Capture-based targeted sequencing using a T-cell control in myeloid malignancies and idiopathic cytopenias.

We report on a study of next-generation sequencing in 257 patients undergoing investigations for cytopenias. We sequenced bone marrow aspirates using a target enrichment panel comprising 82 genes and used T cells from paired blood as a control. One hundred and sixty patients had idiopathic cytopenias, 81 had myeloid malignancies and 16 had lymphoid malignancies or other diagnoses. Forty-seven of the 160 patients with idiopathic cytopenias had evidence of somatic pathogenic variants consistent with clonal cytopenias. Only 39 genes of the 82 tested were mutated in the 241 patients with either idiopathic cytopenias or myeloid neoplasms. We confirm that T cells can be used as a control to distinguish between germline and somatic variants. The use of paired analysis with a T-cell control significantly reduced the time molecular scientists spent reporting compared to unpaired analysis. We identified somatic variants of uncertain significance (VUS) in a higher proportion (24%) of patients with myeloid malignancies or clonal cytopenias compared to less than 2% of patients with non-clonal cytopenias. This suggests that somatic VUS are indicators of a clonal process. Lastly, we show that blood depleted of lymphocytes can be used in place of bone marrow as a source of material for sequencing.

Weekly intravenous bortezomib is effective and well tolerated in relapsed/refractory myeloma.

OBJECTIVES: Bortezomib is an effective antimyeloma therapy, but clinical benefits can be limited by neurotoxicity. In newly diagnosed, older patients, modification of the biweekly dosing schedule to weekly regimens improves tolerability whilst maintaining efficacy. There is less information on the efficacy and tolerability of weekly bortezomib regimens in the relapsed/refractory setting. Here, we report our experience of weekly intravenous bortezomib in clinical practice in relapsed/refractory patients. METHODS: We analysed fifty-two patients who received weekly bortezomib for relapsed/refractory MM. RESULTS: Thirty-one per cent of patients received bortezomib beyond first relapse. Almost all (94%) also received steroids and 48% also received an alkylator. The median cumulative dose was 22.6 mg/m(2) , and median length of treatment was 164 d. Three patients reported grade 2 sensory neuropathy, and one reported grade 3 motor neuropathy. There were no grade 4 neurotoxicities. Eighty-three per cent achieved a PR or greater, and the median PFS for the whole group was 13 months. One-year PFS and OS were 53% (95% CI 39-66.6%) and 78% (95% CI 66.7-89.6%), respectively. CONCLUSIONS: Weekly intravenous bortezomib when used in combination with steroids ± alkylator is effective in relapsed/refractory MM, producing outcomes comparable with biweekly regimens and with lower rates of peripheral neuropathy.

Human sickle cell blood modulates endothelial heme oxygenase activity: effects on vascular adhesion and reactivity.

OBJECTIVE: Sickle cell disease (SCD) is characterized by extensive hemolysis, increased cellular adhesion, and vaso-occlusion. Tissues from sickle patients express heme oxygenase-1 (HO-1), the enzyme that degrades free heme/hemoglobin to the signaling molecule carbon monoxide, and the antioxidants biliverdin/bilirubin. Here, we examined the HO response in endothelial cells exposed to human sickle blood and determined whether this response is beneficial for SCD. METHODS AND RESULTS: We measured HO activity in human and bovine aortic endothelial cells incubated with human sickle or normal blood. Sickle blood increased HO activity, which was enhanced by hypoxia and was caused mainly by the red cell components of sickle blood. Oxidized hemoglobin was higher in sickle blood and increased markedly over time. Interestingly, HO activity correlated inversely with patients' hemoglobin levels and positively with bilirubin and lactate dehydrogenase. HO-1 induction, exogenous biliverdin, or carbon monoxide markedly decreased adhesion of sickle blood to the endothelium, and sickle red cells partially inhibited relaxation mediated by carbon monoxide in isolated aortas. CONCLUSIONS: Our results highlight important associations between SCD and HO byproducts, which may counteract vascular complications of SCD.