title: Interleukin-6 and matrix metalloproteinase expression in the subretinal fluid during proliferative vitreoretinopathy: correlation with extent, duration of RRD and PVR grade.
abstract: OBJECTIVE
  To investigate interleukin (IL)-6 protein levels in the subretinal fluid (SRF) of patients with rhegmatogenous retinal detachment (RRD) complicated by proliferative vitreoretinopathy (PVR); to correlate the IL-6 levels with matrix metalloproteinases (MMP)-1, -2, -3, -8, -9 and tissue inhibitor of metalloproteinases (TIMP)-1 with respect to RRD extent, duration and PVR grade.
  
  
  METHODS
  Thirty-one SRF samples from 31 eyes of 31 patients with RRD complicated with PVR and five SRF samples from five eyes of five patients suffering from RRD not complicated with PVR were collected during treatment by scleral buckling. Enzyme-Linked Immunosorbent Assay was employed for the measurement of IL-6, MMP-1, -3, -8 and TIMP-1 levels while the enzymatic activity of MMP-2 and MMP-9 was assessed by gelatin zymography.
  
  
  RESULTS
  Protein levels of IL-6 (p=0.050), MMP-1 (p=0.001), MMP-3 (p=0.005), MMP-8 (p=0.003), TIMP-1 (p=0.001) as well as enzymatic activity of proMMP-2 (p=0.001), MMP-2 (p=0.023) and MMP-9 (p=0.015), were significantly higher in the SRF of PVR patients compared to controls. IL-6 levels correlated significantly with TIMP-1 (r=0.528, p=0.035). Regarding clinical parameters of the detachment, IL-6 levels correlated with RRD extent (r=0.592, p=0.016), but not with RRD duration (p=0.857) and PVR grade (p=0.594). Regression analysis revealed positive correlations between IL-6 and MMP-2.
  
  
  CONCLUSIONS
  There was a significant correlation between IL-6 and TIMP-1 levels in the SRF of PVR patients. The findings of this study are in agreement with relevant studies concerning IL-6 involvement in the modulation of MMP expression and are indicative of IL-6 and MMP activity during PVR, mainly that of MMP-2 and TIMP-1.
authors.affiliation: 2nd Department of Ophthalmology, Aristotle University of Thessaloniki, Greece.
authors.forename: Chrysanthos
authors.initials: C
authors.lastname: Symeonidis
authors.forename: Eleni
authors.initials: E
authors.lastname: Papakonstantinou
authors.forename: Sofia
authors.initials: S
authors.lastname: Androudi
authors.forename: Konstantinos T
authors.initials: KT
authors.lastname: Tsaousis
authors.forename: Ioannis
authors.initials: I
authors.lastname: Tsinopoulos
authors.forename: Periklis
authors.initials: P
authors.lastname: Brazitikos
authors.forename: Georgios
authors.initials: G
authors.lastname: Karakiulakis
authors.forename: Eudoxia
authors.initials: E
authors.lastname: Diza
authors.forename: Stavros A
authors.initials: SA
authors.lastname: Dimitrakos
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism*; D016014:Linear Models; D008297:Male; D020782:Matrix Metalloproteinases / Q000378:metabolism*; D008875:Middle Aged; D012163:Retinal Detachment / Q000150:complications* / Q000201:enzymology*; D058471:Subretinal Fluid / Q000201:enzymology*; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism; D018630:Vitreoretinopathy, Proliferative / Q000150:complications / Q000201:enzymology* / Q000473:pathology*; D055815:Young Adult
chemical_list: C508600:IL6 protein, human; D015850:Interleukin-6; C560822:TIMP1 protein, human; D019715:Tissue Inhibitor of Metalloproteinase-1; D020782:Matrix Metalloproteinases