Israel Medical Association Journal

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. 

Background: Epidemiological data show significant associations of vitamin D deficiency and autoimmune diseases. Vitamin D may prevent autoimmunity by stimulating naturally occurring regulatory T cells.

Objectives: To elucidate whether vitamin D supplementation increases Tregs[1] frequency (%Tregs) of circulating CD4+ T cells.

Methods: We performed an uncontrolled vitamin D supplementation trial among 50 apparently healthy subjects including supplementation of 140,000 IU at baseline and after 4 weeks (visit 1). The final follow-up visit was performed 8 weeks after the baseline examination (visit 2). Blood was drawn at each study visit to determine 25-hydroxyvitamin D levels and %Tregs. Tregs were characterized as CD4+CD25++ T cells with expression of the transcription factor forkhead box P3 and low or absent expression of CD127.

Results: Forty-six study participants (65% females, mean age ± SD 31 ± 8 years) completed the trial. 25(OH)D[2] levels increased from 23.9 ± 12.9 ng/ml at baseline to 45.9 ± 14.0 ng/ml at visit 1 and 58.0 ± 15.1 ng/ml at visit 2. %Tregs at baseline were 4.8 ± 1.4. Compared to baseline levels we noticed a significant increase of %Tregs at study visit 1 (5.9 ± 1.7, P < 0.001) and 2 (5.6 ± 1.6, P < 0.001).

Conclusions: Vitamin D supplementation was associated with significantly increased %Tregs in apparently healthy individuals. This immunomodulatory effect of vitamin D might underlie the associations of vitamin D deficiency and autoimmune diseases. Hence, our finding provides a rationale for further studies to investigate vitamin D effects on autoimmunological processes.

Approximately 1 in 31 people suffers from an autoimmune disease. The clinical care of patients with autoimmunity crosses multiple disciplines within pediatrics and internal medicine, including, for example, allergy-clinical immunology, rheumatology, nephrology, hematology, pulmonology and neurology. There are two major areas that are considered in the analysis of autoimmunity in human patients. The first of course is etiology and the second, and of even greater importance, is therapy. Towards that end, considerable attention has focused on the role of hematopoietic stem cell transplantation to either reverse or modulate autoimmune disease. Indeed, it is a field that has far more promise than premise based on a variety of issues, including economics, health care delivery, and obviously efficacy and safety. To put this in perspective, we have attempted to review some of the issues that pertain to this novel approach to the management of autoimmunity. Finally, we emphasize the need to incorporate basic research into therapeutic trials, a vacuum all too often present in clinical intervention.