Hypersensitivity to Vitamins with a Focus on Immediate-Type Reactions: Food or Drug Allergy?

Vitamins are essential substances for normal cell functions, growth, and development. However, they cannot be produced by the human organism, so intake must be through the diet. Vitamin deficiency causes the onset of different diseases, ranging from pellagra to pernicious anemia, which can be corrected by reintroducing the missing vitamin form. To supply the right amount of vitamins to the body, every vitamin naturally occurring in foodstuff has been identified, extracted and synthetically produced, thus allowing either food fortification with these compounds or their pharmaceutical production. Furthermore, the increased importance attributed nowadays to body wellness and the pursuit of a permanent status of health at all costs has greatly encouraged a high consumption of vitamin supplements in modern society, since vitamin megadoses may be responsible for adverse or toxic effects. However, excessive vitamins can induce hypervitaminosis. In the USA, a national survey confirmed that 52% of adult Americans take at least one or more supplement products, vitamins and minerals being the most popular supplements in that country. Although vitamins are widespread natural substances, they may induce immediate or delayed type hypersensitivity reactions. Such adverse events are still underestimated and poorly recognized because only single cases have been reported in the literature, and no general review has yet investigated the mechanisms underlying sensitization to each vitamin, the diagnosis, and the management strategies adopted for vitamin hypersensitivity. Although delayed-type reactions to different vitamins are described in the literature, in our review, attention has been focused mainly on immediate- type reactions. Due to the importance of vitamins, further information regarding the above aspects (pathomechanisms, diagnosis and management) would be highly desirable to focus the state of the art on this particular, underestimated form of allergy, thus increasing allergists' awareness on these elusive hypersensitivity reactions.

Neutrophil Extracellular Traps (NETs) and Damage-Associated Molecular Patterns (DAMPs): Two Potential Targets for COVID-19 Treatment.

COVID-19 is a pandemic disease caused by the new coronavirus SARS-CoV-2 that mostly affects the respiratory system. The consequent inflammation is not able to clear viruses. The persistent excessive inflammatory response can build up a clinical picture that is very difficult to manage and potentially fatal. Modulating the immune response plays a key role in fighting the disease. One of the main defence systems is the activation of neutrophils that release neutrophil extracellular traps (NETs) under the stimulus of autophagy. Various molecules can induce NETosis and autophagy; some potent activators are damage-associated molecular patterns (DAMPs) and, in particular, the high-mobility group box 1 (HMGB1). This molecule is released by damaged lung cells and can induce a robust innate immunity response. The increase in HMGB1 and NETosis could lead to sustained inflammation due to SARS-CoV-2 infection. Therefore, blocking these molecules might be useful in COVID-19 treatment and should be further studied in the context of targeted therapy.

Metronomic chemotherapy from rationale to clinical studies: a dream or reality?

Metronomic chemotherapy (MC) refers to the close administration of a chemotherapeutic drug for a long time with no extended drug-free breaks. It was developed to overcome drug resistance, partly by shifting the therapeutic target from tumor cells to the tumor vasculature, with less toxicity. Because of this peculiar way of administration, MC can be viewed as a form of long-term 'maintenance' treatment, and can be integrated with standard and conventional chemotherapy in a "chemo-switching" strategy. Additional mechanisms are involved in its antitumor activity, such as activation of immunity, induction of tumor dormancy, chemotherapy-driven dependency of cancer cells, and the '4D effect'. In this paper we report the most important studies that have analyzed these processes. In fact, a number of preclinical and clinical studies in solid tumors as well as in multiple myeloma, have been reported regarding several chemotherapy drugs which have been proposed with a metronomic schedule: vinorelbine, cyclophosphamide, capecitabine, methotrexate, bevacizumab, etoposide, gemcitabine, sorafenib, everolimus and temozolomide. The results of these studies have been sometimes conflicting, highlighting the need to develop reliable tools for patient selection and stratification. However, a more precise evaluation of MC strategies with the ongoing randomized phase II/III clinical is fundamental, because of the strict correlation of this approach with translational research and target therapy. Moreover, because of the low toxicity of MC, these studies will also help to better evaluate the clinical benefit of this treatment, with a special focus on elderly and low performance status patients.

Antiangiogenic therapeutic approaches in multiple myeloma.

Angiogenesis is a constant hallmark of multiple myeloma (MM) progression and has prognostic potential. The pathophysiology of MM-induced angiogenesis involves both direct production of angiogenic cytokines by plasma cells and their induction within the bone marrow microenvironment. An improved understanding of the importance of angiogenesis-related signaling in MM has allowed for the rational use of antiangiogenic therapies in this tumor. This review article summarizes the literature data concerning the employment of the most important antiangiogenic therapeutic agents actually used in preclinical models and clinical settings for the treatment of MM.

Validation of PDGFRbeta and c-Src tyrosine kinases as tumor/vessel targets in patients with multiple myeloma: preclinical efficacy of the novel, orally available inhibitor dasatinib.

Inhibition of multiple myeloma (MM) plasma cells in their permissive bone marrow microenvironment represents an attractive strategy for blocking the tumor/vessel growth associated with the disease progression. However, target specificity is an essential aim of this approach. Here, we identified platelet-derived growth factor (PDGF)-receptor beta (PDGFRbeta) and pp60c-Src as shared constitutively activated tyrosine-kinases (TKs) in plasma cells and endothelial cells (ECs) isolated from MM patients (MMECs). Our cellular and molecular dissection showed that the PDGF-BB/PDGFRbeta kinase axis promoted MM tumor growth and vessel sprouting by activating ERK1/2, AKT, and the transcription of MMEC-released proangiogenic factors, such as vascular endothelial growth factor (VEGF) and interleukin-8 (IL-8). Interestingly, pp60c-Src TK-activity was selectively induced by VEGF in MM tumor and ECs, and the use of small-interfering (si)RNAs validated pp60c-Src as a key signaling effector of VEGF loop required for MMEC survival, migration, and angiogenesis. We also assessed the antitumor/vessel activity of dasatinib, a novel orally bioactive PDGFRbeta/Src TK-inhibitor that significantly delayed MM tumor growth and angiogenesis in vivo, showing a synergistic cytotoxicity with conventional and novel antimyeloma drugs (ie, melphalan, prednisone, bor-tezomib, and thalidomide). Overall data highlight the biologic and therapeutic relevance of the combined targeting of PDGFRbeta/c-Src TKs in MM, providing a framework for future clinical trials.

Resveratrol exerts antiproliferative activity and induces apoptosis in Waldenström's macroglobulinemia.

PURPOSE: Resveratrol (3,4',5-tri-hydroxy-trans-stilbene) is an antioxidant constituent of a wide variety of plant species including grapes. It has gained considerable attention because of its anticancer properties, as shown in solid and hematologic malignancies. Whether resveratrol could inhibit proliferation or induce cytotoxicity in Waldenström's macroglobulinemia (WM) was investigated. EXPERIMENTAL DESIGN: We studied resveratrol-induced inhibition of proliferation and induction of cytotoxicity in WM cell lines, WM primary tumor cells, IgM-secreting cells, and peripheral blood mononuclear cells. The mechanisms of action and different signaling pathways involved were studied using Western blot and gene expression profile analysis. Resveratrol activity was also evaluated in the bone marrow microenvironment. We finally investigated whether or not resveratrol could have any synergistic effect if used in combination with other drugs widely used in the treatment of WM. RESULTS: A schematic image illustrating the location and expression of the aurora kinases A, B, and C during mitosis. Resveratrol inhibited proliferation and induced cytotoxicity against WM cells, IgM-secreting cells, as well as primary WM cells, without affecting peripheral blood mononuclear cells; down-regulated Akt, extracellular signal-regulated kinase mitogen-activated protein kinases, and Wnt signaling pathways, as well as Akt activity; induced cell cycle arrest and apoptosis; and triggered c-Jun-NH(2)-terminal-kinase activation, followed by the activation of intrinsic and extrinsic caspase pathways. Lastly, adherence to bone marrow stromal cells did not confer protection to WM cells against resveratrol-induced cytotoxicity. Furthermore, resveratrol showed synergistic cytotoxicity when combined with dexamethasone, fludarabine, and bortezomib. CONCLUSION: Our data show that resveratrol has significant antitumor activity in WM, providing the framework for clinical trials in this disease.