Instability of PRV-1 mRNA: a factor to be considered in PRV-1 quantification for the diagnosis of polycythemia vera.

High expression of PRV-1 mRNA in granulocytes has been proposed as a new diagnostic marker for polycythemia vera. We used real-time reverse transcription polymerase chain reaction (RT-PCR) to measure the levels of PRV-1 mRNA, GAPDH mRNA and 18S rRNA in granulocytes obtained from blood samples processed 2, 24 and 48 hours after collection and observed a significant decrease of PRV-1 levels after 24 and 48 hours. The instability of PRV-1 mRNA may affect the diagnostic value of the PRV-1 test in blood samples stored for extended periods.