Journal: Expert review of clinical immunology
Self-nonself discrimination plays a key role in inducing a productive immunity and in preventing autoimmune reactions. Central tolerance within the thymus and peripheral tolerance in peripheral lymphoid organs lead to immunologic nonresponsiveness against self-components. The central tolerance represents the mechanism by which T cells binding with high avidity to self-antigens are eliminated through the so-called negative selection. Thymic medullary epithelial cells and medullary dendritic cells play a key role in this process, through the expression of a large number of tissue-specific self-antigens involving the transcription factor autoimmune regulator (AIRE). Mutations of AIRE result in autoimmune polyendocrinopathy candidiasis ectodermal dystrophy, a rare autosomal recessive disease (OMIM 240300), which is the paradigm of a genetically determined failure of central tolerance and autoimmunity. This review focuses on recent advances in the molecular mechanisms of central tolerance, their alterations and clinical implication.
Currently, imaging in asthma is confined to chest radiography and CT. The emergence of new imaging techniques and tremendous improvement of existing imaging methods, primarily due to technological advancement, has completely changed its research and clinical prospects. In research, imaging in asthma is now being employed to provide quantitative assessment of morphology, function and pathogenic processes at the molecular level. The unique ability of imaging for non-invasive, repeated, quantitative, and in vivo assessment of structure and function in asthma could lead to identification of ‘imaging biomarkers’ with potential as outcome measures in future clinical trials. Emerging imaging techniques and their utility in the research and clinical setting is discussed in this review.
An adjuvant is a substance that enhances the antigen-specific immune response, induces the release of inflammatory cytokines, and interacts with Toll-like receptors and the NALP3 inflammasome. The immunological consequence of these actions is to stimulate the innate and adaptive immune response. The activation of the immune system by adjuvants, a desirable effect, could trigger manifestations of autoimmunity or autoimmune disease. Recently, a new syndrome was introduced, autoimmune/inflammatory syndrome induced by adjuvants (ASIA), that includes postvaccination phenomena, macrophagic myofasciitis, Gulf War syndrome and siliconosis. This syndrome is characterized by nonspecific and specific manifestations of autoimmune disease. The main substances associated with ASIA are squalene (Gulf War syndrome), aluminum hydroxide (postvaccination phenomena, macrophagic myofasciitis) and silicone with siliconosis. Mineral oil, guaiacol and iodine gadital are also associated with ASIA. The following review describes the wide clinical spectrum and pathogenesis of ASIA including defined autoimmune diseases and nonspecific autoimmune manifestations, as well as the outlook of future research in this field.
Our global hypothesis is that atopic conditions and asthma develop because an individual’s immune system is not able to appropriately resolve inflammation resulting from allergen exposures. We propose that the failure to appropriately down-regulate inflammation and produce a toleragenic state results primarily from less robust immune homeostatic processes rather than from a tendency to over-respond to allergenic stimuli. An individual with lower immune homeostatic capacity is unable to rapidly and completely terminate, on average over time, immune responses to innocuous allergens, increasing risk of allergic disease. A lack of robust homeostasis also increases the risk of other inflammatory conditions, such as prolonged respiratory viral infections and obesity, leading to the common co-occurrence of these conditions. Further, we posit that the development of vigorous immune homeostatic mechanisms is an evolutionary adaptation strongly influenced by both 1) exposure to a diverse maternal microbiota through the prenatal period, labor and delivery, and, 2) an orderly assemblage process of the infant’s gut microbiota ecosystem shaped by breastfeeding and early exposure to a wide variety of ingested foods and environmental microbes. This early succession of microbial communities together with early allergen exposures orchestrate the development of an immune system with a robust ability to optimally control inflammatory responses and a lowered risk for atopic disorders.
Rheumatoid arthritis (RA) is a chronic inflammatory disease associated with significant functional impairment and increased risk for cardiovascular disease. Along with pharmacological therapy, exercise seems to be a very promising intervention to improve disease-related outcomes, including functional ability and systemic manifestations, such as the increased cardiovascular risk. In this review, we discuss the physiological mechanisms by which exercise improves inflammation, cardiovascular risk and psychological health in patients with rheumatoid arthritis (RA) and describe in detail how exercise can be incorporated in the management of this disease using real examples from our clinical practice.
The aim of this article was to review current evidence about cryotherapy in inflammatory rheumatic diseases (therapeutic and biological effects). For therapeutic effects, we performed a systematic review (PubMed, EMBASE, Cochrane Library, LILACS databases, unpublished data) and selected studies including non-operated and non-infected arthritic patients treated with local cryotherapy or whole-body cryotherapy. By pooling 6 studies including 257 rheumatoid arthritis (RA) patients, we showed a significant decrease in pain visual analogic scale (mm) and 28-joint disease activity score after chronic cryotherapy in RA patients. For molecular pathways, local cryotherapy induces an intrajoint temperature decrease, which might downregulate several mediators involved in joint inflammation and destruction (cytokines, cartilage-degrading enzymes, proangiogenic factors), but studies in RA are rare. Cryotherapy should be included in RA therapeutic strategies as an adjunct therapy, with potential corticosteroid and nonsteroidal anti-inflammatory drug dose-sparing effects. However, techniques and protocols should be more precisely defined in randomized controlled trials with stronger methodology.
Common variable immunodeficiency (CVID) is the most common symptomatic primary immunodeficiency in adults. As symptoms of CVID are usually heterogeneous and unspecific, diagnosis and follow-up of CVID can be challenging. In light of this, a broad review of advances in management and treatment of CVID is performed here in order to reach a distinct protocol. However, it should be noted that owing to the nature of the disease, it can only be treated symptomatically but not cured. There is little evidence to guide appropriate or universal guidelines to improve the current status of management of the disease. The most satisfactory treatments of CVID could be achieved by the use of immunoglobulin replacement, antibiotics, immunosuppressants and hematopoietic stem cell transplantation. This review is written based on the importance of clinical surveillance of asymptomatic CVID cases and early recognition of different clinical complications. Moreover, for each complication, appropriate interventions for improving outcomes are mentioned.
Biologic drugs have revolutionized the treatment of moderate to severe psoriasis in recent years because of their high efficacy and low risk of toxicity. However, even within the group of biologic therapies, there are differences related to the different mechanisms of action. Areas covered: We review the main adverse events associated with the biologic agents currently available for the treatment of psoriasis and the new inhibitors targeting the p19 subunit of interleukin (IL) 23 and the IL-17A receptor. This review covers injection site reactions, infections, cardiovascular events, demyelinating disorders, tumours, class effects secondary adverse events, immunogenicity, safety in pregnancy and vaccines efficacy. Expert commentary: More than a decade after the first approval of biologic drugs for use in psoriasis, the good safety profile of these drugs is one of the main justifications and incentives for their long-term use. The emergence of new pharmacological groups has made it possible to avoid some of the class effects of first-generation biologic agents and the new therapies appear to pose less risk of reactivation of latent infections, such as hepatitis B virus and tuberculosis. However, they are associated with new adverse effects related to their mechanism of action, including candidiasis and the risk of exacerbation or onset of inflammatory bowel disease.
Systemic lupus erythematosus (SLE) is a multi-system autoimmune disease. There are three drugs licensed for the treatment of lupus: corticosteroids, hydroxychloroquine and belimumab. Immunosuppressants such as azathioprine, methotrexate and mycophenolate are also used. Despite these treatments there is still considerable morbidity. New treatments are needed for the management of active lupus. Epratuzumab a humanized IgG1 monoclonal antibody that targets CD22 resulting in selective B cell modulation that has been considered a potential treatment for SLE. Areas covered: Summary of the relevant pathogenesis and disease activity measurements used in SLE patients, current treatments and unmet needs in SLE, pharmacokinetics and pharmacodynamics of epratuzumab therapy, and a summary of the 7 clinical trials that have investigated the efficacy and safety of epratuzumab in SLE. Expert commentary: It is not clear why trials have failed to demonstrate efficacy but high placebo response rates from optimisation of standard of care and a sub-optimal dosing regimen may have played a role. Post-hoc analysis suggested that there may be subgroups that did respond, such as anti-SSA positive patients with features of Sjogren’s syndrome. Further research is needed to explore this and other potential sub-groups that might respond.
Patients experiencing anaphylaxis who do not recover after treatment with intramuscular adrenaline are regarded as suffering from refractory anaphylaxis. The incidence of refractory anaphylaxis is estimated to range between 3-5% of anaphylaxis cases. The risk factors for refractory anaphylaxis are unknown. Areas covered: In the present analysis, we aimed to evaluate the management and risk factors of refractory anaphylaxis to highlight possible clinical implications for updating current management algorithms. Expert commentary: According to international guidelines, adrenaline given through the intramuscular (i.m.) route is a rapid and safe treatment but may be insufficient. Therefore, defined standardized treatment protocols for such cases of refractory anaphylaxis are needed to optimize the treatment. Point-of-care diagnostics may enable doctors to identify patients experiencing severe, refractory anaphylaxis early in order to initiate intensified critical care treatment.