Distinctive CD8 T cell and MHC class I signatures in polycythemia vera patients.

Polycythemia vera (PV) is a myeloproliferative neoplasm characterized by overproduction of red blood cells. We have performed a comprehensive characterization of blood immune cells for expression of naïve and memory receptors as well as βm-associated and βm-free MHC class I heavy chains, also known as closed and open conformers, respectively, in PV patients and age-matched controls (CTR). We show that the peripheral CD3CD8 T cell pool in PV patients is clearly divided into two discrete populations, a more granular CD3CD8 T cell population enriched in effector-memory CD45RA T cells (CD8 TEMRA) when compared to CTR (P < 0.