Liver Elastography in Acute Cellular Rejection After Liver Transplantation.

Background: Transient elastography is a noninvasive method used to estimate the liver stiffness. There are few studies using elastography in acute cellular rejection (ACR). ACR is one of the main complications after liver transplantation. The golden pattern diagnostic is by liver biopsy, which is invasive and subject to complications. Therefore, this paper aims to evaluate the use of elastography in ACR.

Methods: Prospective and comparative study of patients transplanted from January 2017 to March 2019. Comparison group (ACR vs non-ACR) through liver biopsy. The variables analyzed were liver elastography (FibroScan and acoustic radiation force impulse [ARFI]), laboratory tests, liver biopsy, and ultrasound. Mann-Whitney U test was used to compare independent samples, and P < .05 was considered significant. All tests performed with α of 0.05 and a confidence interval of 95%, by IBM SPSS 25 software.

Results: Forty patients, 25 (62.5%) with ACR and 15 (37.5%) without ACR. Five (20%) cases with early acute rejection, late acute rejection in 19 cases (76%), and chronic rejection in 3 (12%). Comparative ACR vs non-ACR showed results of total bilirubin (P = .03), direct bilirubin (P = .015), aspartate aminotransferase (0.001), alanine aminotransaminase (0.001), and gamma-glutamyl transferase (P = .026). The mean elastography (FibroScan) value in ACR was 12.5 ± 8.2 kPa and without was 8.9 ± 3.7 kPa, P = .05. The mean elastography (ARFI) in ACR was 1.9 ± 0.6 m/s and without was 1.6 ± 0.2 m/s, P > .05. The receiver operator characteristic curve analysis shows the FibroScan for ACR with AUC 0.688 (95% CI 0.511-0.865), P = .049, positive predictive value 0.76, and negative predictive value 0.60.

Conclusions: Transient elastography is an important tool for ACR. There is a significant correlation between ACR and the value of hepatic elastography.