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Patients with multiple myeloma (MM) are susceptible to developing thrombotic microangiopathies (TMAs), an etiologically diverse group of syndromes which include atypical hemolytic uremic syndrome (aHUS) and thrombotic thrombocytopenic purpura (TTP). The TMAs are characterized by thrombocytopenia and microangiopathic hemolytic anemia (MAHA), and are associated with a high mortality risk and irreversible end-organ damage when treatment is delayed. In MM patients, TMAs may be triggered by specific chemotherapies, bone marrow transplantation (BMT), and progression of underlying disease. Because many characteristics of TMAs overlap with sequelae of MM and its treatments, diagnosis requires a high index of suspicion. Furthermore, our understanding of optimal treatments for these entities is rapidly evolving and clinical practice guidelines do not yet exist. Historically, consideration of a diagnosis of TMA has prompted initiation of therapeutic plasma exchange. In this review, we present an overview of the MM-related TMAs, an approach to workup and diagnosis, and argue for initial empiric MM-related TMA treatment with eculizumab rather than plasma exchange., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Acute myeloid leukemia (AML) relapse results from the survival of chemotherapy-resistant and quiescent leukemia stem cells (LSC). These LSCs reside in the bone marrow microenvironment, comprised of other cells and extracellular matrix (ECM), which facilitates LSC quiescence through expression of cell adhesion molecules. We used decellularized Wharton's jelly matrix (DWJM), the gelatinous material in the umbilical cord, as a scaffolding material to culture leukemia cells, because it contains many components of the bone marrow extracellular matrix, including collagen, fibronectin, lumican, and hyaluronic acid (HA). Leukemia cells cultured in DWJM demonstrated decreased proliferation without undergoing significant differentiation. After culture in DWJM, these cells also exhibited changes in morphology, acquiring a spindle-shaped appearance, and an increase in the ALDH + cell population. When treated with a high-dose of doxorubicin, leukemia cells in DWJM demonstrated less apoptosis compared with cells in suspension. Serial colony forming unit (CFU) assays indicated that leukemia cells cultured in DWJM showed increased colony-forming ability after both primary and secondary plating. Leukemia cell culture in DWJM was associated with increased N-cadherin expression by flow cytometry. Our data suggest that DWJM could serve as an ECM-based model to study AML stem cell-like cell behavior and chemotherapy sensitivity., (Copyright © 2018 Elsevier Ltd. All rights reserved.)