Primary Sjögren syndrome complicated by autoimmune hemolytic anemia and pure red cell aplasia.

Patients with primary Sjögren syndrome frequently present hematologic abnormalities, consisting mainly of immune cytopenias. Pure red cell aplasia is a very rare complication of primary Sjögren syndrome. This is the first report in the literature describing the development of pure red cell aplasia combined with autoimmune hemolytic anemia in a 74-year-old woman with primary Sjögren syndrome.

A case of severe sinus bradycardia complicating anicteric leptospirosis.

A potential complication of leptospirosis is cardiovascular involvement. Electrocardiographic abnormalities are frequent. Leptospirosis has been reported to be one of the infectious causes of relative bradycardia, but severe absolute sinus bradycardia has been rarely described as a potential electrocardiographic alteration.

Expression and inducibility of cytoprotective heat shock proteins in the bone marrow of patients with myelodysplastic syndrome: correlation with disease progression.

We determined the intracellular expression and inducibility of heat shock proteins (Hsps) 72, 73 and 27 in the bone marrow of patients with myelodysplastic syndrome (MDS) and controls. Hsps were overexpressed in MDS marrow especially in advanced disease, providing resistance to induction of apoptosis. These data suggest that Hsps could be implicated in the progression of MDS to acute myeloid leukemia.

A probable role for trail-induced apoptosis in the pathogenesis of marrow failure. Implications from an in vitro model and from marrow of aplastic anemia patients.

Aplastic anemia (AA) is a syndrome of hematopoietic failure involving increased apoptosis of stem cells. In order to investigate the molecular mechanisms participated in the process of marrow failure, we created an in vitro model of hematopoietic cell suppression, by continuous addition of TNF-alpha and IFN-gamma in an vitro long-term bone marrow culture system. An up-regulation of Fas expression was observed in CD34+ cells in cytokine treated cultures, compared to controls.

Defective tumor necrosis factor alpha-induced maturation of monocyte-derived dendritic cells in patients with myelodysplastic syndromes.

Myelodysplastic syndromes (MDS) are clonal stem cell disorders, characterized by ineffective and dysplastic hematopoiesis. MDS patients have a defective immune response manifested by increased susceptibility to bacterial infections, autoimmune phenomena, and high incidence of lymphoid malignancies. Presently, we investigated the phenotype and function of monocyte-derived dendritic cells (MoDC) in 23 MDS patients and 15 controls at different stages of differentiation using the maturation stimuli tumor necrosis factor-alpha (TNF-alpha) and LPS.

Impaired generation of bone marrow CD34-derived dendritic cells with low peripheral blood subsets in patients with myelodysplastic syndrome.

Myelodysplastic syndrome (MDS) is a stem cell disorder characterized by ineffective haematopoiesis and blood cytopenias. The present study investigated the potential of bone marrow CD34(+) progenitors in MDS patients to proliferate and differentiate into dendritic cells (DCs) in a cytokine-supplemented liquid culture system and analysed the status of blood DC subsets in these patients. CD34(+) progenitors had low potential to generate DCs in vitro, as the number of DCs obtained from one CD34(+) cell was significantly lower compared with controls (median value 0.

Impaired clonogenic growth of myelodysplastic bone marrow progenitors in vitro is irrelevant to their apoptotic state.

Excessive intramedullary apoptosis has been considered to account for the paradox of hypercellular marrow and refractory cytopenias in myelodysplastic syndrome (MDS). However, a causative relationship of apoptosis to the progenitor's defective clonogenic growth has not been sufficiently demonstrated. We investigated the degree of apoptosis and its contribution to ineffective hematopoiesis in MDS, by assessing the differential clonogenic capacity of purified "apoptotic" and "non-apoptotic" bone marrow progenitors in a short-term semisolid culture system.