Autograft cellular composition and outcome in myeloma patients: Results of the prospective multicenter GOA study

Abstract

<b>Background</b> Autologous stem cell transplantation (auto-SCT) is a widely used treatment option in multiple myeloma (MM) patients. The optimal graft cellular composition is not known.<div><b>Study design and methods</b> Autograft cellular composition was analyzed after freezing by flow cytometry in 127 MM patients participating in a prospective multicenter study. The impact of graft cellular composition on hematologic recovery and outcome after auto-SCT was evaluated.<div><b>Results</b> A higher graft CD34(+) cell content predicted faster platelet recovery after auto-SCT in both the short and long term. In patients with standard-risk cytogenetics, a higher graft CD34(+) count (>2.5 x 10/kg) was linked with shorter progression-free survival (PFS; 28 vs. 46 months, p = 0.04), but there was no difference in overall survival (OS) (p = 0.53). In a multivariate model, a higher graft CD34(+)CD133(+)CD38(-) (>0.065 x 10/kg, p = 0.009) and NK cell count (>2.5 x 10/kg, p = 0.026), lenalidomide maintenance and standard-risk cytogenetics predicted better PFS. In contrast, a higher CD34(+) count (>2.5 x 10/kg, p = 0.015) predicted worse PFS. A very low CD3(+) cell count (<= 20 x 10/kg, p = 0.001) in the infused graft and high-risk cytogenetics remained predictive of worse OS.</div><div><b>Conclusions</b> Autograft cellular composition may impact outcome in MM patients after auto-SCT. More studies are needed to define optimal graft composition.</div></div>