In this iStopMM study Jon Þórir Oskarsson presents the results of determining hemodilution in diagnostic bone marrow samples in multiple myeloma and its precursors by Next-Generation Flow Cytometry (NGF).

Background:

A major limitation for quantification of bone marrow (BM) plasma cells (PC) is the quality of the sample. Hemodilution of BM aspirate samples results in underestimation of PC numbers and may lead to false-negative results in minimal residual disease (MRD) assessment. Next-generation flow (NGF) cytometry has the potential for using BM-associated cell populations as internal sample quality control. However, there is limited data on the reliability of different cell populations as markers of hemodilution.

Conclusions:

In this study of BM samples from screened individuals in the iStopMM study using NGF we found that there is a large difference in the number of PCs between 1st and 2nd pull samples, due to hemodilution. As a consequence, 1st pull samples are preferred as the use of 2nd pull (or later) samples may lead to misdiagnosis. We present a hemodilution score model which can aid in evaluating the quality of BM samples and indicate whether they are appropriate for diagnostic use. Importantly, the model is based on diagnostic samples and further validation is needed in patients undergoing MRD assessment following treatment. By objectively assessing hemodilution, sample quality may be taken into account when interpreting results, providing more information and improved prognostic value and utility of flow cytometry in patients with MM and its precursors.

Authors:

Jon Þórir Oskarsson, MSc, Sæmundur Rögnvaldsson, MD, Sigrún Thorsteinsdóttir, MD, PhD, Hrafnhildur Una Þórðardóttir, Gudlaug Katrin Hakonardottir, Steinar Bragi Gunnarsson, Gudrún Ásta Sigurdardóttir, Ásdis Rósa Thórdardottir, Gauti Gíslason, Andri Olafsson, Jon Kristinn Sigurdsson, Brynjar Vidarsson, MD, Páll Torfi Onundarson, MD, Bjarni Agnar Agnarsson, MD, Robert Palmason, Margrét Sigurdardóttir, MD, Ingunn Thorsteinsdóttir, MD, PhD, Ísleifur Ólafsson, MD, PhD, Juan Flores-Montero, MD, PhD, Alberto Orfao, MD, PhD, Brian G.M. Durie, MD, Thorvardur Jon Love, MD, PhD and Sigurdur Y Kristinsson, MD, PhD

ASH Abstract #3188: https://ash.confex.com/ash/2022/webprogram/Paper168741.html (https://ash.confex.com/ash/2022/webprogram/Paper168741.html)