Chemokine and Cytokine gene expressions on conjunctival impression cytology and their correlations with HLA DR-A and HLA DR-B1

Abstract

Purpose : A variety of inflammatory chemokines and cytokines are known to be implicated in the physiopathology of dry eye. HLA DR was found in several multicenter trials as a potential biomarker of disease severity and prognosis. However no investigation was conducted on the correlation between cytokine expression and heterodimers α and β of HLA DR: HLA DR-A and HLA DR-B1. In this study we used the new Nanostring nCounter technology to analyze the relationships between cytokine and chemokine expressions with HLA DR-A and HLA DR-B1.

Methods : A study was conducted in 82 patients with dry eye disease (DED): ocular symptom scores, ocular staining grades, TBUT, and Schirmer test were evaluated. Conjunctival superficial cells were harvested by impression cytology and total RNAs were extracted. NanoString nCounter technology with inflammatory human Code Set was used to analyze expressed transcripts. Sixty-one inflammatory transcripts were analyzed, comprising 24 chemokines and 8 chemokine receptors, 20 cytokines and 8 cytokine receptors. HLA DR-A and HLA DR-B1 were also included in the Code Set.

Results : Twenty of the 61 molecules were reliably detected in DED patients at various levels. Seventeen targets detected were correlated with HLA DR-A and fourteen targets with HLA DR-B1. Among all the detected molecules, CXCL9, CXCL10, CCL22, CCL5, CCL17, IL-15, IL-10RB have a similar correlations with both HLA DRA and HLA DRB1 (P<0.0001). CXCL3, CCL20, IL-1R1 showed a better correlation with HLA DR-A than with HLADR-B1 but inversely for IL-7, IL-1RN and CXCR2. CXCR4 CXCL6 CXCL1 and CXCL2 were correlated only with HLA DR-A. Finally, IL-8 and IL-18 showed no significant correlation with both HLA DR (A and B1).

Conclusions : Nanostring in impression cytology could be a reliable tool for a larger screening of the inflammatory biomarkers in DED, and even other various ocular surface diseases in the future with tiny samples. Larger combination of biomarkers associated with HLA-DR could be analyzed in order to target new DED therapy.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.