A multicenter study evaluation of the ClearLLab 10C panels.

Multiparameter flow cytometry plays an important role in the diagnosis, staging, and monitoring of patients with a suspected hematological malignancy. The ClearLLab 10C Panels consist of four reagent panels (B-Lineage Tube, T-Lineage Tube, and 2 Myeloid Lineage Tubes), each consisting of 10 color/10 antibody conjugates utilizing Beckman Coulters proprietary dry format optimized for investigating patients with suspected leukemia or lymphoma. A multicenter study was conducted to evaluate the performance of the ClearLLab 10C Panels for qualitative assessment of normal versus abnormal phenotype in peripheral blood, bone marrow, and lymph node samples with suspected hematological malignancies. ClearLLab 10C was compared to laboratory developed tests (LDTs) and final clinical diagnosis. Four clinical sites were used to enroll patient's spent specimens (n = 453); three laboratories in North America and one in Europe. Of the 453 specimens, 198 had no malignancy and 255 contained an abnormal population. The diagnostic accuracy of the ClearLLab 10C Panels was achieved with sensitivity of 96% and specificity of 95% with respect to patient final clinical diagnosis. The agreement of phenotyping between ClearLLab10C Panels and LDTs was 98%. Any differences noted between ClearLLab 10C and LDT were due to either the presence of populations below the level of detection, the lack of clinical information provided to the evaluators, or marker(s) not present in these panels. Overall, the ClearLLab 10C demonstrated excellent agreement to LDTs and diagnosis. These four reagent panels can be adopted by individual laboratories to assess the presence or absence of malignancy.

Determination of platelet aggregation inhibition during percutaneous coronary intervention with the platelet function analyzer PFA-100.

BACKGROUND: A simple device to rapidly evaluate platelet function may aid in optimizing glycoprotein IIb/IIIa inhibition during percutaneous coronary intervention (PCI). We prospectively studied platelet function in 250 patients receiving abciximab or eptifibatide during PCI. METHODS AND RESULTS: The platelet function analyzer PFA-100 (Dade-Behring, Deerfield, Ill) measures platelet function by determining the time to occlusion of an aperture in a biochemically active membrane as whole blood flows under high shear conditions. Platelet aggregation causes aperture occlusion, and results are reported as a closure time (CT). All patients received either abciximab or eptifibatide, along with aspirin and heparin; patients undergoing stent implantation received aspirin and a thienopyridine postprocedure. The CT was measured at baseline and 10 minutes, 4 hours, 12 hours (abciximab-only), and 24 hours after the bolus. Profound inhibition was exhibited in most patients shortly after the platelet inhibitor bolus and during the course of therapy. We observed recovery of platelet function 12 hours after discontinuation of abciximab, with a high degree of interpatient variability, and ongoing profound platelet inhibition 4 to 6 hours after the discontinuation of eptifibatide. Among patients treated with abciximab, patients who were obese recovered from platelet inhibition sooner than patients who were not obese, whereas patients who were elderly had delayed recovery compared with patients who were not elderly. Failure to achieve maximal platelet inhibition (nonclosure) at 10 minutes indicated a possible association with adverse clinical events at the 6-month follow-up examination (60% vs 20%). CONCLUSIONS: PFA-100 is a rapid simple assay used as a means of assessing inhibition of platelet aggregation during PCI performed with glycoprotein IIb/IIIa inhibition. Failure to achieve nonclosure early after the initiation of abciximab therapy warrants further investigation because there may be an association with adverse cardiac events at 6-month follow-up.