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.

INTRODUCTION: Secondary poor graft function (PGF) after autologous hematopoietic stem cell transplantation (Auto-HSCT) for multiple myeloma (MM) is rare, often delayed in recognition, and lacks standardized salvage algorithms.

AREAS COVERED: Using a case-based expert-review format, we summarize diagnostic hallmarks, exclusion work-up, mechanistic drivers, and practical management, with emphasis on autologous stem-cell boost as a rescue option.

CASE SUMMARY: A 59-year-old woman with IgG κ MM achieved timely neutrophil and platelet engraftment after Auto-HSCT, then developed recurrent transfusion-dependent pancytopenia approximately two months later. Relapse, occult infection/viral reactivation, immune cytopenia, nutritional deficiency, and drug-related myelosuppression were systematically excluded, supporting secondary PGF. Growth factors and thrombopoietin-receptor agonists produced only transient benefit. A second infusion of cryopreserved autologous peripheral blood stem cells (PBSCs) (3.621 × 10 CD34/kg) without re-conditioning led to rapid platelet recovery within 7 days and durable trilineage hematopoiesis.

EXPERT OPINION: 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.