Usefulness of the quantitative assessment of PRV-1 gene expression for the diagnosis of polycythemia vera and essential thrombocythemia patients

Abstract

Usefulness of the quantitative assessment of PRV-1 gene expression for the diagnosis of polycythemia vera and essential thrombocythemia patientsIn a recent article in this journal, Klippel et al 1 reported that overexpression of the polycythemia rubra vera 1 gene (PRV-1) in purified granulocytes can distinguish patients with polycythemia vera (PV) from those with secondary erythrocytosis (SE) and from healthy subjects. However, as Klippel et al pointed out, the frequency of PRV-1 overexpression in PV patients still remains to be precisely established; whereas they observed PRV-1 overexpression in all the patients who met the World Health Organization (WHO) criteria, other groups 2-4 reported PRV-1 overexpression in only a percentage of PV patients, ranging from 69% to 91%. These discrepancies may be due to the small number of cases studied, to the different procedures used, and to the fact that the PRV-1 expression has been evaluated in some cases on sorted granulocytes while in others on unfractioned peripheral blood (PB). Finally, the question concerning the PRV-1 expression in essential thrombocythemia (ET) and secondary thrombocytosis (ST) still remains to be answered.To establish the significance of the PRV-1 expression as molecular marker of PV and ET, we carried out the quantitative assessment of the PRV-1 transcript in 119 unfractioned PB samples collected from 34 PV patients; 12 secondary erythrocytosis (SE) cases, represented by 10 patients with lung and heart diseases and 2 cases with familiar erythrocytosis; 32 ET patients; 16 cases of secondary thrombocytosis (ST); and 25 healthy volunteers. PV and ET diagnosis was established according to the WHO criteria.To evaluate the PRV-1 transcript amount, we used a real-time quantitative polymerase chain reaction (PCR) assay based on a specific set of primers and probe (Assays-on-Demand, Gene Expression Products) supplied by Applied Biosystems (Foster City, CA). The values obtained were normalized using Abelson (ABL) as control gene, 5 and the results were expressed using the ⌬⌬Ct method as the efficiencies of both PCR reactions were determined and found to be equal. Normal samples expressed quite constant PRV-1 transcript amount (mean value of 2 Ϫ⌬⌬Ct , 5.3; range, 1-14), and PRV-1 transcript levels in PB from SE, including the 2 cases of familiar erythrocytosis, and ST patients were not significantly different from those detected in healthy subjects: the mean value of 2 Ϫ⌬⌬Ct was 4.8 (range, 1-12) in SE and 4.9 (range, 1-12) in ST (P ϭ .4 and P ϭ .45, respectively, by t test; Figure 1). By contrast, in all PV patients we detected high levels of PRV-1 transcript (mean value of 2 Ϫ⌬⌬Ct , 7517; range, 46-40 342). The difference is highly significant with respect to normal PB samples (P ϭ .005) and to SE (P ϭ .006). Similar results were obtained by analyzing the PB samples from ET patients: the mean value of 2 Ϫ⌬⌬Ct was 3949 (range, 29-38 967; Figure 1). Also, for ET patients the difference of expression is highly significant with respect to healthy subjects (...

Clinical significance of neutrophil CD177 mRNA expression in Ph‐negative chronic myeloproliferative disorders

“…In the last few years there has been considerable interest in the overexpression of neutrophil PRV‐1 mRNA as a specific molecular marker of PV (Klippel et al , 2003; Kralovics et al , 2003; Tefferi et al , 2003; Cilloni et al , 2004; Florensa et al , 2004). In spite of this, little is known about the biological function of this gene (Bock et al , 2003).…”

Retrospektive Analyse des klinischen Verlaufs bei 12 Kindern mit der Verdachtsdiagnose einer essenziellen Thrombozythämie

“…Obgleich diese Patienten einen vergleichsweise schweren Krankheitsverlauf erlitten, verbleibt aufgrund der niedrigen Zahlen die Wertigkeit dieser Untersuchung als Diagnose-und Prognosemarker im Kindesalter unklar. Zusammengenommen scheint das Vorliegen einer PRV-1-mRNA-Überexpression ein sensitiver Marker zu sein, um zwischen einer primären MPD und einer sekundären Erkrankung zu differenzieren [5]. Hämatologie und Stammzelltransplantation 353 ein erworbenes von-Willebrand-Syndrom vorliegt.…”

The PRV-1 gene expression in essential thrombocythemia

“…2 By using this approach, we found that PRV-1 m-RNA is increased in 95% of patients with PV and in all patients with ET, while it is undetectable in secondary erythrocythosis (SE) and thrombocythosis (ST). 2 In other published studies, the PRV-1 m-RNA has been quantitatively evaluated, [3][4][5][6][7][8] and the percentage of PRV-1-positive ET patients varies widely among the mentioned studies, ranging from 16% 3 to 100%. 7 Up to date we have investigated by RT-PCR 75 patients with ET, 27 patients with ST, and 20 healthy individuals.…”

“…2 In other published studies, the PRV-1 m-RNA has been quantitatively evaluated, [3][4][5][6][7][8] and the percentage of PRV-1-positive ET patients varies widely among the mentioned studies, ranging from 16% 3 to 100%. 7 Up to date we have investigated by RT-PCR 75 patients with ET, 27 patients with ST, and 20 healthy individuals. Clinical and laboratory data of patients are shown in Table 1 The authors clearly demonstrated that the detection of PRV-1-positive patients in ET increases by examining purified granulocytes (26% and 46% in unfractionated cells and granulocytes, respectively).…”