Allogeneic Hematopoietic Cell Transplantation for the Treatment of Severe Aplastic Anemia: Evidence-Based Guidelines From the American Society for Transplantation and Cellular Therapy

Allogeneic hematopoietic cell transplantation (HCT) is a potentially curative treatment for severe aplastic anemia aplastic anemia: (ay-PLASS-tik uh-NEE_mee-uh) A rare and serious condition in which the bone marrow fails to make enough blood cells - red blood cells, white blood cells, and platelets. The term aplastic is a Greek word meaning not to form. Anemia is a condition that happens when red blood cell count is low. Most… (SAA). Existing guidance about HCT in SAA is primarily derived from expert reviews, registry data and societal guidelines; however, transplant-specific guidelines for SAA are lacking. A panel of SAA experts, both pediatric and adult transplant physicians, developed consensus recommendations using Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) methodology employing a GRADE guideline development tool. The panel agrees with previous recommendations for the preferential use of bone marrow bone marrow: The soft, spongy tissue inside most bones. Blood cells are formed in the bone marrow. as a graft source and the use of rabbit over horse antithymocyte globulin antithymocyte globulin: ATG is an immunosuppressant, a drug that lowers the body's immune response. It is typically used with cyclosporine as the first-line immunosuppressive therapy (IS) to treat patients with acquired aplastic anemia. In some cases it is used as a treatment for patients with MDS and PNH. (ATG) for HCT conditioning. Fludarabine Fludarabine: The U.S. Food and Drug Administration (FDA) approved fludarabine for treating chronic lymphocytic leukemia (CCL). Researchers are studying fludarabine in combination with other medicines for treating bone marrow failure. containing regimens are preferred for patients at high risk of graft failure and those receiving matched unrelated or haploidentical donor transplant. Given advancements in HCT, the panel does not endorse the historical 40-year age cut-off for considering upfront HCT in adults, acknowledging that fit older patients may also benefit from HCT. The panel also endorses increased utilization of HCT by prioritizing matched unrelated or haploidentical donor HCT over immunosuppressive therapy immunosuppressive therapy: Immunosuppressive drug therapy lowers your body's immune response. This prevents your immune system from attacking your bone marrow, allowing bone marrow stem cells to grow, which raises blood counts. For older patients with acquired aplastic anemia, immunosuppressive drug therapy is the… in children and adults who lack a matched related donor matched related donor: A bone marrow/stem cell donor that is a sibling or another family relation to the patient. . Finally, the panel suggests either calcineurin inhibitor plus methotrexate or post-transplant cyclophosphamide cyclophosphamide: Cyclophosphamide is in a class of medications called alkylating agents. When used to treat cancer, it works by slowing or stopping the growth of cancer cells in your body. When cyclophosphamide is used to treat bone marrow failure, it works by suppressing your body's immune system. -based graft-versus-host disease (GVHD) graft-versus-host disease (GVHD): Also called GVHD, it is a common complication of bone marrow/stem cell transplantation. It is caused when the donor's immune cells, now in the patient, begin to see the the patient's body as foreign and mount an immune response. GVHD most commonly effects the recipient's skin, intestines, or liver… prophylaxis for matched related or matched unrelated donor unrelated donor: A donor that is not a sibling or other familial relation of the patient (recipient). recipients. These recommendations reflect a significant advancement in transplant strategies for SAA and highlight the importance of ongoing and further research to revisit current evidence in terms of donor choice, conditioning chemotherapy chemotherapy: (kee-moe-THER-uh-pee) The use of medicines that kill cells (cytotoxic agents). People with high-risk or intermediate-2 risk myelodysplastic syndrome (MDS) may be given chemotherapy to kill bone marrow cells that have an abnormal size, shape, or look. Chemotherapy hurts healthy cells along with… , GVHD prophylaxis and post-transplant immunosuppression.