The inability to aspirate bone marrow from children with MIOP has hampered both clinical management and research into pathogenesis. For example, it is not possible to perform autologous back-up harvest despite graft rejection being a common event after alternative donor transplantation. In response to this and the leucoerythroblastic blood picture seen in this disease, we measured CD34+ cell count and performed progenitor assays on peripheral blood (PB) from 8 infants (range 1-26 months)with MIOP. Progenitor assays were established in triplicate and compared with normal donor bone marrow (BM). The results of CD34+, CFU-GM and BFU-E precursor assays are shown in the table. CFU-F could not be cultured from any of the patient samples. UPN CD34+ % CFU-GM/10 CFU-GM/10 BFU-E/10' BFU-E/10' cells MIOP PB cells normal BM cells MIOP PB cells normal BM 1 2.14 200 160 60 620 2 6.4 780 170 460 210 3 8.1 20 330 12 140 4 1.6 310 530 110 390 5 3.0 750 410 230 210 6 1.04 660 560 360 290 7 3.2 160 270 140 660 8 n/a 650 300 39 640 mean+/-SD 3.64+/-2.62 368+/-314 341+/-140 176+/-161 395 +/- 210 These results show that the PB of patients with MIOP spontaneously contain CFUGM and BFU-E precursors in comparable numbers to normal BM. This finding has three potential advantages: (1) Cells can be collected for autologous reinfusion in the event of graft rejection - in all cases an exchange transfusion of <200ml would have provided greater than 2×106 CD34/kg recipient weight, (2) in vitro studies of osteoclasts can be performed (Flanagan AM et al. J Bone Min Res. 2000;I5(2):352-60) for correlation of bone biopsy appearances, phenotype, genotype and response to SCT and (3) when used in combination, CD34 assay and osteoclast culture from foetal blood samples may allow antenatal diagnosis in families where the genetic cause of MIOP cannot be established. In future it will be imperative to routinely cryopreserve PB MNC from all patients with MIOP.
|Original language||English (US)|
|Issue number||11 PART II|
|State||Published - Dec 1 2000|