Prophylactic broad spectrum antibiotics as a new anti-myeloma therapy

Secondary Immunodeficiency in Hematological Malignancies: Focus on Multiple Myeloma and Chronic Lymphocytic Leukemia

Secondary immunodeficiency is reported in most patients with hematological malignancies such as chronic lymphocytic leukemia and multiple myeloma. The aim of our review was to evaluate the existing literature data on patients with hematological malignancies, with regard to the effect of immunodeficiency on the outcome, the clinical and therapeutic approach, and on the onset of noninfectious complications, including thrombosis, pleural effusion, and orofacial complications. Immunodeficiency in these patients has an intense impact on their risk of infection, in turn increasing morbidity and mortality even years after treatment completion. However, these patients with increased risk of severe infectious diseases could be treated with adequate vaccination coverage, but the vaccines' administration can be associated with a decreased immune response and an augmented risk of adverse reactions. Probably, immunogenicity of the inactivated is analogous to that of healthy subjects at the moment of vaccination, but it undertakes a gradual weakening over time. However, the dispensation of live attenuated viral vaccines is controversial because of the risk of the activation of vaccine viruses. A particular immunization schedule should be employed according to the clinical and immunological condition of each of these patients to guarantee a constant immune response without any risks to the patients' health.

The Role of the Gut Microbiome in Pathogenesis, Biology, and Treatment of Plasma Cell Dyscrasias

In response to emerging discoveries, questions are mounting as to what factors are responsible for the progression of plasma cell dyscrasias and what determines responsiveness to treatment in individual patients. Recent findings have shown close interaction between the gut microbiota and multiple myeloma cells. For instance, that malignant cells shape the composition of the gut microbiota. We discuss the role of the gut microbiota in (i) the development and progression of plasma cell dyscrasias, and (ii) the response to treatment of multiple myeloma and highlight faecal microbiota transplantation as a procedure that could modify the risk of progression or sensitize refractory malignancy to immunotherapy.

Multiple Myeloma: What Do We Do About Immunodeficiency?

Multiple myeloma (MM) is an incurable hematological malignancy. Immunodeficiency results in the incapability of immunity to eradicate both tumor cells and pathogens. Immunotherapies along with antibiotics and other anti-infectious agents are applied as substitutes for immunity in MM. Immunotherapies including monoclonal antibodies, immune checkpoints inhibitors, affinity- enhanced T cells, chimeric antigen receptor T cells and dendritic cell vaccines are revolutionizing MM treatment. By suppressing the pro-inflammatory milieu and pathogens, prophylactic and therapeutic antibiotics represent anti-tumor and anti-infection properties. It is expected that deeper understanding of infection, immunity and tumor physio-pathologies in MM will accelerate the optimization of combined therapies, thus improving prognosis in MM.

Multiple Myeloma Index for Risk of Infection

Based on our earlier research into the main characteristics and risk factors for infections in hospitalized patients with multiple myeloma, we created the numerical Multiple Myeloma Index for Risk of Infection (MMIRI) to predict infection in myeloma patients. The included factors that could influence the pathogenesis and incidence of infections were sex, performance status, Durie Salmon stage of disease, International Staging System, serum creatinine level, immune paresis, neutropenia, serum ferritin level, the presence of any catheters, disease duration, stable/progressive disease, and type of therapy. For each of these parameters, the strength of association with infection was statistically estimated and specific number of points was assigned to each of these parameters, proportional to the strength of the association. When designing the MMIRI, we included only those parameters that we determined were pathophysiologically associated with the infection. After further statistical analysis, we identified an optimal cutoff score of 6 or above as indicating a significant risk for infection, with a sensitivity of 93.2% and specificity of 80.2%. The scoring system in the retrospective receiver operating characteristic analysis showed an area under the curve of 0.918. The potential value of the MMIRI is the possibility of identifying those patients who would benefit from the prophylactic administration of antibiotics and other anti-infective measures while minimizing the contribution to antibiotic resistance related to the overuse of these drugs. As far as we know, this index represents the first attempt to create such an instrument for predicting the occurrence of infections in myeloma patients.

Role of toll-like receptors in multiple myeloma and recent advances

Multiple myeloma (MM) is a hematologic malignancy characterized as an abnormal proliferation and invasion of plasma cells into the bone marrow. Toll-like receptors (ТLRs) connect the innate and adaptive immune responses and represent a significant and potentially linking element between inflammation and cancer. When TLRs bind to their ligands, they trigger two major signaling pathways such that both share overlapping downstream signals: one is a myeloid differentiation primary response 88 (MyD88)-dependent production and activation of nuclear factor-κB, whereas the other is a MyD88-independent production of type-I interferon. Whereas the MyD88 pathway results in proinflammatory cytokine production, the other pathway stimulates cell proliferation. Dysregulations of these pathways may eventually lead to abnormal cell proliferation and MM. Despite recent biomedical advances, MM continues to be an incurable disease. There are an increasing number of TLR-based therapeutic approaches currently being tested in a number of preclinical and clinical studies. We here attempt to outline in detail the currently available information on TLRs in various types of cancer.