Pb2097: clinical implication of cytogenetic aberrations in non-al amyloidosis monoclonal gammopathy of renal significance: a multi-center chinese case series

Topic: 14. Myeloma and other monoclonal gammopathies - Clinical Background: Reports on cytogenetic aberrations in non-AL amyloidosis-monoclonal gammopathy of renal significance (MGRS) and their impact on treatment efficacy are rare. Aims: Describing case series of patients with renal biopsies-proved non-AL amyloidosis-MGRS receiving bortezomib based clone-directed therapies. Methods: We retrospectively reviewed patients’ data from three hematological centers in China. The clinical characteristics, genetic information and renal outcome were analyzed. Results: Thirty-one patients were subjected to CD138 MACS-fluorescence in situ hybridization (FISH). Twenty-three cases (74.2%) harboured cytogenetic aberrations by magnetic sorting FISH. IgH translocations’ frequency was 61.3% and t(11;14) (q13;q32) accounted for 38.7% (Figure). After first line bortezomib-based treatment, among 21 patients with baseline dFLC (difference between involved and uninvolved serum free light chain level) more than 20 mg/L or SPEP (serum protein electrophoresis) more than 10 g/L, 11 achieved complete response (CR) or very good partial response (VGPR) or low-dFLC response. 9/11 VGPR + CR + low-dFLC response in the non-t (11;14) group while 3/10 achieved VGPR in the t (11;14) group (p = 0.084, Fisher test). According to ISA criteria, renal response was achieved in 15/18 in the non-t (11;14) group vs 3/11 in the t (11;14) group (p = 0.005). The 24h-UTP decreased by a median of 20% in the t (11;14) group and 74.1% in non-t (11;14) group (p = 0.005). Patients without t (11;14) showed a trend of eGFR improvement compared to the t (11;14) group.Summary/Conclusion: 61.3% non-AL-type amyloidosis-MGRS patients had IgH recombination, with t (11;14) (q13; q32) the most common. Patients with t (11;14) may have inferior renal responses to bortezomib-based treatment. Keywords: Multiple myeloma