Abstract
Purpose: :
to evaluate TLR2, TLR4 and TLR9 expression on conjunctival impression cytologies of patients with active Th1– and Th2– driven diseases.
Methods: :
9 patients with severe ocular surface inflammation due to Vernal Keratoconjunctivitis (VKC, n=6) and Sjogren Syndrome (SS, n=3), and 5 healthy controls were included. Patients were divided in two groups: Th1 (SS: age 51±20 years, 1 M and 2 F) and Th2 (VKC: age 16±6 years, 5 M and 1 F) disease. Clinical signs (blepharitis, conjunctival hyperemia, chemosis and papillary reaction, superficial punctuate keratitis and corneal epitelial defects) were evaluated and scored from 0 to 3 based on the severity, the total sign score (TSS) was calculated. Two impression cytologies were performed on bulbar conjunctiva. Total mRNA was extracted with Gentra systems kit (MN, USA) and the TLR2, TLR4 and TLR9 expression was evaluated by Real–time PCR and related to the mRNA levels of the controls by Rest © sofware. TLR2, TLR4 and TLR9 expression was compared between Th1 and Th2 patients by Mann–Whitney U–test and clinical signs scores were related to TLRs expression by Pearson correlation test.
Results: :
TLR2, TLR4 and TLR9 expression by conjunctiva showed an opposite trend between Th2 and Th1 diseases. TLR2 and TLR9 showed decreased levels in VKC group and increased levels in SS patients as compared to controls (TLR2: –77.6 and +1.1; TLR9: –2.2 and +18 fold increase/decrease, respectively). Similarly, TLR4 levels were increased in VKC patients and decreased in the SS group (+4,7 and –28,9 fold increase/decrease vs controls, respectively). TLR4 expression (but not TLR2 and TLR9) was significantly different between Th1 and Th2 groups (p=0,041). TLR4 expression showed significant correlation to conjunctival hyperemia (p=0,028, rho=0,808) in the Th2 group of patients and an inverse correlation to superficial punctuate keratitis and TTS in the Th1 group (p=0,048, rho=–0,997).
Conclusions: :
TLR2, TLR4 and TLR9 showed different expression between Th1 and Th2 driven diseases. TLR4 showed opposite trend between Th1 and Th2 patients and significant correlation to the severity of the diseases, suggesting its possible role as marker of clinical severity.
Keywords: conjunctiva • inflammation • receptors