PT - JOURNAL ARTICLE AU - Kendra A Young AU - Melissa E Munroe AU - Joel M Guthridge AU - Diane L Kamen AU - Timothy B Niewold AU - Gary S Gilkeson AU - Michael H Weisman AU - Mariko L Ishimori AU - Jennifer Kelly AU - Patrick M Gaffney AU - Kathy H Sivils AU - Rufei Lu AU - Daniel J Wallace AU - David R Karp AU - John B Harley AU - Judith A James AU - Jill M Norris TI - Combined role of vitamin D status and <em>CYP24A1</em> in the transition to systemic lupus erythematosus AID - 10.1136/annrheumdis-2016-209157 DP - 2017 Jan 01 TA - Annals of the Rheumatic Diseases PG - 153--158 VI - 76 IP - 1 4099 - http://ard.bmj.com/content/76/1/153.short 4100 - http://ard.bmj.com/content/76/1/153.full SO - Ann Rheum Dis2017 Jan 01; 76 AB - Objective We examined whether measures of vitamin D were associated with transitioning to systemic lupus erythematosus (SLE) in individuals at risk for SLE.Methods 436 individuals who reported having a relative with SLE but who did not have SLE themselves were evaluated at baseline and again an average of 6.3 (±3.9) years later. Fifty-six individuals transitioned to SLE (≥4 cumulative American College of Rheumatology criteria). 25-Hydroxyvitamin D (25[OH]D) levels were measured by ELISA. Six single-nucleotide polymorphisms in four vitamin D genes were genotyped. Generalised estimating equations, adjusting for correlation within families, were used to test associations between the vitamin D variables and the outcome of transitioning to SLE.Results Mean baseline 25[OH]D levels (p=0.42) and vitamin D supplementation (p=0.65) were not different between those who did and did not transition to SLE. Vitamin D deficiency (25[OH]D &lt;20 ng/mL) was greater in those who transitioned compared with those who did not transition to SLE (46% vs 33%, p=0.05). The association between 25[OH]D and SLE was modified by CYP24A1 rs4809959, where for each additional minor allele increased 25[OH]D was associated with decreased SLE risk: zero minor alleles (adjusted OR: 1.03, CI 0.98 to 1.09), one minor allele (adjusted OR: 1.01, CI 0.97 to 1.05) and two minor alleles (adjusted OR: 0.91, CI 0.84 to 0.98). Similarly, vitamin D deficiency significantly increased the risk of transitioning to SLE in those with two minor alleles at rs4809959 (adjusted OR: 4.90, CI 1.33 to 18.04).Conclusions Vitamin D status and CYP24A1 may have a combined role in the transition to SLE in individuals at increased genetic risk for SLE.