The worldwide gradient of autoimmune conditions

The persistent challenge of lupus nephritis

Systemic lupus erythematosus has long been considered the prototypic autoimmune disease. Although the etiology remains enigmatic, there has been vigorous definition of the clinical features and the natural history. In this issue, we review the persistent challenge of lupus nephritis and, in particular, features of diagnosis as well as treatment options. It is clear that major therapeutic advances have occurred but there is still a considerable unmet need in the population. This issue does not review all the clinical problems of lupus nephritis, but rather attempts to place the most recent data in perspective for the clinician.

B cells are resistant to immunomodulation by 'IVIg-educated' dendritic cells

Intravenous immunoglobulin (IVIg) can exert beneficial effects in autoimmune and inflammatory diseases via several mutually non-exclusive mechanisms. While, IVIg can directly modulate the functions of both innate and adaptive immune cells such as dendritic cells (DC), macrophages, B and T cells, several reports have also highlighted that the regulation of immune responses by IVIg can be indirect. In view of these results, we aimed at exploring whether indirect regulation of immune cells by 'IVIg-educated' innate cells is a universal phenomenon. We addressed this question by deciphering the modulation of B cell functions by 'IVIg-educated' DC. Our results indicate that human B cells are resistant to immunomodulation by 'IVIg-educated' DC. However, IVIg at therapeutic concentrations can directly inhibit B cell activation and proliferation. These results thus suggest that, indirect modulation of immune cells by IVIg is not a universal phenomenon.

Air pollution in autoimmune rheumatic diseases: a review

Air pollution consists of a heterogeneous mixture of gasses and particles that include carbon monoxide, nitrates, sulfur dioxide, ozone, lead, toxic by-product of tobacco smoke and particulate matter. Oxidative stress and inflammation induced by inhaled pollutants may result in acute and chronic disorders in the respiratory system, as well as contribute to a state of systemic inflammation and autoimmunity. This paper reviews the mechanisms of air contaminants influencing the immune response and autoimmunity, and it focuses on studies of inhaled pollutants triggering and/or exacerbating rheumatic diseases in cities around the world. Remarkably, environmental factors contribute to the onset of autoimmune diseases, especially smoking and occupational exposure to silica in rheumatoid arthritis and systemic lupus erythematosus. Other diseases such as scleroderma may be triggered by the inhalation of chemical solvents, herbicides and silica. Likewise, primary vasculitis associated with anti-neutrophil cytoplasmic antibody (ANCA) may be triggered by silica exposure. Only few studies showed that air pollutants could trigger or exacerbate juvenile idiopathic arthritis and systemic lupus erythematosus. In contrast, no studies of tropospheric pollution triggering inflammatory myopathies and spondyloarthropathies were carried out. In conclusion, air pollution is one of the environmental factors involved in systemic inflammation and autoimmunity. Further studies are needed in order to evaluate air pollutants and their potentially serious effects on autoimmune rheumatic diseases and the mechanisms involved in the onset and the exacerbation of these diseases.

Autoimmunity in 2010

There is now growing evidence that autoimmunity is the common trait connecting multiple clinical phenotypes albeit differences in tissue specificity, pathogenetic mechanisms, and therapeutic approaches cannot be overlooked. Over the past years we witnessed a constant growth of the number of publications related to autoimmune diseases in peer-reviewed journals of the immunology area. Original data referred to factors from common injury pathways (i.e. T helper 17 cells, serum autoantibodies, or vitamin D) and specific diseases such as multiple sclerosis, systemic lupus erythematosus, and rheumatoid arthritis. As an example, the issue of a latitudinal gradient in the prevalence and incidence rates has been proposed for all autoimmune diseases and was recently coined as geoepidemiology to suggest new environmental triggers for tolerance breakdown. The present article is aimed at reviewing the articles that were published over the past year in the major autoimmunity and immunology journals.

Dietary factors regulate cytokines in murine models of systemic lupus erythematosus

Cytokines play the active roles in the pathogenesis of systemic lupus erythematosus (SLE) and contribute significantly to the immune imbalance in this disease. Conservative therapeutic approaches, such as dietary modifications have been shown to have some beneficial impact on the disease activity of the SLE. Over the past years, accumulating evidences have supported a major role for specific dietary factors, including calorie restriction, n-3/n-6 fatty acids, vitamin A, vitamin D, vitamin E, phytoestrogens or herbal medicine in the regulation of cytokines involved in SLE development. Although there are many reviews that discuss the issue of nutrition and immunity, there are relatively few articles that focus on the regulation of cytokines by dietary factors. This concise review will summarize those animal studies that investigated not only the outcome of autoantibody production and proteinuria, but also cytokines production. However, the field of dietary factors in the immunomodulation of SLE is still in its infancy. More clinical studies are needed to confirm the preliminary results and advance the knowledge in this field. Lifestyle modification and adjustments in diet are important and encouraged to be suggested as an adjuvant therapy for SLE.

Explosion of autoimmune diseases and the mosaic of old and novel factors

In recent decades, an enormous effort has been made to elucidate the pathogenesis of autoimmune and autoinflammatory diseases. Autoimmunity is a multifactorial process in which genetic, immunological, environmental and hormonal factors play in concert, together representing what was termed years ago the 'mosaic of autoimmunity'. To date, more than 80 systemic and organ-specific autoimmune diseases have been defined, and their cumulative burden is substantial, both medically and financially. Furthermore, the burden of autoimmune and autoinflammatory diseases is rising, making these diseases a ubiquitous global phenomenon that is predicted to further increase in the coming decades. In this issue of the journal, additional aspects of autoimmunity are detailed. Immune dysregulation and loss of self-tolerance are the cornerstones of autoimmunity.

Reproductive immunology: a focus on the role of female sex hormones and other gender-related factors

Reproductive immunology has attracted the attention of researchers interested in fertility and pregnancy as well as those interested in immunity and autoimmunity. Over the past couple of decades, a wealth of data on the immune-reproductive interactions has been generated. This issue of the Journal will examine several topics including the role of immune factors in the induction of anti-Ro antibody-mediated autoimmunity in neonates and the immunological effects of gender and sex hormones. The possible implications of the research reviewed here for the development of novel therapeutic approaches are also addressed.

Celiac disease: a model disease for gene-environment interaction

Celiac sprue remains a model autoimmune disease for dissection of genetic and environmental influences on disease progression. The 2010 Congress of Autoimmunity included several key sessions devoted to genetics and environment. Several papers from these symposia were selected for in-depth discussion and publication. This issue is devoted to this theme. The goal is not to discuss genetic and environmental interactions, but rather to focus on key elements of diagnosis, the inflammatory response and the mechanisms of autoimmunity.

Autoimmune or auto-inflammatory syndrome induced by adjuvants (ASIA): old truths and a new syndrome?

There has been considerable interest in the role of environmental factors and the induction of autoimmunity and the ways by which they facilitate loss of tolerance. Clearly both genetic and environmental factors are incriminated, as evidenced by the lack of concordance in identical twins and the relatively recent identification of the shared epitope in rheumatoid arthritis. In this issue a new syndrome called 'Asia'-autoimmune/auto-inflammatory syndrome induced by adjuvants has been proposed. It is an intriguing issue and one that is likely to be provocative and lead to further biologic and molecular investigations.

The autoimmunity of primary biliary cirrhosis and the clonal selection theory

Primary biliary cirrhosis (PBC) is a chronic cholestatic liver disease in which an immune-mediated injury targets the small intrahepatic bile ducts. PBC is further characterized by highly specific serum antimitochondrial autoantibodies (AMA) and autoreactive T cells, a striking female predominance, a strong genetic susceptibility, and a plethora of candidate environmental factors to trigger the disease onset. For these reasons PBC appears ideal to represent the developments of the clonal selection theory over the past decades. First, a sufficiently potent autoimmunogenic stimulus in PBC would require the coexistence of numerous pre-existing conditions (mostly genetic, as recently illustrated by genome-wide association studies and animal models) to perpetuate the destruction of the biliary epithelium by the immune system via the persistence of forbidden clones. Second, the proposed modifications of mitochondrial autoantigens caused by infectious agents and/or xenobiotics well illustrate the possibility that peculiar changes in the antigen structure and flexibility may contribute to tolerance breakdown. Third, the unique apoptotic features demonstrated for cholangiocytes are the ideal setting for the development of mitochondrial autoantigen presentation to the immune system through macrophages and AMA thus turning the non traditional mitochondrial antigen into a traditional one. This article will review the current knowledge on PBC etiology and pathogenesis in light of the clonal selection theory developments.

Autoantibody heritability in thyroiditis: IgG subclass contributions

Using a simple screening technique called regression of offspring on mid-parent (ROMP) to examine the role of IgG subclasses in affected and unaffected siblings of children and adolescents with autoimmune thyroid disease and their parents, both total-restricted and subclass-restricted autoantibodies to thyroglobulin (Tg) were assayed quantitatively for each of the IgG subclasses. There was a significant correlation of anti-Tg titer of probands with parental titers in thyrotoxicosis (TT), (R(2) = 0.569, p = 0.001), but not in chronic lymphocytic thyroiditis. The most striking correlation was in TT patients of African-American ancestry, (R(2) = 0.9863, p = 0.0007). Additional insight is provided by examining the contributions of the IgG subclasses individually, particularly those whose concentrations appear not to have direct influence on the total IgG titers. Thus, using small numbers of patients, and assaying the IgG subclass distributions, as well as any other immunoglobulin isotypes that are significantly altered in autoantibody assays, ROMP can be performed rapidly to ascertain which quantifiable parameters may be usefully extended to predict disease onset and progression.