Search

Disease relapse is an important problem after allogeneic stem cell transplantations in multiple myeloma (MM). To test the hypothesis that natural killer (NK) cell alloreactivity in the setting of a haploidentical stem cell transplantation (haploSCT) can reduce the risk of myeloma relapse, we performed a small prospective phase 2 study in which we transplanted poor-risk MM patients using a killer cell immunoglobulin-like receptor (KIR)-ligand mismatched haploidentical donor. Patients received bone marrow grafts after reduced-intensity conditioning, with post-transplantation cyclophosphamide (PTCY) graft-versus-host-disease (GVHD) prophylaxis. The primary endpoint was 1.5-year progression-free survival (PFS); stopping rules were installed in case interim results made a benefit of 50% PFS at 1.5 years unlikely. After inclusion of 12 patients, of which 9 were evaluable for the primary endpoint, all patients relapsed within a median time of 90 days. All except 1 patient showed engraftment, with a median time to neutrophil recovery of 18 (12–30) days. The study was prematurely terminated based on the predefined stopping rules after the inclusion of 12 patients. With this small study, we show that in chemo-resistant myeloma patients, NK cell KIR-mismatch is not superior to conventional alloSCT. This strategy, however, can serve as a platform for new treatment concepts. Clinical Trial Registry: NCT02519114 [ABSTRACT FROM AUTHOR]

We designed a study to describe the incidence of intracranial hemorrhage according to severity and duration of thrombocytopenia and to quantify the associations of platelet transfusions with intracranial hemorrhage in patients with acute leukemia. In this case-control study nested in a cohort of 859 leukemia patients, cases (n = 17) were patients diagnosed with intracranial hemorrhage who were matched with control patients (n = 55). We documented platelet counts and transfusions for seven days before the intracranial hemorrhage in cases and in a "matched" week for control patients. Three measures of platelet count exposure were assessed in four potentially important time periods before hemorrhage. Among these leukemia patients, we observed the cumulative incidence of intracranial hemorrhage of 3.5%. Low platelet counts were, especially in the three to seven days preceding intracranial hemorrhage, associated with the incidence of intracranial hemorrhage, although with wide confidence intervals. Platelet transfusions during the week preceding the hemorrhage were associated with higher incidences of intracranial hemorrhage; rate ratios (95% confidence interval) for one or two platelet transfusions and for more than two transfusions compared with none were 4.04 (0.73 to 22.27) and 8.91 (1.53 to 51.73) respectively. Thus, among acute leukemia patients, the risk of intracranial hemorrhage was higher among patients with low platelet counts and after receiving more platelet transfusions. Especially, the latter is likely due to clinical factors leading to increased transfusion needs. [ABSTRACT FROM AUTHOR]

Hereditary cerebral haemorrhage with amyloidosis, Dutch type (HCHWA-D), caused by a mutation at codon 693 in the amyloid β precursor protein (βPP) gene, is clinically characterised by haemorrhagic strokes and dementia. The secreted forms βPP751 and βPP770 are identical to protease nexin II (PNII), which is a potent inhibitor of intrinsic blood coagulation factor XIa in vitro. We investigated the concentration of complexes between factor XIa and βPP in vivo, to search for a possible cause of the haemorrhagic strokes in HCHWA-D. In this prospectively designed study, first an enzyme-linked immunosorbent assay (ELISA) was performed with dilutions of the factor XIa-βPP complexes prepared from platelets as a standard curve. By means of this ELISA, the concentration of factor XIa-βPP complexes was measured in plasma samples. Second, plasma of 23 HCHWA-D patients and 23 healthy controls was collected, and the concentration of complexes was measured with this method. The mean concentration of factor XIa-βPP complexes in plasma of HCHWA-D patients (mean 13.73 U/ ml; SD 4.78) was significantly ( P = 0.05) higher than the concentration in plasma of healthy controls (mean 11.37; SD 2.77). The differences, however, were small and there was a major overlap between the concentrations in patients and controls. In HCHWA-D mutation carriers, the concentration of factor XIa-βPP complexes was not related to age, and there was no difference between presymptomatic and symptomatic mutation carriers. From this study, it can be concluded that βPP forms complexes with factor XIa in vivo both in HCHWA-D patients and in normal controls. The concentration in HCHWA-D patients was higher. This is probably the result of diffusion of complexes from the cerebral circulation into plasma. Elevated βPP in cerebrovascular amyloid deposits is possibly a local factor contributing to the development of haemorrhagic strokes. [ABSTRACT FROM AUTHOR]