Secondary loss of hematopoietic engraftment after autologous stem cell transplantation
Yes, hematopoietic engraftment can be lost after initial engraftment following autologous hematopoietic cell transplantation in rare circumstances. Reported examples include secondary failure of platelet recovery after initial engraftment and loss of autologous gene-therapy cell function reflected by declining vector copy number with clinical re-emergence of disease activity. [1], [2]
Definition of “loss of engraftment” in autologous transplant
Loss of engraftment may present as secondary failure of blood count recovery after an initial response, most often described as loss of platelet recovery. [1]
Loss of engraftment can also be reflected by loss of biological activity of the transplanted autologous product, such as a decline in lentiviral vector copy number with clinical re-emergence of disease activity. [2]
Reported clinical evidence
A 2024 case report described secondary failure of platelet recovery occurring after platelet engraftment following autologous stem cell transplantation in primary testicular lymphoma. [1]
A 2024 gene-therapy case (autologous, lentiviral-vector–transduced hematopoietic stem/progenitor cells) documented decline in whole-blood vector copy number from 0.666 copies/mL at 50 days to 0.029 copies/mL by 6 months, alongside re-emergence of MRI findings. [2]
Mechanistic considerations supported by the evidence
Secondary failure of hematologic recovery after initial engraftment in autologous transplantation can be attributable to factors related to conditioning or treatment toxicity, as suggested in the platelet-recovery case report. [1]
Secondary loss of autologous gene-therapy effect can occur with re-emergence of disease activity concurrent with marked reduction in vector copy number, suggesting loss of functional persistence of the transplanted genetically modified cells. [2]
Practical clinical implications
Monitoring strategies commonly include assessment of hematopoietic recovery (including platelet recovery) after transplantation to detect secondary failure. [1]
In autologous gene-therapy recipients, monitoring may include vector copy number to detect decline associated with recurrence of disease activity. [2]
When to suspect secondary loss after initial engraftment
Secondary loss should be suspected when cytopenias recur after documented initial engraftment or when a surrogate marker of product persistence declines in the setting of clinical relapse or return of disease activity. [1], [2]
Diagnostic approach for suspected loss
Evaluation should include hematologic reassessment to characterize the pattern and timing of secondary failure of recovery. [1]
Evaluation in gene-therapy contexts may include laboratory assessment of product persistence through vector copy number and correlation with clinical and imaging changes. [2]
Summary statement
Secondary loss of engraftment or loss of functional persistence after autologous transplantation is possible but appears uncommon, with published examples documenting secondary failure of platelet recovery and autologous gene-therapy activity loss with decreasing vector copy number and clinical re-emergence. [1], [2]