Babesiosis and Sickle Red blood Cells: Loss of Deformability, Heightened Osmotic fragility, and Hypervesiculation.

Babesiosis in sickle cell disease (SCD) is marked by severe anemia but the underlying red blood cell (RBC) rheological parameters remain largely undefined. Here, we describe altered RBC deformability from both primary (host RBC sickle hemoglobin mediated) and secondary changes (Babesia parasite infection mediated) to the RBC membrane using wild type AA, sickle trait AS and sickle SS RBCs. Our ektacytometry (LORRCA) analysis demonstrates that the changes in the host RBC bio-mechanical properties, pre- and post- Babesia infection, reside on a spectrum of severity, with wild type infected AA cells, despite showing a significant reduction of deformability under both shear and osmolarity gradients, exhibiting only a mild phenotype; compared to infected AS RBCs which show median changes in deformability and infected SS RBCs which exhibit the most dramatic impact of infection on cellular rheology, including an increase in Point of Sickling values.

Sex dimorphism in the mouse bone marrow niche regulates hematopoietic engraftment via sex-specific Kdm5c/Cxcl12 signaling.

The bone marrow (BM) niche is critical in regulating hematopoiesis, and sexual dimorphism and its underlying mechanism in BM niche and its impact on hematopoiesis are not well understood. We show that male mice exhibited a higher abundance of leptin-receptor-expressing mesenchymal stromal cells (LepR-MSCs) compared to female mice. Sex-mismatched co-culture and BM transplantation showed that the male BM niche provided superior support for in vitro colony formation and in vivo hematopoietic engraftment.

IFN-I promotes T-cell-independent immunity and RBC autoantibodies via modulation of B-1 cell subsets in murine SCD.

The pathophysiology of sickle cell disease (SCD) is characterized by hemolytic anemia and vaso-occlusion, although its impact on the adaptive immune responses remains incompletely understood. To comprehensibly profile the humoral immune responses, we immunized SCD mice with T-cell-independent (TI) and T-cell-dependent (TD) antigens (Ags). Our study showed that SCD mice have significantly enhanced type 2 TI (TI-2) immune responses in a manner dependent on the level of type I interferons (IFN-I), while maintaining similar or decreased TD immune responses depending on the route of Ag administration.

Supportive care strategies in myelodysplastic syndromes and acute myeloid leukemia in older adults: a national survey of Canadian hematologists.

Myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) are severe myeloid disorders associated with significant morbidity and mortality. Because of patient and disease factors, many older adults are treated as outpatients with less-intensive therapy. Optimal supportive care strategies to minimize bleeding and infectious complications in this patient population have not been systematically evaluated.