Successful Treatment of Systemic Light Chain Amyloidosis with Liver Involvement using Low-Frequency Daratumumab: A Case Report.

BACKGROUND Systemic light chain (AL) amyloidosis is a disease characterized by the deposition of amyloid fibrils throughout tissues due to the production of misfolded immunoglobulin light chains by clonally expanded populations of CD38+ plasma cells. Some patients can have liver involvement, which typically presents with nonspecific symptoms. Daratumumab, a human CD38-targeting antibody, has shown efficacy in improving hematological parameters and organ function in patients with AL amyloidosis. Low-frequency daratumumab can reduce financial burden, but whether it is effective for patients with liver involvement has not been reported. CASE REPORT We present the case of a 64-year-old man admitted to our hospital with fatigue and recurrent fever. Histological analysis of a liver biopsy demonstrated AL amyloidosis. Bone marrow biopsy demonstrated the presence of abnormal plasma cells. Laboratory test results demonstrated increased levels of circulating free kappa (kappa) light chains, which were also seen on blood and urine immunofixation electrophoresis. Based on these findings, AL amyloidosis of the kappa light chain type with liver, cardiac, and renal involvement was diagnosed. The patient ultimately achieved hematological stringent complete response, liver remission, renal complete response, and cardiac very good partial response after 2 cycles of the low-frequency daratumumab, bortezomib, and dexamethasone regimen and 4 cycles of daratumumab and dexamethasone regimen chemotherapy. CONCLUSIONS The case indicates that low-frequency daratumumab treatment can have efficacy in AL amyloidosis with liver involvement.