Imaging features of myeloproliferative neoplasms

Liver and spleen shear-wave elastography in the diagnosis and severity staging of myeloproliferative diseases and myelofibrosis

AIMS

Spleen and liver stiffness, investigated by VCTE (Vibration-Controlled Transient Elastography), have been associated with marrow fibrosis in patients with myeloproliferative neoplasms (MPNs). Tissue stiffness can be assessed by shear wave point (pSWE) and bidimensional elastography (2DSWE). Spleen stiffness (SS) values were higher in Myelofibrosis (MF) and Polycythemia Vera (PV) compared to Essential Thrombocythemia (ET). We aimed to identify SWE differences between MPN patients and healthy volunteers; to evaluate specific SWE features in patients with MF, PV and ET; to establish a correlation with bone marrow fibrosis in patients with myeloproliferative disease.

METHODS

Patients with myeloproliferative disease and healthy volunteers performed evaluation of spleen and liver stiffness (LS) by pSWE and 2DSWE.

RESULTS

A total of 218 subjects were included: 143 with myeloproliferative disease (64 MF, 29.4%, 33 PV, 15.1% and 46 ET, 21.1%), and 75 (34.4%) healthy volunteers. Compared to volunteers, MF patients had greater spleen (pSWE 40.9 vs. 26.3 kPa, p < 0.001; 2DSWE 34.9 vs. 20.1 kPa, p < 0.001), and liver stiffness (pSWE 7.72 vs. 5.52 kPa, p < 0.001; 2DSWE 6.96 vs. 5.01 kPa, p < 0.001). In low (0-1) (n = 81, 60.4%) versus high-grade bone marrow fibrosis (2-3) (n = 42, 39.6%), is evident a higher median stiffness in patients with higher grades of fibrosis both for liver (pSWE 5.2 vs. 6.65 kPa; 2DSWE 5.1 vs. 6.05 kPa) and spleen (pSWE 27.2 vs. 37.9 kPa, 2DSWE 21.7 vs 30.75 kPa-p < 0.001 in both).

CONCLUSION

SWE evaluation distinguishes MF patients from HV and ET/PV and may help in MPN diagnosis. LS and SS values are associated with bone marrow fibrosis grade.

Bomedemstat as an investigative treatment for myeloproliferative neoplasms

INTRODUCTION

Myeloproliferative neoplasm (MPN) is a heterogeneous group of hematopoietic stem cell disorders characterized by clonal proliferation of one of more of the hematopoietic stem cell lineages. Clinical manifestations result from uncontrolled myeloproliferation, extramedullary hematopoiesis with splenomegaly and excessive inflammatory cytokine production. Currently available therapy improves hematologic parameters and symptoms but does not adequately address the underlying neoplastic biology. Bomedemstat has thus far demonstrated clinical efficacy and tolerability in the treatment of MPNs with recent evidence of impacting the malignant stem cell population.

AREAS COVERED

This review summarizes the mechanisms of action, pharmacokinetics and pharmacodynamics, safety and efficacy of bomedemstat in MPN with specific emphasis on essential thrombocythemia (ET) and myelofibrosis (MF).

EXPERT OPINION

In patients with MPNs, bomedemstat appears effective and well tolerated. The signs and symptoms of these diseases are managed as a reduction in the frequency of mutant cells was demonstrated in patients with ET and MF. Ongoing and planned studies of bomedemstat in MPN will establish the position of bomedemstat in MPNs and may help to redefine treatment endpoints of MPNs in the future.

Imaging of bone marrow pitfalls with emphasis on MRI

Normal marrow contains both hematopoietic/red and fatty/yellow marrow with a predictable pattern of conversion and skeletal distribution on MRI. Many variations in normal bone marrow signal and appearances are apparent and the reporting radiologist must differentiate these from other non-neoplastic, benign or neoplastic processes. The advent of chemical shift imaging has helped in characterising and differentiating more focal heterogeneous areas of red marrow from marrow infiltration. This review aims to cover the MRI appearances of normal marrow, its evolution with age, marrow reconversion, variations of normal marrow signal, causes of oedema-like marrow signal, and some common non-neoplastic entities, which may mimic marrow neoplasms.

Gastrointestinal bleeding: imaging and interventions in cancer patients

Gastrointestinal bleeding (GIB) among cancer patients is a major source of morbidity and mortality. Although a wide variety of etiologies contribute to GIB, special considerations should be made for cancer-related factors such as the type of malignancy, location and extent of disease, hemostatic parameters, and treatment effects. Key imaging modalities used to evaluate GIB include computed tomography angiography (CTA), radionuclide imaging, and catheter-based angiography. Understanding the cancer and treatment history and recognizing the associated imaging manifestations are important for identifying the source and potential causes of GIB in cancer patients. This article will review the common clinical presentations, causes, imaging manifestations, and angiographic management of GIB in cancer patients.

The Synergistic Inhibitory Effect of Combining MK-2206 and AZD 6244 in MARIMO Cells Harboring a Calreticulin Gene Mutation

INTRODUCTION

Somatic mutations in the calreticulin (CALR) gene occur in most myeloproliferative neoplasm (MPN) patients who lack Janus kinase 2 or thrombopoietin receptor (MPL) mutations, but the molecular pathogenesis of MPN with mutated CALR is unclear, which limited the further treatment for CALR gene mutant patients.

OBJECTIVES

Previous studies showed that CALR mutations not only activated serine/threonine protein kinase (AKT) in primary mouse bone marrow cells but also mitogen-activated protein kinases (MAPKs) in MARIMO cells harboring a heterozygous 61-bp deletion in CALR exon 9, which were responsible for mutant CALR cell survival, respectively. Hence, we aimed to initially explore the mechanism of AKT activation and observe the synergistic inhibitory effect of combining AKT (MK-2206) and MAPK kinase (AZD 6244) inhibitors in MARIMO cells.

METHODS

We detected the expression of phosphorylated AKT in MARIMO cells treated with inhibitors for 24 or 48 h by western blotting and analyzed cell proliferation, cell cycle, and apoptosis by flow cytometry. We further examined the synergistic inhibitory effect of combining MK-2206 and AZD 6244 in MARIMO cells using the median effect principle of Chou and Talalay.

RESULTS

We found that the AKT was activated in MARIMO cells, and blocking its activity significantly inhibited MARIMO cell growth with downregulation of cyclin D and E, and accelerated cell apoptosis by decreasing Bcl-2 but increasing Bax and cleaved caspase-3 levels in a dose-dependent manner. Further analysis showed that AKT activation was dependent on mammalian target of rapamycin but not on the JAK signaling pathway in MARIMO cells, displaying that inhibition of JAK activity by ruxolitinib (RUX) did not decrease the AKT phosphorylation. Furthermore, the combination of MK-2206 and AZD 6244 produced a significantly synergistic inhibitory effect on MARIMO cells.

CONCLUSIONS

AKT activation is a feature of MARIMO cells and co-targeting of AKT and MAPKs signaling pathways synergistically inhibits MARIMO cell growth.

Kidney Involvement in Patients With Chronic Myelomonocytic Leukemia or BCR-ABL-Negative Myeloproliferative Neoplasms

Introduction

The identification of specific molecular signatures and the development of new targeted drugs have changed the paradigm of onco-nephrology, now allowing a multiscale approach of kidney involvement related to hematologic malignancies relying on combined hematologic and molecular assessments. In this study, we aimed to refine the spectrum of kidney disorders associated with chronic myelomonocytic leukemia (CMML) or BCR-ABL–negative myeloproliferative neoplasms (MPNs), 2 very rare conditions scarcely described.

Methods

Case series. Patients with myeloid neoplasms who were referred to Toulouse University Hospital Nephrology Unit and were diagnosed with acute kidney injury (AKI), chronic kidney disease (CKD), or urine abnormalities were retrospectively included.

Results

Eighteen patients (males n=13, CMML n=8, essential thrombocytosis [ET] n=7, polycythemia vera [PV] n=1, and myelofibrosis n=2) developed kidney disease 7.7±2 years after the diagnosis of the malignancy. Twelve patients had AKI at presentation. Eight patients had glomerular presentation (high-range proteinuria 33%, microscopic hematuria 56%). Kidney biopsy (n=14) showed various patterns, including pauci-immune glomerulosclerosis (n=5), extramedullary hematopoiesis (n=6), or tubular atrophy and interstitial fibrosis with polymorphic inflammation (n=8). Immunostaining of CD61 confirmed the infiltration of megakaryocytes within glomeruli or interstitium in 5 of 8 patients. Other pictures of glomerulopathy were identified in 3 patients (IgA nephropathy n=2, AA amyloidosis n=1). Massive kidney infiltration by CMML was identified in 1 patient. After a mean follow-up of 24±6 months, malignancy was considered as stable in 11 patients (61%), but 22% of patients had progressed to end-stage renal failure. The remaining had persistently reduced kidney function. No correlation between the malignancy and the renal presentation and outcomes could be identified.

Conclusions

Kidney complications of CMML/MPN are heterogenous, and kidney biopsy may help to identify new molecular targets to prevent the development of kidney fibrosis.

[Myelofibrosis: A review]

Myelofibrosis is a BCR-ABL1-negative chronic myeloproliferative neoplasm that includes primary myelofibrosis, post-polycythemia vera myelofibrosis, and post-essential thrombocythemia myelofibrosis. It is characterized by stem cell-derived clonal proliferation that is often, but not always, accompanied by somatic mutations, which are classified into driver mutations (JAK2, CALR, or MPL), subclonal mutations and fibrosis on bone marrow biopsy. Myelofibrosis commonly demonstrates splenomegaly, constitutional symptoms, anemia, thrombocytosis, or thrombocytopenia. Patients may also be asymptomatic. Complications as thromboembolic or hemorrhagic events can reveal the disease. Primary myelofibrosis is the least common myeloproliferative neoplasm but is associated with poor survival and acute leukemic transformation. In contrast to the significant progress made in understanding the disease's pathogenesis, treatment for myelofibrosis remains largely palliative. The JAK2 inhibitor, ruxolitinib is not sufficient in eliminating the underlying myeloid progenitor clone, as disease inevitably returns with therapy discontinuation. Allogeneic hematopoietic stem cell transplantation is the only therapeutic option that offers potential cure. The development of novel treatment strategies aimed at slowing or even reversing disease progression, prolonging patient survival and preventing evolution to blast-phase are still lacking.

Primary myelofibrosis: spectrum of imaging features and disease-related complications

Primary myelofibrosis is a chronic clonal stem cell disorder that results in a build-up of marrow fibrosis and dysfunction, hypermetabolic states, and myeloid metaplasia. The clinical and radiological consequences can be quite diverse and range from the manifestations of osteosclerosis and extramedullary haematopoiesis to thrombohaemorrhagic complications from haemostatic dysfunction. In addition, there is the challenge of identifying less well-recognised sites of extramedullary haematopoiesis and their site-specific complications. The intent of this article is to illustrate the spectrum of primary myelofibrosis as declared though multimodality imaging, with examples of both common and rarer disease manifestations.

Myeloproliferative Neoplasms: A Primer for Radiologists

The myeloproliferative neoplasms (MPNs) are a heterogeneous group of diseases including polycythemia vera, essential thrombocythemia, and primary myelofibrosis. Knowledge of the radiological and clinical features of MPNs and their associated complications is critical for interpreting radiologists. The purpose of this article is to provide a primer to radiologists summarizing the modern understanding of MPNs from an imaging-based perspective, including common disease-related findings and complications related to hematopoietic cell transplant.

The changing face of cancer diagnosis: From computational image analysis to systems biology

ᅟ: KEY POINTS: • Radiomics and radiogenomics will merge radiology, nuclear medicine, pathology and laboratory medicine. • Automation of image data analysis will change the daily routine work. • Image-guided therapy and handling complex radiogenomic data will play a major role.