Israel Medical Association Journal

Immune function is the most basic physiological process in humans and indeed throughout the animal kingdom. Interestingly, the vast majority of textbooks of physiology do not include a chapter on immunity. Our species survival is dependent on the diversity of the immune response and the ability for antigen presentation and effector mechanisms to be enormously promiscuous. As physicians, we are likely all too aware of how brief our life span is and the myriad of diseases and events that shorten it. It is not surprising that we question where our life comes from and our relationship within the universe. Many hypotheses have been offered regarding the likelihood that intelligent life exists elsewhere. We propose that such issues be discussed in the context of basic biologic observations on earth, such as the sight of a dense flock of tens of thousands of starlings maneuvering in rapid twists and turns at dusk before settling in trees for the night. The mathematical likelihood for life elsewhere was proposed by Frank Drake in a classic equation whose 'thesis' has stimulated the search for alien civilizations and the nature of life. A fundamental gap in this equation is the presence of a diverse immune response, a feature essential for survival of Life, presumably also extra-terrestrially.

Sjögren’s syndrome (SS), a chronic systemic autoimmune inflammatory condition involving the exocrine glands, has been suggested to be part of the spectrum of the “Autoimmune/inflammatory Syndrome Induced by Adjuvants” (ASIA). ASIA incorporates an umbrella of clinical conditions including siliconosis, macrophage myofasciitis syndrome, and post-vaccination phenomena that occur after the exposure to a substance, namely the adjuvant. Interestingly, SS and ASIA share several common features. Firstly, a shared pathogenic mechanism involving a disruption of the immune system balance, with B cell proliferation, cytokine production and tissue infiltration, have been proposed. Patients with ASIA often present clinical features resembling those of SS; dry mouth and dry eyes have also been included in the proposed classification criteria for ASIA. Finally, several case reports have suggested that both vaccines and silicone may trigger the development of SS. Unveiling these common pathways will contribute considerably to our understanding and managing of both conditions.

There is growing interest in the contribution of vitamin D deficiency to autoimmunity. Several studies have shown an association between low levels of vitamin D and autoimmune disorders, including multiple sclerosis, rheumatoid arthritis, type 1 diabetes, autoimmune thyroid diseases, celiac disease, and systemic lupus erythematosus (SLE). Vitamin D receptor ligands can mediate immunosuppressive effects. It has been suggested that low levels of this hormone contribute to the immune activation in lupus and other autoimmune diseases. This review updates and summarizes the literature on the association between vitamin D and SLE, and discusses the various correlations between vitamin D and SLE activity, clinical expressions, serology, and gene polymorphisms of vitamin D receptors.

Sarcoidosis is a chronic multisystem disease with variable course resulting from the interaction between environmental factors and the immune system of individuals genetically predisposed. The evidence linking sarcoidosis with environmental triggers such as metals is increasing. We describe the case of a 44 year old female with a history of smoking since age 30 and previous mercury dental filling who presented at physical examination with numerous subcutaneous nodules. Laboratory data showed accelerated erythrocyte sedimentation rate and high titer of anti-U1 ribonucleoprotein antibodies (U1-RNP). Skin biopsy and chest X-ray suggested the diagnosis of sarcoidosis. In this report we illustrate the different causes involved in the onset of sarcoidosis.

Autoimmune diseases are classic examples of multifactorial disorders in which a large number of genes interact with environmental factors to form the final phenotype. Identification of the genes involved in these diseases is a daunting challenge. Initially the search involved the candidate approach where polymorphisms in suspected genes were tested for association in large cohorts of patients and controls. Today, the most widely used method is genome-wide association studies (GWAS), a method based on screening large panels of patients and controls with hundreds of thousands of single nucleotide polymorphisms (SNPs), with microarray-based technology. Unique families in which autoimmune diseases are caused by single genes are another alternative. The identification of candidate genes is often followed by studies that provide biologic plausibility for the findings. The widely expanding list of genes involved in autoimmune conditions show that the same genes frequently underlie the pathogenesis of different autoimmune diseases. Despite all available resources, the main void of heritability in autoimmune conditions is yet to be discovered. Identification of these genes will help define new biological pathways and identify novel targets for the development of new therapeutic drugs.

The increasing use of computerized medical records has made the clinical data of the entire population available for epidemiological research. The resultant accessibility to this information mandates careful adaptions of ethical guidelines regarding the handling of clinical data. At the same time it grants a unique opportunity to explore the clinical nature of health and disease in large populations across all of society’s strata, socioeconomic levels, ethnicities, and geographic locations regardless of their vicinity or distance to tertiary care centers. Analysis of large databases allows us to learn the public‘s behavior towards medical services and to investigate how medical interventions affect outcomes over time. Moreover, interaction between different co-morbidities can also be better understood by large population studies. The huge numbers of patients involved in these studies provide a good model of multivariate analysis, a statistical tool that by following proper population adjustments underlines the true independent associations between different conditions. Nevertheless, the limitations of these studies should be borne in mind, such as in-built imprecision of diagnoses, incompleteness of the medical data, and the fact that these databases were initially planned for clinical and not investigational use.