title: Effect of narrowband ultraviolet B therapy on serum vitamin D and cathelicidin (LL-37) in patients with chronic plaque psoriasis.
abstract: BACKGROUND
  Narrowband ultraviolet B (NB-UVB) has been widely used in the treatment of psoriasis. It has been shown that vitamin D is a major regulator of the expression of human antimicrobial peptide cathelicidin LL-37, which has a critical role in inflammatory cascade in psoriasis.
  
  
  OBJECTIVE
  To evaluate the effect of NB-UVB therapy on serum levels of cathelicidin LL-37 and 25-hydroxyvitamin D [25(OH)D] in psoriasis patients.
  
  
  METHODS
  Ninety-three psoriasis patients and 50 controls were included in the study. For psoriasis patients, serum levels of 25(OH)D and cathelicidin LL-37 were estimated before and after NB-UVB therapy.
  
  
  RESULTS
  Before treatment, serum 25(OH)D levels were significantly lower in psoriasis patients (31.5 ± 14.41 nmol/L) compared to controls (53.5 ± 19.6 nmol/L), p  =  .015. In contrast, serum LL-37 was significantly higher in psoriasis patients (13.24 ± 3.2 ng/mL) than in controls (7.92 ± 5.33 ng/mL), p < .001. After NB-UVB treatment, there was a highly significant elevation of serum 25(OH)D to reach 56.85 ± 5.2 nmol/L (p < .001) and further elevation of serum LL-37 to reach 29.4 ± 4.2 (p  =  .02).
  
  
  CONCLUSIONS
  The elevation of serum 25(OH)D and cathelicidin LL-37 could be an additional possible mechanism of action of NB-UVB therapy in the treatment of psoriasis.
authors.forename: Nawaf
authors.initials: N
authors.lastname: Al-Mutairi
authors.forename: Dalia
authors.initials: D
authors.lastname: Shaaban
mesh_terms: D000328:Adult; D023181:Antimicrobial Cationic Peptides / Q000097:blood*; D016022:Case-Control Studies; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011565:Psoriasis / Q000097:blood* / Q000628:therapy*; D014467:Ultraviolet Therapy / Q000379:methods*; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D054804:Cathelicidins
chemical_list: D023181:Antimicrobial Cationic Peptides; D014807:Vitamin D; C104450:25-hydroxyvitamin D; D054804:Cathelicidins