ABSTRACT
OBJECTIVE: To assess concordance between two point-of-care testing (POCT) devices and the standard laboratory method in screening for gestational diabetes mellitus (GDM) in Huesca. METHODS: Pregnant women who met criteria for an oral glucose tolerance test (OGTT) and attended the laboratory between October 2017 and November 2018 were recruited in this prospective observational study. Glucose was measured in venous (laboratory) and capillary blood (Accu-Chek or Contour Next glucometers). GDM was diagnosed attending to NDDG criteria for venous samples or capillary-specific cut-off. Linear regression, Passing-Bablok, Bland-Altman, and the kappa coefficient were used to study concordance between POCT and laboratory method. RESULTS: Data from 109 women were analyzed (57 for Accu-Chek, 52 for Contour Next). Statistical analyses showed good agreement between both POCT and laboratory method. There were no statistical differences in fasting glucose measurements between capillary and venous samples and both POCT devices meet the ISO 15197 standard. Accu-Chek showed good agreement (k=0.629) regarding the laboratory method in classifying GDM, with an acceptable inter-evaluator bias of 3.5% (P<0.001). CONCLUSION: POCT can be used to obtain fasting values and reduce overall waiting times for patients. Additionally, Accu-Chek can be used to diagnose GDM in remote areas applying specific cut-off values.
Subject(s)
Blood Glucose/analysis , Diabetes, Gestational/diagnosis , Glucose Tolerance Test/methods , Point-of-Care Testing , Adult , Female , Humans , Linear Models , Pregnancy , Prospective StudiesABSTRACT
Objectives: Chosen cutoff for cytokeratin 19 fragment antigen (CYFRA 21-1) as a tumor biomarker considerably influences its diagnostic and prognostic usefulness. The aim of the present study is to determine an optimal cutoff value for diagnostic validity of CYFRA 21-1 by Lumipulse ® technology in patients with suspected cancer and also to determine if CYFRA 21-1 levels provide prognostic value. Methods: A consecutive 284 patients suggestive of malignant disease from six hospitals of Madrid were enrolled in a retrospective design. Optimal CYFRA 21-1 cutoff value was obtained by receiver operating characteristic curve and Youden test. The diagnostic validity was evaluated according to sensitivity, specificity, predictive values and likelihood ratios. The prognostic value of CYFRA 21-1 was checked using multiple logistic regression. Thirty-two diagnostic cancers were confirmed. Results: The most optimal cutoff was 3.15 ng/mL. This cutoff showed a better specificity 93.63% (95% confidence interval [CI], 89.66-96.16), positive predictive value 60.98% (95% CI, 44.54-75.38) and positive likelihood ratio 12.65 (95% CI, 7.64-20.95) than the cutoff recommended by Fujirebio® (1.8 ng/mL) (specificity: 73.71% [95% CI, 67.72-78.95], positive predictive value: 29.79% [95% CI, 21.02-40.23] and positive likelihood ratio 3.43 [95% CI, 2.71-4.35]), improving the current diagnostic accuracy. In multivariate analysis, elevated levels of CYFRA 21-1 (>3.15 ng/mL) was confirmed as an unfavorable prognostic factor. Conclusions: The best cutoff for CYFRA 21-1 obtained was 3.15 ng/mL in patients with suspected cancer. This new cutoff decreases the false positive rate and improves the diagnostic efficacy of CYFRA 21-1 as a tumor marker as well as its association with death events.
ABSTRACT
El tratamiento con metotrexato (MTX) a dosis elevadas implica una monitorización estrecha de los niveles del fármaco para confirmar su correcta eliminación. Uno de los posibles efectos secundarios es el fracaso renal, lo que ocasiona una acumulación de fármaco y un mayor efecto tóxico. La glucarpidasa (carboxipeptidasa-G2 o CPDG2) es una enzima recombinante que se utiliza para disminuir los niveles de MTX en pacientes que desarrollan fallo renal durante el tratamiento con altas dosis de MTX. La enzima reduce la concentración de MTX en un 95-99% de 15 a 30min después de la dosis. La glucarpidasa escinde el MTX en glutamato y ácido 2,4-diamino-N10-metilpteroico un metabolito menor e inactivo. Es conocida la reactividad cruzada del ácido 2,4-diamino-N10-metilpteroico en la medición de MTX mediante ensayos inmunológicos, que da lugar a una enorme sobreestimación de MTX. Sin embargo, los ensayos inmunológicos son la técnica mayoritariamente empleada en los laboratorios clínicos para la medición de MTX. Se presenta un caso de interferencia explicando la detección de MTX en las muestras de suero mediante cromatografía líquida acoplada a espectrometría de masas (LC-UHR-QTOF)
High-dose methotrexate (MTX) treatment involves close monitoring of drug level in order to confirm its proper elimination. One of the possible side effects of this therapy is renal failure, causing accumulation of the drug, and therefore is a mayor toxic effect. Glucarpidase (carboxypeptidase-G2 or CPDG2) is a recombinant enzyme used to reduce MTX serum levels in patients who develop acute renal failure during high-dose MTX treatment. The enzyme reduces MTX concentration by 95-99% within 15-30minutes after the dose. Glucarpidase cleaves MTX into glutamate and 2,4-diamino-N10-methylpteroic acid, a minor and non-active metabolite. Cross-reactivity of 2,4-diamino-N10-methylpteroic acid in immunological assays of MTX has been previously reported, and is said to cause an enormous overestimation in serum MTX analysis. However immunoassay is a widely used technique for MTX analysis, being the main method for its determination in most clinical laboratories. An interference case report is presented and MTX analysis in serum samples by liquid chromatography coupled with Ultra-High Resolution Q-Time of Flight Mass Spectrometry (LC-UHR-QTOF) is described
Subject(s)
Humans , Female , Middle Aged , Methotrexate/adverse effects , Drug Monitoring/methods , Gas Chromatography-Mass Spectrometry/methods , Carboxypeptidases/therapeutic use , Precursor Cell Lymphoblastic Leukemia-Lymphoma/drug therapy , Acute Kidney Injury/chemically induced , Methotrexate/administration & dosage , Metabolic Clearance Rate/physiology , Renal Dialysis/methodsABSTRACT
BACKGROUND: Biological variation (BV) and reference change values (RCVs) have been widely described for the general population, but the use of these data derived from adults in the elderly population is a controversial issue. We determined the within- and between-subject BV and RCV in both elderly and young people and compared them with previously published analyses. METHODS: Samples were collected from 135 volunteers over 80 years of age at weekly intervals over 4 weeks. Eighteen biochemical and eight haematological analytes were measured. The Fraser and Harris methods were used to calculate the components of BV and RCV. To perform a comparative analysis, a reference group of 118 young subjects was studied under the same conditions. RESULTS: The obtained coefficients of BV showed statistical differences in many cases, but in general, both the elderly and young patient data fall within the ranges previously described for the general population. The indexes of individuality for the analytes investigated did not exceed 1.4 in any case and were <0.6 for some analytes. The RCVs derived from elderly subjects were similar to those published in the young population, both in healthy and diseased individuals. CONCLUSIONS: The strong individuality observed supports the preferential use of RCVs rather than population-based reference intervals in elderly people. For most of the analytes studied, data from the young population can be applied to elderly people, but the specific elderly coefficients of BV and RCVs are a recommended option.
