Higher serum soluble PD-L1 levels before and after autologous stem cell transplantation were associated with adverse clinical outcomes including poorer overall survival, disease-free survival, relapse, and graft failure in transplant-eligible multiple myeloma patients.
Pre- and post-transplant serum PD-L1 levels were negatively correlated with overall survival in MM patients undergoing ASCT.
Patients who experienced relapse had significantly higher pre- and post-transplant serum PD-L1 levels compared to those without relapse.
Post-transplant serum PD-L1 levels were significantly higher in patients who experienced graft failure compared to those without graft failure.
Kaplan-Meier survival analysis demonstrated poorer overall survival and disease-free survival among patients with higher PD-L1 levels according to study-defined cutoffs.
The study authors characterized their findings as exploratory due to significant methodological limitations.
This research suggests that a protein called soluble PD-L1, which can be measured in the blood, may serve as a marker for predicting outcomes in multiple myeloma patients who undergo autologous stem cell transplantation (a procedure where patients receive their own previously collected stem cells after high-dose chemotherapy). The study measured blood levels of this protein in 40 patients before and six months after transplantation, and found that patients with higher PD-L1 levels tended to have worse survival, higher rates of disease relapse, and greater risk of graft failure (where the transplant does not work properly). Patients who relapsed had pre-transplant PD-L1 levels of about 119 pg/mL compared to about 75 pg/mL in those who did not relapse, and the difference was even more pronounced after transplant. PD-L1 is known to play a role in helping cancer cells evade the immune system, so elevated levels of its soluble form in the blood may reflect greater immune suppression and a less favorable disease state. This research suggests that monitoring PD-L1 levels could potentially help identify multiple myeloma patients at higher risk for poor outcomes following stem cell transplantation, which could inform more intensive monitoring or treatment strategies. However, it is important to note that this was a small study of only 40 patients at a single hospital with a relatively short follow-up period of 180 days, and the statistical comparisons were not adjusted for multiple testing. The authors themselves emphasize that these findings are preliminary and exploratory. Larger, multi-center studies with longer follow-up are needed to confirm whether serum PD-L1 measurement can reliably guide clinical decision-making in this patient population.
Naguib M, Fathy M, Mohamed H, Moussa M, Eid I. (2026). Elevated serum soluble PD-L1 is associated with adverse outcomes after autologous stem cell transplantation in transplant-eligible multiple myeloma patients.. The Egyptian journal of immunology. https://doi.org/10.55133/eji.330412