Classical and Late-Onset SOS/VOD After Allogeneic HSCT: A Japanese Transplant Registry Analysis

Area of Science:

• Hematology
• Transplantation Immunology
• Oncology

Background:

• Sinusoidal obstruction syndrome/veno-occlusive disease (SOS/VOD) is a life-threatening complication following allogeneic hematopoietic stem cell transplantation (allo-HSCT).
• Current classification distinguishes between classical and late-onset SOS/VOD, but their specific characteristics and implications require further elucidation.

Purpose of the Study:

• To retrospectively analyze the incidence, risk factors, and impact on survival of classical and late-onset SOS/VOD in a large cohort of allo-HSCT recipients.
• To identify distinct risk factors associated with each subtype of SOS/VOD to inform targeted interventions.

Main Methods:

• Retrospective analysis of 16,518 allo-HSCT recipients using Japanese nationwide registry data.
• Evaluation of cumulative incidences, onset times, and hazard ratios for overall survival.
• Identification of risk factors through multivariate analysis, comparing classical and late-onset SOS/VOD.

Main Results:

• Cumulative incidences for classical and late-onset SOS/VOD were 2.5% and 2.2%, with median onset at 13 and 42 days post-transplant, respectively.
• Both classical and late-onset SOS/VOD significantly worsened overall survival (HR 3.45 and 3.98, respectively).
• Distinct risk factors were identified for each type, with some shared factors like hepatic comorbidities and myeloablative conditioning.

Conclusions:

• Classical and late-onset SOS/VOD exhibit different risk factor profiles and significantly impact allo-HSCT outcomes.
• Specific risk factors for classical SOS/VOD include poor performance status and hepatitis C virus positivity.
• Late-onset SOS/VOD is associated with specific conditioning regimens (TBI, BU, MEL) and donor types (cord blood, haploidentical), suggesting the need for tailored monitoring and treatment approaches.