Tear proteome profile in eyes with keratoconus after intracorneal ring segment implantation or corneal crosslinking

Analysis of Cytokine and Chemokine Level in Tear Film in Keratoconus Patients before and after Corneal Cross-Linking (CXL) Treatment

Keratoconus (KC) is a degenerative corneal disorder whose aetiology remains unknown. The aim of our study was to analyse the expressions of cytokines and chemokines in KC patients before and after specified time intervals after corneal cross-linking (CXL) treatment to better understand the molecular mechanisms occurring before and after CXL in KC patients process of corneal regeneration.; Tear samples were gathered from 52 participants immediately after the CXL procedure and during the 12-month follow-up period. All patients underwent a detailed ophthalmological examination and tear samples were collected before and after CXL at regular intervals: 1 day before and after the surgery, at the day 7 visit, and at 1, 3, 6, 9, and 12 months after CXL. The control group consisted of 20 healthy people. 10 patients were women (50%) and 10 were men (50%). The mean age was 30 ± 3 years of age. Tear analysis was performed using the Bio-Plex 3D Suspension Array System. Corneal topography parameters measured by Scheimpflug Camera included: keratometry values (Ks, Kf), PI-Apex, PI-Thinnest, Cylinder.; All the 12 months post-op values of the KC patients' topographic measurements were significantly lower than the pre-op. As for the tear cytokine levels comparison between the patient and control groups, cytokine levels of TNF-α, IL-6, and CXCL-10, among others, were detected in lower amounts in the KC group. The pre-op level of IL-6 exhibited a significant increase the day after CXL, whereas comparing the day after the procedure to 12 months after CXL, this showed a significant decrease. Both TNF-α and IL-1 showed a significant decrease compared to the day before and after CXL. We observed significantly higher levels of IL-1β, IL-10, IFN-γ and TNF-α in moderate and severe keratoconus than in mild keratoconus (p < 0.05). We also demonstrated a statistically significant positive correlation between both pre-op and 12 months after CXL TNF-α, IFN-γ, IL-6 and Ks and Kf values (p < 0.05, r > 0); Alterations of inflammatory mediators in tear fluid after CXL link with topographic changes and may contribute to the development and progression of KC.

Bioinformatics analysis of key candidate genes and pathways in Chinese patients with keratoconus

Keratoconus (KC) is a multifactorial disease in which genetic factors played important roles in its pathogenesis. The purpose of the current study was to identify the key candidate genes and pathways in Chinese patients with KC through bioinformatics analysis. Totally, we identified 71 candidate genes by analyzing the results of whole exome sequencing on 51 Chinese patients with KC, combining with previous reports on differential expression at transcription and protein levels in KC. Gene enrichment analysis with GeneCodis demonstrated that two significantly enriched terms including 21 genes in biological process (BP) were detected, and six significantly enriched terms containing 14 genes in Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway were discovered. The STRING was utilized to construct the protein-protein interaction (PPI) network of identified genes. The result showed that a PPI network consisted of 14 nodes with 14 edges was constructed, and two gene modules were obtained. Eight hub genes (LAMB3, LAMA3, LAMA1, ITGA6, ITGA3, COL6A3, COL6A2, and COL6A1) were identified as key candidate genes for KC by cytoHubba in Cytoscape. Functional enrichment analysis with ClueGO and CluePedia indicated that the ECM-receptor interaction was the key pathway accounted for KC. The findings might provide novel insights on the genetic basis of KC.

Diagnosis and biomarkers for ocular tuberculosis: From the present into the future

Tuberculosis is an airborne disease caused by Mycobacterium tuberculosis (Mtb) and can manifest both pulmonary and extrapulmonary disease, including ocular tuberculosis (OTB). Accurate diagnosis and swift optimal treatment initiation for OTB is faced by many challenges combined with the lack of standardized treatment regimens this results in uncertain OTB outcomes. The purpose of this study is to summarize existing diagnostic approaches and recently discovered biomarkers that may contribute to establishing OTB diagnosis, choice of anti-tubercular therapy (ATT) regimen, and treatment monitoring. The keywords ocular tuberculosis, tuberculosis, Mycobacterium, biomarkers, molecular diagnosis, multi-omics, proteomics, genomics, transcriptomics, metabolomics, T-lymphocytes profiling were searched on PubMed and MEDLINE databases. Articles and books published with at least one of the keywords were included and screened for relevance. There was no time limit for study inclusion. More emphasis was placed on recent publications that contributed new information about the pathogenesis, diagnosis, or treatment of OTB. We excluded abstracts and articles that were not written in the English language. References cited within the identified articles were used to further supplement the search. We found 10 studies evaluating the sensitivity and specificity of interferon-gamma release assay (IGRA), and 6 studies evaluating that of tuberculin skin test (TST) in OTB patients. IGRA (Sp = 71-100%, Se = 36-100%) achieves overall better sensitivity and specificity than TST (Sp = 51.1-85.7%; Se = 70.9-98.5%). For nuclear acid amplification tests (NAAT), we found 7 studies on uniplex polymerase chain reaction (PCR) with different Mtb targets, 7 studies on DNA-based multiplex PCR, 1 study on mRNA-based multiplex PCR, 4 studies on loop-mediated isothermal amplification (LAMP) assay with different Mtb targets, 3 studies on GeneXpert assay, 1 study on GeneXpert Ultra assay and 1 study for MTBDRplus assay for OTB. Specificity is overall improved but sensitivity is highly variable for NAATs (excluding uniplex PCR, Sp = 50-100%; Se = 10.5-98%) as compared to IGRA. We also found 3 transcriptomic studies, 6 proteomic studies, 2 studies on stimulation assays, 1 study on intraocular protein analysis and 1 study on T-lymphocyte profiling in OTB patients. All except 1 study evaluated novel, previously undiscovered biomarkers. Only 1 study has been externally validated by a large independent cohort. Future theranostic marker discovery by a multi-omics approach is essential to deepen pathophysiological understanding of OTB. Combined these might result in swift, optimal and personalized treatment regimens to modulate the heterogeneous mechanisms of OTB. Eventually, these studies could improve the current cumbersome diagnosis and management of OTB.