Autologous bone marrow transplantation in ALL: relapse linked to infusion of tumor cells with the back-up marrow.

A 41-year-old female patient with a pre-B ALL expressing 2 BCR/ABL transcripts e1/a2 and b2/a2 underwent autologous bone marrow transplantation (aBMT) with marrow grown in long-term culture (LTC) for consolidation of remission (CR). After failing to engraft on day 54 she received her back-up marrow. She engrafted by day 23 and developed a full-blown leukemic relapse 2 weeks later. She died from tumor progression 3 months after infusion of the backup marrow. Analysis of the BCR/ABL transcripts weakly positive at time of collection of the backup marrow, negative in the LTC marrow and in the patient after infusion of the LTC marrow, again positive from day 29 after infusion of the backup marrow until death, strongly suggests that infusion of residual tumor cells with the backup marrow contributed to the relapse.