Jonathan A. Cotliar - Atlas of Graft-versus-Host Disease: Approaches to Diagnosis and Treatment

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Pioneering experimentation by Jacobson in the 1940s showed that mice were protected from the deleterious effects of radiation if their spleens were shielded with lead foils [].

Allogeneic HSCT is often the only potentially curative treatment for hematologic malignancies in an advanced stage or for relapsed disease. For early-stage disease such as acute myeloid leukemia (AML) or acute lymphoblastic leukemia (ALL) in first complete remission (CR1), the risk of relapse can be significantly reduced by allogeneic HSCT, but the medical decision is complex and has to be carefully balanced against the risk of transplant-related mortality. In general, allogeneic HSCT is considered for acute leukemia in CR1 with intermediate-risk or high-risk features, or cases that are beyond CR1. In the United States, AML/ALL and myelodysplastic syndromes (MDS) account for 65 % of patients who undergo allogeneic HSCT based on the most recent data provided by the Center for International Blood and Marrow Transplant Research (CIBMTR) []. With the introduction of targeted therapy with tyrosine kinase inhibitors for chronic myeloid leukemia (CML), HSCT is reserved only for patients with refractory disease. Refractory non-Hodgkins lymphoma, chronic lymphocytic leukemia (CLL), and nonmalignant diseases such as aplastic anemia, and paroxysmal nocturnal hemoglobinuria (PNH) comprise the remainder of indications for allogeneic HSCT.

The American Society of Blood and Marrow Transplantation (ASBMT) established a multiple-stakeholder taskforce to study role of HSCT in established disease states and identify emerging indications where HSCT may potentially be beneficial. This task force came out with a white paper in 2015 with clearly defined indications across disease states where HSCT has been shown to be of clinical benefit based on available clinical trial data. Published systematic evidence reviews or guidelines were used as the basis for recommendations to categorize indications for HSCT in pediatric and adult populations [].

Hematopoietic stem cells (HSCs) can be found in a variety of human tissues, but for clinical purposes the most commonly used sources are peripheral blood, bone marrow, and umbilical cord blood. Each source has its unique advantages and drawbacks in clinical settings.