Differences in the Differentiation Potential and Relative Levels of Gene Expression in the Bone Marrow-Derived Fibroblast Colony-Forming Units in Patients during the Onset of Aplastic Anemia Depending on the Disease Severity.

The differentiation potential of individual clones of fibroblast CFU (CFU-F) was studied and the relative expression level of genes was analyzed in the culture of CFU-F from the bone marrow in patients with non-severe and severe forms of aplastic anemia at the onset of the disease. The differentiation potential of CFU-F clones was determined by the relative expression of marker genes using quantitative PCR. In aplastic anemia, the ratio of CFU-F clones with different differentiation potential changes, but the molecular mechanisms of this phenomenon are different in non-severe and severe aplastic anemia. In the culture of CFU-F in non-severe and severe aplastic anemia, the relative expression level of genes associated with the maintenance of the hematopoietic stem cell in the bone marrow niche changes, but the decrease in the expression of immunoregulatory genes occurs in severe form only, which may reflect differences in the pathogenesis of non-severe and severe aplastic anemia.

Bone Marrow Multipotent Mesenchymal Stromal Cells from Patients with Aplastic Anemia Retain Their Ability to Support Hematopoietic Precursors despite Pronounced Changes in Gene Expression.

The properties of bone marrow-derived multipotent mesenchymal stromal cells (MSC) of patients with aplastic anemia at the onset of the disease are studied insufficiently. The aim of this work was to test the ability of MSC from patients with aplastic anemia to maintain hematopoietic precursors and to analyze the expression of genes associated with hematopoiesis and immune response. The ability of MSC to maintain hematopoietic precursors was determined by counting cobblestone area-forming cells; gene expression was analyzed by quantitative PCR. It was shown that MSC of patients with aplastic anemia preserve their ability to maintain hematopoietic precursors. Pronounced changes in the expression of the VEGFA and ANGPT1 genes were found. MSC from aplastic anemia patients with PNH clone significantly differ from those from aplastic anemia patients without PNH clone in terms of the expression of the SDF1, IL1R, and VEGFA genes. Changes in gene expression can be associated with the pathogenesis of the disease.

Comparison of polymerase chain reaction and flow cytometry for measuring telomere length of human leukocytes.

Telomere length can be measured by polymerase chain reaction (PCR), allowing to obtain the absolute length of telomeres (ALT) in base pair, and by flow cytometry, which can only estimate the relative telomere length. The aim of the study was to compare the results of the two methods and to develop an accurate and reliable way of converting the relative telomere length to absolute. The peripheral blood from 21 donors was analyzed. Measurement of leukocyte telomere length by flow cytometry was carried out using a commercial Telomere PNA Kit / FITC (Dako, Denmark) with two CytoFLEX flow cytometers (Beckman Coulter, China) and BD FACSCanto II (Becton Dickinson, USA), obtaining the molecular equivalent of fluorescence (MEF). To measure telomere length by real-time PCR, calibrators with a known number of telomeric repeats were prepared. Two quantitative PCRs were carried out: one for telomeric repeats, the other for determining the number of genome-equivalents of DNA, three times for each sample, which made it possible to calculate ALT. A strong direct relationship was found between the MEF obtained with BD FACSCanto II and CytoFLEX (r = 0.97). Analysis of PCR and flow cytometry results showed a significant correlation between ALT and MEF. We calculated the regression equations of ALT and MEF for CytoFLEX - y = 0.0043x (r = 0.84) and for BD FACSCanto II - y = 0.0051x (r = 0.82). Correlation analysis showed a high comparability of telomere lengths measured by two methods. The obtained regression equations allow converting the results of flow cytometry into absolute values, allowing the comparison of the results of different research groups and the use of this method in clinical trials.

[A case report of familial dyskeratosis congenital. Case report].

Dyskeratosis congenita (DC) is a hereditary syndrome of bone marrow failure, which develops because of telomeres defects and combines with cancer predisposition. Its classical clinical features are skin pigmentation, nail dystrophy, oral leukoplakia (skin-mucosa triad). The goal is to describe the algorithm of diagnosis, clinical specificities of DC and specific treatment for cases of DC in one family. The present report includes descriptions of diagnosis and treatment of family members diagnosed for the first time as having a DC. The report shows an importance of all diagnostic stages: from a medical history and clinical picture to an application of modern high-tech diagnostic methods (flow-FISH, NGS). The report underlines an importance of diagnosis of all family members for excluding an asymptomatic form after a case of DC has been already detected in that family. A high frequency of a toxicity and secondary neoplasia makes it necessary to realize an individual approach at treatment of each patient with DC (the earliest start of androgen treatment, prompt decision of implementation of allogenic hematopoietic stem cell transplantation). The knowledge of pathogenesis, clinical features and principles of diagnosis and therapy of this disease is relevant to pediatricians and hematologists.

[Immunosupressive therapy of aplastic anemia patients: successes and failures (single center experiment 2007-2016)].

Treatment programs for patients with acquired aplastic anemia include two main therapeutic options: allogeneic bone marrow transplantation and combined immunosuppressive therapy (IST). However, combined IST remains the method of choice for most adult AA patients. This study included 120 AA patients who received IST at the National Research Center for Hematology in 20072016. The analysis was applied to 120 patients. Median age was 25 (1765) years, M/F: 66/54, SAA/NSAA: 66%/34%. Effectiveness of IST was carried out in 120 patients with AA. This group did not include 8 SAA patients who died during the first 3 months from the start of treatment from severe infectious complications (early deaths 6.2%) and 2 AA patients who dropped out of surveillance. The observation time was 55 (6120) months. Paroxysmal nocturnal hemoglobinuria (PNH clone) was detected in 67% of AA patients. The median PNH clone size (granulocytes) was 2.5 (0.0199.5)%. The treatment was according to the classical protocol of combined IST: horse antithymocytic globulin and cyclosporin A. Most of patients (87%) responded to combined immunosuppressive therapy. To achieve a positive response, it was sufficient to conduct one course of ATG to 64% of patients, two courses of ATG 24% of patients and 2% of patients responded only after the third course of ATG. A positive response after the first course was obtained in 64% of patients included in the analysis. Most of the responding patients (93%) achieve a positive response after 36 months from the start of treatment. Therefore, the 3rd6th months after the first course of ATG in the absence of an answer to the first line of therapy can be considered the optimal time for the second course of ATG. This tactic allows to get an answer in another 58% of patients who did not respond to the first course of ATG. The probability of an overall 10-year survival rate was 90% (95% confidence interval 83.696.2).