Analysis of Brain, Blood, and Testis Phenotypes Lacking the Vps13a Gene in C57BL/6N Mice.

The Vps13a gene encodes a lipid transfer protein called VPS13A, or chorein, associated with mitochondria-associated endoplasmic reticulum (ER) membranes (MAMs), mitochondria-endosomes, and lipid droplets. This protein plays a crucial role in inter-organelle communication and lipid transport. Mutations in the VPS13A gene are implicated in the pathogenesis of chorea-acanthocytosis (ChAc), a rare autosomal recessive neurodegenerative disorder characterized by chorea, orofacial dyskinesias, hyperkinetic movements, seizures, cognitive impairment, and acanthocytosis. Previous mouse models of ChAc have shown variable disease phenotypes depending on the genetic background. In this study, we report the generation of a Vps13a flox allele in a pure C57BL/6N mouse background and the subsequent creation of Vps13a knockout (KO) mice via Cre-recombination. Our Vps13a KO mice exhibited increased reticulocytes but not acanthocytes in peripheral blood smears. Additionally, there were no significant differences in the GFAP- and Iba1-positive cells in the striatum, the basal ganglia of the central nervous system. Interestingly, we observed abnormal spermatogenesis leading to male infertility. These findings indicate that Vps13a KO mice are valuable models for studying male infertility and some hematological aspects of ChAc.

Primary prophylaxis with pegfilgrastim during the first cycle of R-CHOP to avoid reduction of dose intensity in elderly patients.

The long-term effects of pegfilgrastim administered in the first cycle of chemotherapy in day-to-day practice remain unclear. We retrospectively identified 114 patients aged ≥ 70 years with diffuse large B-cell lymphoma who received a rituximab-cyclophosphamide-doxorubicin-vincristine-prednisolone (R-CHOP) regimen in our institution. Twenty-six patients received pegfilgrastim (pegfilgrastim group); of the 88 patients scheduled to receive conventional granulocyte-colony stimulating factor (G-CSF) when their neutrophil count decreased (neut-adjusted-G group), conventional G-CSF was ultimately administered to 57. During the first cycle of R-CHOP, the incidence of febrile neutropenia was lower in the pegfilgrastim group than in the neut-adjusted-G group (0% vs. 18%, p = 0.020). Throughout all cycles, a higher proportion of patients exhibited sustained relative dose intensity (≥ 80%) in the pegfilgrastim group than in the neut-adjusted-G group (25% vs. 4.0%, p = 0.008). A lower proportion of patients received a reduced dose in the second cycle in the pegfilgrastim group than in the neut-adjusted-G group (0% vs. 10%, p = 0.116). Although the differences were not significant, the pegfilgrastim group showed higher progression-free survival and overall survival than the neut-adjusted-G group. Adequate prevention of febrile neutropenia using pegfilgrastim during the first cycle of R-CHOP may contribute to avoidance of dose intensity reduction in all cycles.

Romiplostim is effective for eltrombopag-refractory aplastic anemia: results of a retrospective study.

Eltrombopag (EPAG) and romiplostim (ROM), thrombopoietin receptor-agonists with demonstrated efficacy against aplastic anemia (AA) in prospective controlled studies, were authorized in Japan for use in adults with aplastic anemia in 2017 and 2019, respectively. So far, no data are available on the potential contribution of switching from ROM to EPAG or vice versa in terms of efficacy or tolerance. Efficacies and tolerance profiles of ten patients, who failed to respond to the maximum dose of EPAG and then switched to ROM, were evaluated. All ten patients received a maximum dose of ROM (20 µg/kg/week). At a median follow-up of twelve months, seven of ten patients (70%) had achieved either neutrophil, erythroid, or platelet response, including one complete response. No patients showed platelet count fluctuations that were reported during ROM treatment for immune thrombocytopenia. In univariate analysis of the relationship between efficacy and demographics, the response had a correlation with neither factors. None of the patients stopped the ROM treatment because of adverse events. Although a larger number of patients and a longer follow-up period are needed to confirm our findings, our results show the efficacy of ROM in patients with EPAG-refractory AA.