title: Vitamin D nutritional status and vitamin D regulated antimicrobial peptides in serum and pleural fluid of patients with infectious and noninfectious pleural effusions.
abstract: BACKGROUND
  Vitamin D and vitamin D dependent antimicrobial peptides such as Cathelicidin (LL-37) and β-defensin 2 have an important role in innate and adaptative immunity, but their role in pleural effusions has not been studied before.
  
  
  METHODS
  Serum and pleural fluid samples from 152 patients with pleural effusion were collected, corresponding to 45 transudates and 107 exudates, 51 infectious effusions (14 complicated and 37 non-complicated), 44 congestive heart failure effusions and 38 malignant effusions. The levels of 25 OH-vitamin D, 1,25-(OH)2-vitamin D, Vitamin D Binding Protein (VDBP), LL-37 and β-defensin 2, both in serum and pleural fluid were evaluated in this prospective study. Differences between groups were analysed using unpaired t tests or Mann-Whitney tests. Correlations between data sets were examined using Pearson correlation coefficient or Spearman rank correlation coefficient. Diagnostic accuracy was estimated using ROC curve analysis.
  
  
  RESULTS
  Low serum 25 OH vitamin D levels were found in all groups. Infectious effusions (IE) had higher serum and pleural fluid LL-37 levels compared to congestive heart failure or malignant effusions. Among IE, complicated had higher serum and pleural fluid LL-37 levels, and lower serum β-defensin-2 levels. Positive correlations were found between serum 25 OH-vitamin D levels and serum or pleural 1,25-(OH)2-vitamin D levels, and between 1,25-(OH)2-vitamin D and LL-37 serum. Diagnostic accuracy of the different molecules was moderate at best.
  
  
  CONCLUSIONS
  Hypovitaminosis D is highly prevalent in pleural effusions. LL-37 is produced intrapleurally in IE. This production is higher in complicated IE. No evidence of pleural production of β-defensin 2 was found in any of the groups. Diagnostic accuracy of the different molecules is at the best moderate for discriminating different types of effusions.
authors.affiliation: Division of Pneumology, Universidad de Cantabria, IDIVAL, Santander, Spain. camado@humv.es.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Amado
authors.affiliation: Clinical Biochemistry, Universidad de Cantabria, IDIVAL, Santander, Spain.
authors.forename: María T
authors.initials: MT
authors.lastname: García-Unzueta
authors.affiliation: Infectious Diseases Hospital Universitario Marqués de Valdecilla (HUMV), Universidad de Cantabria, IDIVAL, Santander, Spain.
authors.forename: M Carmen
authors.initials: MC
authors.lastname: Fariñas
authors.affiliation: Clinical Biochemistry, Universidad de Cantabria, IDIVAL, Santander, Spain.
authors.forename: Francisca
authors.initials: F
authors.lastname: Santos
authors.affiliation: Clinical Biochemistry, Universidad de Cantabria, IDIVAL, Santander, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Ortiz
authors.affiliation: Gerencia Atención Primaria, Servicio Cántabro de Salud, Santander, Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Muñoz-Cacho
authors.affiliation: Division of Endocrinology, Hospital Universitario Marqués de Valdecilla, Universidad de Cantabria, IDIVAL, Santander, Spain.
authors.forename: José A
authors.initials: JA
authors.lastname: Amado
mesh_terms: D023181:Antimicrobial Cationic Peptides / Q000097:blood / Q000737:chemistry*; D015415:Biomarkers / Q000097:blood / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000097:blood / Q000737:chemistry*; D005122:Exudates and Transudates / Q000737:chemistry*; D006333:Heart Failure / Q000150:complications; D006801:Humans; D009752:Nutritional Status; D016066:Pleural Effusion, Malignant / Q000097:blood / Q000737:chemistry* / Q000382:microbiology; D011446:Prospective Studies; D012372:ROC Curve; D013030:Spain; D014157:Transcription Factors / Q000097:blood / Q000737:chemistry*; D014807:Vitamin D / Q000097:blood / Q000737:chemistry*; D023083:beta-Defensins / Q000097:blood / Q000737:chemistry*; D054804:Cathelicidins
chemical_list: D023181:Antimicrobial Cationic Peptides; D015415:Biomarkers; C063898:DBP protein, human; D004268:DNA-Binding Proteins; D014157:Transcription Factors; D023083:beta-Defensins; D014807:Vitamin D; D054804:Cathelicidins
keywords: 25 OH vitamin D; Cathelicidin; LL-37; Pleural effusion; β-defensin-2