- TP53 loss induces therapy resistance by PDL1 expression on tumor cells and extracellular vesicles
- Review Series: immunotherapies for nonmalignant hematologic diseases
- Response-adapted salvage therapy for Hodgkin lymphoma with nivolumab with or without chemotherapy
- Biallelic TP53 loss promotes leukemia transformation in MPNs
- Role of zinc in thymic epithelial regeneration after murine hematopoietic stem cell transplant
- Modeling the impact of storage time of RBC units on adverse outcomes
Salvage therapy with NICE for Hodgkin lymphoma, BMP2/SMAD pathway activation in leukemic transformation, and the role of zinc in T-cell reconstitution after HSCT
In this week’s episode we’ll learn more about salvage therapy with nivolumab plus or minus ICE (or NICE) for Hodgkin lymphoma, discuss the role of BMP2/SMAD pathway activation in leukemic transformation, and learn more about the role of zinc in T-cell reconstitution after transplantation.
This Review Series, edited by past Associate Editor Catherine Bollard, looks at the role of immunotherapy in nonmalignant hematologic diseases. These 3 state-of-the-art reviews focus on the role of complement and complement inhibitors across a spectrum of diseases, the special immunologic challenges of hematopoietic stem cell transplant for nonmalignant diseases where patients have an intact immune system, and the hematologic complications of immune checkpoint inhibitors.
Response-adapted anti-PD-1–based salvage therapy for Hodgkin lymphoma with nivolumab alone or in combination with ICE
Mei and colleagues report on the results of positron emission tomography PET–adapted nivolumab (NIVO) alone or in combination with chemotherapy as first salvage therapy and bridge to autologous transplantation (ASCT) in 43 patients with relapsed/refractory Hodgkin lymphoma. Patients in complete remission by PET after 3 doses of NIVO went directly to ASCT; the remaining patients received salvage chemotherapy as a bridge to ASCT. Two-year progression–free survival (PFS) was 72% overall, with PFS of 95% of those who bridged directly to ASCT after NIVO.
Extracellular vesicles and PD-L1 suppress macrophages, inducing therapy resistance in TP53-deficient B-cell malignancies
Izquierdo and colleagues elucidate the mechanism of chemoimmunotherapy (CIT) resistance in B-cell malignancies with TP53 loss. They demonstrate that TP53 loss interferes in the crosstalk between tumor cells and macrophages by the upregulation of PD-L1 expression on the tumor cell surface and on secreted extracellular vesicles, leading to suppression of phagocytosis. Disruption of PD-L1 expression by antibodies or PD-L1 knockout improves phagocytosis and response to CIT.
BMP2/SMAD pathway activation in JAK2/p53-mutant megakaryocyte/erythroid progenitors promotes leukemic transformation
Leukemic transformation of myeloproliferative neoplasms (MPN) has a poor prognosis and is commonly associated with mutational inactivation of TP53. Li and colleagues demonstrate in mouse models and in primary cells that biallelic TP53 inactivation in the presence of JAK2V617F induces erythroleukemia associated with aberrant activation of the BMP2/SMAD pathway, recurrent copy number alterations, and DNA damage. These observations provide entry points for novel approaches to this lethal complication of MPN.
Activation of the zinc-sensing receptor GPR39 promotes T-cell reconstitution after hematopoietic cell transplant in mice
Immune reconstitution after hematopoietic stem cell transplant (HSCT) depends on thymic regeneration, a capacity that attenuates with age. Zinc has previously been shown to be important for normal T-cell development, but Iovino et al demonstrate a complex role for zinc in thymic repair following injury in mice. Zinc is released into the extracellular thymic milieu after HSCT conditioning, where it stimulates endothelial cell BMP4 release and thymic epithelial regeneration. The role of zinc supplementation in clinical HSCT remains to be investigated.