Friday, 15 Dec 2017

You are here

Vitamin D Insensitivity in the Rheumatoid Joint

Researchers from the University of Birmingham have shown that while Vitamin D may be effective at preventing the onset of inflammation, it is less effective once inflammatory disease is established - largely because, once established, rheumatoid arthritis leads to vitamin D insensitivity. (Citation source https://buff.ly/2iGHYmI)

Another key finding of the research was that the impact of vitamin D on inflammatory disease cannot be predicted using cells from healthy individuals or even from the blood of patients with inflammation as cells from the diseased tissue behave in a very different way.

In addition to its well-established actions on the skeleton, vitamin D is a potent modulator of the immune system. In particular, vitamin D can suppress inflammation in autoimmune diseases such as rheumatoid arthritis. Patients with rheumatoid arthritis are frequently vitamin D deficient and may receive vitamin D supplementation.

1,25-dihydroxyvitaminD3 (1,25(OH)2D3), has potent anti-inflammatory effects, including suppression of IL-17 + and IFNγ+ T cells. They studied cells from paired peripheral blood and synovial fluid (SF) samples patients with active RA. Specifically they sought to assess cellular responses to the active form of vitamin D.

Overall theyfound that cells taken from the joints of RA patients were much less sensitive to active vitamin D. 1,25(OH)2D3 had significantly less suppressive effect on Th17 cells (IL-17+IFNγ-) and Th17.1 cells (IL-17+IFNγ+) from SF compared to those from blood, and had no effect on SF CD4+ or CD8+ IFNγ+ T cell frequencies. Memory T cells (CD45RO+) predominate in SF, and 1,25(OH)2D3 had less effect on memory T cells relative to naïve (CD45RA+) T cells.

Thus the potential anti-inflammatory effects of vitamin D in active RA are impaired because of reduced effects on phenotype-committed, inflammatory memory T cells that are enriched in SF. (Such cells are already overcommitted to inflammation)

Researchers postulated that much higher doses of vitamin D may be needed to overcome the vitamin D insensitivity within the joint. Restoration of 1,25(OH)2D3 responses in memory T cells, by whatever means,  may provide a new strategy for treatment of inflammatory diseases such as RA. 

Disclosures: 
The author has no conflicts of interest to disclose related to this subject

Add new comment

More Like This

Kidney Dysfunction Frequent in RA

Renal dysfunction is common among patients with rheumatoid arthritis (RA), particularly among older patients, women, and those with hypertension, Japanese researchers reported.

Using absolute estimated glomerular filtration rates (eGFR), 33.8% of patients had renal dysfunction, according to Shunsuke Mori, MD, of Kumamoto Saishunsou National Hospital in Kohshi, and colleagues. 

Offspring of RA Women Have Higher Risk of RA and Other Diseases

Despite a growing body of evidence suggesting that maternal health is more important than maternal medications to fetal and infant outcomes, little is known about the long term oucomes of infants born to mothers with rheumatoid arthritis (RA). Using Danish population data, researchers have shown in utero exposure to maternal RA is associated with an increased risk of thyroid disease, and an increased risk of future RA.

CDC Lyme Disease Surveillance Report

Lyme disease, caused by the spirochete Borrelia burdofgeri, is the most common vector-borne illness reported in the U.S. Cases occur mainly in the Northeast, Mid-Atlantic and upper Midwest as well as certain areas of the Pacific coast, with a geographic distribution based on residence of Ixodes scapularis (Ixodes pacificus on the West Coast), the vectors that transmits Lyme disease.

Stroke Increased in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic, inflammatory disease with systemic effects beyond the joints. While RA patients are known to have signficantly higher risks for cardiovascular disease and venous thromboembolic events, an association with stroke (CVA) is unclear.

A study claims data from Israel analyzed 11,782 RA patients and 57,973 age- and gender-matched controls.

Comparative Risk of Biologic Therapies in RA Patients Undergoing Elective Arthroplasty

During today’s plenary session Micheal D. George, et al. presented results of a study that sought to compare risk of post-op infections in RA patients undergoing arthroplasty exposed to biologic DMARDs versus methotrexate.