JAMA Ophthalmology Journal Club Slides: Effects of Azithromycin in Patients With Meibomian Gland Disease Zhang L, Su Z, Zhang Z, Lin J, Li D-Q, Pflugfelder SC. 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. JAMA Ophthalmol. Published online July 23, 2015. doi:10.1001/jamaophthalmol.2015.2326.

Introduction Meibomian gland disease (MGD) is the most prevalent type of blepharitis, but the etiology of most cases of MGD remains to be determined. Azithromycin has been shown to have anti-inflammatory properties. Using impression cytology to obtain cells from the surface of the eyelid margin and conjunctiva, this study characterized the gene expression profiles of proinflammatory and anti-inflammatory mediators in samples from patients with MGD and further evaluated the anti-inflammatory properties of topical azithromycin application on the expression of these mediators in the eyelid margin and conjunctiva as well as its effects on tear matrix metalloproteinase 9 (MMP-9) activity. Objective To explore the effects of azithromycin therapy on expression of proinflammatory and anti-inflammatory mediators in MGD.

Methods Case-control study performed in a clinic setting in 2010. Sixteen patients with posterior blepharitis and conjunctival inflammation due to MGD were enrolled and followed up over time, and their findings were compared with a 1-time measurement in healthy participants. The patients were treated with azithromycin, 1%, drops for 4 weeks. Impression cytology of the lower eyelid margin and tarsal conjunctiva as well as tear collection were performed once in healthy participants and 5 times in patients (every 2 weeks for 8 weeks), before, during, and after azithromycin treatment.

Methods Cytokine expression was measured in the eyelid margin and conjunctiva by quantitative real-time polymerase chain reaction, and MMP-9 activity was measured in tears. One-way analysis of variance was used to make comparisons among 3 or more groups, followed by Dunnett post hoc test, and t test was used to compare differences between 2 groups.

Results Compared with a 1-time measurement in healthy participants, the mean fold change of messenger RNA (mRNA) expression of proinflammatory mediators interleukin 1β (IL-1β), IL-8, and MMP-9 increased to 13.26, 9.38, and 13.49, respectively, in conjunctival cells and to 11.75, 9.31, and 11.52, respectively, in the eyelid margin of patients with MGD. The mean fold change of expression of transforming growth factor β1 (TGF-β1) mRNA decreased to 0.58 and 0.63 in conjunctival and eyelid margin cells, respectively, of patients with MGD.

Results Cytokine Expression Profiles in MGD by Quantitative Real-Time Polymerase Chain Reaction

Results After 4 weeks of azithromycin treatment, mean mRNA expression of IL-1β, IL-8, and MMP-9 in conjunctival cells decreased to 2.88, 2.82, and 4.44 fold, respectively, while that of TGF-β1 increased to 1.16 fold. Four weeks after azithromycin withdrawal, expression of IL-1β, IL-8, and MMP-9 slightly rebounded but was still lower than the pretreatment levels; expression of TGF-β1 decreased slightly but remained at levels similar to the healthy controls. The expression pattern of IL-1β, IL-8, MMP-9, and TGF-β1 by eyelid margin cells showed a similar response to azithromycin.

Effects of Azithromycin on Cytokine Profiles in MGD Results Effects of Azithromycin on Cytokine Profiles in MGD

Results Tear MMP-9 Activity Mean tear MMP-9 activity decreased from 30.1 ng/mL to 9.4 and 6.1 ng/mL after azithromycin treatment for 2 to 4 weeks, respectively, and remained 70% lower than pretreatment levels for up to 4 weeks after cessation of azithromycin.

Comment Topical azithromycin suppressed mRNA expression of proinflammatory mediators IL-1β, IL-8, and MMP-9 and increased expression of TGF-β1. Increased levels TGF-β1 may contribute to the anti-inflammatory activity of azithromycin in ocular surface inflammatory diseases. Limitations: the study did not control for potential confounding factors over time independent of the intervention that may have contributed to the results.

Conflict of Interest Disclosures Contact Information If you have questions, please contact the corresponding author: Stephen C. Pflugfelder, MD, Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, 6565 Fannin St, NC-505, Houston, TX 77030 (stevenp@bcm.edu). Funding/Support This work was supported in part by grant EY011915 from the National Eye Institute (Dr Pflugfelder) and by Inspire, Inc, Research to Prevent Blindness, the Oshman Foundation, and the William Stamps Farish Fund. Conflict of Interest Disclosures None reported.