Sinusoidal Obstruction Syndrome After Allogeneic Hematopoietic Cell Transplantation With Post-Transplant...

Area of Science:

• Hematology
• Transplantation Immunology

Background:

• Sinusoidal obstruction syndrome/veno-occlusive disease (SOS/VOD) is a severe complication post-allogeneic hematopoietic cell transplantation (HCT).
• Limited data exist on SOS/VOD incidence and outcomes with post-transplant cyclophosphamide (PTCy)-based graft-versus-host disease (GVHD) prophylaxis.

Purpose of the Study:

• To evaluate the incidence, clinical features, risk factors, treatment, and outcomes of SOS/VOD in HCT recipients receiving PTCy-based GVHD prophylaxis.
• To identify specific risk factors and assess the impact of SOS/VOD on survival post-HCT.

Main Methods:

• A single-center observational study of 532 adult HCT recipients with PTCy between 2017-2024.
• Prospective data collection on demographics, transplant procedures, toxicities, and complications; chart review for missing information.
• SOS/VOD diagnosis and severity grading using EBMT criteria; multivariable analysis for risk factors.

Main Results:

• SOS/VOD occurred in 35 patients (6.6% 100-day cumulative incidence), with 40% late-onset cases.
• Risk factors identified: prior transplantation, prior antibody-drug conjugates, and higher CD3+ cell dose.
• Four patients (11.4%) died from SOS/VOD, all very severe cases; SOS/VOD did not impact overall survival or nonrelapse mortality.

Conclusions:

• SOS/VOD is a clinically manageable complication post-HCT with PTCy, characterized by a modest incidence and relatively low mortality.
• Identifying risk factors like prior transplantation and higher CD3+ cell doses is crucial for vigilant monitoring and individualized management.
• Late-onset SOS/VOD and severe presentations necessitate tailored strategies for optimal patient outcomes.