Miscellaneous Complications of Hematopoietic Cellular Transplantation

Advancements in hematopoietic cell transplantation (HCT) have been associated with expanding indications and eligibility, alternative donor options, and improvement in overall survival. Yet, HCT for hematologic malignancies are still associated with the potential for significant toxicities that may be influenced by the primary diagnosis, prior treatment history, comorbid conditions and/or preparative regimen, and/or donor source. Candidates for HCT undergo comprehensive medical evaluations to confirm eligibility and inform ultimate preparative regimen and donor selection. Acute toxicities associated with HCT can generally be classified as infectious or noninfectious. Infectious complications of HCT are outside the scope of this chapter. Toxicities of HCT may occur during administration of the preparative regimen, around HCT infusion, and/or following HCT. Early toxicities are usually related to the specific agents used as part of the preparative regimen. These agents and/or prior toxic injuries to the endothelium may also contribute to post-HCT endotheliopathies such as preengraftment or engraftment syndrome, venoocclusive disease now more commonly referred to as sinusoidal obstructive syndrome, transplant-associated thrombotic microangiopathy, and/or diffuse alveolar hemorrhage. Poor immune reconstitution post-HCT may be associated with clinical sequelae such as posttransplant lymphoproliferative disease, which historically was associated with very poor outcomes. Patients undergoing HCT may also develop endocrinopathies, acute fluid overload, acute kidney injury, acute respiratory failure, and/or neurologic sequelae. A significant number of patients undergoing HCT may develop multiorgan dysfunction syndrome and/or require critical care support. High vigilance and/or early initiation of specific therapies when available and/or appropriate supportive care may significantly mitigate toxicities.