Image: The small plastic chip about the size of a credit card that can deliver the same diagnostic information as a bone marrow biopsy but using a simple blood draw instead (Photo courtesy of the University of Kansas).
The diagnosis of multiple myeloma, a cancer affecting plasma cells, traditionally forces patients to suffer through a painful bone biopsy. Doctors insert a bone-biopsy needle through an incision to get a bone marrow sample or make a larger incision and remove a section of bone via surgery.
However, the days of using bone biopsies to guide treatment for multiple myeloma and other cancers, such as many types of leukemia, may be numbered. A low-cost, reliable blood test that uses a small plastic chip about the size of a credit card that can deliver the same diagnostic information as a bone biopsy, but using a simple blood draw instead.
Scientists collaborating with those at the University of Kansas (Lawrence, KS, USA) took blood samples from patients with plasma cell disorders, which were analyzed for the presence of circulating plasma cells (CPCs) using a microfluidic device modified with monoclonal anti-CD138 antibodies. CPCs were immuno-phenotyped using a CD38/CD56/CD45 panel and identified in 78% of patients with monoclonal gammopathy of undetermined significance (MGUS), all patients with festering and symptomatic multiple myeloma (MM), and none in the controls.
The burden of CPCs was higher in patients with symptomatic MM compared with MGUS and festering MM. Fluorescence in situ hybridization (FISH) analysis revealed the presence of chromosome 13 deletions in CPCs that correlated with bone marrow results. Point mutations in KRAS were identified, including different mutations from sub-clones derived from the same patient. The authors concluded that the microfluidic assay represents a highly sensitive method for enumerating CPCs and allows for the cytogenetic and molecular characterization of CPCs.
Steven A. Soper, PhD, the Distinguished Professor of Chemistry and Mechanical Engineering, and the senior author of the study, said, “The chip we're using, because it is made from a plastic, can be injection molded, the same method that is used to produce CDs, DVDs and Blu-ray Discs. What's really nice is we can produce these chips for a couple of dollars per chip, which makes it really appropriate for testing in a clinical setting.” The new test will be brought to market by BioFluidica (San Diego, CA, USA). The study was originally published on January 22, 2018, in the journal Integrative Biology.
University of Kansas