Patterns and kinetics of T-cell chimerism after allo transplant with alemtuzumab-based conditioning: mixed chimerism protects from GVHD, but does not portend disease recurrence

Leuk Lymphoma. 2009 Nov;50(11):1809-17. doi: 10.3109/10428190903200790.


We analyzed the kinetics of CD3 chimerism in 120 consecutive allogeneic hematopoietic cell transplantation (HCT) recipients receiving alemtuzumab-based conditioning. Fifty-two received fludarabine/melphalan, 44 received fludarabine/busulfan, and 24 received clofarabine/melphalan in addition to alemtuzumab. Post-transplant GVHD prophylaxis consisted of tacrolimus. No prophylactic donor lymphocyte infusion or other interventions were used for mixed donor chimerism (MDC). Bone marrow (BM) and/or peripheral blood (PB) samples were obtained at 30 days, 100 days, 180 days, and 1 year following HCT. On Day 30, 15% of assessable patients had MDC in the CD3 compartment. This had increased to 50% by Day 100, and to 63% by Day 180. MDC predicted for a lower risk of acute (p = 0.08) and particularly of chronic GVHD (p = 0.01). MDC was not associated with subsequent relapse or TRM (p = 0.67 and 0.72, respectively). A decline of more than 15% in CD3 chimerism between Day 30 and Day 180 predicted for a 40% risk of subsequent disease recurrence. The observation of MDC after alemtuzumab conditioning does not by itself constitute a risk factor for relapse and should not be used to guide therapeutic intervention. By contrast, declining donor chimerism between Day 30 and Day 180 is associated with a somewhat increased risk of disease recurrence. The high incidence of MDC after alemtuzumab containing conditioning contributes to the low risk of acute and chronic GVHD.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Alemtuzumab
  • Antibodies, Monoclonal / administration & dosage*
  • Antibodies, Monoclonal, Humanized
  • Antibodies, Neoplasm / administration & dosage*
  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use
  • CD3 Complex / blood
  • Graft vs Host Disease / diagnosis
  • Graft vs Host Disease / prevention & control
  • Hematopoietic Stem Cell Transplantation*
  • Humans
  • Leukemia / blood
  • Leukemia / therapy
  • Lymphoma / blood
  • Lymphoma / therapy
  • Middle Aged
  • Tacrolimus / administration & dosage
  • Time Factors
  • Transplantation Chimera*
  • Transplantation Conditioning / methods*
  • Transplantation, Homologous
  • Treatment Outcome
  • Young Adult


  • Antibodies, Monoclonal
  • Antibodies, Monoclonal, Humanized
  • Antibodies, Neoplasm
  • CD3 Complex
  • Alemtuzumab
  • Tacrolimus