#2800 AL amyloidosis with renal involvement: TAPSE and new therapies

Abstract Background and Aims Light chain (LA) deposition amyloidosis is the most common type of renal amyloidosis. It may be associated with monoclonal gammopathy of uncertain significance (MGUS), meeting criteria for monoclonal gammopathy of renal significance (MGRS), or present in the course of multiple myeloma. The therapy of choice is autologous hematopoietic stem cell transplantation (TAPSE), although given the associated risks, not all patients are considered candidates, and different therapeutic regimens may be used as an alternative or induction prior to TAPSE (Bortezomib/dexamethasone, daratumumab/bortezomib, cyclophosphamide-bortezomib-Dexamethasone (CyBorD). Method Retrospective observational study of a cohort of patients with AL amyloidosis evidenced by renal biopsy by spectrometry or immunohistochemistry. Data extracted from the HUVM biopsy registry (2017-2022). Results 12 patients. Median age: 64 years. 6 women and 6 men. Mean creatinine 1.14 ± 0.6 mg/dl and proteinuria 3.8 ± 2.9 g/24 h. Median monoclonal peak 0.348 g/dl. Light chain involved: 7 Lambda and 5 Kappa. 2 patients met criteria for MM. 2 Bence-Jones positive. The 4 patients who did not have a renal response achieved a renal response, while of the 6 who did have a response, only 3 had a response (p = 0.091), 2 of them with previous induction with DARATUMUMAB, representing 100% of the total number of patients with this scheme. 3 patients died, with a median from diagnosis of 508 days. 1 of them had previously received TAPSE, out of a total of 6, while among the 5 patients who did not undergo this therapy, we found 2 exitus (p = 0.387). Conclusion The most common form of presentation in our sample was as MSG, with only 2 patients with MM criteria at the time of diagnosis. It also associated a reduced monoclonal component, and the Bence-Jones study was mostly negative. We did not find significant prognostic differences between the different therapeutic groups, although it is worth noting the worse renal response in the TAPSE group (p = 0.091) and the better data associated with the DARATUMUMAB group.