Undisclosed interference in 25-OH-Vitamin D immunoassay on Liaison XL analyzer when using heparin plasma tubes.

This study investigates the impact of sample type on the measurement of 25-OH-vitamin D using the Liaison XL (Diasorin) and Cobas e801 (Roche). This investigation was motivated by the need to optimize sample volume usage, which led us to adopt the use of heparin plasma, an alternative proposed by Diasorin in their specification. Discordant and unexplainable results were observed, prompting us to evaluate the effect of sample type on the accuracy of the 25-OH-vitamin D measurements. We collected 34 different paired samples from a randomly selected patients who had two types of tubes taken simultaneously: serum-gel and lithium-heparin plasma tubes. The 25-OH-vitamin D levels were measured using Cobas e801 and Liaison. Statistical analysis was performed using the Mann-Whitney test to calculate the p-value. Biases were also calculated. When comparing the heparin matrix with the serum matrix on the Liaison XL analyzer, a higher proportion (p < .0001; 79% versus 64%) of patients were classified in the 'normal group', while fewer were classified in the 'insufficiency' or 'deficiency group'. The heparin tubes on the Liaison XL analyzer showed a mean bias of 57.5%) (p-value < .001; 95%CI: 37.6-77.4) compared to the serum tubes. On the other hand, the heparin tubes on the Cobas e801 analyzer showed a mean bias of -0.2% (95%CI: -4.8 to 4.5) compared to the serum tubes. It is imperative for laboratory professionals to be aware of this interference for an accurate measurement of 25-OH-vitamin D levels on the Liaison XL. Further research is needed to understand the mechanism of this interference.

Cross-evaluation of five slidemakers and three automated image analysis systems: The pitfalls of automation?

INTRODUCTION: Automated slidemakers and stainers and digital microscopes are coupled with haematology analysers to achieve better efficiency and cost-effectiveness. This study evaluates the integrated performance of slidemakers and digital microscopes commonly available on the market. METHODS: We compared the percentage of neutrophils for five slidemakers (two Siemens Advia Autoslides, a SysmexSP-10 and SP-50 and an Abbot Alinity hs) and a Horiba Hemaprep to the corresponding haematology analyser data (Siemens Advia 2120i, Sysmex XN and Abbot Alinity hq). Differential leucocyte counting (DLC) was performed on three different CellaVision digital microscopes (DM96, DM1200 and DI-60) and manually. The quality of the smears was assessed using a CellaVision SmearChecker. RESULTS: We observed a significant positive absolute bias (P < .05) for the percentage of neutrophils with the Autoslide and Alinity hs smears on the digital microscopes, but not when DLC was performed manually. The SP-10 and SP-50 showed no bias regardless of the DLC method. No bias was observed for the Hemaprep smears. All the smears had an acceptable monolayer quality, stain intensity and colour. All smears, except those from Sp-10, were of an acceptable length. CONCLUSION: Users should be aware of a potential lack of accuracy that can be encountered when using some slidemakers and digital microscopes. All laboratories should validate or verify the differential counts from slidemakers and digital microscope with automated cell differential counters. Manual count validation should only be considered if a significant proportion of clinically relevant abnormal cells are present. Otherwise, haematology analyser results should be favoured.

Glucocorticoids modulate tumor radiation response through a decrease in tumor oxygen consumption.

PURPOSE: We hypothesized that glucocorticoids may enhance tumor radiosensitivity by increasing tumor oxygenation (pO(2)) through inhibition of mitochondrial respiration. EXPERIMENTAL DESIGN: The effect of three glucocorticoids (hydrocortisone, dexamethasone, and prednisolone) on pO(2) was studied in murine TLT liver tumors and FSaII fibrosarcomas. At the time of maximum pO(2) (t(max), 30 min after administration), perfusion, oxygen consumption, and radiation sensitivity were studied. Local pO(2) measurements were done using electron paramagnetic resonance. The oxygen consumption rate of tumor cells after in vivo glucocorticoid administration was measured using high-frequency electron paramagnetic resonance. Tumor perfusion and permeability measurements were assessed by dynamic contrast-enhanced magnetic resonance imaging. RESULTS: All glucocorticoids tested caused a rapid increase in pO(2). At t(max), tumor perfusion decreased, indicating that the increase in pO(2) was not caused by an increase in oxygen supply. Also at t(max), global oxygen consumption decreased. When irradiation (25 Gy) was applied at t(max), the tumor radiosensitivity was enhanced (regrowth delay increased by a factor of 1.7). CONCLUSION: These results show the potential usefulness of the administration of glucocorticoids before irradiation.

Performance and abnormal cell flagging comparisons of three automated blood cell counters: Cell-Dyn Sapphire, DxH-800, and XN-2000.

OBJECTIVES: To compare two hematological analyzers-the DxH-800 (DxH; Beckman-Coulter, Miami, FL) and XN-2000 (XN; Sysmex, Kobe, Japan)-with the Cell-Dyn Sapphire (SAPH; Abbott, Santa Clara, CA). METHODS: We analyzed 4,375 samples. Slide reviews were made in the presence of blast, abnormal lymphocyte, and immature granulocyte (IG) flags or nucleated RBC (NRBC) count. RESULTS: The analyzers exhibited excellent correlations for CBC and neutrophils but displayed a limit correlation for lymphocytes. The XN did not miss circulating blasts (0.5%-95% in microscopy). For NRBCs, the XN demonstrated a sensitivity of 90%; DxH, 74%; and SAPH, 29%. Only the XN demonstrated a correlation with microscopy, permitting a WBC six-part differential until 15% of NRBCs. The XN and DxH gave useful IG counts with a cutoff less than 5% and a WBC level more than 2,500/mm(3). For abnormal lymphocytes detection, only XN demonstrated sensitivity of more than 95%, but its specificity of 54% requires adaptation. CONCLUSION: The XN increases the sensitivity of abnormal cell detection compared with the other counters, permitting a seven-part differential between predefined levels, decreasing the slide review from 20% to 9%.