Israel Medical Association Journal

Vitamin D deficiency is becoming an increasing problem worldwide. It should not be underestimated, not only due to the well-known consequences vitamin D deficiency has on bone health, but primarily because recent studies have shown how the biologically active form of vitamin D – 1,25(OH)2D – is involved in many biological processes, including immune system modulation. Moreover, the presence of a vitamin D receptor was discovered in almost all immune cells and some of its polymorphisms were found to be associated with increased incidence of autoimmune diseases. This finding led to a proposed link between vitamin D deficiency and autoimmune diseases. Patients affected by various autoimmune diseases showed low levels of vitamin D. However, it is not always clear whether vitamin D deficiency is the cause or rather a consequence of the disease. Limitations of the studies, such as the small number of patients, heterogeneity of selected groups, environmental conditions, methods used to measure vitamin D serum concentration and other confounding factors do not lead to unequivocal results to demonstrate a direct link between low vitamin D levels and autoimmune disease. Therefore, randomized trials are needed to clarify conflicting results.

Autoimmune diseases constitute a diverse group of disorders characterized by cellular and humoral responses against self. The humoral autoimmune responses are directed against various cellular and extracellular components. These responses are highly specific for each autoimmune disease and result in the production of autoantibodies that characterize certain disease entities, representing a valuable tool for the diagnosis of autoimmune diseases. Furthermore, certain autoantibodies are helpful in the prognosis of disease development, progression and severity, as well as in the classification of patients with distinct disease subtypes. Today, the value of autoantibodies in the follow-up of patients is limited, but preliminary data suggest that they may be useful in predicting response to treatment. 

The European Union defines rare diseases (RDs) as life-threatening or chronically debilitating conditions whose prevalence is less than 5 per 10,000. Moreover, for many RDs, including those of genetic origin, combined efforts are required to reduce morbidity or perinatal or early mortality, and address the considerable decline in an individual's quality of life and socioeconomic potential. Their specificities, i.e., a limited number of patients and scarcity of relevant knowledge and expertise, make RDs a unique condition which requires wide cooperation at a supranational level. Many steps were therefore taken to develop a network of European Reference Centers and to improve RDs coding and classification. In Italy, the RDs issue was addressed in 2001 with the development of a national network and a national registry coordinated by the National Center for RDs of the Italian National Institute of Health. Registries are an important resource for the development of appropriate public health policies and research on specific RDs. Research on RDs is essential for the development of novel therapeutic approaches and requires the involvement of scientific societies and patient organizations. Nevertheless, the management of patients with chronic RDs requires a qualified care network. The network for RDs of Piedmont and Aosta Valley (North-West Italy) represents an example of health care organization based on the availability of advanced therapies close to the patient’s home.

Long-term extension studies and observational drug registers have revealed an increased risk of serious infections in patients treated with anti-tumor necrosis factor agents, particularly infliximab, etanercept and adalimumab. The same may be true for the newer biological drugs rituximab, tocilizumab and abatacept, although this has yet to be confirmed by long-term observational studies. We review the risk of tuberculosis, herpes zoster and other opportunistic infections, and the recommendations for screening for tuberculosis and hepatitis B and C infections in patients affected by rheumatoid arthritis, with the aim of informing patients and encouraging greater awareness among physicians.

Behçet’s disease (BD) is a systemic inflammatory disorder characterized by a protean clinical spectrum and an enigmatic pathogenesis. After being classified as an autoimmune disorder, spondyloarthritis and vasculitis, today BD is considered at the crossroad between autoimmune and auto-inflammatory syndromes. Many pathogenetic, clinical and therapeutic clues support this recent interpretation, enabling novel treatment choices such as interleukin (IL)-1 inhibition. Thus, in the last decade the IL-1 receptor antagonist anakinra and the anti-IL-1β monoclonal antibody canakinumab were increasingly administered in BD patients resistant to standard therapies, leading to interesting results and new intriguing pathogenetic implications. However, further studies are essential to both establish how the innate and acquired immune systems interact in BD patients and identify the best way of administering anti-IL-1 agents with regard to dosage, interval of administration and organ response.

Autoimmune rheumatic diseases (ARD) affect mainly young women during their reproductive years. Fertility is usually not diminished but the time it takes to conceive is usually longer. Factors related to an ARD or to its treatment are responsible for this effect. In addition, contraception counseling is required to prevent negative fetal outcome and exacerbation of disease symptoms. In recent years, advances in therapies, clarification of risk factors for adverse pregnancy outcomes, and a multidisciplinary approach have vastly improved obstetric management, increasing the possibility of successful pregnancy with a high likelihood of favorable outcome.