Hemato, Volume 3, Issue 2 (June 2022) – 6 articles

Extracellular vesicles (EVs) are nano-sized particles released from cells and transferring molecules (proteins, lipids and nucleic acids such as mRNA, tRNA and miRNA) to recipient cells. Surface antigens and components are important for the functions as cell-to-cell communication of EVs. Thus, EVs are useful biomarkers for various diseases including leukemias and other types of malignancies. We evaluated whether miRNAs in EVs released from chronic myelogenous leukemia (CML) cells could be used for diagnosis. Microarray analysis of miRNAs in EVs obtained from the culture supernatants of two CML cell lines showed that miR-494 and miR-373-5p were significantly decreased by tyrosine kinase inhibitor for BCR-ABL1. Validation analysis with Taqman-based qRT-PCR of whole serum obtained patients with CML in the chronic phase (n = 5) did not show a significant difference in miR-494 levels compared to the CML accelerated phase and blast crisis patients (n = 5). However, the levels of miR-494 were 2.9-fold higher in the accelerated phase or blast crisis than in the chronic phase (p < 0.05). These results indicate that it is important to measure miR-494 using only EVs rather than whole serum. Our data suggest that EV-miR-494 is a useful biomarker of CML progression and evaluation of response to tyrosine kinase inhibitors. Full article

Background: AL amyloidosis is a systemic disorder characterized by extracellular deposition of characteristic fibrils that results in progressive multi-organ failure and premature death. Recently daratumumab has been demonstrating higher hematological and organ response rates when compared to the standard of care. We hereby report our long-term experience on the effects of daratumumab given alone on the deposition of amyloid as evaluated in repeat renal biopsy. Results: Six patients were enrolled. All patients had proteinuria that was associated with renal function impairment in four. After therapy with daratumumab, four patients achieved complete hematological response and two had partial hematological response at the end of treatment. With regard to renal response, four out of six patients achieved an organ response; one patient had fluctuating proteinuria levels and did not meet the needed criteria at the end of the treatment and the last patient, who was already in dialysis at the time of therapy initiation, remained on dialysis despite complete hematological and cardiac responses. A significant decrease in 24-h proteinuria from 7.9 g/24 h to 1.1 (p < 0.005) with stabilization or improvement of sCr (from 1.5 mg/dL to 1.2 mg/dL; p = 0.34) were observed. All patients underwent a repeat biopsy after 24 administrations of daratumumab. In five patients, the repeat biopsy showed unchanged features; while in one it showed an improvement. Conclusions: Our data, based on real life experience, show that daratumumab monotherapy can be an effective therapeutic option. It is capable not only of achieving a substantial rate of renal improvement in pre-treated and naïve patients, but also of limiting renal deposition Full article

Sickle cell disease and its variants constitute the most common inherited blood disorders affecting millions of individuals worldwide. Significant information regarding the nature of the genetic mutations and modifier genes that result in increased or decreased severity of the disease are available. In recent years, detailed data regarding molecular genetics, pathophysiology, mechanisms for the development of symptoms and side effects of sickle cell disease have been published. The relationship of physiological changes, cellular interactions, coexisting coagulation disorders, effects of association with other genetic disorders and a number of intervening factors have been explored. New techniques for pre-conception, prenatal, in utero, and neonatal screening are available. Means for prediction of the severity of the disease, clinical course of the disorder, and prevention of some of its major complications have been developed. The effects of psychosocial and environmental factors have been explored. Various therapeutic strategies including bone marrow and stem cell transplantation are currently employed in the treatment of patients with sickle cell disease. Recent progress in understanding the molecular pathways controlling mammalian erythropoiesis and globin switching, as well as advances in genome engineering, particularly the gene-editing techniques, have opened a venue for genetic-based treatment of the disease. Currently, sickle cell disease is often associated with a high rate of complications and mortality. The development of new pharmacological agents, methods for gene therapy, and alterations and modification of the coexisting genetic factors and modifiers for treatment of the disease are encouraging. Full article

Primary cutaneous B-cell lymphomas (PCBCLs) account for 25% of all primary cutaneous lymphomas. Three major types are currently recognized by the WHO classification: primary cutaneous marginal zone B-cell lymphoma (PCMZL), primary cutaneous follicle centre lymphoma (PCFCL) (both considered indolent lymphomas) and primary cutaneous diffuse large B-cell lymphoma, leg-type (PCDLBCL-LT), which is, instead, a very aggressive disease. Nowadays, the PCBCL’s category also includes some rare entities such as intravascular B-cell lymphoma (IVBL) and the EBV+ mucocutaneous ulcer (EBVMCU). Furthermore, controversies still exist concerning the category of primary cutaneous diffuse large B-cell lymphoma (PCDLBCL), because some cases may present with clinical and histological features between PCFCL and PCDLBCL-LT. Therefore, some authors proposed introducing another category called PCDLBCL, not otherwise specified (NOS). Regardless, PCBCLs exhibit distinct features and differ in prognosis and treatment from their nodal/systemic counterparts. Therefore, clinicopathologic analysis is a key diagnostic element in the work-up of these lymphomas. Full article

AL amyloidosis is an incurable plasma cell dyscrasia with limited therapeutic options. The pathogenetic mechanism in AL amyloidosis is the deposition of insoluble fibrillary aggregates of misfolded immunoglobulin (Ig) free light chains (FLC) and chaperone proteins in target organs. Therefore, AL amyloidosis is the prototypic, protein-toxicity hematologic disorder. Based on laboratory evidence of increased, constitutive proteotoxic stress, PCs are intrinsically vulnerable to agents that target proteins whose function is to guarantee that nascent polypeptides either reach a functional conformation or are disposed of (proteostasis network). The clinical efficacy of proteasome inhibitors (PIs), such as bortezomib, in the treatment of plasma cell (PC) disorders has provided proof of concept that disrupting protein homeostasis is an effective and generally safe therapeutic approach. Therefore, the intrinsic biology of PC offers us the opportunity to rationally develop therapies that target this distinct proteostasis vulnerability of PC dyscrasias. In this manuscript, we will review the laboratory rationale for the effectiveness of FDA-approved and investigational agents targeting protein homeostasis in AL amyloidosis and related PC disorders. Full article

Although treatment of multiple myeloma has changed dramatically over time, there is still a subpopulation of patients who do not respond to treatments and are labeled as high risk. A combination of serum and genomic markers can be used to identify and stratify these patients according to associations with outcome. The most common method of identifying the genomic markers of high-risk multiple myeloma is using fluorescence in situ hybridization using probes to identify IgH translocations or copy number changes including the t(4;14), t(14;16), t(14;20), gain 1q, and del(17p). However, as research studies utilize newer technologies, such as whole genome sequencing, more high-risk factors are being identified including mutations of TP53, DIS3, BRAF, and complex structural events. Integration of comprehensive genomic studies into clinical trials will aid in defining the genomic high-risk landscape of multiple myeloma, which in turn can be transferred to individual patient diagnostics and treatment management. Full article