1.0 CHECKLIST FOR PATIENT ELIGIBILITY PRIOR TO BMT 
NO YES 
Age less than 21 years at time of diagnosis 
Receiving unpurged autologous BMT for therapy of leukemia or solid 
tumor 
To check eligibility call Dr. Heslop at 531-2529 or Dr. Krance at 522-0336. 
Informed consent explained to and signed by patient/guardian 
Check table in Section 8.2 of this protocol to see necessary baseline and 
follow-up studies 
2.0 OBJECTIVES 
2.1 To compare hemopoietic reconstitution (time to 100 neutrophils, time to 500 
neutrophils and persistence of engraftment) of untreated and ex-vivo expanded 
aliquots of CD34 selected cells in patients receiving unpurged autografts as 
therapy for pediatric malignancy. 
2.2 To evaluate the safety of ex vivo treatment of marrow with growth factors. 
3.0 BACKGROUND AND RATIONALE 
3.1 Use of autologous BMT as therapy for pediatric malignancy 
The use of autologous BMT in pediatric malignancy either as consolidation therapy in 
high risk patients or as salvage therapy after relapse is increasing. The underlying 
rationale for this approach is that the availability of cryopreserved marrow for reinfusion 
allows the administration of intensive chemotherapy where hemopoietic suppression 
would otherwise be dose limiting. This increased dose of chemotherapy and radiation 
therapy may allow a higher proportion of patients to be cured than would be possible 
with conventional therapy. 
Despite this increasing utilization the biology of autologous BMT has been poorly 
understood. It was unknown for example whether the procedure merely provided a 
temporary source of hemopoietic cells until hemopoiesis was re-established from residual 
recipient cells. In previous studies in which the harvested bone marrow from patients 
with AML or neuroblastoma was marked with a neomycin resistance gene, we have 
shown that the marker gene continues to be detected for up to two years post BMT. This 
result demonstrates that the infused marrow does indeed contribute to sustained long term 
[490] 
Recombinant DNA Research, Volume 19 
