Contributions
Abstract: EP584
Type: E-Poster Presentation
Session title: Bone marrow failure syndromes incl. PNH - Biology & Translational Research
Background
Acquired idiopathic neutropenia is a rare disorder associated with impaired proliferation and differentiation of neutrophil precursors. The stromal microenvironment plays an important role in the regulation of the maturation of granulocyte colony-forming units (CFU-G). The bone marrow stroma regulates hematopoiesis locally in hematopoietic niches and by producing cytokines and growth factors in normal conditions and in various hematologic diseases. Thus, the efficiency of hematopoiesis directly depends on the functional state of the mesenchymal stromal cells (MSC) of the bone marrow. The study of the mechanisms of interaction and ways of regulating of the development hematopoietic and stromal cells` is necessary to establish the hypoplastic variant of neutropenia.
Aims
To assess the cytokine-producing ability of MSC of the bone marrow in patients with hypoplastic neutropenia.
Methods
The bone marrow of 17 patients with neutropenia at the age from 2.5 to 17 (median - 9.5) years was researched. The determination of the proliferative potential and differentiation ability of the bone marrow was carried out by counting the CFU-G formed in a 14-day culture based on the morphological recognition of their cellular elements. Cultivation of MSC carried out on the surface of plastic flasks under conditions of 5% carbon dioxide at a temperature of 37 ° C. The levels of interleukins (IL) -1β, -2, -6, tumor necrosis factor α (TNFα) and transforming growth factor β (TGFβ) determined by enzyme-linked immunosorbent assay in supernatants of MSC cultures
Results
In 13 of 17 (76.5%) patients the content CFU-G was decreased to 20-60 (with a normal range of 70-350) per 1x106 nuclear cells. It made it possible to establish a hypoplastic variant of neutropenia. The absolute content of neutrophils of peripheral blood in these patients was 170-1325 (Me = 920) in 1 μl. There was no significant correlation between the number of bone marrow CFU-G and the level of neutrophils in the peripheral blood (Pearson's correlation coefficient r = 0.07). The levels of MSC cytokine production were: IL-1β 0.49-0.82 (Me = 0.70) pg / ml / day, IL-2 0.369-1.591 (Me = 0.589) pg / ml / day, IL-6 87.7-127.3 (Me = 108.0) pg / ml / day, TGFβ 5.26-28.91 (Me = 13.76) pg / ml / day. An inverse relationship between the number of CFU-G and the concentration of IL-1β, IL-6 and TGFβ was found (r = -0.59, -0.84, -0.50, respectively). The correlation coefficient between the production of IL-2 MSCs, TGFβ and the content of neutrophils in peripheral blood was -0.66 and 0.50, respectively.
Conclusion
A cultural research of the myeloid lineage of the bone marrow and the stromal microenvironment with an assessment of the functional activity of MSC is an important part of diagnostic of a hypoplastic variant of neutropenia. The depth of CFU-G decreasing is associated with the level of secretion IL-1β, IL-6 and TGFβ by of MSC, and neutrophil quantity – IL-2 and TGFβ.
Keyword(s): Chemokine, Mesenchymal cells, Neutropenia
Abstract: EP584
Type: E-Poster Presentation
Session title: Bone marrow failure syndromes incl. PNH - Biology & Translational Research
Background
Acquired idiopathic neutropenia is a rare disorder associated with impaired proliferation and differentiation of neutrophil precursors. The stromal microenvironment plays an important role in the regulation of the maturation of granulocyte colony-forming units (CFU-G). The bone marrow stroma regulates hematopoiesis locally in hematopoietic niches and by producing cytokines and growth factors in normal conditions and in various hematologic diseases. Thus, the efficiency of hematopoiesis directly depends on the functional state of the mesenchymal stromal cells (MSC) of the bone marrow. The study of the mechanisms of interaction and ways of regulating of the development hematopoietic and stromal cells` is necessary to establish the hypoplastic variant of neutropenia.
Aims
To assess the cytokine-producing ability of MSC of the bone marrow in patients with hypoplastic neutropenia.
Methods
The bone marrow of 17 patients with neutropenia at the age from 2.5 to 17 (median - 9.5) years was researched. The determination of the proliferative potential and differentiation ability of the bone marrow was carried out by counting the CFU-G formed in a 14-day culture based on the morphological recognition of their cellular elements. Cultivation of MSC carried out on the surface of plastic flasks under conditions of 5% carbon dioxide at a temperature of 37 ° C. The levels of interleukins (IL) -1β, -2, -6, tumor necrosis factor α (TNFα) and transforming growth factor β (TGFβ) determined by enzyme-linked immunosorbent assay in supernatants of MSC cultures
Results
In 13 of 17 (76.5%) patients the content CFU-G was decreased to 20-60 (with a normal range of 70-350) per 1x106 nuclear cells. It made it possible to establish a hypoplastic variant of neutropenia. The absolute content of neutrophils of peripheral blood in these patients was 170-1325 (Me = 920) in 1 μl. There was no significant correlation between the number of bone marrow CFU-G and the level of neutrophils in the peripheral blood (Pearson's correlation coefficient r = 0.07). The levels of MSC cytokine production were: IL-1β 0.49-0.82 (Me = 0.70) pg / ml / day, IL-2 0.369-1.591 (Me = 0.589) pg / ml / day, IL-6 87.7-127.3 (Me = 108.0) pg / ml / day, TGFβ 5.26-28.91 (Me = 13.76) pg / ml / day. An inverse relationship between the number of CFU-G and the concentration of IL-1β, IL-6 and TGFβ was found (r = -0.59, -0.84, -0.50, respectively). The correlation coefficient between the production of IL-2 MSCs, TGFβ and the content of neutrophils in peripheral blood was -0.66 and 0.50, respectively.
Conclusion
A cultural research of the myeloid lineage of the bone marrow and the stromal microenvironment with an assessment of the functional activity of MSC is an important part of diagnostic of a hypoplastic variant of neutropenia. The depth of CFU-G decreasing is associated with the level of secretion IL-1β, IL-6 and TGFβ by of MSC, and neutrophil quantity – IL-2 and TGFβ.
Keyword(s): Chemokine, Mesenchymal cells, Neutropenia