title: Vitamin D status and expression of vitamin D receptor and LL-37 in patients with spontaneous bacterial peritonitis.
abstract: BACKGROUND
  Vitamin D, which exerts its effect through vitamin D receptor (VDR), and LL-37, a vitamin D-dependent antimicrobial peptide, are involved in many infectious diseases.
  
  
  OBJECTIVE
  The objective of this study was to evaluate whether vitamin D status and expressions of VDR and LL-37 are involved in the pathogenesis of spontaneous bacterial peritonitis (SBP).
  
  
  METHODS
  Serum and ascitic fluid 25-dihydroxyvitamin D [25(OH)D] concentrations and levels of VDR and LL-37 in peritoneal leukocytes were measured by ELISA and real-time PCR methods in cirrhotic patients with SBP (n = 19) and cirrhotic patients with simple ascites (n = 28). The correlations between these levels and clinical variables were evaluated.
  
  
  RESULTS
  Cirrhotic patients with ascites showed low vitamin D concentrations in both serum and ascitic fluid. Lower serum vitamin D concentrations were observed in cirrhotic patients with Child-Pugh C class. 25(OH)D concentrations in ascitic fluid were positive correlated with that in serum (r = 0.74, P < 0.001). The SBP group showed significantly higher levels of both VDR and LL-37 mRNA expressions in peritoneal leukocytes than the simple ascites group (P = 0.005 and P = 0.003, respectively). In the SBP group, VDR and LL-37 expressions in peritoneal leukocytes were positively correlated (r = 0.70, P = 0.001).
  
  
  CONCLUSIONS
  Vitamin D insufficiency was universal among cirrhotic patients with ascites, and the situation was more severe with more serious cirrhosis. Expressions of peritoneal leukocytes VDR and LL-37 genes were simultaneously up-regulated in cirrhotic patients with SBP when compared with cirrhotic patients with simple ascites. It is indicated that the vitamin D-VDR system and its downstream gene, LL-37, are involved in the pathogenesis and antibacterial immune response to SBP.
authors.affiliation: Department of Infectious Diseases, Shengjing Hospital Affiliated to China Medical University, Shenyang 110004, China.
authors.forename: Chong
authors.initials: C
authors.lastname: Zhang
authors.forename: Lianrong
authors.initials: L
authors.lastname: Zhao
authors.forename: Li
authors.initials: L
authors.lastname: Ma
authors.forename: Cheng
authors.initials: C
authors.lastname: Lv
authors.forename: Yang
authors.initials: Y
authors.lastname: Ding
authors.forename: Tingting
authors.initials: T
authors.lastname: Xia
authors.forename: Jingyan
authors.initials: J
authors.lastname: Wang
authors.forename: Xiaoguang
authors.initials: X
authors.lastname: Dou
mesh_terms: D000328:Adult; D000368:Aged; D023181:Antimicrobial Cationic Peptides / Q000378:metabolism*; D001201:Ascites / Q000453:epidemiology / Q000378:metabolism; D001202:Ascitic Fluid / Q000378:metabolism; D001424:Bacterial Infections / Q000453:epidemiology / Q000378:metabolism*; D016022:Case-Control Studies; D015897:Comorbidity; D005260:Female; D006801:Humans; D007962:Leukocytes / Q000378:metabolism; D008103:Liver Cirrhosis / Q000453:epidemiology / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010537:Peritoneum / Q000378:metabolism; D010538:Peritonitis / Q000453:epidemiology / Q000378:metabolism* / Q000382:microbiology*; D018167:Receptors, Calcitriol / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D015854:Up-Regulation / Q000502:physiology; D014807:Vitamin D / Q000378:metabolism*; D054804:Cathelicidins
chemical_list: D023181:Antimicrobial Cationic Peptides; D018167:Receptors, Calcitriol; D014807:Vitamin D; D054804:Cathelicidins