Possible Early Clinical Management of Systemic Mastocytosis Patients with Recently FDA Approved Drug Avapritinib By Molecular Diagnosis Using a Highly Sensitive KIT D816 Mutation Assay

Recently in June 2021, the Food and Drug Administration approved avapritinib (Ayvakit™) for adult patients with advanced systemic mastocytosis (AdvSM), including patients with aggressive systemic mastocytosis (ASM), systemic mastocytosis with an associated hematological neoplasm (SM-AHN), and mast cell leukemia (MCL). Mastocytosis is a heterogeneous, neoplastic disorder characterized by infiltration of abnormal mast cells in one or more organs. Mastocytosis subtypes are defined by disease distribution and the clinical features include, cutaneous mastocytosis (CM), where mast cell infiltration is confined to the skin, and systemic mastocytosis (SM) in which at least one extracutaneous organ is involved, with or without evidence of skin lesions. CM is most common in pediatric patients whereas SM typically presents in adulthood. The presence of somatic, activating mutations in KIT codon 816, predominantly D816V (A2447T), can be identified in the mast cells of 95% or more of patients with systemic mastocytosis (SM) and represent clonal markers in the disease. KIT is located on chromosome 4q12 and encodes for the mast/stem cell growth factor receptor, a type III receptor tyrosine kinase. Detection of KIT D816 mutations serve as a World Health Organization (WHO) minor criterion for the diagnosis of systematic mastocytosis and appear to confer relative resistance to tyrosine kinase inhibitors. Versiti Blood Center of Wisconsin Diagnostics laboratory which is certified under the Clinical Laboratory Improvement Amendments (CLIA) and qualified to perform high complexity clinical laboratory testing has developed a highly sensitive clinical test for the detection of KIT D816 mutations and molecular diagnosis of systemic mastocytosis patients. The KIT D816 mutation assay is a unique laboratory developed test based on highly sensitive allele specific PCR and its performance characteristics were determined by our laboratory. The sensitivity of the KIT D816 assay is 0.25% allele proportion. The specificity for the D816V mutation is > 99%. Systemic Mastocytosis (SM) is classified as myeloid neoplasm by WHO, however SM may be missed in suspected myeloid neoplasm work up by conventional sequencing technology including NGS which might not be able to achieve higher sensitivity. It is important to have a highly sensitive KIT D816 mutation analysis assay to detect low levels of KIT D816 allele burden that may be present in blood or bone marrow especially at early stage disease. Our highly sensitive laboratory developed KIT D816 assay based on allele specific PCR with a limit of detection of 0.25% could help physicians identify SM patients and clinically manage the disease. Disclosures No relevant conflicts of interest to declare. OffLabel Disclosure: Recently FDA approved Avapritinib for adult patients with advanced systemic mastocytosis (AdvSM), including patients with aggressive systemic mastocytosis (ASM), systemic mastocytosis with an associated hematological neoplasm (SM-AHN), and mast cell leukemia (MCL).

Effectiveness of the BNT162b2mRNA Covid-19 Vaccine in Patients with Hematological Neoplasms

Evidence regarding the effectiveness of covid-19 vaccine in patients with impaired immunity, is limited. Initial observations suggest a lower humoral response in these patients. We evaluated the relative effectiveness of the mRNA BNT162b2 vaccine in patients with hematological neoplasms compared to matched controls. Data on patients with hematological neoplasms after two vaccine doses were extracted and matched 1:1 with vaccinated controls. Subpopulation analyses focused on patients receiving therapy for the hematological neoplasm, patients without treatment who are only followed, and recipients of specific treatments. The analysis focused on covid-19 outcomes from day 7 through 43 following the second vaccine dose: Documented covid-19 infection by PCR; Symptomatic infection; Hospitalizations; Severe covid-19 disease and covid-19-related death. Of a population of 4.7 million insured people, 32,516 patients with hematological neoplasms were identified, of whom 5,017 were receiving therapy for an active disease. Vaccinated patients with hematological neoplasms, compared with vaccinated matched controls, had an increased risk of documented infections (RR 1.60, 95% confidence interval [CI] 1.12-2.37), symptomatic covid-19 (RR 1.72, 95% CI 1.05-2.85), covid-19 related hospitalizations (RR 3.13, 95% CI 1.68-7.08), severe covid-19 (RR 2.27, 95% CI 1.18-5.19) and covid-19 related death (RR 1.66, 95% CI 0.72-4.47). Limiting the analysis to patients on hematological treatments showed a higher increased risk. This analysis shows that vaccinated patients with hematological neoplasms, in particular patients on treatment, suffer from covid-19 outcomes more than vaccinated individuals with intact immune system. Ways to enhance covid-19 immunity in this patient population, such as additional doses, should be explored.

Coexistence of Prefibrotic Myelofibrosis with Monoclonal Gammopathy of Undetermined Significance: A Case Report

The coexistence of dual hematological neoplasms is an unusual and challenging presentation due to the different combination of etiopathology. The presentation of synchronous dual hematological malignancies can be one of the 3 types: myeloid + lymphoid or dual lymphoid or dual myeloid. Here, we are reporting a case of a 53-year-old male with simultaneous presence of JAK<i>2 V617F</i>-positive myeloproliferative neoplasm with features favoring prefibrotic phase of primary myelofibrosis (pre-PMF) in combination with monoclonal gammopathy of undetermined significance (MGUS). In such cases of simultaneous existence of dual hematological neoplasm management, it is recommended to treat the more aggressive one. Currently, our management plan is focusing on treating the pre-PMF and observation of MGUS with regular monitoring for transformation to MM.

AATF/Che-1, a new component of paraspeckles, controls R-loops formation and Interferon activation in Multiple Myeloma.

Multiple myeloma (MM) is a hematological neoplasm of plasma cells characterized by abnormal production of immunoglobulins. Che-1/AATF (Che-1) is an RNA binding protein involved in transcription regulation and is highly expressed in this malignancy. Here we experimentally show that Che-1 interacts with paraspeckle components, including the lncRNA NEAT1_2 (NEAT1), which serves as the seed for the maintenance of these structures. Che-1 and NEAT1 localize on R-loops, three-stranded RNA:DNA hybrids structures involved in DNA transcription and repair. Depletion of Che-1 produces a marked accumulation of RNA:DNA hybrids sustaining activation of a systemic inflammatory response. We provide evidence that high levels of Unfolded Protein Response (UPR) in MM cells induces RNA:DNA hybrids and an interferon (IFN) gene signature. We found that MM patients exhibit elevated R-loops levels and paraspeckle genes mRNAs increase linearly to MM progression. Strikingly, patients showing elevated IFN genes signature are associated with a marked poor prognosis. Overall, these findings delineate that elevated R-loops accumulation and inflammatory signaling may contribute to MM progression and that Che-1/NEAT1 plays an essential role in maintaining R-loops homeostasis by preventing excessive inflammatory signaling.

HCP5, as the sponge of miR-1291, facilitates AML cell proliferation and restrains apoptosis via increasing PIK3R5 expression

Background Acute myeloid leukemia (AML) is recognized as a hematological neoplasm with heterogenetic cytology and short-term outcome. HCP5 has been proven to be related with the pathogenesis of AML. However, the underlying mechanism of HCP5 in AML remains unclear. Methods Clinical profiles of AML patients were downloaded from TCGA and GTEx databases. LncBase and TargetScan online tools were utilized to predict potential targets, and dual-luciferase reporter assay was performed to verify the association between miR-1291 and HCP5 or PIK3R5. Cell Counting Kit 8 and flow cytometry tests were implemented to evaluate the effects of HCP5/miR-1291/PIK3R5 axis in AML cells. Quantitative RT-PCR and Western blot were conducted to detect the expression levels of genes. Results HCP5 and PIK3R5 were significantly increased in AML tissue samples compared with healthy controls. HCP5 facilitated AML cells viability and inhibited apoptosis. There was a positive relationship between HCP5 and PIK3R5, but miR-1291 negatively regulated PIK3R5. Overexpression of PIK3R5 enhanced the promoting effect of HCP5 in the development of AML, while weakened the suppression of miR-1291 to AML progression. Conclusion Our findings manifested that HCP5 was remarkably upregulated in AML and upregulated HCP5 promoted the malignant behaviors of AML cells by mediating miR-1291/PIK3R5 axis, which would provide a new insight for the treatment of AML.

Radiation diagnosis of gastrointestinal tract lesions in multiple myeloma

Multiple myeloma (MM) is an unusual type of malignant hematological neoplasm, which, mainly affecting the bone marrow, occasionally spreads to other organs, which is manifested by various clinical symptoms. Involvement of the gastrointestinal tract (GI) in the pathological process of MM is extremely rare. In this observation, we report such a case of damage to the horseshoe of the duodenum by myeloma cells, detected by radiation methods, confirmed by endoscopic and immunohistological studies.

MO085MONOCLONAL GAMMOPATHY OF UNKNOWN SIGNIFICANCE AMONG MEMBRANOPROLIFERATIVE GLOMERULONEPHRITIS PATIENTS

Background and Aims Monoclonal gammopathy is an entity where a B-cell or plasma cell clone produces monoclonal immunoglobulin. When paraproteinemia and a kidney disease is discovered without criteria for treatment of haematological malignangy, the entity is called monoclonal gammopathy of unknown significance (MGUS) or of renal significance (MGRS). It can cause variable histology, among which membranoproliferative glomerulonephritis (MPGN) has been described. Direct entrapment of paraprotein in glomeruli/tubules can be observed by immunofluorescence (IF), but IF can also be negative as paraprotein can cause complement-associated disease by acting as an activator of the classical pathway or as a dysregulator of the alternative pathway. Electron microscopy (EM) is needed to differentiate possible organized deposits. Method We investigated the prevalence, clinical parameters, histology, and the type of monoclonal gammopathy in biopsy-proven MPGN between 2006-2017. A total of 15 adult patients with a detected urine and/or serum paraprotein with concurrent biopsy-proven diagnosis were discovered among 60 patients (Figure 1). Two diagnostic biopsies were from transplants. Results MGUS was diagnosed in 15/60 (25%) of patients. Clinical variables are summarized in Table 1. The mean age at presentation was 59 years (37-79), 47-% were males. Smoldering myeloma was diagnosed in 2 (13%) patients and overt malignancy in 3 (20%) patients. Histological features are summarized in Table 2. There were 7 (47%) with dominant staining for C3 (6 with C3 glomerulonephritis, 1 Dense Deposition Disease) and 8 (53%) with dominant staining for Ig, of which 4 (31%) had mesangioproliferative, 4 (31%) membranoproliferative, 3 (23%) minimal change, 2 (15%) crescentic and 1 (8%) exudative pattern in light microscopy (LM). Seven (47%) biopsies, which did not stain for kappa or lambda light chains. The most common EM deposit location was subendothelial (69%). Conclusion MPGN was associated with a significant risk of underlying monoclonal gammopathy, as many (25%) patients were diagnosed with concurrent MGUS. When MPGN is observed, it should prompt investigations of the possible underlying monoclonal gammopathy and possibly, hematological neoplasm.

Treatment of Multiple Myeloma and the Role of Melphalan in the Era of Modern Therapies—Current Research and Clinical Approaches

Multiple myeloma (MM) accounts for 10% of all hematological malignancies, and it is the second most common hematological neoplasm for which chemotherapy is an important pharmacological treatment. High dose melphalan followed by autologous stem cell transplantation remains the standard of treatment for transplant-eligible patients with MM. In this review, we describe aspects of the pharmacokinetics and pharmacodynamics of melphalan therapy and related compounds. In addition, we describe the use of melphalan in innovative therapies for the treatment of MM, including the development of drug carriers to reduce systemic toxicity, combination therapy to improve the effectiveness of cancer therapy, and the chemical modification of the melphalan molecule to improve antitumor activity.

The Role of lncRNAs in the Pathobiology and Clinical Behavior of Multiple Myeloma

MM is a hematological neoplasm that is still considered an incurable disease. Besides established genetic alterations, recent studies have shown that MM pathogenesis is also characterized by epigenetic aberrations, such as the gain of de novo active chromatin marks in promoter and enhancer regions and extensive DNA hypomethylation of intergenic regions, highlighting the relevance of these non-coding genomic regions. A recent study described how long non-coding RNAs (lncRNAs) correspond to 82% of the MM transcriptome and an increasing number of studies have demonstrated the importance of deregulation of lncRNAs in MM. In this review we focus on the deregulated lncRNAs in MM, including their biological or functional mechanisms, their role as biomarkers to improve the prognosis and monitoring of MM patients, and their participation in drug resistance. Furthermore, we also discuss the evidence supporting the role of lncRNAs as therapeutic targets through different novel RNA-based strategies.