Supersonic shear-wave elastography and APRI for the detection and staging of liver disease in pediatric cystic fibrosis.

Background: Current diagnostic methods for the diagnosis of Cystic fibrosis (CF)-associated liver disease (CFLD) are non-specific and assessment of disease progression is difficult prior to the advent of advanced disease with portal hypertension. This study investigated the potential of Supersonic shear-wave elastography (SSWE) to non-invasively detect CFLD and assess hepatic fibrosis severity in children with CF.

Methods: 125 children were enrolled in this study including CFLD (n = 55), CF patients with no evidence of liver disease (CFnoLD = 41) and controls (n = 29). CFLD was diagnosed using clinical, biochemical and imaging best-practice guidelines. Advanced CFLD was established by the presence of portal hypertension and/or macronodular cirrhosis on ultrasound. Liver stiffness measurements (LSM) were acquired using SSWE and diagnostic performance for CFLD detection was evaluated alone or combined with aspartate aminotransferase-to-platelet ratio index (APRI).

Results: LSM was significantly higher in CFLD (8.1 kPa, IQR = 6.7-11.9) versus CFnoLD (6.2 kPa, IQR = 5.6-7.0; P < 0.0001) and Controls (5.3 kPa, IQR = 4.9-5.8; P < 0.0001). LSM was also increased in CFnoLD versus Controls (P = 0.0192). Receiver Operating Characteristic (ROC) curve analysis demonstrated good diagnostic accuracy for LSM in detecting CFLD using a cut-off = 6.85 kPa with an AUC = 0.79 (Sensitivity = 75%, Specificity = 71%, P < 0.0001). APRI also discriminated CFLD (AUC = 0.74, P = 0.004). Classification and regression tree modelling combining LSM + APRI showed 14.8 times greater odds of accurately predicting CFLD (AUC = 0.84). The diagnostic accuracy of SSWE for discriminating advanced disease was excellent with a cut-off = 9.05 kPa (AUC = 0.95; P < 0.0001).

Conclusions: SSWE-determined LSM shows good diagnostic accuracy in detecting CFLD in children, which was improved when combined with APRI. SSWE alone discriminates advanced CFLD.