6553 Background: Allogeneic stem cell transplantation is used to treat different types of hematologic malignancies. The target stem cell dose typically is based on the recipient’s ideal body weight (IBW) with CD34 dose of 2.0–5.0 ×106/Kg. The dose of CD3 in the infusate is typically not taken into account in a stem cell product, except in T-depleted transplantation. The dose of T-cells in peripheral blood stem cell collections has been found to be at least 10-fold more than that in a bone marrow harvest product. Combined CD4+ and CD25+ cells infused have been directly correlated with increased incidence of GVHD. Methods: This is a retrospective study reporting the correlation of the CD34 and CD3 doses of stem cell transplant with incidence of acute GVHD in 67 consecutive patients who were treated between 2003 and 2005. All patients were followed up for at least 100 days following the stem cell transplant. Results: Among the 67 patients, 35 patients developed acute GVHD, while 32 patients had no evidence of acute GVHD. The CD3 and CD34 doses did not correlate. The correlation coefficient was 0.14 (P value: 0.27). Using t-test, there was NO statistical difference between the mean CD34 dose when comparing the group of patients who developed acute GVHD with the group that did not develop acute GVHD (P value: 0.31). Those who developed acute GVHD (n = 35) received a mean CD3 dose of 41.9 × 107/kg IBW (95% CI: 35.9–47.9). Those who did NOT develop acute GVHD (n= 32) received a mean CD3 dose of 33.5 × 107/kg IBW (95% CI: 27.3–39.8). By using the t-test, the P value for the different means was 0.0575. However, using a CD3 dose cutoff value of 30 × 107/kg IBW, the incidence of acute GVHD was statistically significantly less among those who received CD3 dose < 30 × 107/kg IBW. The Chi Square P value was 0.04. Conclusions: In our series, CD3 dose less than 30 × 107/kg IBW was associated with reduced risk of acute GVHD (P value: 0.04). There was no correlation between CD3 and CD34 counts in peripheral stem cell product. In addition, the CD34 dose did not influence the incidence of acute GVHD. These data suggest that, in addition to considering CD34 dose required for engraftment in allogeneic transplant, the CD3 dose will need to be considered to try to minimize the risk of acute GVHD. No significant financial relationships to disclose.
Experience in Facilitating Stem Cell Product for Matched Unrelated Donor Transplant in a Developing Country