PRV-1 mRNA expression discriminates two types of essential thrombocythemia

• Published in: Annals of hematology 2004-06, Vol.83 (6), p.364-370
• Main Authors: Griesshammer, M, Klippel, S, Strunck, E, Temerinac, S, Mohr, U, Heimpel, H, Pahl, H L
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Blotting, Northern; Cohort Studies; Diagnosis, Differential; Erythroid Precursor Cells - cytology; Erythroid Precursor Cells - pathology; Female; Gene Expression; GPI-Linked Proteins; Humans; Isoantigens - biosynthesis; Isoantigens - genetics; Male; Medical treatment; Membrane Glycoproteins - biosynthesis; Membrane Glycoproteins - genetics; Middle Aged; Polycythemia Vera - blood; Polycythemia Vera - complications; Polycythemia Vera - diagnosis; Polycythemia Vera - pathology; Receptors, Cell Surface; Retrospective Studies; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - biosynthesis; RNA, Messenger - genetics; Survival Analysis; Thrombocythemia, Essential - blood; Thrombocythemia, Essential - complications; Thrombocythemia, Essential - diagnosis; Thrombocythemia, Essential - pathology
• ISSN: 0939-5555; 1432-0584
• DOI: 10.1007/s00277-004-0864-9

Essential thrombocythemia (ET) is a heterogeneous disorder. For example, the growth of erythropoietin-independent erythroid colonies, termed "endogenous erythroid colonies (EECs)", has previously been observed in only 50% of ET patients. We have recently described the overexpression of a hematopoietic receptor, PRV-1 (polycythemia rubra vera-1), in patients with polycythemia vera (PV). Here, we compare PRV-1 expression and EEC formation in a cohort of 30 patients with ET; 50% of the ET patients in our cohort displayed EEC growth. Likewise, 50% of the ET patients overexpressed PRV-1. Remarkably, only the 15 ET patients displaying EEC growth showed elevated PRV-1 expression, while the 15 EEC-negative ET patients expressed normal PRV-1 levels. It has previously been reported that EEC-positive ET patients develop PV during long-term follow-up. Here, we show that 40% of the PRV-1-positive patients develop symptoms of PV during the course of their disease. In contrast, none of the 15 PRV-1-negative patients displayed such symptoms (p=0.017). Moreover, PRV-1-positive patients had a significantly higher number of thromboembolic or microcirculatory events (p=0.003). We propose that PRV-1-positive ET comprise a pathophysiologically distinct subgroup of patients, one that is at risk for the development of complications and for the emergence of PV.