Secondary poor graft function after autologous stem cell transplantation in multiple myeloma: a case-based expert review and successful rescue with secondary autologous stem cell infusion

Secondary PGF after Auto-HSCT appears multifactorial, involving quantitatively adequate but qualitatively fragile grafts, inflammatory/microenvironmental injury, and therapy-related megakaryocytic vulnerability (including heavy lenalidomide exposure). When backup cells are available and reversible causes are excluded, early unpreconditioned autologous PBSC boost is a safe, feasible, and likely under-utilized salvage strategy. Strategic PBSC banking and early recognition may prevent life-threatening PGF.