High-dose therapy in patients with Hodgkin's disease: the use of selected CD34(+) cells is as safe as unmanipulated peripheral blood progenitor cells

Register data suggest that patients with Hodgkin's disease (HD) given high- dose therapy (HDT) with peripheral blood progenitor cells (PBPC) have a les s favourable prognosis as compared to those given bone marrow as stem cell support. Since this can be due to infusion of tumour cells contaminating th e PBPC grafts, we initiated a feasibility study in which PBPC grafts from H D patients were purged by CD34(+) cell enrichment. Controversy exists about whether the use of CD34(+) enriched stem cells leads to a delayed haematol ogical and immune reconstitution. We compared these parameters, including r isk of infections and clinical outcome after HDT, in patients with HD given either selected CD34+ cells or unmanipulated PBPC as stem cell support. Fr om October 1994 to May 2000, 40 HD patients with primary refractory disease or relapse were treated with HDT and supported with either selected CD34() cells (n = 21) or unmanipulated PBPC (n = 19) as stem cell support. All p atients had chemosensitive disease at the time of transplantation. A median of 5.8 (range 2.7-20.0) vs 4.5 (range 2.3-17.6) x 10(6) CD34(+) cells per kilo were reinfused in the CD34(+) group and PBPC group, respectively. No d ifference was observed between the two groups with regard to time to haemat ological engraftment, reconstitution of B cells, CD56(+) cells and T cells at 3 and 12 months and infectious episodes after HDT. Two (5%) treatment-re lated deaths, one in each group, were observed. The overall survival at 4 y ears was 86% for the CD34(+) group and 74% for the PBPC group with a median follow-up of 37 months (range 1-61) and 46 months (range 4-82), respective ly (P = 0.9). The results of this study demonstrate that the use of CD34(+) cells is safe and has no adverse effects either with respect to haematolog ical, immune reconstitution or to infections after HDT.