Comparative Analysis between Urinary Calprotectin and Serum Creatinine for Early Detection of Intrinsic Acute Kidney Injury

Background: Acute kidney injury (AKI) is a common and important clinical condition that may lead to chronic kidney disease if it is not diagnosed and treated in its early stages. Urinary calprotectin is a valuable recognized biomarker that can be used to differentiate prerenal and intrinsic AKI. However, till date only a few reports on urine calprotectin measurement in early diagnosis of intrinsic AKI are available. In this study, we compared the sensitivity and specificity of urinary calprotectin with those of serum creatinine in detecting early intrinsic AKI.
Methods: Over 6 months period (April to October 2018), 81 of 408 patients admitted to the pediatric intensive care unit met the criteria of this cross-sectional study. Their serum creatinine and urinary calprotectin were measured on the first and third day of admission using Jaffe and Elisa radioimmunoassay methods, respectively. The AKI was defined according to the pRIFLE criteria.
Results: Of the total 81 patients, 67 had the criteria of intrinsic AKI. Of these 62% were female and 38% were male. The mean age of the patients was 22 months. According to data analysis, the area under the curve of ROC of urinary calprotectin on day-1 to detect renal failure is 0.93 with the best cutoff point obtained at 530 ng/mL. The sensitivity, specificity, positive, and negative predictive values of urinary calprotectin levels in diagnosing AKI at this cutoff point are 92.5%, 92.8%, 98.4, and 72.2%, respectively. Besides, urinary calprotectin changes occur much earlier than the rising of serum creatinine.
Conclusion: Urinary level of calprotectin is a very sensitive biomarker for early diagnosis of intrinsic AKI in children and it can be used in intensive care units or anywhere critically ill children admitted to detect intrinsic AKI. Besides, this study shows that urine calprotectin may be a more sensitive and specific biomarker than serum creatinine in the early phases of intrinsic AKI.

High-performance surface-enhanced Raman spectroscopy chip integrated with a micro-optical system for the rapid detection of creatinine in serum

To improve the sensitivity of disease biomarker detection, we proposed a high-performance surface-enhanced Raman spectroscopy (SERS) chip integrated with a micro-optical system (MOS). The MOS, which is based on the micro-reflecting cavity and the micro-lens, optimizes the optical matching characteristics of the SERS substrate and the Raman detection system, and greatly improves the SERS detection sensitivity by improving the collection efficiency of the Raman scattering signal. A uniform single layer of silver nanoparticles on a gold film was prepared as the SERS substrate using a liquid-liquid interface self-assembly method. The micro-reflecting cavity and micro-lens were prepared using micro-processing technology. The SERS chip was constructed based on the MOS and the Au film-based SERS substrate, and experimental results showed an EF of 1.46×108, which is about 22.4 times higher than that of the Si-based SERS substrate.
The chip was used for the detection of creatinine and the detection limit of creatinine in aqueous solution was 1 µM while the detection limit in serum was 5 µM. In addition, SERS testing was conducted on serum samples from normal people and patients with chronic renal impairment. Principal component analysis and linear discriminant analysis were used for modeling and identification, and the results showed a 90% accuracy of blind sample detection. These results demonstrate the value of this SERS chip for both research and practical applications in the fields of disease diagnosis and screening.

Drain fluid creatinine-to-serum creatinine ratio as an initial test to detect urine leakage following cystectomy: A retrospective study

Introduction: Urine leak following radical cystectomy is a known complication. Among the various methods to diagnose this, assessment of drain fluid creatinine is a relatively easy procedure. We aimed to ascertain the validity of the drain fluid creatinine-to-serum creatinine ratio (DCSCR) as an initial indicator of urinary leak in patients undergoing radical cystectomy.
Methods: We retrospectively identified consecutive patients with documentation of drain fluid creatinine in the postoperative period following cystectomy and urinary diversion at our institution between January 2009 and December 2018. All continent diversions and any patient with a DCSCR >1.5:1 underwent contrast study postoperatively. A diagnosis of urine leak was made following confirmatory imaging. Receiver operative characteristic curves were created, and Youden’s index was used to determine the strength and clinical utility of DCSCR as a diagnostic test.
Results: Two hundred forty-four of the 340 patients included in the study underwent cystectomy with conduit and 81 underwent neobladder creation. Sixteen out of 340 (4.7%) patients had radiologically confirmed urinary leak. DCSCR was elevated in all ureteric anastomotic leaks and in 1 out of the 7 neobladder-urethral anastomotic (NUA) leaks. The sensitivity and specificity of DCSCR to predict all urinary leaks were 68.8% and 80.9% at 1.12 (area under the curve [AUC] = 0.838), whereas at a value of 1.18 (AUC = 0.876) and with the exclusion of NUA leaks, the sensitivity was 77.8% and specificity was 87.6%.
Conclusions: DCSCR is a good preliminary test for identifying patients who need prompt confirmatory testing for localizing urinary leaks. A drain creatinine level just 18% higher than the serum creatinine level can signify a urine leak. This is different from general assumptions of a higher DCSCR.

Creatinine Serum Detection Kit

SKT-217-192 Stressmarq 2 plates of 96 wells 248 EUR

Multi-Species Creatinine Detection Kit for Plasma and Serum

IMLCRKTPS Innovative research each 395 EUR

Multi-Species Creatinine Detection Kit for Plasma and Serum

MBS8420180-1Kit MyBiosource 1Kit 565 EUR

Multi-Species Creatinine Detection Kit for Plasma and Serum

MBS8420180-5x1Kit MyBiosource 5x1Kit 2555 EUR

Urine Creatinine Detection Kit

SKT-200-192 Stressmarq 2 plates of 96 wells 226 EUR

Urine Creatinine Detection Kit

MBS807896-10x96Wells MyBiosource 10x96Wells 1710 EUR

Urine Creatinine Detection Kit

MBS807896-2x96Wells MyBiosource 2x96Wells 375 EUR

Creatinine Urinary Detection Kit (2 Plate)

K002-H1 Arbor Assays 2x96 well plates 296 EUR

Creatinine Urinary Detection Kit (10 Plate)

K002-H5 Arbor Assays 10x96 well plates 1182 EUR

OKAU00002-2PLATE - Creatinine Urinary Detection Kit

OKAU00002-2PLATE Aviva Systems Biology 2plate 259 EUR

Multi-Species Creatinine Detection Kit for Urine

IMLCRKTBF Innovative research each 387 EUR

Multi-Species Creatinine Detection Kit for Urine

MBS8420179-1Kit MyBiosource 1Kit 555 EUR

Multi-Species Creatinine Detection Kit for Urine

MBS8420179-5x1Kit MyBiosource 5x1Kit 2510 EUR

OKAU00002-10PLATE - Creatinine Urinary Detection Kit

OKAU00002-10PLATE Aviva Systems Biology 10plate 879 EUR

Creatinine Serum Samples

MBS173604-1Sample MyBiosource 1Sample 310 EUR

Creatinine Serum Samples

MBS173604-5Samples MyBiosource 5Samples 1005 EUR

Creatinine Serum Samples

MBS173604-5x5Samples MyBiosource 5x5Samples 4310 EUR

Creatinine Serum Kit (2 Plate)

KB02-H1 Arbor Assays 2x96 well plates 302 EUR

Creatinine Serum Kit (4 Plate)

KB02-H2 Arbor Assays 4x96 well plates 484 EUR

OKAU00065-1PLATE - Creatinine Serum Kit

OKAU00065-1PLATE Aviva Systems Biology 1plate 379 EUR

OKAU00065-2PLATE - Creatinine Serum Kit

OKAU00065-2PLATE Aviva Systems Biology 2plate 269 EUR

OKAU00065-4PLATE - Creatinine Serum Kit

OKAU00065-4PLATE Aviva Systems Biology 4plate 439 EUR

DetectX® Creatinine Reagent, 20ML

C004-20ML Arbor Assays 20ML 254 EUR

DetectX® Creatinine Reagent, 50ML

C004-50ML Arbor Assays 50ML 360 EUR

Creatinine Serum Low Sample Volume Kit (384-well Plate)

KB02-H1D Arbor Assays 1x384 well plate 431 EUR

Serum Creatinine ELISA kit (colorimetric, all species), 96 tests, quantitative

100-300-SCR Alpha Diagnostics 1 kit 343.2 EUR

Serum Creatinine ELISA kit (colorimetric, all species), 2x96 tests, quantitative

100-305-SCR Alpha Diagnostics 1 kit 562.8 EUR

Potassium (Serum) Detection Assay Kit (Fluorometric)

K940-100 Biovision each 738 EUR

Utility of measuring serum creatinine to detect renal compromise in ED patients receiving IV contrast-enhanced CT scan

Objective: The objectives of this study are to determine the efficacy of a roster of clinical factors in identifying risk for renal insufficiency in emergency department (ED) patients requiring intravenous contrast-enhanced CT scan (IVCE-CT) and to help mitigate potential for developing contrast-induced nephropathy (CIN).
Methods: A review was conducted of consecutive ED patients who received IVCE-CT during a 4-month period in our urban ED. The values of ED serum creatinine (SCr) performed were tabulated. The medical records of all patients with an elevated SCr (> 1.4 mg/dL) were reviewed to determine and correlate the presence of clinical risk factors for underlying renal insufficiency.
Results: During the 4-month study period, there were 2260 consecutive cases who received IVCE-CT; of these, 2250 (99.6%) had concomitant measurement of SCr. Elevated SCr occurred in 141 patients (6.2%); of these, 75 had a SCr > 2 mg/dL. In all, 139/141 (98.6%) with an elevated SCr had an underlying chronic or acute medical condition identified by medical record review which potentially compromised renal function, including chronic renal disease, diabetes mellitus, HIV infection, cancer, hypertension, congestive heart failure, sepsis/septic shock, chronic alcoholism, and sickle cell disease. Two patients with no identified risk factor each had (mildly) elevated SCr; both had a normal SCr measured post-CT scan. The total cost of performing serum basic metabolic panel to measure SCr in all patients during the 4-month study period was $94,500.
Conclusions: Elevated SCr is rarely present in ED patients without recognized risk factors who receive IVCE-CT scan. The vast majority with underlying renal insufficiency are readily identified by a review of the patient’s medical history and/or clinical findings. Routine SCr measurement on all ED patients regardless of risk stratification prior to IVCE imaging is neither time nor cost-effective.