title: Effects of azithromycin on gene expression profiles of proinflammatory and anti-inflammatory mediators in the eyelid margin and conjunctiva of patients with meibomian gland disease.
abstract: OBJECTIVE
  Topical application of azithromycin suppresses expression of proinflammatory mediators while restoring transforming growth factor β1 (TGF-β1) levels as evaluated by eyelid margin and conjunctival impression cytology.
  
  
  OBJECTIVE
  To explore the effects of azithromycin therapy on expression of proinflammatory and anti-inflammatory mediators in meibomian gland disease (MGD).
  
  
  METHODS
  Case-control study performed in a clinic setting from August 17, 2010, to December 31, 2010. Sixteen patients with posterior blepharitis and conjunctival inflammation due to MGD were treated with azithromycin, 1%, drops for 4 weeks. Impression cytology of the lower eyelid margin and tarsal conjunctiva to measure cytokine expression by quantitative real-time polymerase chain reaction as well as tear collection to measure matrix metalloproteinase 9 (MMP-9) activity were performed once in 8 asymptomatic healthy control participants and 5 times in the 16 symptomatic patients (every 2 weeks for 8 weeks), before, during, and after azithromycin treatment.
  
  
  METHODS
  Azithromycin, 1%, drops for 4 weeks.
  
  
  METHODS
  Cytokine expression in the eyelid margin and conjunctiva, and MMP-9 activity in tears.
  
  
  RESULTS
  Compared with a 1-time measurement of 8 healthy participants, among 16 symptomatic patients, the mean (SD; 95% CI) fold change of expression of proinflammatory mediators interleukin 1β (IL-1β), IL-8, and MMP-9 increased to 13.26 (4.33; 11.14-15.38; P < .001), 9.38 (3.37; 7.73-11.03; P < .001), and 13.49 (4.92; 11.08-15.90; P < .001), respectively, in conjunctival cells and to 11.75 (3.96; 9.81-13.69; P < .001), 9.31 (3.28; 7.70-10.92; P < .001), and 11.52 (3.50; 9.81-13.24; P < .001), respectively, in the eyelid margin of patients with MGD. In contrast, the mean (SD; 96% CI) fold change of expression of TGF-β1 messenger RNA (mRNA) decreased to 0.58 (0.25; 0.46-0.70; P = .02) and 0.63 (0.14; 0.56-0.70; P = .02) in conjunctival and eyelid margin cells, respectively, of patients with MGD. Azithromycin, 1%, caused a change in the expression pattern of these mediators toward normal levels during 4 weeks of treatment. Levels of IL-1β, IL-8, and MMP-9 mRNA remained suppressed, although they rebounded toward pretreatment values 4 weeks after azithromycin withdrawal. Expression of TGF-β1 increased during treatment and remained at levels similar to the healthy controls after drug withdrawal. Change in tear MMP-9 activity was similar to the pattern of MMP-9 transcripts.
  
  
  CONCLUSIONS
  While the study did not control for potential confounding factors over time independent of the intervention that may have contributed to the results, topical azithromycin suppressed expression of proinflammatory mediators and increased expression of TGF-β1 to normal levels. Increased TGF-β1 expression may contribute to the anti-inflammatory activity of azithromycin in MGD.
authors.affiliation: Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas.
authors.forename: Lili
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas.
authors.forename: Zhitao
authors.initials: Z
authors.lastname: Su
authors.affiliation: Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas.
authors.forename: Zongduan
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas.
authors.forename: Jing
authors.initials: J
authors.lastname: Lin
authors.affiliation: Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas.
authors.forename: De-Quan
authors.initials: DQ
authors.lastname: Li
authors.affiliation: Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas.
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Pflugfelder
mesh_terms: D000287:Administration, Topical; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D017963:Azithromycin / Q000627:therapeutic use*; D001762:Blepharitis / Q000188:drug therapy* / Q000209:etiology / Q000235:genetics; D016022:Case-Control Studies; D003231:Conjunctivitis / Q000188:drug therapy* / Q000209:etiology / Q000235:genetics; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D005136:Eye Proteins / Q000235:genetics* / Q000378:metabolism; D005141:Eyelid Diseases / Q000150:complications*; D006801:Humans; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism; D008537:Meibomian Glands / Q000473:pathology*; D008875:Middle Aged; D009883:Ophthalmic Solutions; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D013666:Tears / Q000201:enzymology; D059467:Transcriptome; D053773:Transforming Growth Factor beta1 / Q000235:genetics / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D016207:Cytokines; D005136:Eye Proteins; D009883:Ophthalmic Solutions; D012333:RNA, Messenger; D053773:Transforming Growth Factor beta1; C042434:tear proteins; D017963:Azithromycin; D020780:Matrix Metalloproteinase 9