Clinical Applicability of Tissue Polypeptide Antigen and CA-125 in Gynecological Malignancies.

BACKGROUND: Nowadays there still is no sufficient screening tool for ovarian and uterine cancer. OBJECTIVE: The current study aimed to investigate whether cancer antigen 125 (CA-125), tissue polypeptide antigen (TPA) or the combination of both markers are able to act as screening tools for ovarian or uterine cancer. METHODS: A total of 275 blood samples from different cohorts (ovarian cancer, uterine cancer, benign control group) were prospectively drawn and analyzed. RESULTS: Established biomarkers TPA and CA-125 showed elevated serum concentrations in patients with malignant tumors as compared to healthy women and women with benign diseases. In ROC curve analyses, both biomarkers were well able to discriminate between malignant and healthy, benign or overall non-malignant cases in the whole sample, with AUCs of 0.842 and above. While TPA was the best diagnostic marker in patients with uterine cancer, CA 125 was the best in patients with ovarian cancer. CONCLUSIONS: TPA and CA-125 both showed promising results for the detection of gynecologic malignancies. The combination of CA-125 and TPA did not improve sensitivity in comparison to single markers.

Evaluation of the New Cyclosporine and Tacrolimus Automated Electrochemiluminescence Immunoassays under Field Conditions.

BACKGROUND: Careful monitoring of the post-transplantation immunosuppressant drugs (ISDs) cyclosporine (CsA) and tacrolimus (TAC) in whole blood is essential to prevent adverse drug events. Immunoassays represent the most widely used methodology for therapeutic drug monitoring. In this study, the technical performance of the new automated electrochemiluminescence immunoassays (ECLIAs) for CsA and TAC measurement were assessed under field conditions. METHODS: Residual whole blood samples from patients undergoing CsA or TAC therapy following organ transplant were used to evaluate the assays at six independent laboratories across four countries. Experiments included within-run imprecision using PreciControl ISD controls and recovery of commercial external quality assurance (EQA) scheme samples. Both assays were compared with liquid chromatography-tandem mass spectrometry (LC-MS/MS), using methods routinely employed at each investigational site, as well as with an equivalent commercial chemiluminescent microparticle immunoassay (CMIA) and enzyme multiplied immunoassay (EMIT). RESULTS: Within-run imprecision testing gave coefficients of variation of ≤ 5% in the > 90.0 - 2000 ng/mL range for the CsA ECLIA and ≤ 4.2% in the 3.5 - 12 ng/mL range and ≤ 4.9% in the > 12 - 40 ng/mL range for the TAC ECLIA. EQA sample recovery by ECLIA gave a mean bias of 6.9% for CsA and 4.9% for TAC versus the spiked concentration or the mean LC-MS/MS value. Deming regression analysis of ECLIA method comparison to LC-MS/MS for all sites yielded a slope of 1.22, intercept 8.43 ng/mL and r = 0.97 for CsA and a slope of 1.22, intercept -0.51 ng/mL and r = 0.96 for TAC. Comparison with CMIA yielded a slope of 0.87, intercept 5.51 ng/mL and r = 0.97 for CsA and a slope of 0.98, intercept 0.12 ng/mL and r = 0.97 for TAC. Comparison with EMIT yielded a slope of 1.23, intercept -8.74 ng/mL and r = 0.96 for CsA. CONCLUSIONS: The CsA and TAC ECLIA compare favorably with existing commercial immunoassays and with LC-MS/MS. They represent modern generation assays that meet the demands of monitoring drug concentrations in current immunosuppressive regimens. This study also highlights the importance of standardizing protocols and LC-MS/MS methods to give improved comparability between ISD assays.

Accuracy and clinical implications of seven 25-hydroxyvitamin D methods compared with liquid chromatography-tandem mass spectrometry as a reference.

BACKGROUND: The most reliable assessment of vitamin D status is measurement of plasma 25-hydroxyvitamin D (25[OH]D) concentration. High variability in 25(OH)D measurements due to utilized test and assay technologies and the lack of standardization against reference materials and reference method often confounds proper assessment of vitamin D status. METHODS: We evaluated the accuracy of six routinely available methodologies: high-performance liquid chromatography (HPLC), the IDS-radioimmunoassay (IDS-RIA) and enzyme immunoassay (IDS-EIA), the Nichols Advantage automated protein-binding assay (Advantage), two versions of the DiaSorin automated immunoassay (Liaison 1 and Liaison 2)--and one prototype automated immunoassay (Elecsys) for assessment of the 25(OH)D(3) status in a cohort of 300 randomly selected patients' samples compared with the reference method liquid chromatography-tandem mass spectrometry (LC-MS/MS). RESULTS: Passing-Bablok regression analysis demonstrated a slope for each method compared with LC-MS/MS that varied from 0.62 (IDS-EIA) to 1.0 (HPLC). The Advantage and the Liaison 1 showed significant deviation from linearity with highly variable individual results vs. the LC-MS/MS. Difference plots revealed a considerable persistent proportional bias for the IDS-RIA and IDS-EIA. All evaluated methods except HPLC demonstrated a more or less considerable deviation of individual 25(OH)D(3) values compared with LC-MS/MS defined target concentrations. CONCLUSIONS: Standardization of methods for the quantification of 25(OH)D on a human-based sample panel by means of LCMS/MS would help to reduce the inter-method variability with respect to accuracy existing in 25(OH)D measurement considerably. However, there will still remain differences in the accuracy of methods utilizing sample purification before final quantification or immunological reaction when compared with those methods without separate sample purification.

Quantitative bedside testing of troponin T: is it equal to laboratory testing? The Cardiac Reader Troponin T (CARE T) study.

The progressive evolution of cardiac marker testing in patients with acute coronary syndromes has extended their role into risk stratification and guidance of therapeutic regimen. To provide utilization of cardiac markers around the clock and facilitate the diagnostic work-up of patients with acute chest pain in the emergency room, a point-of-care system for quantitative troponin T and myoglobin testing in whole blood samples was developed. Aim of this multicenter study was to evaluate bedside quantitative determination of myoglobin and troponin T in chest pain patients in a clinical routine setting. Five hospitals in Germany were contributing to blood sampling and 741 patients were included four hours (median) after onset of cardiac pain. Comparison between the rapid test and the established laboratory-based method showed a sufficient agreement of results with a correlation of r = 0.89 (Y = 0.856x + 0.029) for troponin T and r = 0.912 (Y= +1.145x + 3.457) for myoglobin. Diagnostic sensitivity and prognostic power of the troponin T results obtained in the emergency unit were thoroughly equivalent to the laboratory-based method. The results show that the cardiac reader system represents a promising alternative to central laboratory testing with an accuracy sufficiently for rapid decision making in the emergency room. Myoglobin results in this study did not add supplementary information to the cardiac reader troponin result. However, point-of-care testing of troponin T is advantageous whenever marker results could positively effect initial triage decisions and interventional management choices.