title: Correlation of urine and plasma cytokine levels among reproductive-aged women.
abstract: BACKGROUND
  Inflammation is implicated in many adverse health conditions, and recent interest has focused on the effects of chronic low-grade inflammation in generally healthy populations. Cytokines measured in plasma or serum are commonly used as biomarkers of systemic levels of inflammation. Measurement of cytokines in urine may offer a simpler and less invasive alternative, although the degree to which levels of cytokines correlate in plasma and urine among healthy individuals is unknown.
  
  
  METHODS
  We assessed the correlation of blood and urine levels of 13 cytokines, including interleukin (IL)-1b, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12(p70) and IL-13, granulocyte macrophage colony-stimulating factor, interferon gamma and tumour necrosis factor alpha in 61 healthy women aged 18-30. Cytokine concentrations were considered with and without correction for creatinine.
  
  
  RESULTS
  Plasma and urine levels of the 13 cytokines were not significantly correlated using measured urinary cytokine concentrations and after adjustment for creatinine. Correlation coefficients for log-transformed cytokine concentrations in paired plasma and urine specimens ranged from -0.28 to 0.087.
  
  
  CONCLUSIONS
  These results suggest that urine has limited utility as a proxy for plasma for the measurement of inflammatory factors in a healthy population with low levels of inflammation.
authors.affiliation: Division of Biostatistics & Epidemiology, Department of Public Health, School of Public Health & Health Sciences, Arnold House, University of Massachusetts, Amherst, MA, USA.
authors.forename: Carrie
authors.initials: C
authors.lastname: Nobles
authors.forename: Elizabeth R
authors.initials: ER
authors.lastname: Bertone-Johnson
authors.forename: Alayne G
authors.initials: AG
authors.lastname: Ronnenberg
authors.forename: Joyce M
authors.initials: JM
authors.lastname: Faraj
authors.forename: Sofija
authors.initials: S
authors.lastname: Zagarins
authors.forename: Biki B
authors.initials: BB
authors.lastname: Takashima-Uebelhoer
authors.forename: Brian W
authors.initials: BW
authors.lastname: Whitcomb
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000097:blood / Q000652:urine; D003404:Creatinine / Q000097:blood / Q000652:urine; D016207:Cytokines / Q000097:blood* / Q000652:urine*; D005260:Female; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000097:blood / Q000652:urine; D006801:Humans; D007249:Inflammation; D007371:Interferon-gamma / Q000097:blood / Q000652:urine; D016753:Interleukin-10 / Q000097:blood / Q000652:urine; D018664:Interleukin-12 / Q000097:blood / Q000652:urine; D018793:Interleukin-13 / Q000097:blood / Q000652:urine; D053583:Interleukin-1beta / Q000097:blood / Q000652:urine; D007376:Interleukin-2 / Q000097:blood / Q000652:urine; D015847:Interleukin-4 / Q000097:blood / Q000652:urine; D015848:Interleukin-5 / Q000097:blood / Q000652:urine; D015850:Interleukin-6 / Q000097:blood / Q000652:urine; D015851:Interleukin-7 / Q000097:blood / Q000652:urine; D016209:Interleukin-8 / Q000097:blood / Q000652:urine; D014409:Tumor Necrosis Factor-alpha / Q000097:blood / Q000652:urine; D055815:Young Adult
chemical_list: D015415:Biomarkers; C508606:CXCL8 protein, human; D016207:Cytokines; C508609:IL10 protein, human; C508585:IL1B protein, human; C508594:IL2 protein, human; C508598:IL4 protein, human; C508599:IL5 protein, human; C508600:IL6 protein, human; C508605:IL7 protein, human; D018793:Interleukin-13; D053583:Interleukin-1beta; D007376:Interleukin-2; D015848:Interleukin-5; D015850:Interleukin-6; D015851:Interleukin-7; D016209:Interleukin-8; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D018664:Interleukin-12; D015847:Interleukin-4; D007371:Interferon-gamma; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D003404:Creatinine
keywords: Biomarkers; correlation; cytokines; inflammation; plasma; urine