scholarly journals New Electrochemiluminescent Immunoassay for the Determination of CYFRA 21-1: Analytical Evaluation and Clinical Diagnostic Performance in Urine Samples of Patients with Bladder Cancer

1999 ◽  
Vol 45 (11) ◽  
pp. 1944-1953 ◽  
Author(s):  
Marta Sánchez-Carbayo ◽  
Antonia Espasa ◽  
Virtudes Chinchilla ◽  
Enrique Herrero ◽  
Julián Megías ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
Roc Analysis ◽  
Threshold Value ◽  
Urine Samples ◽  
Cytokeratin 19 ◽  
Analytical Evaluation ◽  
Clinical Value ◽  
Sensitivity Measurement ◽  
Serum And Urine

Abstract Background: A new electrochemiluminescent immunoassay (ECLIA) has been developed for the determination of cytokeratin 19 (CYFRA 21-1) in the Elecsys 2010 immunoassay system. Urinary CYFRA 21-1 might have a role in the diagnosis of bladder cancer. Methods: We performed an analytical evaluation of the CYFRA 21-1 ECLIA for serum and urine samples. The clinical value of urinary CYFRA 21-1 for the detection of bladder cancer was evaluated through its measurement in 226 urine samples from symptomatic and asymptomatic controls. Results: At concentrations of 2–30 μg/L, within-assay imprecision (CV) was below 2.1% for sera and 3.3% for urines, with interassay CVs below 3.3% for sera and 4.9% for urines. The day-to-day CV was <20% at concentrations >0.2 μg/L (functional sensitivity). Measurement of diluted samples showed that the assay estimated CYFRA 21-1 between 98% and 103% for sera and 98% and 105% for urines. Recovery of added CYFRA 21-1 was 99–105% for sera and 96–115% for urines. We separately compared serum and urine CYFRA 21-1 ECLIA results with those obtained with an IRMA (CIS bio international). Regression analysis for sera was: CYFRA 21-1 (ECLIA) = 0.520 + 1.018 CYFRA 21-1 (IRMA); [95% confidence interval (CI) (y-intercept), −0.260 to 1.309]; 95% CI (slope), 0.978–1.060; n = 100; Sy|x = 3.242; r2 = 0.987. For urine samples it was: CYFRA 21-1 (ECLIA) = 0.716 + 0.966 CYFRA 21-1 (IRMA); 95% CI (y-intercept), 0.009–1.422; 95% CI (slope), 0.956–0.976; n = 100; Sy|x = 4.136; r2 = 0.986. In urine samples voided by patients with and without bladder cancer, the best ROC analysis discrimination provided 81.0% (95% CI, 72.7–87.7%) sensitivity and 97.2% (95% CI, 90.2–99.6%) specificity at a threshold value of 5.7 μg/L. Conclusions: Our initial evaluation showed reliable analytical performance for urinary CYFRA 21-1, which might assist urologists in the detection of bladder cancer as a noninvasive adjunct to cystoscopy.

Modification of the choriogonadotropin beta-subunit radioimmunoassay for determination of urinary choriogonadotropin.

1978 ◽  
Vol 24 (11) ◽  
pp. 1958-1961 ◽  
Author(s):  
J McCready ◽  
G D Braunstein ◽  
D Helm ◽  
M E Wade
Keyword(s):  
Pregnant Women ◽  
Radioreceptor Assay ◽  
Beta Subunit ◽  
Urine Samples ◽  
Human Choriogonadotropin ◽  
Analytical Recovery ◽  
Antibody Method ◽  
Serum And Urine ◽  
Serum And Urine Samples

Abstract The choriogonadotropin beta-subunit radioimminoassay has been used extensively to measure human choriogonadotropin in the sera of pregnant women and individuals with trophoblastic and nontrophoblastic tumors. Unmodified, this method cannot be used to measure choriogonadotropin in urine because of interfering substances. We circumvented the non-parallelism between the standards and serial dilutions of urine containing choriogonadotropin by adding pooled urine from men to the standard tubes and limiting the volume of urine to 100 microliter. This modified assay has a sensitivity of 3 int. units/liter of urine and is specific for choriogonadotropin concentrations of 40 int. units/liter of urine. Analytical recovery of choriogonadotropin added to urine ranged from 96 to 105%. The within-assay CV was 7.6%; the between-assay CV was 11.8%. Concentrations of choriogonadotropin in concurrently collected serum and urine samples from pregnant women correlated well. The test can be performed within 24 h by using the double-antibody method for separating bound from free hormone, or in 3 h with a dioxane method. The assay is about 20-fold more sensitive than the 2-min or 2-h slide and tube pregnancy tests, and seven-to 12-fold more sensitive than the radioreceptor assay.

Maltotetraose as a substrate for enzyme-coupled assay of amylase activity in serum and urine.

1979 ◽  
Vol 25 (3) ◽  
pp. 481-483 ◽  
Author(s):  
K J Whitlow ◽  
N Gochman ◽  
R L Forrester ◽  
L J Wataji
Keyword(s):  
Amylase Activity ◽  
Biological Fluids ◽  
Urine Samples ◽  
Coupled Assay ◽  
Serum And Urine ◽  
Serum And Urine Samples

Abstract The use of maltotetraose ss a new substrate for the enzyme-coupled determination of amylase activity in biological fluids was developed by Beckman Microbics. We evaluated a manual and a centrifugal analyzer version of the method in comparison with two commonly used manual starch-dye amylase techniques: Roche Amylochrome and Pharmacia Phadebas. Both maltotetraose amylase procedures proved to be rapid and precise, and results correlated satisfactorily with the starch-dye methods for serum and urine samples.

Prognostic and Predictive Significance of ErbB-2 Breast Tumor Levels Measured by Enzyme Immunoassay

2001 ◽  
Vol 19 (3) ◽  
pp. 645-656 ◽  
Author(s):  
Serenella Eppenberger-Castori ◽  
Willy Kueng ◽  
Christopher Benz ◽  
Rosmarie Caduff ◽  
Zsuzsanna Varga ◽  
...  
Keyword(s):  
Enzyme Immunoassay ◽  
Survival Data ◽  
Breast Tumor ◽  
Patient Survival ◽  
Threshold Value ◽  
Bimodal Distribution ◽  
Receptor Expression ◽  
Breast Cancers ◽  
Clinical Value

PURPOSE: A retrospective analysis to assess the prognostic and predictive clinical value of breast tumor ErbB-2 receptor expression quantified by enzyme immunoassay (EIA), to compare levels measured by EIA with ErbB-2 status determined by immunohistochemistry (IHC), and to correlate receptor content with levels of phosphorylated (Y1248-P) ErbB-2, a measure of functional tyrosine kinase activity. MATERIALS AND METHODS: EIA quantification of ErbB-2 was performed on membrane extracts from 3,208 well-characterized primary breast cancers. Overall, relapse-free, distant disease-free, and local/regional-free patient survival data were available on 1,123 of these tumors. IHC scoring for ErbB-2 status (HercepTest; DAKO, Glostrup, Denmark) was performed on adjacent sections of 151 cases, and receptor functionality was measured in 230 tumors by an antibody specific for phosphorylated (Y1248-P) ErbB-2. RESULTS: Unlike nonmalignant breast tissues, breast tumors showed increased ErbB-2 levels in a bimodal distribution, with 12% constituting a distinct set of ErbB-2–overexpressing tumors. The intermodal threshold value for ErbB-2 overexpression distinguished tumors with reduced estrogen and progesterone receptor content, high IHC score for ErbB-2, and significantly increased levels of phosphorylated (Y1248-P) ErbB-2 receptor. By multivariate analysis, EIA-determined ErbB-2 overexpression predicted significantly reduced patient survival that was unaffected by tamoxifen or cyclophosphamide, methotrexate, and fluorouracil adjuvant therapy. CONCLUSION: Determination of ErbB-2 receptor expression by EIA offers a clinically valuable alternative to semiquantitative IHC assessment of breast tumor ErbB-2 overexpression and affords the opportunity to evaluate ErbB-2 phosphorylation, which may represent an important predictive parameter of receptor functionality.

Nonenzymatic stopped-flow fluorimetric method for direct determination of uric acid in serum and urine.

1989 ◽  
Vol 35 (2) ◽  
pp. 230-233 ◽  
Author(s):  
D Pérez-Bendito ◽  
A Gómez-Hens ◽  
M C Gutiérrez ◽  
S Antón
Keyword(s):  
Hydrogen Peroxide ◽  
Uric Acid ◽  
Direct Determination ◽  
Urine Samples ◽  
Stopped Flow ◽  
Fluorimetric Determination ◽  
Kinetic Measurements ◽  
Serum And Urine ◽  
Serum And Urine Samples

Abstract A simple, direct, sensitive, and selective stopped-flow method for the fluorimetric determination of uric acid in serum and urine samples is described. The variation of fluorescence intensity during the reaction between uric acid and 1,1,3-tricyano-2-amino-1-propene (triap) in the presence of hydrogen peroxide is monitored. For these kinetic measurements peroxide is monitored. For these kinetic measurements we used a versatile stopped-flow module that can be fitted to any fluorimeter. The linear range of the proposed method is 0.08-3.00 mg of uric acid per liter, and the detection limit is 0.03 mg/L. Within- and between-assay CVs and selectivity data are reported. Results for serum and urine samples correlated well with those obtained by the uricase method The proposed method is inexpensive and requires no sophisticated detection equipment.

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