P1: SBT
0521779407-04 CUNY1086/Karliner 0 521 77940 7 June 13, 2007 7:8
Aplastic Anemia 151■transfuse only CMV negative, irradiated blood products, avoid family
members as donors
■treat any underlying infections
■consider referral to specialized center
specific therapy
■indicated for patients with severe aplastic anemia defined as:
➣hypocellular bone marrow (< 25% cellularity) and
➣at least two markedly depressed peripheral blood counts:
neutrophils <500
platelets <20,000
corrected reticulocytes <1% (<60,000/microliter)Treatment Options
1) allogeneic bone marrow transplantation (Rx of choice in children
and young adults who have an HLA-matched sibling)
■Advantages:
➣Restores normal hematopoiesis (curative potential, 80–90%)
➣Little risk of relapse or secondary clonal disease
➣Prompt hematopoietic recovery
■Disadvantages:
➣High morbidity/mortality (GVHD, infections) especially in
patients >40
➣cure rate <50% in patients >40
➣Not available to most patients (age restriction, requires HLA-
identical sib for best results)
➣alternative donors (unrelated or mismatch grafts) have lower
cure rates because of GVHD and generally are not recommended
for initial therapy.
2) antithymocyte globulin and cyclosporine (ATG/CSA)
■Advantages:
➣Does not require a stem cell donor
➣No risk of GVHD
➣No age restrictions, available to virtually all patients with SAA
■Disadvantages:
➣Does not usually restore normal hematopoiesis (not curative)
➣majority of patients will relapse, become dependent of
cyclosporine or develop secondary clonal disease (PNH, MDS,
leukemia)
➣Slow hematopoietic improvement
➣Serum sickness, requirement for high-dose steroids, risk of avas-
cular necrosis (up to 10%)