A team of researchers have developed a new device which they say can capture circulating clonal plasma cells in the blood of patients with multiple myeloma. Their study could lead to new ways to monitor patients while in remission and assess their risk of relapse.
When these myeloma cells leave the bone marrow and enter the bloodstream, the patient may be at an increased mortality risk. However, these circulating clonal plasma cells (cCPCs) are difficult to detect, especially at low levels.
The research, led by PhD Candidate Dongfang Ouyang under the supervision of Associate Professor Lidan You of the University of Toronto, and in collaboration with Dr Yonghua Li, Director of the haematology department at Guangzhou General Hospital, first used a computer model to design a microfluidic device containing tiny pillars that can isolate cCPCs from small samples of blood.
The tiny diamond-shaped pillars are organised to allow normal blood cells through the filter while capturing the cancerous circulating clonal plasma cells. cCPCs are not able to deform and squeeze between the pillars, so get stuck in the filter.
The system isolates cCPCs based on their size and mechanical properties rather than using antibody labels to capture them. The advantage of this ‘label-free’ system is that it would be possible to safely extract the cCPCs after capture in order to study them further.
The device was first tested using a myeloma cell line spiked into blood samples from healthy donors. Later, it was tested using blood samples donated by myeloma patients. The team found that the amount of cCPCs captured from patients with relapsed disease was much higher than from patients in remission, or from healthy volunteers.
Co-senior author Dr Lidan You said: “This device shows great potential as a noninvasive method for either early detection or monitoring of multiple myeloma disease progression.”
Details of the study appeared last week in the journal Biomicrofluidics.
Ouyang D, Li Y, He W, Lin W, Hu L, Wang C, Xu L, Park J, You L (2019) “Mechanical segregation and capturing of clonal circulating plasma cells in multiple myeloma using micropillar-integrated microfluidic device”, Biomicrofluidics, doi:10.1063/1.5112050