Performance of Vibration-Controlled Transient Elastography and Clinical Prediction Models In Liver Transplant Recipients

Liver Transplantation and Metabolic Dysfunction Associated Steatotic Liver Disease Is Associated with Markers of Metabolic Risk and Inflammation

BACKGROUND

Liver transplant (LT) recipients are at high risk of cardiometabolic disease and mortality. However, routinely employed clinical risk tools have sub-optimal diagnostic performance due to transplant related biological changes. Metabolic vulnerability index (MVX) is a serum-based composite biomarker comprised of nutritional risk [metabolic malnutrition index or MMX] and chronic inflammation [inflammatory vulnerability index or IVX]. MVX is a predictor of cardiovascular risk and all-cause mortality in the general population, however, the effect of LT on MVX is unknown.

METHODS

To better quantify MVX after transplantation, LT recipients (n = 181) prospectively enrolled in a natural history study were matched with non transplant controls from the MESA study of healthy individuals. All controls were matched 1:1 regarding age and gender. Additionally, lean controls were identified as those with BMI < 25 kg/m2 and BMI-matched controls who were propensity matched for BMI.

RESULTS

Compared to matched controls, LT recipients had significantly higher MVX (56.9 ± 10.1 vs. 45.8 ± 9.4 vs. 44.8 ± 9.3, p < 0.001), IVX [53.1 ± 12 vs. 39.3 ± 11.2 vs. 40.2 ± 10.9, p < 0.001), and MMX (58.7 ± 8.2 vs. 55.4 ± 6.5 vs. 53.1 ± 6.0, p < 0.001). No significant differences were noted in MVX in LT recipients who developed metabolic dysfunction associated steatotic liver disease (MASLD) after LT. In a multivariate analysis, MVX scores were positively associated with female gender, diabetes, serum AST and BMI, and negatively with dyslipidemia.

CONCLUSION

LT is associated with a significant increase in MVX and its components, suggesting a heightened risk in LT recipients that is above that of the non-LT population. Future well designed prospective studies are required to calibrate MVX to clinical outcomes in LT patients.

Development of Clinical Algorithm Utilizing Vibration-Controlled Transient Elastography to Detect Advanced Hepatic Fibrosis in Liver Transplant Recipients

INTRODUCTION

Vibration-controlled transient elastography (VCTE) based liver stiffness measurement (LSM) is an excellent 'rule-out' test for advanced hepatic fibrosis in liver transplant (LT) recipients, however, its ability to 'rule-in' the disease is suboptimal. The study aimed to improve diagnostic performance of LSM in LT recipients.

METHODS

Adult LT recipients with a liver biopsy and VCTE were included (N = 150). Sequential covering analysis was performed to create rules to identify patients at low or high risk for advanced fibrosis (stage 3-4).

RESULTS

Advanced hepatic fibrosis was excluded in patients with either LSM < 7.45 kPa (n = 72) or 7.45 ≤ LSM < 12.1 kPa and time from LT < 5.6 years (n = 25). Conversely, likelihood of advanced fibrosis was 95% if patients had LSM > 14.1 and controlled attenuation parameter > 279 dB/m (n = 21). Thus, 118 (79%) were correctly identified and 32 (21%) would have required a biopsy to establish the diagnosis. Compared to previously established LSM based cutoff values of 10.5 kPa (Youden index) and 13.3 kPa (maximized specificity), the false positive rates of sequential covering analysis was 1% compared to 16.5% with LSM ≥ 10.5 kPa and 8.3% with LSM ≥ 13.3 kPa. The true positive rates were comparable at 87% for sequential covering analysis, 93% for LSM ≥ 10.5 kPa and 83% for LSM ≥ 13.3 kPa.

CONCLUSION

The proposed clinical sequential covering analysis allows for better risk stratification when evaluating for advanced fibrosis in LT recipients compared to LSM alone. Additional efforts are necessary to further reduce the number of patients with indeterminate results in whom a liver biopsy may be required.