INFLUENCE OF TOTAL NUCLEATED CELL DOSE FROM MARROW HARVESTS ON OUTCOME IN PATIENTS WITH ACUTE MYELOGENOUS LEUKEMIA UNDERGOING AUTOLOGOUS TRANSPLANTATION

This retrospective study was conducted to determine whether the total number of nucleated cells (TNC)/kg collected at marrow harvest was ass ociated with out-come in 151 patients with acute myelogenous leukemia (AML) who received an autologous purged (n = 67) or non-purged (n = 84 ) marrow transplant, At the time of transplant 33 patients were in fir st complete remission (CR), 47 in second CR, 54 in first relapse and 1 7 beyond second CR, Ninety patients received busulfan (BU) 16 mg/kg an d cyclophosphamide (CY) 120 or 200 mg/kg, 51 patients received CY 120 mg/kg and total body irradiation (TBI) 12-15.75 Gy and 10 patients rec eived BU 8 mg/kg, CY 60 mg/kg and TBI 12 Gy as conditioning regimens, Patients whose marrow harvest yielded <2 x 10(8) TNC/kg did not underg o purging with 4-hydroperoxycyclophosphamide (4HC). This group of pati ents (n = 28) had a 100 day mortality of 50% and only 54% achieved a g ranulocyte levels of >0.5 x 10(9)/l and 29% achieved platelet transfus ion independence, Patients whose marrow harvest yielded 2-4 x 10(8) TN C/kg and did not undergo marrow purging had a 20% mortality by day 100 , 91% recovered granulocytes to >0.5 x 10(9)/l and 61% became platelet independent, Patients whose marrow harvest yielded 2-4 x 10(8) TNC/kg and underwent marrow purging with 4HC had a 50% mortality by day 100 and 58% achieved a granulocyte levels of >0.5 x 10(9)/l and 42% became platelet transfusion independent. Patients whose marrow yielded >4 x 10(8) TNC/kg and underwent marrow purging with 4HC had a 35% mortality by day 100 and 79% achieved a granulocyte levels of >0.5 x 10(9)/l an d 51% became platelet independent. In a multivariate analysis, non-pur ged cell doses of 2-4 x 10(8) TNC/kg were significantly associated wit h a decreased 100-day mortality compared with a dose of <2 x 10(8) TNC /kg (P = 0.005) after adjusting for disease status and patient age at transplant, Purged cell doses of 2-4 and >4 x 10(8) TNC/kg were not si gnificantly different from the non-purged dose of <2 x 10(8) TNC/kg in terms of 100-day mortality (P = 0.75 and 0.14, respectively), Engraft ment of granulocytes and platelets was delayed in patients receiving < 2 x 10(8) TNC/kg or purged marrows compared with patients receiving no n-purged 2-4 x 10(8) TNC/kg, Increasing cell dose in both purged and n on-purged groups was significantly associated with improved EFS, This study also suggests that patients in whom <2 x 10(8) TNC/kg is harvest ed probably should not be transplanted casing autologous marrow alone.