scholarly journals Sensitive Assays for Urinary Retinol-Binding Protein and β-2-Glycoprotein-1 Based on Commercially Available Standards

1998 ◽  
Vol 35 (1) ◽  
pp. 115-119 ◽  
Author(s):  
M Lapsley ◽  
K Akers ◽  
A G W Norden
Keyword(s):  
Reference Range ◽  
Binding Protein ◽  
Healthy Adults ◽  
Retinol Binding Protein ◽  
Healthy Children ◽  
Creatinine Concentration ◽  
Reference Limit ◽  
Renal Tubular ◽  
Upper Reference Limit

Measurements of urinary retinol-binding protein (RBP) and β-2-glycoprotein-1 (β2G1) provide sensitive indicators of proximal renal tubular malfunction. β2G1 is very stable in urine but RBP, which is much less stable, has been more extensively studied. We have designed two similar immunoassays allowing measurement of both proteins from one urine dilution. The assays both use widely available commercial standards and permit accurate measurement throughout most of the reference range. We measured both proteins in the urine of 70 healthy adults and 80 healthy children aged between three and 16 years, expressing the results as a ratio to creatinine concentration. Using the 98th centile as the upper reference limit, adults excreted up to 17 μg/mmol RBP (median 8) and up to 30 μg/mmol β2G1 (median 15) with no difference between the sexes. Children had different ranges to adults with excretion of up to 22 μg/mmol RBP (median 10) and up to 80 μg/mmol β2G1 (median 24).

Neuroblastoma—When are Urinary Catecholamines and Their Metabolites ‘Normal’?

1988 ◽  
Vol 25 (6) ◽  
pp. 620-626 ◽  
Author(s):  
D J Worthington ◽  
E M Hammond ◽  
B B Eldeeb ◽  
A Green ◽  
G M Addison ◽  
...  
Keyword(s):  
Urinary Excretion ◽  
The Other ◽  
Published Data ◽  
Single Test ◽  
Creatinine Concentration ◽  
Urinary Catecholamines ◽  
Clinical Sensitivity ◽  
Reference Limit ◽  
Upper Reference Limit ◽  
The Individual

The overproduction of catecholamines and their metabolites is a well recognised feature of neuroblastoma. Published data are scarce for their urinary excretion in children with neuroblastoma and in ill children in whom this diagnosis may be considered. We have determined a graphical upper reference limit for total catecholamines, total metadrenalines and HMMA in urine, expressed as a ratio to the creatinine concentration, for a group of 174 children with neuroblastoma and 704 hospitalised children with other disorders. This graph has been determined by examining the overlap region between the results for the two groups of children and avoids the irregularities caused by statistical outliers. The sensitivity and specificity of the individual tests indicate that total catecholamines is marginally the best single test to perform when trying to diagnose neuroblastoma, with the best clinical sensitivity being achieved by examining both total catecholamines and HMMA. Only two of the 174 children with neuroblastoma would not have been detected using these two tests. Total metadrenalines did not appear to add any further information and could be dropped from the repertoire in favour of the other two measurements.

scholarly journals Evaluation of a sandwich enzyme-linked immunosorbent assay for the measurement of serum heart fatty acid-binding protein

2002 ◽  
Vol 39 (4) ◽  
pp. 404-405 ◽  
Author(s):  
Franca Pagani ◽  
Roberto Bonora ◽  
Graziella Bonetti ◽  
Mauro Panteghini
Keyword(s):  
Fatty Acid ◽  
Immunosorbent Assay ◽  
Fatty Acid Binding Protein ◽  
Binding Protein ◽  
Characteristic Curve ◽  
Enzyme Linked Immunosorbent Assay ◽  
Fatty Acid Binding ◽  
Reference Limit ◽  
Acid Binding Protein ◽  
Upper Reference Limit

Background: We evaluated the sandwich enzyme-linked immunosorbent assay (ELISA) MARKIT®-M for the determination of heart fatty-acid-binding protein (H-FABP). Results and Conclusions: The between-run coefficient of variation of this assay was <3·9 and it showed good correlation with a previously established ELISA method. The upper reference limit in 30 healthy individuals was 6·1 μg/L. Admission serum H-FABP was evaluated against myoglobin in 41 patients with suspected myocardial infarction (onset of symptoms ≤ 5 h). H-FABP showed the same diagnostic efficiency as myoglobin [area (standard error) under the receiver operating characteristic curve: 0·798 (0·079) for H-FABP, 0·771 (0·085) for myoglobin, P = 0·55]. However, using the upper reference limit as decision cut-off, the sensitivity for H-FABP [91%; 95% confidence interval (CI): 76-98%] was significantly ( P = 0·019) higher than that of myoglobin (65%; 95% CI: 47-80%).

scholarly journals Measurement of urinary 5-HIAA: correlation between spot versus 24-h urine collection

2019 ◽  
Vol 8 (8) ◽  
pp. 1082-1088 ◽  
Author(s):  
Matilde Calanchini ◽  
Michael Tadman ◽  
Jesper Krogh ◽  
Andrea Fabbri ◽  
Ashley Grossman ◽  
...  
Keyword(s):  
Reference Method ◽  
Neuroendocrine Neoplasms ◽  
Urine Collection ◽  
Creatinine Concentration ◽  
Spot Urine ◽  
Reference Limit ◽  
Spot Urine Sample ◽  
Hydroxyindoleacetic Acid ◽  
Upper Reference Limit

Background The 24-h urinary output of 5-hydroxyindoleacetic acid (5-HIAA) is used to monitor disease progression and treatment responses of neuroendocrine neoplasms (NENs). Several conditions are required for 5-HIAA assay, involving urine collection/preservation and food/drug restrictions. Aim To evaluate the correlation between 5-HIAA concentration in a spot urine sample and the output in a 24-h urine collection, and whether spot urine specimens can replace 24-h collection. Methods Patients with NENs or symptoms suggestive of NENs were asked to provide a separate spot urine at the end of the 24-h urine collection for 5-HIAA assessment. The upper reference limit for 24-h urinary 5-HIAA was 40 µmol/24 h. 5-HIAA measurements in spot urine samples were corrected for variation in urine flow rate by expressing results as a ratio to creatinine concentration. Results We included 136 paired urinary samples for 5-HIAA assessment from 111 patients (100 NENs). The correlation between 5-HIAA values measured in 24-h and spot urines was r = +0.863 (P < 0.001) and r = +0.840 (P < 0.001) including only NEN patients. Using the 24-h urinary 5-HIAA as reference method, the AUC on ROC analysis for spot urinary 5-HIAA was 0.948 (95% CI, 0.914–0.983; P < 0.001), attaining a sensitivity of 83% and specificity of 95% using 5.3 mol/mmol as cut-off for the spot urine. The AUC among NEN patients alone was 0.945 (95% CI, 0.904–0.987; P < 0.001). Conclusions The ratio of 5-HIAA to creatinine in a spot urine could replace the measurement of 5-HIAA output in a 24-h urine collection, especially for follow-up of patients with known elevated 5-HIAA levels.

scholarly journals Cerebrospinal Fluid Protein Concentration in Japanese Healthy Older Volunteers

2021 ◽  
Author(s):  
Tatsuya Yoshihara ◽  
Masayoshi Zaitsu ◽  
Kazuya Ito ◽  
Ryuzo Hanada ◽  
Eunhee Chung ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Protein Concentration ◽  
Reference Range ◽  
Asian Population ◽  
Reference Limit ◽  
Older Volunteers ◽  
The Mean ◽  
Upper Reference Limit ◽  
Age Range ◽  
Cerebrospinal Fluid Protein

The concentration of cerebrospinal fluid total protein (CSF-TP) is important for the diagnosis of neurological emergencies. Recently, some Western studies have shown that the current upper reference limit of CSF-TP is quite low for older patients. However, little is reported about the concentration of CSF-TP in older Asian population. In this study, we retrospectively analyzed the CSF-TP concentrations in Japanese healthy older volunteers. CSF samples in 69 healthy Japanese volunteers (age range: 55–73 years) were collected by lumbar puncture, and the data of CSF were retrospectively analyzed. The mean (standard deviation) CSF-TP was 41.7 (12.3) mg/dL. The older group (≥ 65 years old) had higher CSF-TP concentration than the younger group (55–64 years old). The 2.5th percentile and 97.5th percentile of CSF-TP were estimated as 22.5 and 73.2 mg/dL, respectively, which were higher than the current reference range in Japan (10–40 mg/dL).

Use of free and transthyretin-bound retinol-binding protein in serum as tests of vitamin A status in humans: effect of high creatinine concentrations in serum

1990 ◽  
Vol 36 (4) ◽  
pp. 674-676 ◽  
Author(s):  
B J Burri ◽  
D D Bankson ◽  
T R Neidlinger
Keyword(s):  
Renal Failure ◽  
Acute Renal Failure ◽  
Vitamin A ◽  
Serum Creatinine ◽  
Binding Protein ◽  
High Serum ◽  
Retinol Binding Protein ◽  
Creatinine Concentration ◽  
Vitamin A Status ◽  
Chromatographic Peaks

Abstract We measured immunologically active (apo + holo) retinol-binding protein (RBP), vitamin A-carrying (holo) free RBP, and transthyretin-bound (TTR) holo-RBP in serum from 34 retrospective cases of fluctuating acute renal failure. All subjects had high serum creatinine concentrations caused by renal failure. Apo + holo, holo-TTR-RBP, and (especially) holo-free RBP all correlated poorly but significantly with serum creatinine concentration. Therefore, the use of any form of RBP to measure vitamin A status may be of limited value in subjects with high creatinine concentrations in serum. However, molecular-exclusion HPLC may be able to distinguish increases in RBP concentration associated with renal failure from those caused by altered vitamin A status, because renal failure causes abnormalities in the number and retention times of chromatographic peaks as well as their areas.

scholarly journals Longitudinal characterization of renal proximal tubular markers in normotensive and preeclamptic pregnancies

2017 ◽  
Vol 312 (5) ◽  
pp. R773-R778 ◽  
Author(s):  
Elisabeth Codsi ◽  
Vesna D. Garovic ◽  
Maria L. Gonzalez-Suarez ◽  
Natasa Milic ◽  
Kristi S. Borowski ◽  
...  
Keyword(s):  
Cell Injury ◽  
Gestational Hypertension ◽  
Binding Protein ◽  
Retinol Binding Protein ◽  
Enzyme Linked Immunosorbent Assay ◽  
Tubular Dysfunction ◽  
Second Trimester ◽  
Tubular Injury ◽  
Creatinine Concentration ◽  
Proximal Tubular

Glomerular damage is common in preeclampsia (PE), but the extent and etiology of tubular injury are not well understood. The aim of this study was to evaluate tubular injury in patients with PE and to assess whether it predates clinical disease. We performed a prospective cohort study of 315 pregnant women who provided urine samples at the end of the second trimester and at delivery. This analysis included women who developed PE ( n = 15), gestational hypertension (GH; n = 14), and normotensive controls (NC; n = 44). Urinary markers of tubular injury, α1-microglobulin (A1M), retinol-binding protein (RBP), kidney-injury molecule-1 (KIM1), complement C5b-9, tissue inhibitor metalloproteinase-2 (TIMP-2), and insulin-like growth factor binding protein-7 (IGFBP-7) were measured by enzyme-linked immunosorbent assay (ELISA) and reported in relation to urine creatinine concentration. Second-trimester concentrations of all markers were similar among groups. At delivery, A1M concentrations were higher in the PE group than in the GH and NC groups as an A1M/creatinine ratio >13 (66.7, 8.3, and 35%, respectively, P = 0.01). Concentrations of C5b-9 were higher in the PE group than in the GH and NC groups (medians 9.85, 0.05, and 0.28 ng/mg, respectively, P = 0.003). KIM1, RBP, TIMP-2, and IGFBP-7 concentrations did not differ among groups at delivery. In conclusion, proximal tubular dysfunction, as assessed by A1M and C5b-9, developed during the interval between the end of the second trimester and delivery in patients with PE. However, this was not matched by abnormalities in markers previously associated with tubular cell injury (KIM-1, IGFBP-7, and TIMP-2).

scholarly journals Reference values of fecal calgranulin C (S100A12) in school aged children and adolescents

2017 ◽  
Vol 56 (1) ◽  
Author(s):  
Anke Heida ◽  
Anneke C. Muller Kobold ◽  
Lucie Wagenmakers ◽  
Koos van de Belt ◽  
Patrick F. van Rheenen
Keyword(s):  
Characteristic Curve ◽  
Reference Value ◽  
Reference Interval ◽  
Enzyme Linked Immunosorbent Assay ◽  
Healthy Children ◽  
Healthy Controls ◽  
Reference Limit ◽  
School Aged Children ◽  
Activated Neutrophils ◽  
Upper Reference Limit

AbstractBackground:Calgranulin C (S100A12) is an emerging marker of inflammation. It is exclusively released by activated neutrophils which makes this marker potentially more specific for inflammatory bowel disease (IBD) compared to established stool markers including calprotectin and lactoferrin. We aimed to establish a reference value for S100A12 in healthy children and investigated whether S100A12 levels can discriminate children with IBD from healthy controls.Methods:In a prospective community-based reference interval study we collected 122 stool samples from healthy children aged 5–19 years. Additionally, feces samples of 41 children with suspected IBD (who were later confirmed by endoscopy to have IBD) were collected. Levels of S100A12 were measured with a sandwich enzyme-linked immunosorbent assay (ELISA) (InflamarkResults:The upper reference limit in healthy children was 0.75 μg/g (90% confidence interval: 0.30–1.40). Median S100A12 levels were significantly higher in patients with IBD (8.00 μg/g [interquartile range (IQR) 2.5–11.6] compared to healthy controls [0.22 μg/g (IQR<0.22); p<0.001]). The best cutoff point based on receiver operating characteristic curve was 0.33 μg/g (sensitivity 93%; specificity 97%).Conclusions:Children and teenagers with newly diagnosed IBD have significantly higher S100A12 results compared to healthy individuals. We demonstrate that fecal S100A12 shows diagnostic promise under ideal testing conditions. Future studies need to address whether S100A12 can discriminate children with IBD from non-organic disease in a prospective cohort with chronic gastrointestinal complaints, and how S100A12 performs in comparison with established stool markers.

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