The model allows the identification of female donors who eventually have a significant risk of harvest failure if requested to donate for recipients with a high body weight.

This study was conducted to characterize and compare peripheral blood stem cell grafts from healthy donors who underwent granulocyte colony-stimulating factor (G-CSF) mobilization and subsequently received 1 dose of plerixafor after insufficient stem cell yields were achieved at the first apheresis. Aliquots from 35 donors were collected from the first apheresis after mobilization with G-CSF alone and from the second apheresis after additional plerixafor administration. Samples were freshly analyzed for cellular subsets by 8-color flow cytometry. Leukapheresis samples mobilized with additional plerixafor showed a significant increase of total nucleated cells, including B cells, CD4 and CD8 T cells, and CD34 hematopoietic stem and progenitor cells. Absolute numbers of plasmacytoid dendritic cells were also significantly increased, whereas no changes were detected for myeloid dendritic cells. Furthermore, absolute numbers of regulatory T cells increased, with naive CD45RA regulatory T cells showing the highest rise. Finally, strikingly higher numbers of myeloid-derived suppressor cells were detected in the plerixafor and G-CSF-mobilized graft. The mobilization of peripheral stem cells in healthy donors with G-CSF and plerixafor led to a significant difference in cellular graft composition compared with G-CSF alone. The clinical impact of the different cell composition for the graft recipient warrants further clinical investigation.

Inflammation plays an important role in CAR-T-cell therapy, especially in the pathophysiology of cytokine-release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). Clonal hematopoiesis of indetermined potential (CHIP) has also been associated with chronic inflammation. The relevance of CHIP in the context of CAR-T-cell treatment is currently widely unknown. We longitudinally evaluated the prevalence of CHIP, using a targeted deep sequencing approach in a cohort of patients with r/r B-NHL before and after CAR-T-cell treatment. The aim was to define the prevalence and variation of CHIP over time and to assess the influence on clinical inflammation syndromes (CRS/ICANS), cytopenia and outcome. Overall, 32 patients were included. CHIP was found in 11 of 32 patients (34 %) before CAR-T-cell therapy. CHIP progression was commonly detected in the later course. Patients with CHIP showed a comparable response rate to CAR-T-cell treatment but had an improved OS (not reached vs. 265 days, p=0.003). No significant difference was observed in terms of the occurrence and severity of CRS/ICANS, therapeutic usage of tocilizumab and glucocorticosteroids, paraclinical markers of inflammation (except ferritin) or dynamics of hematopoietic recovery. CHIP is commonly observed in patients undergoing CD19-directed CAR-T-cell therapy and is not associated with an inferior outcome.