Liver stiffness in AL amyloidosis: interest in diagnosis and prognosis.

INTRODUCTION: Liver is frequently involved in AL amyloidosis. Diagnosis usually relies on hepatomegaly and elevated alkaline phosphatase levels. Liver stiffness (LS) at diagnosis and, overall, its follow-up remains to be further explored. MATERIAL AND METHODS: We assessed LS at diagnosis in a retrospective multicenter cohort. Patients were classified as having liver involvement only (group 1), heart involvement only (group 2), both (group 3), or neither (group 4). In a prospective monocentric cohort, we evaluated changes in LS over time. RESULTS: In the retrospective cohort of 56 patients, median LS values were 75 kPa in group 1 (n = 14), 11.6 kPa in group 2 (n = 17), 28.8 kPa in group 3 (n = 13), and 6.4 kPa in group 4 (n = 12). The ROC curve in patients with liver involvement identified an optimal cutoff of 13.6 kPa, with 92% sensitivity and 71% specificity. In the prospective cohort of 19 treated patients, median LS decreased with 91% reduction, 26% reduction, 79% reduction and 19% reduction respectively in groups 1, 2, 3 and 4. CONCLUSION: LS is useful for diagnosing hepatic involvement in amyloidosis. A threshold of 13.6 kPa, in the absence of other etiologies, could be prosposed as diagnostic criteria. A decrease in LS greater than 50% can be a marker of hepatic recovery. Clinically and prognostically significant cutoffs still need to be confirmed in future, larger-scale studies.