Mindray BC-6800 body fluid mode, performance of nucleated cells, and differential count in ascitic and pleural fluids.

INTRODUCTION: An accurate and rapid analysis of cells in body fluids (BFs) is important for diagnosis and follow-up in many pathological conditions. We evaluated the analytical performance of the module BF Mindray BC-6800 (BC-6800-BF) for cytometric analysis of ascitic and pleural fluids. METHODS: A total of 99 ascitic and 45 pleural samples were collected and assessed with BC-6800-BF and optical microscopy. This study also includes the evaluation of limit blank (LoB), limit detection (LoD), limit quantitation, (LoQ), carryover, linearity, and diagnostic concordance between the two methods. RESULTS: For TC-BF, LoB was 1 × 10(6) cells/L, LoD was 3 × 10(6) cells/L, and LoQ was 4 × 10(6) cells/L. Linearity was excellent (r(2) = 0.99) and carryover was negligible. TC-BF performed with the two methods showed Pearson's correlation of 0.99 (P < 0.0001), Passing-Bablok regression y = 1.04x - 1.17, and bias 33.7 cells. In ascitic fluids, polymorphonuclear cells (PMN) showed an area under curve (AUC) of 0.98 (P < 0.0001). In pleural fluids, mononuclear cells (MN) and PMN % displayed an AUC of 0.79 (P < 0.0001) and 0.93 (P < 0.0001), respectively. CONCLUSIONS: BC-6800-BF in ascitic and pleural fluids offers rapid and accurate cell and differential counts in clinically relevant concentration ranges. The use of BC-6800-BF may allow to replace routine optical counting, except for samples displaying abnormal cell counts or abnormal DIFF scattergram.

Evaluation of the Abbott AxSYM cytomegalovirus (CMV) immunoglobulin M (IgM) assay in conjunction with other CMV IgM tests and a CMV IgG avidity assay.

The measurement of the avidity of cytomegalovirus (CMV) immunoglobulin G (IgG) antibodies has been shown by several investigators to be useful in identifying and excluding primary CMV infections in pregnant women. In this work, we examined the diagnostic utility of reflex testing of CMV IgM-positive specimens from pregnant women by using a CMV IgG avidity assay. The utility of this approach was directly dependent on the sensitivity of the CMV IgM assay employed during the initial screen. The higher initial reactivity rate of the AxSYM CMV IgM assay was necessary in order to detect CMV IgM in specimens containing low-avidity CMV IgG antibodies, indicative of a primary CMV infection, which other CMV IgM assays (Behring, Vidas, Captia, and Eurogenetics) fail to detect in some cases. The use of the AxSYM CMV IgM assay, followed by an avidity test, should result in more accurate diagnosis of CMV infection in pregnant women.

Verapamil acute administration: a new dynamic test in hyperprolactinemic states.

We studied the effect of acute administration of the calcium-channel blocker verapamil (VER) in 27 patients with tumoral hyperprolactinemia ([THPRL] prolactinomas and pseudoprolactinomas). We also studied the effect of VER in seven patients with idiopathic hyperprolactinemia (IHPRL) and a small group of patients with normal prolactin (PRL) levels and minimal incidental anomalies shown by magnetic resonance imaging (MRI). The study was performed on 2 separate days: on the first day, all subjects received VER, and on the second they received placebo. Acute administration of VER evoked a remarkable increase in serum PRL in IHPRL (as in normal healthy subjects used as controls), but no response was shown in THPRL, with no overlap between the two conditions. Acute administration of VER stimulated PRL secretion in patients with minimal incidental lesions shown by MRI; however, this increase was smaller in patients whose PRL level consistently reached the upper-normal limit. Although the meaning of such minimal anomalies shown by MRI is unknown, this could suggest that the test is precociously altered. To further elucidate the action of VER on lactotropes, we investigated the effect of VER given intravenously (IV) and compared different oral formulations in healthy subjects. Our data show that the VER test is effective in distinguishing between THPRL and IHPRL, but unfortunately, like other tests, it is not able to individualize patients in whom THPRL is the result of diminished dopaminergic tone (pseudoprolactinoma). From a pathophysiological point of view, calcium influx would appear less important in PRL regulation in chronic disorders of PRL secretion. VER given IV did not stimulate PRL release in normal subjects. This suggests that IV administration could produce a peak with an inadequate duration or that oral formulations may act also by metabolites formed on first-pass metabolism in the liver.

Lithium and rubidium activities on platelet aggregation.

Lithium (Li) has been shown to increase the platelet number after chemotherapy. The present paper suggests that Li may increase the platelet aggregation induced by sub-optimal concentrations of ADP. Conversely, rubidium does not modify platelet aggregation in the present experiments.

Screening for hemoglobin C using Technicon H-6000: the effect of formalin.

It has recently been shown that the automated H-6000 cell counter is unable to correctly process blood samples containing hemoglobin C. In this paper, we report that formalin is responsible for the failure of red blood cell lysis in the H-6000.