Clinical Indications of Hematopoietic Stem Cell Transplantation: A Clinical Review

Abstract

Hematopoietic stem cells (HSCs) are multipotent, self-renewing progenitor cells that develop from mesodermal hemangioblast cells. All differentiated blood cells from the lymphoid and myeloid lineages arise from HSCs. HSCs can be found in adult bone marrow, peripheral blood, and umbilical cord blood. Classic studies in mice describe two populations of Hematopoietic Stem Cells, Long Term and Short Term. Long term HSCs are capable of self renewal, while short term HSCs do not have this capacity. Short term HSCs, also called progenitor or precursor cells, can differentiate into all types of blood cells, which can be characterized by specific markers. Hematopoietic stem cell transplantation (HSCT) involves the intravenous infusion of autologous or allogeneic stem cells collected from bone marrow, peripheral blood, or umbilical cord blood to reestablish hematopoietic function in patients with damaged or defective bone marrow or immune systems. HSCT is used throughout this article as a general term covering transplantation of progenitor/stem cells from any source (e.g., bone marrow, peripheral blood, and cord blood). Interpretation of the results of trials of bone marrow transplantation is always complicated by the problem of patient selection. The efficacy of transplantation can be underestimated if only patients with the worst prognoses are studied, or it can be overestimated if only those with the best prognoses are studied. HSCT has led to the cure of diverse forms of cancer, bone marrow failure, hereditary metabolic disorders, and severe congenital immunodeficiency’s that would otherwise have been fatal. The indications for HSCT vary according to disease categories and are influenced by factors such as cytogenetic abnormalities, response to prior therapy, patient age and performance status, disease status (remission vs. relapse), disease-specific prognostic factors, and, most importantly, availability of a suitable graft source. The aim of present article is to provide in depth knowledge about Hematopoietic stem cell transplantation (HSCT) as well as various clinical indications of HSCT.

KEYWORDS: Hematopoietic stem cells, HSCs, HSCT, Stem Cells, Stem Cell Treatments.