Next generation flow cytometry for MRD detection in patients with AL amyloidosis. (2nd January 2021)

• Record Type: Journal Article
• Authors: Kastritis, Esftathios; Kostopoulos, Ioannis V.; Theodorakakou, Foteini; Fotiou, Despina; Gavriatopoulou, Maria; Migkou, Magdalini; Tselegkidi, Maria Irini; Roussou, Maria; Papathoma, Alexandra; Eleutherakis-Papaioakovou, Evangelos; Dialoupi, Ioanna; Kanellias, Nikolaos; Ntalianis, Argyrios; Rousakis, Pantelis; Trougakos, Ioannis P.; Tsitsilonis, Ourania; Gakiopoulou, Charikleia; Terpos, Evangelos; Dimopoulos, Meletios A.
• Is Part Of: Amyloid. Volume 28:Number 1(2021)
• Page Start: 19
• Page End: 23
• Publication Date: 2021-01-02
• Subjects: EuroFlow -- free light chains -- minimal residual disease -- next generation flow cytometry -- NTproBNP; Amyloidosis -- Periodicals; 616.3995
• DOI: 10.1080/13506129.2020.1802713
• Languages: English
• ISSNs: 1350-6129

Abstract

Abstract: The treatment of AL amyloidosis aims to eradicate the plasma cell clone and eliminate toxic free light chain production. Only in a minority of patients the plasma cell clone is completely eradicated; residual light chain production may still exist while clonal relapse may occur. We used sensitive next-generation flow cytometry (NGF) to detect minimal residual disease (MRD) in AL amyloidosis patients at complete haematologic response. MRD evaluation was feasible in 51 of 52 (98%) tested patients and at a median sensitivity of 2.3 × 10 −6 MRD was undetectable in 23 (45%). An organ response occurred in 86% of MRDneg vs 77% in MRDpos; renal response in 15/17(88%) of MRDneg vs in 14/16(87.5%) of MRDpos and cardiac response in 10/10(100%) of MRDneg vs 11/15(73%) of MRDpos patients. After a median follow-up of 24 months post MRD testing, no MRDneg patient had a haematologic relapse vs 6/28(21%) MRDpos ( p = .029). Pooling haematologic and organ progressions, 9 (32%) MRDpos patients had disease progression vs only 1 (4%) MRDneg patient ( p = .026). In conclusion, MRD detection using NGF has profound clinical implications, so that AL patients with undetectable MRD have a very high probability of organ response and a very low probability of haematologic relapse.