CREB3L1 overexpression as a potential diagnostic marker of Philadelphia chromosome-negative myeloproliferative neoplasms.

Discrimination of Philadelphia-negative myeloproliferative neoplasms (Ph-MPNs) from reactive hypercytosis and myelofibrosis requires a constellation of testing including driver mutation analysis and bone marrow biopsies. We searched for a biomarker that can more easily distinguish Ph-MPNs from reactive hypercytosis and myelofibrosis by using RNA-seq analysis utilizing platelet rich plasma (PRP) derived RNAs from patients with essential thrombocythemia (ET) and reactive thrombocytosis, and CREB3L1 was found to have an extremely high impact in discriminating the two disorders. To validate and further explore the result, expression levels of CREB3L1 in PRP were quantified by reverse transcription quantitative PCR and compared among patients with ET, other Ph-MPNs, chronic myeloid leukemia (CML), and reactive hypercytosis and myelofibrosis. A CREB3L1 expression cut-off value determined based on PRP of 18 healthy volunteers accurately discriminated 150 driver mutation-positive Ph-MPNs from other entities (71 reactive hypercytosis and myelofibrosis, 6 CML, and 18 healthy volunteers) and showed both sensitivity and specificity of 1.0000. Importantly, CREB3L1 expression levels were significantly higher in ET compared to reactive thrombocytosis (p < 0.0001), and polycythemia vera compared to reactive erythrocytosis (p < 0.0001). Pathology-affirmed triple-negative ET (TN-ET) patients were divided into a high and low CREB3L1 expression group, and some patients in the low expression group achieved a spontaneous remission during the clinical course. In conclusion, CREB3L1 analysis has the potential to single-handedly discriminate driver mutation-positive Ph-MPNs from reactive hypercytosis and myelofibrosis, and also may identify a subgroup within TN-ET showing distinct clinical features including spontaneous remission. Table S1. Clinical characteristics of 150 patients with driver mutation-positive Philadelphia-negative myeloproliferative neoplasms. Table S2. List of the 57 differentially expressed genes (DEGs) and results of differential expression analysis and principal component analysis. Table S3. Clinical characteristics of pathology-affirmed triple-negative essential thrombocythemia patients with or without CREB3L1 overexpression. Fig. S1. Schematic illustration of the filtering process of CREB3L1 as an MPN-specific diagnostic marker. Fig. S2. Scatter plots showing correlations between CREB3L1 expression levels and various parameters. Fig. S3. CREB3L1 expression diminished after successful bone marrow transplantation. This article is protected by copyright. All rights reserved.