Safety and efficacy assessment of plerixafor in patients with multiple myeloma proven or predicted to be poor mobilizers, including assessment of tumor cell mobilization.

This was an open-label, single-center, phase II study of 20 patients with multiple myeloma who were either proven poor mobilizers (n=10; group A) or predicted poor mobilizers (n=10; group B) and were planned for autologous hematopoietic SCT. The aim was to assess the safety and efficacy of plerixafor for stem cell mobilization and tumor cell contamination. The peripheral blood (PB) CD34+ cell count was generally very low pre- plerixafor and increased significantly post-plerixafor administration. Cumulative apheresis yields of > or =2 x 10(6) CD34+ cells/kg were observed in 7 of 10 patients (group A) and 8 of 10 patients (group B). Among the proven poor mobilizers, there was no evidence of tumor cell mobilization in the PB after G-CSF plus plerixafor treatment. Seventeen of 20 (85%) patients underwent transplantation. Neutrophil engraftment occurred at a median of 13 days for all patients. Platelet engraftment occurred at a median of 16 days and 19 days for all proven and predicted poor mobilizers, respectively. At 12 months, 12 of 17 patients had documented durable grafts, 3 of 17 patients died and 2 of 17 patients were lost to follow-up; but they had documented graft durability at the previous 3- and 6-month visit. The safety profile of plerixafor in all patients was consistent with previous reports.

Pulmonary T cell repertoire in patients with graft-versus-host disease following blood and marrow transplantation.

Pulmonary inflammation is one of the risk factors associated with blood and marrow transplantation (BMT). To determine the potential role of T cells in pulmonary complications after transplantation, we analyzed the T-cell repertoire expressed in bronchoalveolar lavage fluids from eleven patients with graft-versus-host disease following BMT. A reverse transcriptase-polymerase chain reaction was used to amplify rearranged TCR transcripts in unfractionated, CD4+, and CD8+ T cells from bronchoalveolar lavage fluids. The relative expression of TCR variable (V) gene families and the diversity of junctional region lengths associated with different AV and BV gene families were analyzed. Nearly all TCR AV and BV gene families were detected in bronchoalveolar lavage cells from BMT recipients. Oligoclonal patterns of TCR junctional region lengths were observed in unfractionated, CD4+, and CD8+ bronchoalveolar T cells. The oligoclonal expansion of bronchoalveolar T cells in patients was confirmed by DNA sequencing. TCRV gene expression is almost completely restored in the lungs of BMT recipients as early as two weeks after transplantation. Increased oligoclonality among TCR gene families suggests either an incomplete restoration of TCR diversity or an antigen-driven expansion of T cells in the lungs of BMT recipients with graft-versus-host disease, not necessarily related to pulmonary infection.