Margherita Zen

The kaleidoscope of glucorticoid effects on immune system.

Glucocorticoids (GCs) are potent anti-inflammatory and immunosuppressive agents which exert multiple effects on immune cell functions. Although their use dates back 60 years, their functions and mode of action have not been completely elucidated yet. GCs act through different genomic and non genomic mechanisms which are mediated by the binding to cytosolic glucocorticoid receptor as well as to cell membrane receptors, or by interacting directly with enzymes and other cell proteins. T cell subtypes have a different sensitivity and response to GCs; in fact, GCs have an immunosuppressive effect on pro-inflammatory T cells, while they stimulate regulatory T cell activity. The effect of GCs on B cells is less clear. Interestingly, treatment with GCs may determine apoptosis of autoreactive B cells by reducing the B cell activator factor (BAFF). Tolerogenic dendritic cells which express low levels of Major Histocompatibility Complex class II, co-stimulatory molecules and cytokines, such as IL-1β, IL-6, and IL-12, can be induced by GCs. GCs at low levels stimulate and at high levels inhibit macrophage activity; moreover, they reduce the number of basophils, stimulate the transcription of inhibitors of leukocyte proteinases and the apoptosis of neutrophils and eosinophils. Finally, GCs inhibit the synthesis and function of some cytokines, particularly T helper type 1 cytokines, and to a lesser extent the secretion of chemokines and co-stimulatory molecules from immune and endothelial cells.

Infections and autoimmunity: the multifaceted relationship

Multiple factors are thought to contribute to the development of immune response to self, including differences in genotypes, hormonal milieu, and environmental factors. This review focuses on the pivotal role of infection in the induction of autoimmune disorders. Although the development of autoimmune phenomena linked to infections is a common finding, the onset of autoimmune diseases is a rare event, arising from a combination of genetic susceptibility and environmental factors. There are several mechanisms through which pathogens can initiate or perpetuate autoimmunity. Some of them are antigen‐specific, including molecular mimicry, expression of modified, cryptic, or new antigenic determinants, and superantigens. Others are nonspecific and collectively known as “bystander activation.” They include enhanced processing and presentation of self‐antigens, immune cell activation, cytokine release, and cell apoptosis/necrosis. Infections may also trigger organ‐specific autoimmune diseases, but studies carried out until now have provided conflicting and inconclusive results regarding the role of viral and bacterial agents. Infections and autoimmune diseases have multifaceted and multidirectional relationships. It has been suggested recently that infections cannot only induce or precipitate autoimmune diseases, but they may also protect from autoimmunity or even abrogate an ongoing autoimmune process depending on the interaction between microorganisms and host. Therefore, we should look at microorganisms, not only as causes of infections but also as potential agents able to modulate the immune system. On the other hand, numerous evidences have emerged regarding the higher susceptibility of autoimmune patients to infections, possibly as a result of immunosuppressive therapy and treatment with biologic agents.

Infections as triggers and complications of systemic lupus erythematosus

A growing body of experimental and clinical evidence supports the pivotal role of infections in the induction or exacerbation of systemic lupus erythematosus (SLE). Infections can be responsible for aberrant immune response leading to a loss of tolerance towards native proteins. Molecular mimicry, especially between Sm or Ro autoantigens and EBV Nuclear Antigen-1 response, as well as the over-expression of type 1 INF genes are among the major contributors to SLE development. On the other hand infections are very common in SLE patients, where they are responsible for 30-50% of morbidity and mortality. Several factors, either genetic, including complement deficiencies or mannose-binding lectin deficiency or acquired such as severe disease manifestations or immunosuppressant use, predispose SLE patients to infections. All types of infections, including bacterial, viral and opportunistic infections, have been reported and the most frequently involved sites of infections are the same as those observed in the general population, including respiratory, skin, and urinary tract infections. Some preventive measures could be adopted in order to reduce the rate of infections in SLE patients: i.e. screening for Mycobacterium tuberculosis and for some chronic viral infections before immunosuppressive treatment; adequate prophylaxes or drug adjustments when indicated, and pneumococcal and influenza vaccinations in patients with stable disease.

SLE diagnosis and treatment: when early is early.

Around 1980 antinuclear antibody testing became widely used in routine laboratory practice leading to a tapering in the lag time between SLE onset and diagnosis. Since then nothing relevant has been introduced which could help us in making the diagnosis of SLE earlier than now. Notably, there is increasing evidence that early diagnosis and treatment could increase SLE remission rate and improve patient prognosis. Although it has been shown that autoantibodies appear before clinical manifestations in SLE patients, currently we cannot predict which autoantibody positive subjects will eventually develop the disease. Thus, great effort should be made in order to identify new biomarkers able to improve our diagnostic potential. B lymphocyte stimulator (BLyS), anti-ribosomal P protein and anti-C1q antibodies are among the most promising. In recent years, some therapeutic options have emerged as appropriate interventions for early SLE treatment, including antimalarials, vitamin D, statins and vaccination with self-derived peptides. All these immune modulators seem to be particularly useful when introduced in an early stage of the disease.

Emerging and critical issues in the pathogenesis of lupus.

Systemic lupus erythematosus (SLE) is a multisystemic, autoimmune disease, encompassing either mild or severe manifestations. SLE was originally labeled as being an immune complex-mediated disease, but further knowledge suggested its pathogenesis is motlier than that, involving complex interactions between predisposed individuals and their environment. People affected with SLE have their immune system skewed toward aberrant self-recognition usually after encountering a triggering agent. Defeats in early and late immune checkpoints contribute to tolerance breakdown and further generation and expansion of autoreactive cell-clones. B and T cells play a master role in SLE, however clues are emerging about other cell types and new light is being shed on SLE autoantibodies, since some of them display really harmful potential (pathogenic antibodies), while others are just connected with disease development (pathological antibodies) and may even be protective. Autoantibody generation is elicited by abnormal apoptosis and inefficient clearance of cellular debris causing intracellular autoantigens (e.g. nucleosomes) to persist in the extracellular environment, being further recognized by autoreactive cells. Here we explore the complexity of SLE pathogenesis through five core issues, i.e. genetic predisposition, B and T cell abnormalities, abnormal autoantigen availability, autoantibody generation and organ damage, relying on current knowledge and recent insights into SLE development.

Overlap connective tissue disease syndromes.

Overlap Syndromes (OSs) have been defined as entities satisfying classification criteria of at least two connective tissue diseases (CTDs) occurring at the same or at different times in the same patient. CTDs include systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), systemic sclerosis (SSc), polymyositis/dermatomyositis (PDM), and Sjögren syndrome (SS). Every combination between these disorders has been reported. In some OS a specific autoantibody has been indentified, supporting the hypothesis that these syndromes are not a mere association of two or more CTD in the same patient, but a well defined clinical entity with specific clinical characteristics. As an example, anti-t-RNA synthetase syndrome is characterized by the presence of anti-t-RNA synthetase antibodies. Notably, clinical manifestations observed in OS may be different from those observed in the single CTD. The treatment of OS is mainly based on the use of corticosteroids and immunosuppressants. Biologic drugs, i.e. anti-TNFα or anti-CD20 monoclonal antibodies, have been recently introduced as alternative treatments in refractory cases. Moreover, there are some concerns with the use of anti-TNF agents in patients with systemic autoimmune diseases due to the risk of triggering disease exacerbations. In this paper the most frequent OS are described with a special focus on the specific immunologic and clinical aspects. Furthermore, some personal data on anti-t-RNA synthetase syndrome and rhupus syndrome are reported.

The clinical features, diagnosis and classification of dermatomyositis

Dermatomyositis (DM) is an idiopathic inflammatory myopathy (IIM) characterized by an inflammatory infiltrate primarily affecting the skeletal muscle and skin. Most common and peculiar cutaneous lesions include Gottrons papules, Gottrons sign and heliotrope rash. Different DM subsets have been identified until now encompassing classic DM, amyopathic DM, hypomyopathic DM, post-myopathic DM, and DM sine dermatitis. Patients with DM have a higher incidence rate of malignancy than the normal population. In these patients cancer occurs in about 30% of cases with higher occurrence in men and in elderly people. Bohan and Peters diagnostic criteria, proposed in 1975, have been widely accepted and used until now. In the last ten years muscle immunopathology, myositis specific autoantibodies testing, and the use of new techniques of muscle imaging such as contrast-enhanced ultrasound or Magnetic Resonance Imaging have been introduced in the diagnostic work-up of patients with DM leading to the development of new diagnostic criteria.

Anti-annexins autoantibodies: Their role as biomarkers of autoimmune diseases

Annexins are a group of 12 highly conserved proteins which exert several regulatory functions on cell biology. There are involved in numerous cell processes including vesicle trafficking, calcium signaling, cell growth, division, and apoptosis. Autoantibodies directed toward annexin I, II, V and XI have been reported, but their role and their clinical correlates are controversial. Annexin I exerts an anti-inflammatory effect by suppressing the generation of inflammatory mediators and anti-annexin I antibodies were detected in patients affected with rheumatoid arthritis, systemic (SLE) and cutaneous lupus erythematosus. Annexin II and V have a high affinity for phospholipids playing a pivotal role in the regulation of coagulation cascade. Anti-annexin II and anti-annexin V antibodies were found in patients with arterial or venous thrombosis, especially in those with autoimmune rheumatic diseases (ARD) such as SLE, primary antiphospholipid syndrome (APS) or systemic sclerosis. Anti-annexin V antibodies were also found in patients with pregnancy loss with or without APS. Annexin XI is involved in several biological pathways, particularly apoptosis and cell proliferation. Anti-annexin XI antibodies have been found in patients with SLE, undifferentiated connective tissue disease, rheumatoid arthritis, Sjögrens syndrome and APS. The metanalysis of studies published up to now showed that the Odds Ratio for having an ARD in anti-annexin XI positive patients was 5.08 (95% CI 2.06-12.58).

Factors and comorbidities associated with first neuropsychiatric event in systemic lupus erythematosus: does a risk profile exist? A large multicentre retrospective cross-sectional study on 959 Italian patients

OBJECTIVE To analyse risk factors and comorbidities potentially associated with CNS involvement in a large cohort of Italian patients affected by SLE. METHODS A number of generic (not strictly SLE related) and specific (disease related) risk factors to which all patients have been exposed in the span of 5 years before the first neuropsychiatric (NP) event or before the last available observation were checked for and their distribution was analysed in 959 SLE patients with and without NP involvement; all the first NP events that occurred in a time frame of 10 years were recorded and categorized as SLE related or SLE unrelated. RESULTS Three hundred and twenty-six SLE patients with and 633 SLE patients without NP manifestations were included in the study. A total of 469 NP events were recorded. Headache (26.1%), cerebrovascular events (22.7%), mood disorders (8.9%), seizures (14.4%) and cognitive dysfunctions (9.5%) were the most frequent SLE-related NP events. More risk factors [mean 4.52 (2.44) vs 3.73 (2.01); P < 0.0001] were observed in patients with than without NP involvement. Overall, aPLs, LA and APS were factors more strongly associated with NP involvement. CONCLUSIONS In SLE, NP involvement and aPLs were confirmed as closely related. Furthermore, other modifiable generic risk factors, such as hypertension, carotid vasculopathy and dyslipidaemia, appeared to be related to the occurrence of cerebral vascular accident (CVA) and cognitive dysfunctions, suggesting the need for a more intensive preventive strategy to optimize the management of NP lupus.

Optimizing outcome in SLE: treating-to-target and definition of treatment goals.

Patients affected with systemic lupus erythematosus (SLE) display poor-long term prognosis and increased mortality in respect of general population. This may be due to continuous organ damage accrual which is fostered both by persistent disease activity (mainly in the short term) and prolonged corticosteroid exposure (mainly in the long term). The effort of defining novel therapeutic goals to which patients should be treated in order to have their prognosis improved is named treat-to-target. Remission in SLE was shown to be associated with better outcome and prolonged survival; in clinical practice, patients may experience either complete or clinical remission, which are defined as complete clinical/serological healing or no clinical signs of lupus with active serology, respectively. The main treat-to-target in SLE is complete remission, however since longitudinal observations suggest that clinical remission or low disease activity even with minimal corticosteroid intake do improve patients prognosis and survival as well, they may be assumed as acceptable alternative targets. Suitable therapeutic strategies have to be defined in order for these goals to be achieved including early diagnosis, effective treatment and proper corticosteroid tapering which in turn require development of more reliable serum biomarkers for early disease detection and less toxic targeted therapies with a steroid-sparing potential.