Myelodysplastic Syndromes/Myeloproliferative Overlap Neoplasms and Differential Diagnosis in the WHO and ICC 2022 Era: A Focused Review

Clonal monocytosis of renal significance

Clonal monocytosis reflects a preneoplastic or neoplastic sustained increase in the absolute monocyte count in the absence of reactive causes. Causes of clonal monocytosis include clonal cytopenias with monocytosis and acute and chronic myeloid neoplasms. Chronic myelomonocytic leukemia is a prototypical myelodysplastic/myeloproliferative overlap neoplasm in adults, characterized by sustained peripheral blood monocytosis. Kidney abnormalities, including acute kidney injury and chronic kidney disease, are frequent in patients with chronic myelomonocytic leukemia and are predictors of worse outcomes. In addition, acute kidney injury/chronic kidney disease often limits eligibility for allogeneic stem cell transplantation or enrollment in clinical trials. In this review, we highlight clonal monocytosis-related etiologies that give rise to acute kidney injury and chronic kidney disease, with special emphasis on chronic myelomonocytic leukemia and lysozyme-induced nephropathy. Monocytes produce lysozyme, which, in excess, can accumulate in and damage the proximal renal tubular epithelium. Early identification of this etiology and a timely reduction in monocyte counts can salvage kidney function. Other etiologies of kidney injury associated with clonal monocytosis include direct renal infiltration by monocytes, renal extramedullary hematopoiesis, myeloproliferative neoplasm-associated glomerulopathy, autoimmune (membranous nephropathy, minimal change disease) and paraneoplastic manifestations, thrombotic microangiopathy, obstructive nephropathy due to myeloproliferation, and urate nephropathy due to tumor lysis syndrome. We propose to group these mechanistic etiologies of kidney injury as clonal monocytosis of renal significance and provide guidance on their diagnosis and management.

miR-15a targets the HSP90 co-chaperone Morgana in chronic myeloid leukemia

Morgana is a ubiquitous HSP90 co-chaperone protein coded by the CHORDC1 gene. Morgana heterozygous mice develop with age a myeloid malignancy resembling human atypical myeloid leukemia (aCML), now renamed MDS/MPN with neutrophilia. Patients affected by this pathology exhibit low Morgana levels in the bone marrow (BM), suggesting that Morgana downregulation plays a causative role in the human malignancy. A decrease in Morgana expression levels is also evident in the BM of a subgroup of Philadelphia-positive (Ph+) chronic myeloid leukemia (CML) patients showing resistance or an incomplete response to imatinib. Despite the relevance of these data, the mechanism through which Morgana expression is downregulated in patients' bone marrow remains unclear. In this study, we investigated the possibility that Morgana expression is regulated by miRNAs and we demonstrated that Morgana is under the control of four miRNAs (miR-15a/b and miR-26a/b) and that miR-15a may account for Morgana downregulation in CML patients.

Case report: Safety and efficacy of synergistic treatment using selinexor and azacitidine in patients with atypical chronic myeloid leukemia with resistance to decitabine

Background

Atypical chronic myeloid leukemia (aCML) is a BCR::ABL1 negative myelodysplastic/myeloproliferative neoplasm with poor overall survival. Some patients can be treated by allogeneic hematopoietic stem cell transplantation (allo-HSCT) from suitable donors. The effectiveness of decitabine or azacitidine (AZA) has recently been reported; however, their combined efficacy with selinexor has not yet been reported.

Case description

In this study, we report the case of a patient with aCML who was successfully treated with selinexor combined with AZA. A 67-year-old man with a history of gastric mucosa-associated lymphoid tissue (MALT) lymphoma was admitted to the hospital with fatigue and emaciation. He was diagnosed with aCML and no longer responded to decitabine treatment after undergoing seven cycles. The patient was subsequently administered hydroxyurea (HU), selinexor, and AZA. After four courses of combination therapy, his blood cell counts improved; he no longer required transfusions and was able to discontinue HU. The patient continued receiving selinexor and AZA without severe complications. This case is the first to show that combinatorial selinexor and AZA therapy can effectively treat aCML.

Conclusion

Our case sheds light on the importance of selinexor and AZA combined therapy in the exploration of new treatment strategies for aCML. Moreover, this treatment approach offers the possibility of bridging with allo-HSCT.