Ficolled bone marrow is superior to bone marrow buffy coat for detection of minimal residual disease in multiple myeloma

ABSTRACT

Objective: Buffy coat and ficoll of bone marrow (BM) are viable options for the study of minimal residual disease (MRD) in multiple myeloma (MM). As yet, there is no data about the superiority of either sample types. Herein, we aimed to address this issue.

Methods: Forty pairs of ficolled BMs and BM buffy coats of 19 MM patients were studied for MRD by allele-specific oligonucleotide real-time quantitative PCR, with patient-specific primers/probes whenever appropriate.

Results: There were 41 pairs of MRD data for comparison analysis due to one patient with biclonal disease. MRD levels in ficolls and buffy coats were highly concordant (r_s = 0.936, P < 0.0001), with 31 (76%) and seven (17%) pairs being concomitantly MRD-positive or -negative. On the other hand, apart from the 16 pairs being both MRD-negative, or -positive but not quantifiable in ficolls and buffy coats, majority (n = 22, 88%) had higher MRD levels in ficolled BMs than BM buffy coats. Furthermore, in 17 pairs, in which MRD was quantifiable in both, MRD levels in ficolled BMs were 3.1 times those of BM buffy coats (median, 567/10⁵ vs. 184/10⁵, P = 0.001).

Conclusion: Taken together, ficolled BM is more sensitive than BM buffy coat for MRD detection in MM, hence should be recommended.

KEYWORDS:

• Minimal residual disease
• ficolled bone marrow
• bone marrow buffy coat
• multiple myeloma
• sample preparation
• ASO RQ-PCR
• sensitivity
• red cell lysis

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

Dr Yinlei Bai completed his PhD program on minimal residual disease detection in multiple myeloma under the supervision of Prof Chim. Currently, he is a postdoctoral research fellow in Tsinghua University, doing research in immunology.

Prof Chor Sang Chim is the SH Ho Professor in Hematology & Oncology at the University of Hong Kong, and Honorary Consultant to the Department of Medicine at Queen Mary Hospital. His research interests include epigenetic alterations in hematological malignancies and minimal residual disease detection in multiple myeloma. Moreover, Prof Chim is an international myeloma expert. He is a member of the International Myeloma Working Group (IMWG), Executive Council Member of Asian Myeloma Network (AMN), invited founding member of International Academy of Clinical Hematology (IACH), invited member of the Global Committee of the European Society for Blood & Marrow Transplantation (EBMT) & research advisor of the Nanyang Academy of Science. Locally, he is the Founding & current Chairman of the Hong Kong Society of Myeloma (HKSOM), and has spearheaded the establishment of the myeloma patient group, the Hong Kong Myeloma Care & Share.

ORCID

Chor Sang Chim http://orcid.org/0000-0003-2427-915X

Additional information

Funding

This work was supported by National Natural Science Foundation of China [grant number 81470369] awarded to CSC.