title: Vitamin D deficiency is associated with an increased autoimmune response in healthy individuals and in patients with systemic lupus erythematosus.
abstract: OBJECTIVE
  Vitamin D deficiency is widespread and has been associated with many chronic diseases, including autoimmune disorders. A study was undertaken to explore the impact of low vitamin D levels on autoantibody production in healthy individuals, as well as B cell hyperactivity and interferon α (IFNα) activity in patients with systemic lupus erythematosus (SLE).
  
  
  METHODS
  Serum samples from 32 European American female patients with SLE and 32 matched controls were tested for 25-hydroxyvitamin D (25(OH)D) levels, lupus-associated autoantibodies and serum IFNα activity. Isolated peripheral blood mononuclear cells were tested for intracellular phospho-ERK 1/2 as a measure of B cell activation status.
  
  
  RESULTS
  Vitamin D deficiency (25(OH)D <20 ng/ml) was significantly more frequent among patients with SLE (n=32, 69%) and antinuclear antibody (ANA)-positive controls (n=14, 71%) compared with ANA-negative controls (n=18, 22%) (OR 7.7, 95% CI 2.0 to 29.4, p=0.003 and OR 8.8, 95% CI 1.8 to 43.6, p=0.011, respectively). Patients with high B cell activation had lower mean (SD) 25(OH)D levels than patients with low B cell activation (17.2 (5.1) vs 24.2 (3.9) ng/ml; p=0.009). Patients with vitamin D deficiency also had higher mean (SD) serum IFNα activity than patients without vitamin D deficiency (3.5 (6.6) vs 0.3 (0.3); p=0.02).
  
  
  CONCLUSIONS
  The observation that ANA-positive healthy controls are significantly more likely to be deficient in vitamin D than ANA-negative healthy controls, together with the finding that vitamin D deficiency is associated with certain immune abnormalities in SLE, suggests that vitamin D plays an important role in autoantibody production and SLE pathogenesis.
authors.affiliation: Arthritis and Clinical Immunology, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA.
authors.forename: Lauren L
authors.initials: LL
authors.lastname: Ritterhouse
authors.forename: Sherry R
authors.initials: SR
authors.lastname: Crowe
authors.forename: Timothy B
authors.initials: TB
authors.lastname: Niewold
authors.forename: Diane L
authors.initials: DL
authors.lastname: Kamen
authors.forename: Susan R
authors.initials: SR
authors.lastname: Macwana
authors.forename: Virginia C
authors.initials: VC
authors.lastname: Roberts
authors.forename: Amy B
authors.initials: AB
authors.lastname: Dedeke
authors.forename: John B
authors.initials: JB
authors.lastname: Harley
authors.forename: R Hal
authors.initials: RH
authors.lastname: Scofield
authors.forename: Joel M
authors.initials: JM
authors.lastname: Guthridge
authors.forename: Judith A
authors.initials: JA
authors.lastname: James
mesh_terms: D000974:Antibodies, Antinuclear / Q000097:blood; D015551:Autoimmunity / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D016898:Interferon-alpha / Q000097:blood; D008180:Lupus Erythematosus, Systemic / Q000209:etiology* / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000150:complications* / Q000276:immunology*
chemical_list: D000974:Antibodies, Antinuclear; D016898:Interferon-alpha; D014807:Vitamin D; C104450:25-hydroxyvitamin D