictive ability of urinary biomarkers for outcome in children with acute kidney injury

BACKGROUND

Urinary neutrophil gelatinase-associated lipocalin (NGAL), N-acetyl-beta-D-glucosaminidase (NAG), and interleukin 18 (IL-18) were found to be useful for early detection of acute kidney injury (AKI). The objective of this study was to determine the predictive ability of biomarkers for mortality and variation in levels in relation to different stages of AKI, need for dialysis, etiologies, and with duration of hospital stay.

METHODS

Urinary NGAL, NAG, and IL-18 levels were measured in 50 children with AKI and 30 age- and gender-matched healthy controls. AKI was classified as per pediatric Risk, Injury, Failure, Loss, and End-stage (RIFLE) criteria.

RESULTS

Median NGAL, NAG, and IL-18 values were significantly increased in AKI patients compared with controls (p < 0.001), with significant increase among risk, injury, and failure stages. Nonsurvivors had significantly higher median levels of NGAL (p = 0.008) and NAG (p = 0.018) than survivors. NGAL had highest area under the curve (AUC) at 0.750 [confidence interval (CI) 0.580-0.920], followed by NAG at 0.724 (CI 0.541-0.907), with sensitivity and specificity of 75 % each; and IL-18 (AUC 0.688, CI 0.511-0.864), with sensitivity 62.5 % and specificity 70.8 %, for predicting mortality. Values were significantly higher in patients who required peritoneal dialysis (PD) than in those in whom it was not indicated. Levels were comparable among different etiologies. Only NGAL level was found to be a significant risk factor associated with longer duration of hospital stay.

CONCLUSIONS

Urinary NGAL and NAG had modest predictive ability for mortality. Children requiring dialysis had significantly raised levels, and the NGAL level had significant association with duration of hospital stay.

Urinary exosomal activating transcriptional factor 3 as the early diagnostic biomarker for sepsis-induced acute kidney injury

Background

An early sepsis-induced acute kidney injury (sepsis-AKI) biomarker is currently in needed. Urinary neutrophil gelatinase-associated lipocalin (uNGAL) is a candidate of sepsis-AKI biomarker but with different cut-point values. Urinary exosomal activating transcriptional factor 3 (uATF3) has been mentioned as an interesting biomarker.

Methods

We conducted experiments in mice and a prospective, multicenter study in patients as a proof of concept that urine exosome is an interesting biomarker. An early expression of ATF3 in kidney of CD-1 mice at 6 h after cecal ligation and puncture implied the possibility of uATF3 as an early sepsis-AKI biomarker. Increase serum creatinine (Scr) ≥0.3 mg/dL from the baseline was used as an AKI diagnosis and urine was analyzed for uATF3 and uNGAL. Patients with baseline Scr at admission ≥1.5 mg/dL were excluded.

Results

The analysis showed higher Scr, uNGAL and uATF3 in patients with sepsis-AKI in comparison with patients with sepsis-non-AKI and healthy volunteers. A fair correlation, r² = 0.47, between uATF3 and uNGAL was showed in sepsis-AKI group with Scr ≥2 mg/dL. To see if uATF3 could be an early sepsis-AKI biomarker, urine sample was collected daily during the first week of the admission. In sepsis-AKI and sepsis-non-AKI groups, uNGAL were 367 ± 43 ng/mL and 183 ± 23 ng/mL, respectively; and uATF3 were 19 ± 4 ng/mL and 1.4 ± 0.8 ng/mL, respectively. With the mean value of uNGAL and uATF3 in sepsis AKI as a cut-off level, AUROC of uNGAL and uATF3 were 64% (95% CI 0.54 to 0.74) and 84% (95% CI 0.77 to 0.91), respectively.

Conclusions

Urine exosome is an interesting source of urine biomarker and uATF3 is an interesting sepsis-AKI biomarker.

Role of Urinary Neutrophil Gelatinase-associated Lipocalin as a Biomarker of Acute Kidney Injury in Patients with Circulatory Shock

Background

The early prediction of acute kidney injury (AKI) by the current clinical and laboratory methods remains inadequate. Neutrophil gelatinase-associated lipocalin (NGAL) has emerged as a promising noninvasive biomarker of kidney injury in shock. The aim of this study was to assess the ability of urinary NGAL (uNGAL) to predict AKI in adult Intensive Care Unit (ICU) patients.

Materials and Methods

We prospectively studied 70 patients with circulatory shock admitted to the ICU over a period of 1 year. uNGAL was analyzed at ICU admission and after 24 h. Risk, injury, failure, loss, and end-stage kidney criteria were calculated at admission and for consecutive 4 days. The primary outcome was AKI defined as an increase in creatinine of at least 50% from baseline or a reduction in urine output to <0.5 ml/kg/h for 6 h.

Results

uNGAL was a good diagnostic marker for AKI development; at day 1, the cutoff value 48.54 ng/mL had a sensitivity and specificity of 79.49 and 73.14, respectively, and the area under the curve (AUC) of 0.82 (95% confidence interval [CI], 0.75-0.87) for predicting AKI. At day 2, the cutoff value 190.92 ng/mL had a sensitivity and specificity of 90.0 and 64.66, respectively, and the AUC of 0.76 (95% CI, 0.70-0.88) for predicting AKI.

Conclusion

uNGAL could be a good early predictor biomarker of AKI following circulatory shock.

Diagnosis and prognosis of neutrophil gelatinase-associated lipocalin for acute kidney injury with sepsis: a systematic review and meta-analysis

Background

Neutrophil gelatinase-associated lipocalin (NGAL) has been identified as an early biomarker for prediction of acute kidney injury (AKI). However, the utility of NGAL to predict the occurrence of AKI in septic patients remains controversial. We performed a systematic review and meta-analysis to evaluate the evidence on diagnosis of sepsis AKI and the prediction of other clinical outcomes.

Method

The MEDLINE, EMBASE, Cochrane Library, Wanfang, and CNKI databases were systematically searched up to August 19, 2015. Quality assessment was applied by using the Quality Assessment for Studies of Diagnostic Accuracy (QUADAS-2) tool. The diagnostic performance of NGAL for the prediction of AKI in sepsis was evaluated using pooled estimates of sensitivity, specificity, likelihood ratio, and diagnostic odds ratio (DOR), as well as summary receiver operating characteristic curves (SROC).

Results

Fifteen studies with a total of 1,478 patients were included in the meta-analysis. For plasma NGAL, the pooled sensitivity and specificity with corresponding 95 % confidence intervals (CI) were 0.83 (95 % CI: 0.77 − 0.88) and 0.57 (95 % CI: 0.54 − 0.61), respectively. The pooled positive likelihood ratio (PLR) was 3.10 (95 % CI: 1.57 − 6.11) and the pooled negative likelihood ratio (NLR) was 0.24 (95 % CI: 0.13 − 0.43). The pooled DOR was 14.72 (95 % CI: 6.55 − 33.10) using a random effects model. The area under the curve (AUC) for SROC to summarize diagnostic accuracy was 0.86. For urine NGAL, the pooled sensitivity, specificity, PLR, NLR, DOR, and AUC values were 0.80 (95 % CI: 0.77 − 0.83), 0.80 (95 % CI: 0.77 − 0.83), 4.42 (95 % CI: 2.84 − 6.89), 0.21 (95 % CI: 0.13 − 0.35), 24.20 (95 % CI: 9.92 − 59.05) and 0.90, respectively. Significant heterogeneity was explored as a potential source. There was no notable publication bias observed across the eligible studies. NGAL for prediction of renal replacement therapy (RRT) and mortality associated with AKI in septic patients were also evaluated.

Conclusion

To a certain extent, NGAL is not only an effective predictive factor for AKI in the process of sepsis, but also shows potential predictive value for RRT and mortality. However, future trials are needed to clarify this controversial issue.

Thrombocytopenia as a predictor of severe acute kidney injury in patients with heat stroke

BACKGROUND

Abnormalities of blood system often occur several days before acute kidney injury (AKI) in patients with heat stroke (HS). We aimed to investigate the prevalence and prognostic value of the early hematological markers in patients with AKI induced by HS.

METHODS

In a retrospective cohort study, we analyzed the case records of 176 patients with HS and evaluated the hematological markers for early prediction and risk classification in the patients with AKI.

RESULTS

Of 176, 103 (58%) HS cases developed AKI, and men comprised more than half (75%) of the sample population. The nadir platelet count significantly correlated with the levels of peak serum creatinine (r = -0.608, p < 0.01) and blood urea nitrogen (r = -0.546, p < 0.01), and the length of hospital stay (r = -0.393, p < 0.01). The areas under the receiver operating characteristic curves (AU-ROC) indicated the prognostic accuracy of hematological markers, AU-ROC was significantly higher with the nadir platelet count than that with the admission platelet count (AU-ROC of the nadir platelet: 0.73; 95% CI: 0.67-0.82; vs. AU-ROC of the admission platelet: 0.67; 95% CI: 0.59-0.75; p < 0.01). Multiple logistic regression results indicated that the nadir platelet count (adjusted ORs: 37.92; 95% CI: 2.18-87.21; p < 0.01) was independent predictor of AKI in HS.

CONCLUSION

The high mortality observed in HS complicated with AKI, and among the various hematological parameters assessed, thrombocytopenia is associated with AKI induced by HS independently.

Spontaneous neutrophil migration patterns during sepsis after major burns

Finely tuned to respond quickly to infections, neutrophils have amazing abilities to migrate fast and efficiently towards sites of infection and inflammation. Although neutrophils ability to migrate is perturbed in patients after major burns, no correlations have yet been demonstrated between altered migration and higher rate of infections and sepsis in these patients when compared to healthy individuals. To probe if such correlations exist, we designed microfluidic devices to quantify the neutrophil migration phenotype with high precision. Inside these devices, moving neutrophils are confined in channels smaller than the neutrophils and forced to make directional decisions at bifurcations and around posts. We employed these devices to quantify neutrophil migration across 18 independent parameters in 74 blood samples from 13 patients with major burns and 3 healthy subjects. Blinded, retrospective analysis of clinical data and neutrophil migration parameters revealed that neutrophils isolated from blood samples collected during sepsis migrate spontaneously inside the microfluidic channels. The spontaneous neutrophil migration is a unique phenotype, typical for patients with major burns during sepsis and often observed one or two days before the diagnosis of sepsis is confirmed. The spontaneous neutrophil migration phenotype is rare in patients with major burns in the absence of sepsis, and is not encountered in healthy individuals. Our findings warrant further studies of neutrophils and their utility for early diagnosing and monitoring sepsis in patients after major burns.