Biomarker Detection and Validation for Corneal Involvement in Patients With Acute Infectious Conjunctivitis
Authors: Seitzman Gerami D. , Prajna Lalitha , Prajna N. Venkatesh , Sansanayudh Wiwan , Satitpitakul Vannarut , Laovirojjanakul Wipada , Chen Cindi , Zhong Lina , Ouimette Kevin , Redd Travis , Deiner Michael C. , Porco Travis C. , McLeod Stephen D. , Lietman Thomas M. , Hinterwirth Armin , Doan Thuy ,   SCORPIO Study Group, Gunasekaran Ramesh , Sharma Sankalp Singh , Teja Vishnu , Chaudhary Meenu , Situala Sanjeeta , Sié Ali , Coulibaly Boubacar , Bountogo Mamadou , Somkijrungroj Thanapong , Tran Huy , Mai Linh Hoàng , Xuân Thảo Hạ , Tran Yen , Urzua Cristhian A. , Vega Fabian , Salgado Felipe , Cuitino Loreto , Pérez Fernando Pérez , Martínez Jaime Macías , Lansingh Van Charles , Thanapaisal Sukhumal , McKie George , Hwang De-Kuang , Fan Nai-Wen , Chavez Kenia , Redd Travis , Chamberlain Winston , Cheng Angel , Tham Vivien , Bograd Alexandra , Tappeiner Christoph , Goldblum David , Yakoura Abba Kaka Hajia , Amza Abdou , Youssoufou Souley Abdoul Salam , Nouhou Diori Adam , Kadri Boubacar , Mariama Boubacar , Ibrahim Cissé Mamadou , Roufaye Lamine Aboubacar , Beido Nassirou , Boulhassane Ramatou , Ali Saley , Abdou Zakou , Livny Etian , Bahar Irit , Goren Lee , Sella Ruti , Kelliher Clare , Green Laura , Ong Hong Shing , Mehta Jodhbir S. , Liu Yu-Chi , Chiong Hong Sheng , Lacorzana Javier , Cabrera-Aguas Maria , Watson Stephanie , Kanai Kuniyoshi , Whiteside Meredith , Tsui Edmund , Cherian Nina M. , Feit-Leichman Rachel , Hughes Reginald E. , Onclinx Tania , Salgado Jose Torres , Privratsky Joseph K. , Yu Carol , McClean Esmeralda , Molina Iliana , Kim Philip , Yu Danny , Lebas Elodie , Colby Emily , Abraham Thomas , Liu YuHeng , Yeh Steven , Fashina Tolulope , Chodosh James , Tarkap Bridgit , Garap Jambi N. , Mangot Magdalene , Amel Edwin , Taleo Fasihah , Kasso Johnson , Willie Kalbule , Nanu Madopule , Rymill Prudence , Solomon Anthony W. 
Published: August 2024

ImportanceInfectious conjunctivitis can lead to corneal involvement and result in ocular morbidity. The identification of biomarkers associated with corneal involvement has the potential to improve patient care.ObjectiveTo identify biomarkers in patients with acute infectious conjunctivitis.Design, Setting, and ParticipantsThis cross-sectional study took place from December 2016 to March 2024. Analyses were performed in 3 phases. First, logistic regression and machine learning algorithms were used to predict the probability of demonstrating corneal involvement in patients with presumed infectious conjunctivitis. Second, quantitative reverse transcription polymerase chain reaction (RT-qPCR) was used to confirm the most important biomarker gene identified by the algorithm. Third, the biomarker gene was validated in prospectively collected conjunctival samples of adult patients from 3 outpatient centers in Thailand and 1 in India. Patients with signs and symptoms of infectious conjunctivitis and onset within less than 14 days were eligible. Exclusion criteria were the inability to consent, presumed toxicity, or allergic conjunctivitis.ExposuresAcute infectious conjunctivitis.Main Outcomes and MeasuresThe identification and validation of ocular surface gene expression associated with corneal findings on slitlamp examination.ResultsThirteen genes exhibited a 1.5–log2 fold change in expression in patients with corneal involvement compared to patients without corneal involvement. Using the 13 genes to train and cross validate, logistic regression produced the highest mean area under the receiver operating characteristic curve (AUROC; 0.85; 95% CI, 0.84-0.86) for corneal involvement. The removal of apolipoprotein E (APOE) from the gene ensemble led to a decline in predictive performance of the logistic regression classifier (from mean AUROC 0.85 [95% CI, 0.84-0.86] to 0.74 [95% CI, 0.73-0.75]; adjusted P = .001 [Tukey test]). Orthogonal testing of APOE expression level with RT-qPCR showed that APOE expression was higher in patients with corneal involvement compared to patients without (median [IQR], 0.23 [0.04-0.47] vs 0.04 [0.02-0.06]; P = .004 [Mann-Whitney U test]). Using a Youden index of 0.23 Δ threshold cycle, APOE had a sensitivity of 56% (95% CI, 33-77) and a specificity of 88% (95% CI, 79-93) in 106 samples with conjunctivitis at Aravind, India (P &amp;lt; .001 [Fisher exact test]). When applied to a different patient population in Thailand, the same criteria could discriminate between disease states (58 samples; sensitivity, 47%; 95% CI, 30-64 and specificity, 93%; 95% CI, 77-99; P = .001 [Fisher exact test]).Conclusions and RelevanceThe results from this study suggest that the host conjunctival immune response can be meaningfully interrogated to identify biomarkers for ocular surface diseases.