This study evaluated liver stiffness measurement (LSM) as a tool to predict and diagnose sinusoidal obstructive syndrome (SOS) following allogeneic hematopoietic stem cell transplantation (allo-HSCT). LSM guided conditioning regimen adjustments in high-risk patients and demonstrated diagnostic accuracy for SOS in patients with elevated bilirubin post-transplant.
Background
Sinusoidal obstructive syndrome (SOS) is a rare but severe complication after HSCT, with an incidence of about 10% in adults and mortality up to 80% in severe cases. SOS pathogenesis involves sinusoidal endothelial injury leading to hepatic congestion and portal hypertension, manifesting clinically as hyperbilirubinemia, hepatomegaly, ascites, and weight gain. Diagnosis relies on EBMT clinical criteria, but specificity is limited due to overlapping conditions. Liver stiffness measurement (LSM) is a non-invasive method used to assess liver fibrosis and portal hypertension and has been explored for SOS assessment.
Data Highlights
Group
Number of Patients
LSM Threshold (kPa)
Conditioning Regimen Adjustment
SOS Diagnosis Method
Pre-HSCT (High-risk)
11
>7 kPa
Low-toxicity regimen if LSM >7
Clinical follow-up
Post-HSCT (Elevated Bilirubin ≥2 mg/dl)
17
Determined by ROC analysis
N/A
EBMT criteria
Key Findings
Baseline LSM >7 kPa identified high-risk patients who benefited from conditioning regimen modification to reduce SOS risk.
Patients with LSM ≤7 kPa proceeded with standard conditioning despite elevated liver enzymes without increased SOS incidence.
Post-HSCT LSM significantly increased in patients who developed SOS compared to those who did not.
LSM demonstrated diagnostic accuracy for SOS in patients with bilirubin ≥2 mg/dl within 21 days post-transplant.
ROC analysis was used to determine optimal LSM cut-off values for SOS diagnosis, improving specificity over clinical criteria alone.
Clinical Implications
LSM can be integrated into pre-transplant evaluation to identify patients at high risk for SOS, allowing for tailored conditioning regimens that reduce toxicity. Additionally, LSM serves as a valuable adjunct diagnostic tool post-HSCT to differentiate SOS from other causes of liver injury, potentially enabling earlier and more accurate diagnosis and management.
Conclusion
Liver stiffness measurement is a promising non-invasive modality for both predicting SOS risk before allo-HSCT and diagnosing SOS after transplantation, supporting its use in clinical decision-making to improve patient outcomes.
References
EBMT Guidelines 2021 -- Diagnosis and Management of SOS
Debureaux et al. 2019 -- Liver Stiffness in HSCT Patients
Sheba Medical Center Study 2023 -- LSM and SOS Assessment
