Thrombocytosis and STAT5 activation in chronic myelogenous leukaemia are not associated with JAK2 V617F or calreticulin mutations. Issue 8 (11th January 2016)

• Record Type: Journal Article
• Authors: Turakhia, Samir K; Murugesan, Gurunathan; Cotta, Claudiu V; Theil, Karl S
• Is Part Of: Journal of clinical pathology. Volume 69:Issue 8(2016)
• Page Start: 713
• Page End: 719
• Publication Date: 2016-01-11
• Subjects: CHRONIC MYELOID LEUKAEMIA -- CYTOGENETICS -- HAEMATOPATHOLOGY -- MYELOPROLIFERATIVE DISEASE -- THROMBOCYTHAEMIA; Pathology -- Periodicals; Pathology, Molecular -- Periodicals; 616.0705
• DOI: 10.1136/jclinpath-2015-203498
• Languages: English
• ISSNs: 0021-9746

Abstract

Abstract : Aims: Marked thrombocytosis is uncommon in chronic myelogenous leukaemia (CML) but may be associated with mutation of JAK2 V617F, calreticulin ( CALR ) and/or phospho-STAT5 (p-STAT5) activation in other myeloproliferative neoplasms (MPNs), particularly essential thrombocythaemia (ET). We investigated the JAK2 V617F, CALR and STAT5 activation status in patients with CML and thrombocytosis (CML-T) that mimicked ET, trying to identify a common mechanism for thrombocytosis in MPN. Methods: Blood and bone marrow morphological findings were reviewed from seven CML-T, four otherwise typical CML and one CML in blast phase. All cases were analysed for BCR-ABL1, JAK2 V617F and CALR exon 9 mutation and p-STAT5 expression. Results: Four of seven cases of CML-T had marked thrombocytosis (>1000×10 9 /L). Eleven of 12 cases had megakaryocyte morphology typical for CML. All cases were BCR-ABL1 positive. Eleven of 12 cases were negative for JAK2 V617F, while STAT5 was activated in six of seven CML-T and in four of five CML cases. No case had a detectable CALR exon 9 mutation. One case of CML developed ET-like morphology and had JAK2 V617F detected while in molecular remission for CML. Conclusions: Detection of BCR-ABL1 is critical in the distinction of ET from CML. Thrombocytosis and STAT5 activation in CML-T are not consistently associated with CALR exon 9 or JAK2 V617F mutation.