Identification of the Cysteine Protease Legumain as a Potential Chronic Hypoxia-Specific Multiple Myeloma Target Gene

Multiple myeloma (MM) is the second most common hematologic malignancy, which is characterized by clonal proliferation of neoplastic plasma cells in the bone marrow. This microenvironment is characterized by low oxygen levels (1–6% O2), known as hypoxia. For MM cells, hypoxia is a physiologic feature that has been described to promote an aggressive phenotype and to confer drug resistance. However, studies on hypoxia are scarce and show little conformity. Here, we analyzed the mRNA expression of previously determined hypoxia markers to define the temporal adaptation of MM cells to chronic hypoxia. Subsequent analyses of the global proteome in MM cells and the stromal cell line HS-5 revealed hypoxia-dependent regulation of proteins, which directly or indirectly upregulate glycolysis. In addition, chronic hypoxia led to MM-specific regulation of nine distinct proteins. One of these proteins is the cysteine protease legumain (LGMN), the depletion of which led to a significant growth disadvantage of MM cell lines that is enhanced under hypoxia. Thus, herein, we report a methodologic strategy to examine MM cells under physiologic hypoxic conditions in vitro and to decipher and study previously masked hypoxia-specific therapeutic targets such as the cysteine protease LGMN.

Pityriasis lichenoid-like mycosis fungoides

Sir, Mycosis fungoides is a primary cutaneous T–cell lymphoma, secondary clonal proliferation of mature skin-homing T cells, mostly CD4-positive, with a predilection for involving the epidermis. It is an indolent lymphoma that progresses over several years and represents 50% of primary cutaneous T-cell lymphomas [1]. Its clinical presentation is variable, thus leading to several clinical variants. Herein, we describe a rare variant of mycosis fungoides: pityriasis lichenoid-like mycosis fungoides. A 45-year-old female was referred to our department with a papular rash evolving for the last year without regression. The patient had a history of breast carcinoma in complete remission for two years. A clinical examination revealed erythematous, scaly, non-itchy papules covering the entire body but sparing the face (Figs. 1 and 2). There was no scalp involvement or associated lymphadenopathy. Based on the clinical presentation, the suggested diagnosis was pityriasis lichenoid. A histological examination revealed Pautrier’s microabscesses, atypical lymphocyte infiltration along the basal layer and papillary dermis, and prominent epidermotropism (Fig. 3). There was pilotropism without mucin. Besides, hyperkeratosis with focal parakeratosis and perivascular infiltrate were noted. An immunohistochemical analysis revealed infiltrates of T cells expressing CD3, CD2, CD5, and a predominance of CD4-positive T cells in the epidermis compared to CD8-positive T cells. CD7 and CD30 were, however, negative. These findings were consistent with pityriasis lichenoid-like mycosis fungoides. The patient was classified as a IB stage and received UVB phototherapy with good progress.

Bacterial meningitis in the practice of a primary care physician. Clinical and immunological efficacy of recombinant interleukin-2 in the complex therapy of bacterial meningitis

The article analyzes the pathogenetic features of bacterial meningitis and substantiates the scheme of complex therapy of the disease using the recombinant cytokine interleukin-2 (IL2). The clinical, immunological and microbiological efficacy of the complex therapy scheme has been revealed. It has been shown that the pleiotropic effects of recombinant IL-2, its effect on the activity of metabolic processes at the cellular and subcellular levels, the ability to stabilize the system of lipid peroxidation of cell membranes, the ability to influence the processes of clonal proliferation and differentiation of T- and B-lymphocytes, make its use justified in complex therapy of meningitis.

Biochemical profile of multiple myeloma about 50 cases

Multiple myeloma (MM) is a clonal proliferation of plasma cells invading the bone marrow and secreting monoclonal immunoglobulin. In order to study the epidemiological and biological and biochemical characteristics of MM, we carried out a retrospective work on a cohort of 50 cases collected at the Avicenna Military Hospital in Marrakesh, during a period of 5 years (from January 2013 to December 2017). Our study included 32 men (64%) and 18 women (36%), with an average age of 60.6 years, with extremes at 44 and 87 years. The circumstances of discovery were dominated by bone pain and alteration in general condition, which are revealing in more than 65% of cases. Biologically: the sedimentation rate was accelerated in 86% of cases, a monoclonal peak appearance was revealed on serum proteins electrophoresis in 88%of cases, most often located in the γ zone (64%), a predominance of the Ig G isotype (64%), and kappa light chains in 60% of cases, Bence Jones protein (BJP) was found in 7 patients, i.e. 14% of cases, and plasmacytosis over 10% was found on the myelograms in 90 % of cases.

Mast cells and tryptase. Modern aspects

The present review considers the role of mast cells (MC) and tryptase levels in various pathological conditions in children and adults. The main causes of hypertryptasemia are presented, as well as a list of the most important stimuli that can cause activation of MC. Cliical allergologists should focus their clinical practice on the patients with anaphylaxia and suspected MC activation syndromes. Moreover, hypertryptasemia (> 20 ng/ml) is considered an additional diagnostic criterion for systemic mastocytosis, according to the WHO recommendations. As a rule, the level of tryptase is constantly elevated in most patients with systemic mastocytosis, whereas it is undergo changes in acute IgE-mediated hypersensitivity reactions. In cases of anaphylaxia, tryptase concentration should be determined in the patients during the first hours following onset of acute allergic reaction, and 24-48 hours later. Recommendations are given for determining tryptase levels in blood serum of the patients (basal and peak values), and algorithms are provided for usage of these indexes in various diseases. The article also provides the assessed threshold values of tryptase when diagnosing anaphylaxia, MC activation syndromes, and a novel disorder – alpha-tryptasemia. In the diagnosis of hereditary alpha-tryptasemia, as well as MC activation syndromes (primary and secondary), clinical manifestations in the patient and time dynamics of tryptase levels should be taken into account. The accumulated experience allowed to consider, first of all, frequency of severe allergic reactions (most often as anaphylaxia) in the patients with suspected MC activation syndromes. The syndrome of MC activation is characterized by excessive release of their granule contents without signs of clonal proliferation, which in many cases may be due to gene allele duplication, especially, TPSAB1 α-tryptase gene. For patients with hereditary alpha-tryptasemia, the most characteristic manifestations are represented by vegetative-vascular dystonia (orthostatic tachycardia), joint hypermobility, etc. Hence, determination of tryptase level (especially in time course) should be given more attention in the practice of clinicians. Difficulties with interpretation of the results arise in cases when tryptase concentration remains within normal range (up to 11.4 ng/ml), and the patient has clinically evident mastocytosis, or MC activation syndromes. If the patient has a history of anaphylaxia, especially after bites of hymenoptera insects, the TC activation syndromes should be excluded.

tRNA Derivatives in Multiple Myeloma: Investigation of the Potential Value of a tRNA-Derived Molecular Signature

Multiple myeloma (MM) is a hematologic malignancy arising from the clonal proliferation of malignant plasma cells. tRNA-derived RNA fragments (tRFs) constitute a class of small non-coding RNAs, deriving from specific enzymatic cleavage of tRNAs. To the best of our knowledge, this is one of few studies to uncover the potential clinical significance of tRFs in MM. Total RNA was extracted from CD138+ plasma cells of MM and smoldering MM patients, and in vitro polyadenylated. First-strand cDNA synthesis was performed, priming from an oligo-dT-adaptor sequence. Next, real-time quantitative PCR (qPCR) assays were developed for the quantification of six tRFs. Biostatistical analysis was performed to assess the results and in silico analysis was conducted to predict the function of one of the tRFs. Our results showed that elevated levels of five out of six tRFs are indicators of favorable prognosis in MM, predicting prolonged overall survival (OS), while two of them constitute potential molecular biomarkers of favorable prognosis in terms of disease progression. Moreover, three tRFs could be used as surrogate prognostic biomarkers along with the R-ISS staging system to predict OS. In conclusion, tRFs show molecular biomarker utility in MM, while their mechanisms of function merit further investigation.

CD73-positive extracellular vesicles promote glioblastoma immunosuppression by inhibiting T-cell clonal expansion

Extracellular vesicles are involved in the occurrence, progression and metastasis of glioblastoma (GBM). GBM can secrete a variety of tumour-derived extracellular vesicles (TDEVs) with high immunosuppressive activity that remotely suppress the systemic immune system, and therapy targeting TDEVs has potential efficacy. In this study, we detected a higher concentration of CD73+ TDEVs enriched in exosomes in central and peripheral body fluids of GBM patients than in those of patients with other brain tumours (low-grade glioma or brain metastases from melanoma or non-small-cell lung cancer). High CD73 expression was detected on the surface of T cells, and this CD73 was derived from TDEVs secreted by GBM cells. In vitro, we observed that CD73+ TDEVs released by GBM cell lines could be taken up by T cells. Moreover, excess adenosine was produced by AMP degradation around T cells and by adenosine receptor 2A (A2AR)-dependent inhibition of aerobic glycolysis and energy-related metabolic substrate production, thereby inhibiting the cell cycle entry and clonal proliferation of T cells. In vivo, defects in exosomal synthesis and CD73 expression significantly inhibited tumour growth in GBM tumour-bearing mice and restored the clonal proliferation of T cells in the central and peripheral regions. These data indicate that CD73+ TDEVs can be used as a potential target for GBM immunotherapy.

New Horizons in Myeloproliferative Neoplasms Treatment: A Review of Current and Future Therapeutic Options

Philadelphia-negative myeloproliferative neoplasms (MPN) are aggressive diseases characterized by clonal proliferation of myeloid stem cells. The clonal process leads to excessive red cells production, platelets production, and bone marrow fibrosis. According to the phenotype, MPN can be classified as polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). MPN patients have shortened survival due to the increased risk of thrombosis, hemorrhages, and transformation to acute myeloid leukemia (AML). Prognosis is variable, with a shorter life expectancy in myelofibrosis. Currently, drug therapy can reduce symptoms, splenomegaly, and risk of thrombosis. Still, some patients can be resistant or intolerant to the treatment. At the same time, allogeneic stem cell transplant (ASCT) is the only treatment modality with the potential to cure the disease. Nevertheless, the ASCT is reserved for high-risk leukemic progression patients due to the risk of treatment-related death and comorbidity. Therefore, there is a need for new drugs that can eradicate clonal hematopoiesis and prevent progression to more aggressive myeloid neoplasms. Thanks to the better understanding of the disease’s molecular pathogenesis, many new potentially disease-modifying drugs have been developed and are currently in clinical trials. This review explores the most promising new drugs currently in clinical trials.

New Markers of Disease Progression in Myelofibrosis

Primary myelofibrosis (PMF) is a myeloproliferative neoplasm due to the clonal proliferation of a hematopoietic stem cell. The vast majority of patients harbor a somatic gain of function mutation either of JAK2 or MPL or CALR genes in their hematopoietic cells, resulting in the activation of the JAK/STAT pathway. Patients display variable clinical and laboratoristic features, including anemia, thrombocytopenia, splenomegaly, thrombotic complications, systemic symptoms, and curtailed survival due to infections, thrombo-hemorrhagic events, or progression to leukemic transformation. New drugs have been developed in the last decade for the treatment of PMF-associated symptoms; however, the only curative option is currently represented by allogeneic hematopoietic cell transplantation, which can only be offered to a small percentage of patients. Disease prognosis is based at diagnosis on the classical International Prognostic Scoring System (IPSS) and Dynamic-IPSS (during disease course), which comprehend clinical parameters; recently, new prognostic scoring systems, including genetic and molecular parameters, have been proposed as meaningful tools for a better patient stratification. Moreover, new biological markers predicting clinical evolution and patient survival have been associated with the disease. This review summarizes basic concepts of PMF pathogenesis, clinics, and therapy, focusing on classical prognostic scoring systems and new biological markers of the disease.

Cutaneous mastocytosis in an infant: Case report and clinicopathological correlation

Mastocytosis is a disorder of clonal proliferation of the mast cells, which can be cutaneous or systemic. Abnormal mast cell infiltration comprising multifocal compact clusters or cohesive aggregates can affect one or more organ systems. Cutaneous mastocytosis is a relatively uncommon condition in the pediatric population. We report a case of 9 month infant presented with multiple papular and vesicular skin rashes since 6 months of age. On clinical examination Darier’s sign was negative. The serum tryptase levels were within normal limits. Clinical differential diagnoses were benign cephalic histiocytosis vs cutaneous mastocytosis. Skin biopsy revealed a mononuclear cell infiltrate in the papillary dermis reaching up to the dermo-epidermal junction. Toluidine blue staining highlighted the metachromatic granules. CD117, CD30 IHC stains were positive which confirmed the diagnosis of cutaneous mastocytosis. This case is presented to highlight the histomorphology and the special stains in cases of mastocytosis.