Bone Marrow Transplant for Anemia
Bone marrow transplant (BMT) is NOT a treatment for anemia in general—it is only indicated for specific life-threatening hematologic disorders that cause anemia, such as severe aplastic anemia, higher-risk myelodysplastic syndromes (MDS), thalassemia major, and sickle cell disease. 1
When BMT Is Indicated for Anemia-Causing Conditions
Severe Aplastic Anemia
BMT should be considered first-line therapy for severe aplastic anemia after HLA typing is completed at diagnosis. 2
- HLA-identical sibling donors are the first choice, with 5-year survival rates of 91% using fludarabine/cyclophosphamide/ATG or cyclophosphamide/ATG conditioning regimens 3
- HLA-matched unrelated donors are the second choice, with 5-year survival rates of 75-80% 3
- HLA-haploidentical donors are the third option if matched unrelated donors are not rapidly available 2
- BMT is preferred over immunosuppressive therapy because it provides cure with lower long-term risks of disease relapse, secondary MDS, or acute myeloid leukemia 2
Higher-Risk Myelodysplastic Syndromes (MDS)
Allogeneic stem cell transplantation is the only potentially curative treatment for higher-risk MDS and should be offered to all patients <65-70 years old without major comorbidities who have a suitable donor. 1
- Patients aged <55 years without comorbidities should receive myeloablative conditioning 1
- Reducing marrow blast count before transplant with chemotherapy or hypomethylating agents is recommended when marrow blasts are ≥10% 1
- Iron overload before transplant is associated with increased transplant-related mortality and should be addressed with chelation therapy 1
Lower-Risk MDS with Anemia
BMT is NOT routinely indicated for lower-risk MDS—these patients should receive medical management first 1
- First-line treatment without del(5q): Erythropoiesis-stimulating agents (ESAs) at doses of 30,000-80,000 units EPO weekly, achieving ~60% response rates 1
- First-line treatment with del(5q): Lenalidomide 10 mg/day for 3 weeks out of every 4 weeks, achieving 60-65% response rates 1
- Chronic RBC transfusions remain standard supportive care when drug therapies fail 1
Thalassemia Major
BMT is the only curative approach for transfusion-dependent thalassemia major and should be offered as soon as possible to avoid transfusion-associated complications in patients with an HLA-identical sibling or well-matched donor. 1
- Patient status at transplant (Pesaro risk score) is the critical predictor of outcome 1
- Control of iron overload before transplant is essential for optimal outcomes 1
- HLA-matched sibling cord blood is an acceptable alternative source with adequate cell dose (>3.5×10⁷/kg) 1
- Matched unrelated donor transplant is suitable for children with life-threatening disease when well-matched donors are available 1
Sickle Cell Disease
Young patients with symptomatic SCD who have an HLA-matched sibling donor should be transplanted as early as possible, preferably at pre-school age. 1
- Unmanipulated bone marrow or umbilical cord blood from matched sibling donors are the recommended stem cell sources 1
- Peripheral blood stem cells should be avoided due to significantly higher chronic GVHD rates 1
- Alternative donor transplantation (unrelated or haploidentical) should only be considered in controlled trials at experienced centers 1
Critical Pitfalls to Avoid
- Do not offer BMT for simple nutritional anemias (B12, folate, iron deficiency)—these require vitamin/mineral replacement 4
- Do not delay HLA typing—it should be performed at diagnosis for conditions where BMT may be indicated 2
- Do not use peripheral blood stem cells in non-malignant diseases—bone marrow is preferred due to lower chronic GVHD risk 1
- Do not proceed to BMT without addressing iron overload in heavily transfused patients—chelation therapy is essential before transplant 1
- Do not assume all siblings are matches—only 25% of siblings will be HLA-matched 5