No abstract

Several factors may influence the analysis of endothelial cells (ECs) by flow cytometry: separation of mononuclear cell, washing and centrifugation steps, panel of monoclonal antibodies, and the lack of standardization of gating technique. Therefore, the reliable quantification of ECs remains a technical challenge. The purpose of this study is to define a new flow cytometric protocol to characterize and quantitate ECs. In previous investigations, increased numbers of circulating ECs have been found in sickle cell disease. The patients with sickle cell disease might provide useful material for the study. We performed flow cytometry on whole blood from 20 normal controls and 31 patients with sickle cell disease (20 patients with steadystate disease and 11 patients with vaso-occlusive crises) using a lyse/no-wash procedure, specific and nonspecific antibody combinations (CD146, CD144, CD34, and CD117), and broad gating. This protocol produced much higher values for the number of circulating ECs (a mean of 2,396.55 ± 658.37 ECs/mL in controls vs 6,709.60 ± 1,772.32 ECs/mL in the steady-state group, or 18,213.50 ± 8,451 in the vaso-occlusive crises group, P < 0.001 for both), and also showed variable EC size and granularity, which may reflect activated, or early release ECs. This novel protocol performed comparably in terms of reproducibility, reliability, and dilution linearity with a previously described protocol. This approach has significant advantages for the characterization and quantitation ECs compatible with the pathophysiology. Using the specific antibodies, CD146 and CD144, together may give more informative EC data than the general approach used. Am. J. Hematol. 82:706-711, 2007. V

The Eastern Mediterranean is among the regions where sickle cell disease (SCD) is common. The morbidity and mortality of this disease can be postponed to adulthood through therapies implemented in childhood. The present study focuses on the organ damage-reducing effects of the Baskent Sickle Cell Medical Care Development Program (BASCARE), which was developed by a team who lives in this region and has approximately 25 years of experience. The deliverables of the program included the development of an electronic health recording system (PRANA) and electronic vaccination system; the use of low citrate infusion in routine prophylactic automatic erythrocyte exchange (ARCE) programs including pregnant women; the use of leukocyte-filtered and irradiated blood for transfusion; the use of magnetic resonance imaging methods (T2∗) for the management of transfusion-related hemosiderosis; and the implementation of an allogeneic hematopoietic stem cell transplantation protocol for adult patients. The sample was composed of 376 study subjects and 249 control subjects. The hospital's Data Management System and the central population operating system were used for data collection. BASCARE enabled better analysis and interpretation of complication and mortality data. Vaccination rates against influenza and pneumococcal disease improved (21.5% vs 50.8% and 21.5% vs 49.2%, respectively). Effective and safe ARCE with low citrate infusion were maintained in 352 subjects (1003 procedures). Maternal and fetal mortality was prevented in 35 consecutive pregnant patients with ARCE. Chelating therapy rates reduced from 6.7% to 5%. Successful outcomes could be obtained in all 13 adult patients who underwent allogeneic peripheral stem cell transplantation from a fully matched, related donor. No patients died by day 100 or after the first year. Cure could be achieved without graft loss, grades III to IV acute graft versus host disease, extensive chronic graft versus host disease, or other major complications. The BASCARE program significantly improved patient care and thereby prolonged the life span of SCD patients (42 ± 13 years vs 29 ± 7 years, P < .001). We may recommend using such individualized programs in centers that provide health care for patients with SCD, in accordance with holistic approach due to the benign nature but malignant course of the disease.

Background: The apoptosis of human polymorphonuclear leukocytes (PMNs) in patients with sickle cell disease (SCD) is not well understood. The goal of this study was to examine the apoptosis of PMNs in patients with SCD and in controls.Methods: Flow cytometric quantitation of PMN apoptosis was performed in 17 patients during and after sickle cell vasoocclusive crisis and in 17 healthy volunteers. Plasma nitric oxide concentrations were also measured in patients with SCD.Results: The mean of annexin-V and annexin-V/PI staining (early and late apoptotic cells) increased to a greater degree in patients with SCD than in healthy controls for patients with SCD during and after vasoocclusive crisis. The mean of PI staining showing dead cells was higher only in patients after SCD crisis than in healthy controls. In the SCD groups during and after vasoocclusive crisis, there was no difference between PMN apoptosis levels. Furthermore, plasma nitric oxide concentrations were not correlated with PMN apoptosis.Conclusions: There was an evidence that the alteration of blood PMN apoptosis could contribute to the pathogenetic mechanisms of vasoocclusion in patients with SCD. This can be attributed to the effects of numerous inflammatory mediators rather than simply the effects of nitric oxide. q 2006 International