title: PRV-1 mRNA expression discriminates two types of essential thrombocythemia.
abstract: 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.
authors.affiliation: Department of Medicine III, Hematology, Oncology, Rheumatology and Infectious Diseases, University of Ulm, Robert-Koch-Strasse 5, 89081 Ulm, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Griesshammer
authors.forename: S
authors.initials: S
authors.lastname: Klippel
authors.forename: E
authors.initials: E
authors.lastname: Strunck
authors.forename: S
authors.initials: S
authors.lastname: Temerinac
authors.forename: U
authors.initials: U
authors.lastname: Mohr
authors.forename: H
authors.initials: H
authors.lastname: Heimpel
authors.forename: H L
authors.initials: HL
authors.lastname: Pahl
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015152:Blotting, Northern; D015331:Cohort Studies; D003937:Diagnosis, Differential; D015672:Erythroid Precursor Cells / Q000166:cytology / Q000473:pathology; D005260:Female; D058851:GPI-Linked Proteins; D015870:Gene Expression; D006801:Humans; D007519:Isoantigens / Q000096:biosynthesis* / Q000235:genetics; D008297:Male; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000235:genetics; D008875:Middle Aged; D011087:Polycythemia Vera / Q000097:blood / Q000150:complications / Q000175:diagnosis* / Q000473:pathology; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000235:genetics; D011956:Receptors, Cell Surface; D012189:Retrospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016019:Survival Analysis; D013920:Thrombocythemia, Essential / Q000097:blood / Q000150:complications / Q000175:diagnosis* / Q000473:pathology
chemical_list: C407242:CD177 protein, human; D058851:GPI-Linked Proteins; D007519:Isoantigens; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D011956:Receptors, Cell Surface