blood test for multiple myeloma

Scientists in Toronto and China have developed a new blood test for multiple myeloma, which will make it much easier to detect this very common blood cancer.

Multiple Myeloma is the second most common cancer of the blood.  It is also the cause of nearly 20% of all blood cancer deaths.  In this cancer, some of the white blood cells start to multiply rapidly in the bone marrow (the red spongy tissue found inside many of our bones). Since the bone marrow is where most of our blood cells are produced, other important blood cells get crowded out.

As a result, patients become very sick and start to suffer from symptoms such as bone pain, anemia, and kidney failure. Their immune system is weakened by lowered levels of healthy white blood cells and they are at a higher risk of dying from deadly infections such as pneumonia.

Some of these white blood cells leave the bone marrow and enter the bloodstream where they are known as clonal circulating plasma cells or CPCs.  Unfortunately, there are only limited tests available to detect CPCs and they are not always reliable.  In the end, patients often have to undergo painful bone marrow extractions to test for cancerous cells.

Building a better mousetrap…

Scientists at the University of Toronto, in collaboration with colleagues in China have developed a new blood test for multiple myeloma that is much more reliable and easy to use. They relied on the fact that some of the properties of CPCs are different from other cells in the blood. CPCs are bigger than red blood cells and most white blood cells.  They can, therefore, be trapped in a filter that would let other blood cells pass through freely.

Dongfang Youang’s team developed a special microarray structure that contains pillars and spaces organized in a diamond pattern with holes small enough to trap CPCs.  When blood is run through this microarray structure, almost everything squeezes through except for some large white blood cells and CPCs.  The method is so successful that it captures over 20% of all the CPCs in a real blood sample, and over 50% of CPCs placed in a liquid with characteristics similar to blood plasma.

This means that samples with even small amounts of CPCs can be tested.  The system is sensitive enough to detect just a few CPCs present in half a millilitre of blood, which is roughly how many CPCs are usually found in a healthy person’s system or in a patient whose cancer is in remission.

A very promising future

There are many possible uses for this new blood test for multiple myeloma.  It is so sensitive that it can be used to test for the first signs of cancer or for relapses in patients where the number of CPCs found in blood begins to increase above normal.

But scientists are also very excited by the possibilities of using their new microarray structure for research.  By reversing the flow of the liquid, they can release the captured CPCs and use them to study cells from cancer patients.  Such concentrated samples of cells would be perfect for use in studies on the cell structure and the genetics of multiple myeloma, which could help to finally beat this disease.

 

Written by Nancy Lemieux

 

References:

  1. Youang, D. et al (2019). Mechanical segregation and capturing of clonal circulating plasma cells in multiple myeloma using micropillar-integrated microfluidic device. Retrieved 20 November 2019, from https://aip.scitation.org/doi/10.1063/1.5112050
  2. Tiny filters help detect cancerous blood cells. (2019). Retrieved 20 November 2019, from https://www.eurekalert.org/pub_releases/2019-11/aiop-tfh111219.php
  3. Myeloma Canada | What is Multiple Myeloma?. (2019). Retrieved 20 November 2019, from https://myeloma.ca/en/about-multiple-myeloma/what-is-myeloma
  4. Multiple myeloma. (2019). Retrieved 20 November 2019, from https://en.wikipedia.org/wiki/Multiple_myeloma

Image by Michal Jarmoluk from Pixabay

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