Coexistance of Multiple Myeloma and Myelodysplastic Syndrome or Lymphoid Diseases At Diagnosis: Evidence for Two Clonal and Independent Chromose Abnormalities
Authors: Mossafa Hossein , Defasque Sabine , Fourcade Christine , Hurst JeanPierre , Joly Bertrand 
Published: October 2019

Abstract
Abstract 5063
Introduction, We describe the simultaneous presentation of multiple myeloma (MM) and yeloproliferative disorders (MPD) or lymphoid diseases (LD) at diagnosis. Therapy-related myelodysplasia (tMDS) occurring during the course of MM is generally believed as a result from hematopoietic stem cell-toxic therapies, such as ionizing radiation and alkylating agent-based chemotherapies (melphalan, nitrosoureas).Patients and methods, We study a total of 342 patients (151 F, 191 M; median age 68.1 years; range 42 to 93 Years), diagnosed with MM based on the International Staging System. The basis for inclusion of patients in this study was with previous untreated MM ones. The study was performed in accordance with the declaration of Helsinki. To determine whether chemotherapies for MM factors play the critical role in the development of secondary disease, simultaneously two different cultures were processed, an unstimulated 96 hours culture (U96HC) on whole BM(WBM), a short-time 24 hours culture (ST24HC) after CD138+ plasma cells (PCs) depleted on negative fraction (CD138- cells) of BM and the FISH was investigated on purified CD138+.All samples were enriched in PCs by the Automated Magnetic Cell Sorter (Miltenyi technology)proceeded with anti-CD138 specific antibodies applied. The CD138+ PCs and the CD138- cells were collected in different tubes. The CD138− cells were used for a ST24HC. FISH was performed on the purified CD138+, PCs with a recommended FISH panel (MM International Working Group). Screening was performed systematically for the following unbalanced alterations and reciprocal rearrangements: del(13)(q14)(D13S25), del(17)(p13)(TP53),+3(D3Z), +9(D9Z1), +15(D15Z14), t(4;14)(p16;q32)/IGH-FGFR3, t(11;14)(q13;q32)/IGH-CCND1 (Abbott).After observing the results of U96HC on whole BM (CD138+ and CD138− cells), ST24HC (CD138− cells) and FISH for each patient, two clone cytogenetically were distinct and unrelated chromosomal abnormalities were found in 40 (11.7%) of the 342 MM patients (6 F, 34 M; median age 74 years; range 42 to 87 Years) 34 had a MPD and 6 had a LD. A second immunophenotyping analysis confirmed the presence of those LD/MM simultaneous haematological malignancy. In the cases of the patients with MM/ MPD, the frequency of cytogenetic abnormality unrelated to the myeloma clone was respectively; the 20q deletion, detected for 13 the 34 patients, the 20q- is a sole abnormality for 12 cases and associated with a complex caryotype in 1 case. The trisomy of chromosome +8 was observed in 7 cases, the del(7q) or monosomy 7 in 5 cases, loss of gonosome Y in 4 cases, del(11) for 2 cases, translocation t(9;22) in one case, 5q abnormality in one case and trisomy 9 with JAK2 V617F mutation in one case. For the patients with MM/LD, 5 patients had a trisomy +12 and or trisomy +18 like sole abnormality or associated with others cytogenetics abnormalities and one patient had 6q deletion. Discussion, Whereas in the literature the most common cytogenetic abnormalities typifying MPD after alkylator-based therapy include partial or complete deletions of chromosomes 5, 7, and 20 as well as trisomy 8. In our study we observed those abnormalities with the same frequency for the patients had simultaneous MPD associated in untreated MM at diagnosis. Six patients had simultaneous LD and MM. The marginal zone lymphoma was confirmed for 3 patients. The CC observed a trisomy +12 for those three patients associated with +18 and +19 for 2 cases and del(13) and trisomy 3 for one among them. We demonstrated in untreated MM patients the coexistence of MM and MPD or LD at diagnosis with MPD-type or LD-type chromosome abnormalities within MM signature karyotype. We hence recommend that CC studies, 96 hours WBM, 24 hours on negative fraction CD138− cells and FISH on purified CD138+ PCs, the three should be an integral part of the evaluation of patients with MM at diagnosis into clinical trials using HDT is warranted to determine whether patients who are predisposed to developing tMDS/sAML, they can be identified prospectively.

Disclosures:
No relevant conflicts of interest to declare.