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Stillwater, MN, United States

Maters A.W.,Johns Hopkins University | Wright C.V.,Johns Hopkins University | Lee M.T.,Johns Hopkins University | Schwichtenberg G.,DiaSorin Inc | Detrick B.,Johns Hopkins University
Diagnostic Microbiology and Infectious Disease | Year: 2012

Type-specific serologic tests for human herpes simplex virus (HSV) are critically important for sexually transmitted disease evaluation. We compared the LIAISON® HSV-1 and HSV-2 Type Specific assays relative to an established commercial ELISA. The overall agreement of the chemiluminescence immunoassay versus the ELISA assay was 99.6% (HSV-1) and 100% (HSV-2). The LIAISON® methodology has several advantages. © 2012 Elsevier Inc.

Hsu S.A.,Cleveland Clinic | Soldo J.,DiaSorin Inc | Gupta M.,Cleveland Clinic
Journal of Steroid Biochemistry and Molecular Biology | Year: 2013

Background/methods: A total of 95 human serum specimens, and a 12 specimen precision panel, were measured by 2 automated immunoassays (investigation use only DiaSorin LIAISON® 25 OH Vitamin D TOTAL Assay [LSN], and Siemens ADVIA Centaur® Vitamin D Total (VitD) assay [Centaur]) and the results compared against LC-MS/MS [LCMS] used as the reference method (Esoterix Inc.). For functional sensitivity and precision, 12 serum specimens [range 1.2-148 ng/mL] were run in six replicates [N = 30] or four replicates [N = 20], respectively, for 5 consecutive days. Results: Passing-Bablok fit and Difference plot analysis [N = 92] showed that although both immunoassays had comparable correlation coefficient [r] values to LCMS (0.936 and 0.933), the LSN assay results were statistically equivalent to those given by LCMS (slope 0.93, intercept-2.5), whereas the results of the Centaur assay showed overall significant assay bias compared to LCMS (slope 1.30, intercept-15.8) and this bias was more significant for doses <30 ng/mL by LCMS [bias-30.4%; 95% limits of agreement-72.4% to 11.7%]. For specificity, based on 25-OHD2 and 25-OHD3 levels assessed by LCMS, we divided the specimens into 2 groups, one with detectable 25-OHD2 [Group 1, N = 41] and the other with no detectible 25OHD2 [Group 2, N = 51]. The 2 groups showed comparable correlation coefficient [r] values between the methods, but showed significant differences in slope: Centaur [1.48 with group 1 and 1.18 with group 2] compared to LSN [0.91 with Group 1 and 0.96 with Group 2]. LSN demonstrated better precision [total CV range 5.5-10.0%] compared to Centaur [total CV range 11.0-16.3%]. Functional sensitivity was calculated per EP-17A: 2.15 ng/mL by LSN and 4.57 ng/mL by Centaur. Conclusions: Though there was good overall correlation, substantial bias was present in Centaur. Although LSN had a slope and intercept that was not significantly different than LCMS, Centaur had a significantly higher slope in specimens containing measurable 25-OHD2 levels, a large negative intercept and a significant negative dose bias for doses <30 ng/mL by LCMS, suggesting the Centaur assay would report a higher frequency of patients with apparent vitamin D insufficiency/deficiency at the low end and apparent vitamin D toxicity at the high end compared against LCMS. © 2012 Elsevier Ltd. All rights reserved.

Viaene L.,Catholic University of Leuven | Behets G.J.,University of Antwerp | Claes K.,Catholic University of Leuven | Meijers B.,Catholic University of Leuven | And 4 more authors.
Nephrology Dialysis Transplantation | Year: 2013

Background. Derangements in bone metabolism and vascular calcification (VC) substantially contribute to the accelerated cardiovascular morbidity and mortality in chronic kidney disease (CKD). The Wnt signalling pathway is increasingly recognized to play an important role in bone homeostasis and VC. Circulating levels of the Wnt inhibitor sclerostin are elevated in CKD patients. The present study investigated whether the circulating levels of sclerostin are associated with all-cause mortality in haemodialysis (HD) patients. Methods. We performed a post-hoc survival analysis in 100 prevalent HD patients (68 ± 13 years, 40 male) recruited in 2006 who were prospectively followed for median 637 (8-1000, range) days. Parameters of mineral metabolism including bone-specific alkaline phosphatase (bsAP) and serum sclerostin were determined in spare blood samples collected at baseline. Results. Serum concentrations of serum sclerostin amounted to 110 (82-151) [median (iqr)] pmol/L. Patients with sclerostin levels above median were characterized by older age, higher haemoglobin and creatinine level and lower bsAP concentration. During a median follow-up of 637 days, 31 patients died. Higher circulating sclerostin levels were associated with decreased mortality in prevalent HD patients: unadjusted hazard ratio (HR) 0.51 (0.24-1.06) (P = 0.06); HR adjusted for age and gender for serum sclerostin levels above versus below median was 0.33 (0.15-0.73) (P = 0.006). When bsAP was entered in the Cox regression analysis, it replaced sclerostin in the final model. Conclusions. Our data show that high circulating sclerostin levels are associated with improved survival and suggest that a low bsAP activity may be in the causal pathway. © The Author 2013. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

Farrell C.,Laverty Pathology | Soldo J.,DiaSorin Inc | Williams P.,University of Sydney | Herrmann M.,Laverty Pathology | Herrmann M.,University of Sydney
Clinical Chemistry and Laboratory Medicine | Year: 2012

Background : Clinical laboratories require accurate and precise 25-hydroxyvitamin D (25-OHD) immunoassays to allow comparison of patient results with published decision limits. However, some variation in performance has been found with the previous generation of automated 25-OHD immunoassays. This study assessed the performance of four recently released automated 25-OHD immunoassays against a liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay. Methods : A total of 983 samples from apparently healthy adults, plus 253 samples chosen to challenge the performance of the assays, were analyzed by the latest generation of immunoassays from Abbott, DiaSorin, Roche and Siemens. LC-MS/MS analysis was performed on a random subset of 264 samples. The precision of the immunoassays was assessed over 5 days with samples ranging between 3.0 and 370 nmol/L in concentration. Results : Immunoassays showed significant differences in precision at 25-OHD concentrations of 3.0 - 86.5 nmol/L but all showed acceptable precision at higher concentrations. The DiaSorin assay agreed with LC-MS/MS across the measuring range of samples tested (7.7 - 425 nmol/L). The other assays showed generally good performance, but had some limitations when their performance was challenged with samples with low and high 25-OHD concentrations, heterophilic antibodies or high 25-OHD 2 concentrations. The C3-epimer of 25-OHD was identified in 40.4 % of healthy adults tested and was a source of analytical variance in immunoassays. Conclusions : The latest generation of 25-OHD immunoassays has improved performance compared to previous assays. However, some immunoassays can still give discrepant results and this is most apparent when immunoassays are evaluated with a range of samples that challenge their analytical performance. © 2012 by Walter de Gruyter Berlin Boston.

DiaSorin Inc. | Date: 2003-09-23

Medical devices, namely, kits containing antigen-coated slides and in vitro diagnostic reagents, for immunofluorescence detection and titration of antinuclear antibodies.

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