Bone marrow-derived mononuclear cell populations in pediatric and adult patients

Many clinical trials are currently evaluating the safety and efficacy of autologous bone marrow (BM) mononuclear cells (MNC) for various pathologies in younger and older non-cancer patients. Concern has been raised that autologous MNC derived from elderly patients may be less effective as a therapeutic option.

We compared the MNC yield, viability, phenotypic markers and in vitro functionality in pediatric patients compared with adult patients enrolled in clinical trials evaluating autologous BM MNC transplantation. Thirty-six patients (n=10 pediatric and n=26 adult) were included in this analysis. All patients underwent BM harvest in which 1-3 mL/kg was aspirated under local anesthesia. MNC were isolated by gradient densitometry. The average age of the older and younger patient groups was 59+/-7 years and 9+/-3 years, respectively.

The average total MNC recovered from the BM in pediatric patients was 2.1 x 10(6)/mL and in older patients was 3.2 x 10(6)/mL. There were no differences in cell viability (>97%) or phenotypic markers identifying T cells, natural killer (NK) cells and neutrophils between the two groups. Of note, the Lin(-)CD34(+) cell population was not different between the groups. Average post-processing CFU-F, CFU-GEMM and BFU-E were not statistically different but there were significantly increased levels of CFU-GM in the older population.

These results suggest that MNC from younger and older non-cancer patients are similar, but the data must be interpreted with caution given the small sample size and limited general understanding of MNC mechanisms of action on target cells. It is still possible that cells from older patients may produce fewer cytokines or be functionally impaired.