CLINICAL OBSERVATIONS, INTERVENTIONS, AND THERAPEUTIC TRIALS Association of CD34 cell dose with hematopoietic recovery, infections, and other outcomes after HLA-identical sibling bone marrow transplantation

Although CD34 cell dose is known to influence outcome of peripheral stem cell– and/or T-cell–depleted transplantation, such data on unmanipulated marrow transplantation are scarce. To study the influence of CD341 cell dose on hematopoietic reconstitution and incidence of infections after bone marrow transplantation, we retrospectively analyzed 212 patients from January 1994 to August 1999 who received a transplant of an unmanipulated graft from an HLA-identical sibling donor. Median age was 31 years; 176 patients had hematologic malignancies. Acute graft-versus-host disease prophylaxis consisted mainly in cyclosporin associated with methotrexate (n 5 174). Median number of bone marrow nucleated cells and CD341 cells infused were 2.4 3 108/kg and 3.7 3 106/kg, respectively. A CD341 cell dose of 3 3 106/kg or more significantly influenced neutrophil (hazard ratio [HR] 5 1.37, P 5 .04), monocyte (HR 5 1.47, P 5 .02), lymphocyte (HR 5 1.70, P 5 .003), erythrocyte (HR 5 1.77, P 5 .0002), and platelet (HR 5 1.98, P 5 .00008) recoveries. CD341 cell dose also influenced the incidence of secondary neutropenia (HR 5 0.60, P 5 .05). Bacterial and viral infections were not influenced by CD34 cell dose, whereas it influenced the incidence of fungal infections (HR 5 0.41, P 5 .008). Estimated 180-day transplantation-related mortality (TRM) and 5-year survival were 25% and 56%, respectively, and both were highly affected by CD341 cell dose (HR 5 0.55, P 5 .006 and HR 5 0.54, P 5 .03, respectively). Five-year survival and 180-day TRM were, respectively, 64% and 19% for patients receiving a CD341 cell dose of 3 3 106/kg or more and 40% and 37% for the remainders. In conclusion a CD341 cell dose of 3 3 106/kg or more improved all hematopoietic recoveries, decreased the incidence of fungal infections and TRM, and improved overall survival. (Blood. 2002;99:2726-2733)