In a controlled clinical trial, researchers found that the expression of PD1 and various microparticles were associated with proliferation and resistance to standard treatment in multiple myeloma (MM). Their findings were published in Scientific Reports. According to lead study author, Asmaa M. Zahran, the study’s examination of PD1 and different microparticles “suggested that they played a crucial role in myeloma progression.”
Thirty patients with newly diagnosed MM, along with 19 healthy participants of comparable age and sex, were enrolled in the study. All participants’ blood was collected for flow cytometric detection of CD4+, CD8+, CD4+PD1+, and CD8+PD1+T cells, total microparticles, CD138+ microparticles, and platelet microparticles.
MM patients had significantly higher levels of total microparticles and CD138+ microparticles compared to the control group, while platelet microparticles exhibited no significant difference between the two groups. Patients with MM exhibited significantly higher percentages of CD8+, PD1CD8+, and PD1CD4+T cells compared to controls, while the control group had a significantly higher percentage of CD4+T cells than MM patients.
Patients who did not achieve complete response had significantly higher percentages of platelet microparticles, CD138+ microparticles, PD1+CD8+, PD1+CD4+, and CD8+T cells (cutoff values = 61, 10.6, 13.5, 11.3, and 20.1, respectively; p = 0.002, 0.003, 0.017, 0.001 and 0.008 respectively).
The study’s authors ultimately surmised that expression of various microparticles and PD1 could be associated with proliferative potential and resistance to bortezomib-based treatments in patients with MM, and that they appear to play a role in disease progression as well.