Disease management of patients with immune thrombocytopenia-results of a representative retrospective survey in Germany.

Clinical research has resulted in an improvement of treatment options for patients with immune thrombocytopenia (ITP) over the last years. However, only few data exist on the real-life management of patients with ITP. To expand the knowledge, a multicenter, national survey was undertaken in 26 hematology practices distributed all over Germany. All patients with a diagnosis of ITP were documented using questionnaires, irrespective of the diagnosis date over a period of 2 years. Overall, data of 1023 patients were evaluated with 56% of patients being older than 60 years. Seventy-nine percent of the patients had chronic (> 12 months), 16% persistent (> 3-12 months), and 5% newly diagnosed (0-3 months) ITP. In 61% of cases, the disease lasted 3 or more years before survey documentation started. Main strategies applied as first-line therapy consisted of steroids in 45% and a "watch and wait" approach in 41% of patients. During second- and third-line strategies, treatment with steroids decreased (36% and 28%, respectively), while treatment modalities such as TPO-RAs increased (19% and 26%, respectively). As expected, patients with a low platelet count and thus a higher risk for bleeding and mortality received treatment (esp. steroids) more frequently during first line than those with a higher platelet count. Up to a third of patients were treated with steroids for more than a year. Overall, our study provides a cross-section overview about the current therapeutic treatment landscape in German ITP patients. The results will help to improve therapeutic management of ITP patients.

Successful Use of Eltrombopag in a Young Child With Chronic Immune Thrombocytopenia.

The disease course in a young girl with chronic immune thrombocytopenia (ITP) at the initial age of 19 months, treated with eltrombopag, was evaluated retrospectively and is presented as a case record and discussed against the background of the available literature. A stable response and reduction in clinical symptoms, over several years and without frequent dose changes, was achieved. Bleeding symptoms were mild to moderate and occurred particularly frequently in combination with low platelet counts. Raising the platelet count, in turn, was accompanied by a decreased bleeding tendency. Eltrombopag was tolerated well. No new safety signals were observed during the treatment. Based on a follow-up of more than 2.5 years, our case confirms that a child with chronic ITP can benefit from treatment with eltrombopag in the regular care setting. We assume that early treatment with a thrombopoietin receptor agonist could save many children from repeated and lengthy hospitalizations with intravenous immunoglobulins and prolonged administration of corticosteroids.

Mouse neutrophilic granulocytes express mRNA encoding the macrophage colony-stimulating factor receptor (CSF-1R) as well as many other macrophage-specific transcripts and can transdifferentiate into macrophages in vitro in response to CSF-1.

The differentiation of macrophages from their progenitors is controlled by macrophage colony-stimulating factor (CSF-1), which binds to a receptor (CSF-1R) encoded by the c-fms proto-oncogene. We have previously used the promoter region of the CSF-1R gene to direct expression of an enhanced green fluorescent protein (EGFP) reporter gene to resident macrophage populations in transgenic mice. In this paper, we show that the EGFP reporter is also expressed in all granulocytes detected with the Gr-1 antibody, which binds to Ly-6C and Ly-6G or with a Ly-6G-specific antibody. Transgene expression reflects the presence of CSF-1R mRNA but not CSF-1R protein. The same pattern is observed with the macrophage-specific F4/80 marker. Based on these findings, we performed a comparative array profiling of highly purified granulocytes and macrophages. The patterns of mRNA expression differed predominantly through granulocyte-specific expression of a small subset of transcription factors (Egr1, HoxB7, STAT3), known abundant granulocyte proteins (e.g., S100A8, S100A9, neutrophil elastase), and specific receptors (fMLP, G-CSF). These findings suggested that appropriate stimuli might mediate rapid interconversion of the major myeloid cell types, for example, in inflammation. In keeping with this hypothesis, we showed that purified Ly-6G-positive granulocytes express CSF-1R after overnight culture and can subsequently differentiate to form F4/80-positive macrophages in response to CSF-1.

Epigenetic regulation of the dendritic cell-marker gene ADAM19.

Human ADAM19 (MADDAM) is a molecular marker for human dendritic cells and not expressed in macrophages. To investigate its cell-type-specific expression, we defined the transcriptional start site and the proximal promoter. Sequence analysis of the promoter revealed putative binding sites for several transcription factors including Sp1, Sp3, NF-kappaB, and VDR. A minimal promoter construct of 150 bp showed little difference in reporter activity between macrophages and dendritic cells. Transfection of monocytic THP-1 with the 150-bp fragment also resulted in significant reporter activity, despite the lack of endogenous MADDAM expression. TSA, a known inhibitor of histone deacetylation, led to a dose-dependent induction of MADDAM mRNA in THP-1. ChIP assays demonstrated high levels of acetylated histone H3 in the proximal promoter region of the MADDAM gene in TSA-treated THP-1 cells and dendritic cells as compared to macrophages, indicating an important role of histone acetylation in the regulation of the MADDAM gene.

Regulation of 25-hydroxyvitamin D3-1 alpha-hydroxylase and production of 1 alpha,25-dihydroxyvitamin D3 by human dendritic cells.

25-Hydroxyvitamin D3-1 alpha-hydroxylase (25(OH)D3-1 alpha-hydroxylase), the key enzyme of 1 alpha,25-dihydroxyvitamin D3 (1,25(OH)2D3) production, is expressed in monocyte-derived macrophages (MACs). Here we show for the first time constitutive expression of 25(OH)D3-1 alpha-hydroxylase in monocyte-derived dendritic cells (DCs), which was increased after stimulation with lipopolysaccharide (LPS). Accordingly, DCs showed low constitutive production of 1,25(OH)2D3, but activation by LPS increased 1,25(OH)2D3 synthesis. In addition, 25(OH)D3-1 alpha-hydroxylase expression was found in blood DCs but not in CD34+-derived DCs. Next we analyzed the functional consequences of these results. Addition of 1,25(OH)2D3 at concentrations comparable with those produced by DCs inhibited the allostimulatory potential of DCs during the early phase of DC differentiation. However, terminal differentiation decreased the responsiveness of DCs to 1,25(OH)2D3. In conclusion, DCs are able to produce 1,25(OH)2D3 especially following stimulation with LPS. Terminal maturation renders DCs unresponsive to the effects of 1,25(OH)2D3, but those cells are able to suppress the differentiation of their own precursor cells in a paracrine way through the production of 1,25(OH)2D3.