Contributing Authors. Preface. Acknowledgments. Chapter 1. Erythrocytes. Chapter 2. Leukocytes. Chapter 3. Hematopoietic Neoplasia. Chapter 4. Hemostasis. Chapter 5. Water, Electrolytes, and Acid Base. Chapter 6. Proteins, Lipids, and Carbohydrates. Chapter 7. Liver. Chapter 8. Digestive System. Chapter 9. Urinary System. Chapter 10. Muscle. Chapter 11. Endocrine System. Chapter 12. Cytology. Chapter 13. Generating and Interpreting Test Results: Test Validity, Quality Control, Reference Values, and Basic Epidemiology. Case Studies. Index.

Duncan & Prasse's veterinary laboratory medicine: clinical pathology.

As a first step towards a fully disposable stand-alone diagnostic microchip for determination of urinary human serum albumin (HSA), we report the use of a thin-film organic light emitting diode (OLED) as an excitation source for microscale fluorescence detection. The OLED has a peak emission wavelength of 540 nm, is simple to fabricate on flexible or rigid substrates, and operates at drive voltages below 10 V. In a fluorescence assay, HSA is reacted with Albumin Blue 580, generating a strong emission at 620 nm when excited with the OLED. Filter-less discrimination between excitation light and generated fluorescence is achieved through an orthogonal detection geometry. When the assay is performed in 800 µm deep and 800 µm wide microchannels on a poly(dimethylsiloxane)
				(PDMS) microchip at flow rates of 20 µL min−1, HSA concentrations down to 10 mg L−1 can be detected with a linear range from 10 to 100 mg L−1. This sensitivity is sufficient for the determination of microalbuminuria (MAU), an increased urinary albumin excretion indicative of renal disease (clinical cut-off levels: 15–40 mg L−1)

Towards microalbuminuria determination on a disposable diagnostic microchip with integrated fluorescence detection based on thin-film organic light emitting diodes

Chronic kidney disease, hypertension, diabetes, and obesity in the adult population of Morocco: how to avoid “over”- and “under”-diagnosis of CKD

SELDI-TOF-MS is a highly sensitive protein-analysis tool capable of detecting minute protein profile differences between biological samples. As proteins have been associated with urinary tract calculi, protein-based urinalysis may offer insights into their diagnosis. The purpose of this study was to evaluate SELDI-TOF-MS as a potential method for identifying urinary biomarkers of urolithiasis. Midstream sterile urine samples were obtained from 25 male patients with a confirmed diagnosis of urolithiasis (test group) and 25 male subjects with no known history of the disease (controls). Urinary levels of oxalate, total protein, albumin, and osteopontin were determined. Protein profiles were generated using SELDI-TOF-MS.SELDI-TOF-MS profiling revealed a relationship between protein peak intensities at 67 and 24 kDa that differed between the two groups. The ratio of p67:p24 was found to be less than 1.0 in all of the control samples (mean 0.26), while 18 out of 25 (72%) of the test group samples displayed a ratio greater than 1.0 (total group mean 4.75, P<0.001). Albumin, total protein, and oxalate levels were higher in the test group than the controls. Although SELDI-TOF-MS is not yet in widespread use in hospital and diagnostic laboratories, this system represents a promising new method for rapidly identifying patients with urolithiasis.

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Surface-enhanced laser desorption/ionization-time of flight-mass spectrometry (SELDI-TOF-MS): a new proteomic urinary test for patients with urolithiasis.

Objective

The Fontan operation is a palliative procedure for congenital single ventricle heart disease. Long-term kidney function in this cohort is not well-known. Our aim was to evaluate renal function in long-term survivors post-Fontan palliation, and we hypothesize that this cohort will have a higher prevalence of chronic kidney disease (CKD) compared to controls.



Design

We performed a retrospective cohort study of 68 subjects evaluated through the Single Ventricle Survivorship Program at the Children's Hospital of Philadelphia between July 2010 and December 2014 compared to 70 healthy children similar in age and sex. Primary outcome was CKD, defined as estimated glomerular filtration rate (eGFR) <90 mL/min/1.73 m2 using creatinine and cystatin C–based estimating equations. Secondary outcomes included proteinuria and elevated intact parathyroid hormone.



Results

The Fontan cohort included 68 subjects with median age 13 years (IQR 9.0, 17.3) who were median 11.1 years (IQR 6.5, 15.7) post-Fontan palliation. This cohort was compared to 70 healthy individuals (median age 15.5 years (IQR 12.5, 18.3). Although median eGFRs were comparable: 102.6 vs. 101.9 mL/min/1.73 m2 (P = .89) in Fontan vs. healthy subjects <18 years of age (Full CKiD equation), and 128.5 vs. 129.7 mL/min/1.73 m2 (P = .56) in Fontan vs. healthy subjects ≥18 years of age (CKD-EPI creatinine and cystatin formula); 10% of Fontan subjects had an eGFR<90 mL/min/1.73 m2. Median intact parathyroid hormone level was higher at 59.4 pg/mL (IQR 43.0, 83.1) in the Fontan group compared to 23.4 pg/mL (IQR 16.7, 30.0) in controls (P ≤ .001). Proteinuria was present in 10% of the Fontan group compared to 4.7% in controls (P = .27).



Conclusion

Ten percent of long-term survivors post-Fontan palliation had eGFR <90 ml/min/1.73 m2, and higher median parathyroid hormone levels compared to controls. Taken together, these measures may indicate early kidney disease. Future studies will focus on longitudinal assessment of kidney function and evaluation of risk factors for CKD post-Fontan palliation.

Assessment of Kidney Function in Survivors Following Fontan Palliation

The goal of our study was to perform a multisite evaluation of a new urine dipstick called Multistix PROtrade mark (Bayer, Elkhart, IN), which has reagent pads for the simultaneous assay of urinary albumin, protein, and creatinine. Patients' urine specimens were assayed at four sites with these dipsticks and with the familiar Bayer Multistix 10SG dipsticks for protein. The new dipstick pads for albumin are impregnated with bis (3',3"-diiodo-4',4"-dihydroxy-5',5"-dinitrophenyl)-3,4,5,6-tetrabromo-sulfonephthalein (DIDNTB) dye. These dipsticks also have a novel pad that estimates urinary creatinine using the peroxidase activity of the copper-creatinine complex. We determined the interlaboratory agreement of these dipsticks by comparing dipstick results to values obtained by quantitative analytical methods. We found that dividing the dipsticks' albumin or protein results by the creatinine concentration reduced the number of false-positive albumin or protein values observed in concentrated urines, and reduced the number of false negatives in dilute urines. The ratio of albumin to creatinine, or protein to creatinine gives a better measure of albumin or protein excretion. Compared to reading by eye, the dipstick results agreed better with the quantitative assays when they were read by a reflectometer (Bayer Clinitek).

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Multisite evaluation of a new dipstick for albumin, protein, and creatinine.

We tested patients’ urines for albumin, protein, and creatinine by quantitative and dipstick methods. The concentrations of these analytes were established by quantitative, cuvet-based chemistry methods that we assumed gave the “correct” values. There was good to excellent agreement of the dipstick results with the quantitative methods for the above three analytes. We found many patients who excreted pathological amounts of albumin and/or protein who did not have a diagnosis of kidney disease or other likely causes of proteinuria, suggesting that albuminuria and/or proteinuria were underdiagnosed in our group of patients. Those with cardiovascular disease, kidney disease, or diabetes showed the greatest predictive value of a positive test for albumin or protein by dipstick. Dipstick testing for albumin, protein, and creatinine had good or excellent agreement with quantitative methods. The dipstick tests were easy to use, simple, and low in cost, and can serve well for point-of-care testing. J. Clin. Lab. Anal. 15:295–300, 2001. © 2001 Wiley-Liss, Inc.

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Michael Sheehan

Papers

Multisite evaluation of a new dipstick for albumin, protein, and creatinine.

Albuminuria and proteinuria in hospitalized patients as measured by quantitative and dipstick methods.