In patients with treatment-naive and inflammatory early active rheumatoid arthritis (RA), the vitamin D metabolite 1,25(OH)2D is inversely associated with disease activity and positively associated with anticitrullinated protein antibodies (ACPA), according to results published in the Scandinavian Journal of Immunology.
These results indicate that the degree of inflammatory activity and the diagnostic sensitivity and specificity might affect or be affected by 1,25(OH)2D levels in patients with RA.
The study included patients with inflammatory active and treatment-naive early RA (n=160). The researchers measured serum levels of vitamin D metabolites (25OHD2, 25OHD3, and 1,25(OH)2D) using isotope dilution mass spectrometry and radioimmunoassays at baseline. They recorded participant and disease characteristics, including gender, number of tender joints, number of swollen joints, Health Assessment Questionnaire (HAQ), visual analog scores (VAS), C-reactive protein (CRP) level, Disease Activity Score in 28 joints calculated with CRP (DAS28-CRP), erosive status (Total Sharp Score), ACPA, and immunoglobulin M rheumatoid factor status.
The results indicated a statistically significant inverse association between 1,25(OH)2D and DAS28-CRP (P =.004), HAQ results (P =.005), CRP level (P =.001), and VAS of patient pain (P =.008). The researchers also found a positive association between 1,25(OH)2D and ACPA-status (P =.04).
“In future studies we recommend measurement of all vitamin D metabolites as well as calcium, phosphate, parathyroid hormone, and albumin to evaluate the interplay between vitamin D metabolites and calcium metabolism in RA,” the researchers wrote.
Herly M, Stengaard-Pedersen K, Vestergaard P, et al. The D-vitamin metabolite 1,25(OH)2D in serum is associated with disease activity and anti-citrullinated protein antibodies in active and treatment naïve, early rheumatoid arthritis patients [published online July 20, 2018]. Scand J Immunol. doi:10.1111/sji.12704