Haploidentical Stem Cell Transplantation With Post-Transplantation Cyclophosphamide for Aggressive Lymphomas: How Far Have We Come and Where Are We Going?

Is it time to reconsider prophylactic antimicrobial use for hematopoietic stem cell transplantation? a narrative review of antimicrobials in stem cell transplantation

INTRODUCTION

Hematopoietic Stem Cell Transplantation (HSCT) is a life-saving procedure for multiple types of hematological cancer, autoimmune diseases, and genetic-linked metabolic diseases in humans. Recipients of HSCT transplant are at high risk of microbial infections that significantly correlate with the presence of graft-versus-host disease (GVHD) and the degree of immunosuppression. Infection in HSCT patients is a leading cause of life-threatening complications and mortality.

AREAS COVERED

This review covers issues pertinent to infection in the HSCT patient, including bacterial and viral infection; strategies to reduce GVHD; infection patterns; resistance and treatment options; adverse drug reactions to antimicrobials, problems of antimicrobial resistance; perturbation of the microbiome; the role of prebiotics, probiotics, and antimicrobial peptides. We highlight potential strategies to minimize the use of antimicrobials.

EXPERT OPINION

Measures to control infection and its transmission remain significant HSCT management policy and planning issues. Transplant centers need to consider carefully prophylactic use of antimicrobials for neutropenic patients. The judicious use of appropriate antimicrobials remains a crucial part of the treatment protocol. However, antimicrobials' adverse effects cause microbiome diversity and dysbiosis and have been shown to increase morbidity and mortality.

Hematopoietic Stem Cell Transplantation in Egypt: Challenges and Opportunities

Hematopoietic stem cell transplantation (HSCT) is now an established treatment modality with definitive indications for many hematological disorders. However, HSCT requires tremendous resources, and it is increasingly challenging for transplantation experts to practice in the developing world and to reach a compromise between requirements and available resources. Based on 30 years of experience and 4256 transplants (60% allogeneic and 40% autologous), this article focuses on the challenges our HSCT program encountered since it started in 1989 and what opportunities we see to solve them. Since 1997, HSCT procedures increased dramatically with the opening of 15 HSCT units distributed all over Egypt.

GPRASP proteins are critical negative regulators of hematopoietic stem cell transplantation

Hematopoietic stem cell (HSC) transplantation (HSCT) is often exploited to treat hematologic disease. Donor HSCs must survive, proliferate, and differentiate in the damaged environment of the reconstituting niche. Illuminating molecular mechanisms regulating the activity of transplanted HSCs will inform efforts to improve HSCT. Here, we report that G-protein-coupled receptor-associated sorting proteins (GPRASPs) function as negative regulators of HSCT. Silencing of Gprasp1 or Gprasp2 increased the survival, quiescence, migration, niche retention, and hematopoietic repopulating activity of hematopoietic stem and progenitor cells (HSPCs) posttransplant. We further show that GPRASP1 and GPRASP2 promote the degradation of CXCR4, a master regulator of HSC function during transplantation. CXCR4 accumulates in Gprasp-deficient HSPCs, boosting their function posttransplant. Thus, GPRASPs negatively regulate CXCR4 stability in HSCs. Our work reveals GPRASP proteins as negative regulators of HSCT and CXCR4 activity. Disruption of GPRASP/CXCR4 interactions could be exploited in the future to enhance the efficiency of HSCT.