Maria Podolak-Dawidziak

Endothelial progenitor cells and left ventricle function in patients with acute myocardial infarction: potential therapeutic considertions.

Endothelial progenitor cells (EPCs) play a key role in angiogenesis and vascular repair, although their exact functions are still disputable. The impact of EPC on left ventricular ejection fraction (LVEF) during acute myocardial infarction (MI) in patients treated with primary percutaneous coronary intervention (PCI) is also under investigation. The aim of this study was to assess the impact of different populations of EPC on LVEF during and 6 months after acute MI treated with primary PCI. The study included 34 patients with documented acute anterior wall MI. The control group consisted of 19 apparently healthy subjects. Blood for EPC assessments was obtained during the first 24 hours after MI and at 7 days and 6 months after PCI. CD34+/CD133+/CD45−, CD34+/CD31+/CD45−, CD34+/CD105+/CD45−, and CD31+/CD133+/CD45− cell types were studied by flow cytometry. Echocardiography has been performed simultaneously with the EPC measurements. We observed a significant elevation of CD34+/CD133+/CD45−, CD34+/CD105+/CD45−, and CD31+/CD133+/CD45− EPC at 7 days after PCI in comparison with 24 hours and 6 months after the MI. Patients with preserved LVEF at 7 days after PCI had also higher levels of CD31+/CD133+/CD45−. Acute anterior wall MI treated with primary PCI is followed by enhanced mobilization of EPC among which a high level of CD31+/CD133+/CD45− subtype was strongly associated with the most preserved LVEF for up to 6 months after the index event. These data may provide some insight for future therapeutic strategies.

Altered plasma fibrin clot properties and fibrinolysis in patients with multiple myeloma

Multiple myeloma (MM) is associated with increased risk of venous and arterial thromboembolism. Formation of denser and poorly lysable fibrin clots is observed in patients with arterial and venous thromboembolism. We investigated fibrin clot properties and their determinants in MM patients.

Recommendations for the diagnosis and treatment of patients with polycythaemia vera

To present the Central European Myeloproliferative Neoplasm Organisation (CEMPO) treatment recommendations for polycythaemia vera (PV).

MRP1 protein expression in leukemic stem cells as a negative prognostic marker in acute myeloid leukemia patients

It is well established that expression of multi‐drug resistance (MDR) proteins (MDR1, BCRP, MDR3, MRP1, and LRP) in leukemic blasts correlates with acute myeloid leukemia (AML) patients’ clinical response. Assuming that leukemic stem cells (LSC) are resistant to chemotherapy and responsible for relapse, it might be clinically relevant to evaluate the expression level of MDR proteins in LSC and relate it to the clinical outcome.

Megakaryocytopoiesis in patients with myelodysplastic syndromes (MDS) with and without del(5q)

To the editor: Juvonen et al. (1) published the results of a study on megakaryocytic colony formation by marrow progenitors of 40 patients with MDS. Megakaryocyte colonies were decreased in number or absent in 30 patients. There was no obvious correlation between megakaryocyte colony formation with any specific chromosomal abnormality, in particular, out of 5 MDS patients with del(5q), 2 had normal megakaryocyte growth, 2 had decreased number of colonies, and 1 exhibited no colony growth. 4 of these 5 patients had normal platelet count. We examined colony-forming units-megakaryocyte (CFU-Mk) in 10 consecutively admitted MDS patients, 4 females and 6 males, aged from 57 to 85 yr (mean 69.5), 4 with refractory anaemia (RA), 3 with refractory anaemia with excess of blasts (RAEB) and 3 with sideroblastic anaemia (SA). Serving as control were 10 normal subjects, 5 females and 5 males, aged from 30 to 67 yr (mean 54.8). CFU-Mk assay was based on the method of Messner et al. (2). The study was performed at the Dept. of Haematology, University of Wales, College of Medicine, Cardiff, U.K. and the project was approved by the South Glamorgan Joint Committee. As shown in Table 1, all MDS patients had defective megakaryocytic colony formation and 5 of them did not show any CFU-Mk growth when MDS plasma was added to the cultures. The present results confirm our previous observation that the number of CFU-Mk from normal marrow was significantly lower when stimulated by MDS plasma than by normal plasma (3). 4 of our 5 MDS patients who did not grow CFU-Mk had a clonal del(5q), 3 patients (Nos. 4,6 and 10) showed the classic deletion of q13-33, and the 4th case (No. 5) had a minor deletion affecting q12-13. Their megakaryocyte number varied from 0.16 to 0.20% with a high proportion of immature megakaryocytes but in all of these patients the platelet count remained normal. It seems that our MDS patients with del (5q) had a greater failure of CFU-Mk growth than patients without this chromosomal abnormality. Although it is now known that the affected segment of chromosome 5q contains the genes for interleukin-3 (IL-3) (4), granulocyte/macrophage colony stimulating factor (GM-CSF) and human c-fms protooncogene (FMS) (5), the role of del(5q) in dysmegakaryocytopoiesis in MDS is not clear.