ABSTRACT
BACKGROUND AND PURPOSE: Leukoerythroblastic reaction (LER) is characterized by the presence of immature erythroid cells and myeloid precursors (metamyelocytes, myelocytes, promyelocytes, myeloblasts, and blasts) as well as, exclusively in myelofibrotic disorders, teardrop cells in the peripheral blood (J Pathol Bacteriol, 42, 1936, 541; Semaine Med, 22, 1902, 373). Research on how to interpret LER and its meaning in clinical practice is scarce, and there is no consensus on the diagnostic criteria. We summarize the current evidence with the aim of clarifying the knowledge on this subject. METHODS: We conducted a comprehensive search of the PubMed-MEDLINE, EMBASE and ELSEVIER databases, the Cochrane Library, Google Scholar, and medical journals to identify relevant papers. RESULTS: Our search identified 425 papers, of which, 35 (11 trials and 24 case reports) ultimately met the inclusion criteria. These showed two principal groups of diseases associated with leukoerythroblastosis (LEB), corresponding to solid and hematological malignancies. The other etiologies, in order of frequency, were hemolytic diseases, infection, and others, while hemorrhage was only reported in the trials group. CONCLUSION: The literature on LER is scarce and heterogeneous. The etiological factors of LER are diverse, and its presence in malignant disease is an indicator of disease progression and an adverse prognosis suggesting poor survival. In those cases where LER had neither hematological nor solid neoplasms, its manifestation, prognosis and its impact on our daily clinical practice are unknown.
Subject(s)
Disease Susceptibility , Erythroid Cells/pathology , Leukocytes/pathology , Myeloproliferative Disorders/diagnosis , Myeloproliferative Disorders/etiology , Animals , Disease Management , Humans , Medical History Taking , Myeloproliferative Disorders/therapyABSTRACT
If cultured in appropriate conditions, such as supplementing culture media with costly cytokines and growth factors, hematopoietic stem/progenitor cells (HSPCs) from different origins have shown to be an adequate source of erythroid cells. This requirement turns erythroid cells production into a complicated process to be scaled-up for future applications. The aim of our work was to genetically modify HSPCs with human erythropoietin (hEPO) sequence by lentiviral transgenesis in order for cells to secrete the hormone into the culture medium. Initially, we evaluated erythroid differentiation in colony forming units (CFU) assays and further analyzed cell expansion and erythroid differentiation throughout time in suspension cultures by flow cytometry and May-Grünwald-Giemsa staining. Additionally, we studied hEPO production and its isoforms profile. The different assessment approaches demonstrated erythroid differentiation, which was attributed to the hEPO secreted by the HSPCs. Our data demonstrate that it is possible to develop culture systems in which recombinant HSPCs are self-suppliers of hEPO. This feature makes our strategy attractive to be applied in biotechnological production processes of erythroid cells that are currently under development.
Subject(s)
Cell Culture Techniques/methods , Cell Differentiation/genetics , Erythroid Cells/cytology , Erythropoietin/genetics , Erythropoietin/metabolism , Hematopoietic Stem Cells/cytology , Hematopoietic Stem Cells/metabolism , Lentivirus/genetics , Biotechnology/methods , Cells, Cultured , Colony-Forming Units Assay , Erythroid Cells/metabolism , Erythropoietin/biosynthesis , Erythropoietin/chemistry , Humans , Lentivirus/metabolismABSTRACT
Properly metabolized globin synthesis and iron uptake are indispensable for erythroid cell differentiation and maturation. Mitochondrial participation is crucial in the process of haeme synthesis for cytochromes and haemoglobin. We studied the final biosynthesis site of haemoglobin using an ultrastructural approach, with erythroid cells obtained from rabbit embryos, in order to compare these results with those of animals treated with saponine or phenylhydrazine. Our results are similar to those obtained in assays with adult mammals, birds, amphibians, reptiles and fish, after induction of haemolytic anaemia. Therefore, the treatment did not interfere with the process studied, confirming our previous findings. Immunoelectron microscopy showed no labelling of mitochondria or other cellular organelles supposedly involved in the final biosynthesis of haemoglobin molecules, suggesting instead that it occurs free in the cytoplasm immediately after the liberation of haeme from the mitochondria, by electrostatic attraction between haeme and globin chains.