\u201cCD34+ selected versus un-manipulated autologous stem cell transplantation in multiple myeoloma: impact on dendritic and immune recovery and on complications due to infections\u201d.

Background: Large-scale CD34+ enrichment has been demonstrated a safe method in autologous transplantation for multiple myeloma. However, the high CD34+ enrichment and the consequent plasma cell purging result in concomitant T-cell and dendritic-cell (DC) depletion, theoretically increasing the risk of life-threatening infections. Patients and methods: We evaluated immunological and dendritic reconstitution in 72 myeloma patients who had undergone CD34+-selected (n = 45) and unmanipulated (n = 27) stem cell transplant, and its correlation with infections. Results: Haematological recovery occurred promptly in all patients. Only a slight delay in platelet recovery to >50 7 109/l was observed in patients receiving CD34+-enriched graft. Natural killer (NK) cell count recovered in all patients within 2 months and B-cell count had recovered by 6 months post-transplant in both groups. CD3 cells remained lower than normal in both groups. CD8 cells increased above the normal level, reaching a peak at day 90, and lowered to normal level within 1 year post-transplant. CD4 lymphocytes remained