Hematopoietic Stem Cell Transplantation
Following a brief overview of the topic, we present a discussion on the frequency of noninfectious complications, associated risk factors, and the impact of noninfectious complications on outcome.
Important considerations in hematopoietic stem cell transplantation are discussed below. Subsequently, solid organ transplantation is discussed in a separate section.
Hematopoietic stem cell transplantation (HSCT) primarily is used to treat hematological and lymphoid cancers, selected solid tumors, and nonneoplastic diseases including autoimmune disorders, amyloidosis, and aplastic anemia.1 Over 30,000 autologous and 25,000 allogeneic HSCTs are performed annually worldwide.2 The most common graft source is peripheral blood.2 Other graft sources include bone marrow and cord blood. A total of 7892 allogeneic and 12047 autologous HSCTs were performed in 2011 in the United States.2 The main indications for autologous transplant include multiple myeloma and lymphomas, and allogeneic transplant is most commonly performed for acute and chronic leukemia, lymphoma, and myelodysplastic syndrome. A conditioning regimen is employed before transplantation to eradicate malignant cells and, in allogeneic transplantation, to induce immunosuppression that permits engraftment.1 Some patients are also given total-body irradiation for myeloablation and immunosuppression. The conditioning regimen can be termed myeloablative, reduced intensity, or nonmyeloablative.3
Following HSCT, the immune system recovers along predictable patterns depending on the underlying disorder, stem cell source, and complications such as graft versus host disease (GVHD).4 Recovery occurs faster in autologous recipients, in those who receive peripheral blood stem cell grafts, and after nonmyeloablative conditioning. The posttransplant period is divided into three phases: Pre-engraftment, early posttransplant, and late posttransplant.5 The pre-engraftment phase (0–30 days) is characterized by neutropenia and breaks in the mucocutaneous barriers. The early post-engraftment phase (30–100 days) is dominated by impaired cell-mediated immunity. The impact of this cell-mediated defect is determined by the development of GVHD and the corresponding immunosuppressant medications. The late posttransplant phase (>100 days) is characterized by defects in cell-mediated and humoral immunity, as well as function of the reticuloendothelial system in allogeneic transplant recipients. The development of noninfectious pulmonary complications follows characteristic temporal patterns.6 Pulmonary edema, diffuse alveolar hemorrhage (DAH), and peri-engraftment respiratory distress syndrome (PERDS) usually occur during the first 30 days posttransplant (Fig. 95-1). Idiopathic pneumonia syndrome (IPS) can occur at any time following transplant.
The temporal pattern of major noninfectious pulmonary complications following hematopoietic stem cell transplantation.
The mortality of patients following HSCT is high and depends on the underlying disease and type of transplant.2 Patients receiving human leukocyte antigen (HLA)-identical sibling transplants for acute myelogenous leukemia (AML) in remission have a 100-day mortality rate of 7% to 9%, compared with 22% for patients with active leukemia at the time of transplantation. Early mortality after an unrelated donor transplant is higher than after ...