Identifying TNF and IL6 as potential hub genes and targeted drugs associated with scleritis: A bio-informative report.

Background: Scleritis is a serious inflammatory eye disease that can lead to blindness. The etiology and pathogenesis of scleritis remain unclear, and increasing evidence indicates that some specific genes and proteins are involved. This study aimed to identify pivotal genes and drug targets for scleritis, thus providing new directions for the treatment of this disease. Methods: We screened candidate genes and proteins associated with scleritis by text-mining the PubMed database using Python, and assessed their functions by using the DAVID database. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were used to identify the functional enrichment of these genes and proteins. Then, the hub genes were identified with CytoHubba and assessed by protein-protein interaction (PPI) network analysis. And the serum from patients with active scleritis and healthy subjects were used for the validation of hub genes. Finally, the DGIdb database was used to predict targeted drugs for the hub genes for treating scleritis. Results: A total of 56 genes and proteins were found to be linked to scleritis, and 65 significantly altered pathways were identified in the KEGG analysis (FDR < 0.05). Most of the top five pathways involved the categories "Rheumatoid arthritis," "Inflammatory bowel disease", "Type I diabetes mellitus," and "Graft-versus-host disease". TNF and IL6 were considered to be the top 2 hub genes through CytoHubba. Based on our serum samples, hub genes are expressed at high levels in active scleritis. Five scleritis-targeting drugs were found among 88 identified drugs. Conclusions: This study provides key genes and drug targets related to scleritis through bioinformatics analysis. TNF and IL6 are considered key mediators and possible drug targets of scleritis. Five drug candidates may play an important role in the diagnosis and treatment of scleritis in the future, which is worthy of the further experimental and clinical study.

Mendelian Randomization Shows a Causal Effect of Low Vitamin D on Non-infectious Uveitis and Scleritis Risk.

PURPOSE: To investigate a causal relationship between Vitamin D levels and non-infectious uveitis and scleritis using Mendelian randomization (MR) techniques. DESIGN: Two-sample Mendelian randomization case-control study. METHODS: The study setting was a biobank of an academic, integrated health care system. The patient population comprised 375 case patients with a non-infectious uveitis and/or scleritis diagnosis and no diagnosis of infectious, trauma-related, or drug-induced uveitis/scleritis. In addition, there were 4167 controls with no uveitis or scleritis diagnosis. Causal effect estimates of low 25-hydroxy Vitamin D (25OHD) on uveitis/scleritis risk were calculated. RESULTS: We found an association of genetically decreased 25OHD with uveitis/scleritis risk (odds ratio [OR] = 2.16, 95% CI = 1.01-4.64, P = .049, per SD decrease in log25OHD). In a first sensitivity MR analysis excluding the genetic variants that are unlikely to have a role in biologically active 25OHD, effect estimates were consistent with those from the primary analysis (OR = 2.38, 95% CI =1.06-5.36, P = 0.035, per SD of log25OHD). Furthermore, in a second sensitivity analysis using only the 6 variants within the CYP2R1 locus (which encodes 25OHD hydroxylase, the liver enzyme responsible for converting Vitamin D to 25OHD), genetically decreased 25OHD was strongly associated with increased uveitis/scleritis risk (OR = 6.42, 95% CI = 3.19-12.89, P = 1.7 × 10-7, per SD of log25OHD). CONCLUSIONS: Our findings suggest a causal relationship between low Vitamin D levels and higher risk of non-infectious uveitis and scleritis. Vitamin D supplementation may be a low-cost, low-risk intervention to mitigate non-infectious uveitis and scleritis risk, and should be explored in a prospective trial.

Innate and Adaptive Gene Single Nucleotide Polymorphisms Associated With Susceptibility of Severe Inflammatory Complications in Acanthamoeba Keratitis.

Purpose: Over a third of patients with Acanthamoeba keratitis (AK) experience severe inflammatory complications (SICs). This study aimed to determine if some contact lens (CL) wearers with AK were predisposed to SICs due to variations in key immune genes. Methods: CL wearers with AK who attended Moorfields Eye Hospital were recruited prospectively between April 2013 and October 2014. SICs were defined as scleritis and/or stromal ring infiltrate. Genomic DNA was processed with an Illumina Low Input Custom Amplicon assay of 58 single nucleotide polymorphism (SNP) targets across 18 genes and tested for association in PLINK. Results: Genomic DNA was obtained and analyzed for 105 cases of AK, 40 (38%) of whom experienced SICs. SNPs in the CXCL8 gene encoding IL-8 was significantly associated with protection from SICs (chr4: rs1126647, odds ratio [OR] = 0.3, P = 0.005, rs2227543, OR = 0.4, P = 0.007, and rs2227307, OR = 0.4, P = 0.02) after adjusting for age, sex, steroids prediagnosis, and herpes simplex keratitis (HSK) misdiagnosis. Two TLR-4 SNPs were associated with increased risk of SICs (chr9: rs4986791 and rs4986790, both OR = 6.9, P = 0.01). Th-17 associated SNPs (chr1: IL-23R rs11209026, chr2: IL-1ß rs16944, and chr12: IL-22 rs1179251) were also associated with SICs. Conclusions: The current study identifies biologically relevant genetic variants in patients with AK with SICs; IL-8 is associated with a strong neutrophil response in the cornea in AK, TLR-4 is important in early AK disease, and Th-17 genes are associated with adaptive immune responses to AK in animal models. Genetic screening of patients with AK to predict severity is viable and this would be expected to assist disease management.

The haplotypes of various TNF related genes associated with scleritis in Chinese Han.

BACKGROUND: Several studies have stated that TNF-α participates in the pathogenesis of scleritis, but also in several systemic autoimmune diseases and vasculitis, of which some are associated with scleritis. Earlier GWAS and SNP studies have confirmed that multiple SNPs of TNF related genes are associated with many immune-mediated disorders. The purpose of this study was to examine the association of TNF related gene polymorphisms with scleritis in Chinese Han. A case-control study was carried out in 556 non-infectious scleritis cases and 742 normal controls. A total of 28 single-nucleotide polymorphisms (SNPs) were genotyped by the iPLEXGold genotyping assay. RESULTS: No significant correlations were seen between the individual SNPs in the TNF related genes and scleritis. Haplotype analysis showed a significantly decreased frequency of a TNFAIP3 TGT haplotype (order of SNPs: rs9494885, rs3799491, rs2230926) (Pc = 0.021, OR = 0.717, 95% CI = 0.563-0.913) and a significantly increased frequency of a TNFSF4 GT haplotype (order of SNPs: rs3850641, rs704840) (Pc = 0.004, OR = 1.691, 95% CI = 1.205-2.372) and TNFSF15 CCC haplotype (order of SNPs: rs6478106, rs3810936, rs7865494) (Pc = 0.012, OR = 1.662, 95% CI = 1.168-2.363) in patients with scleritis as compared with healthy volunteers. CONCLUSIONS: This study reveals that a TGT haplotype in TNFAIP3 may be a protective factor for the development of scleritis and that a GT haplotype in TNFSF4 and a CCC haplotype in TNFSF15 may be risk factors for scleritis in Chinese Han.

Identification of susceptibility SNPs in CTLA-4 and PTPN22 for scleritis in Han Chinese.

The aim of this study was to determine the association between 13 single nucleotide polymorphisms (SNPs) in the cytotoxic T lymphocyte-associated antigen-4 (CTLA4) and protein tyrosine phosphatase non-receptor type 22 (PTPN22) genes with scleritis in a Chinese Han population. We recruited 432 scleritis patients and 710 healthy controls. Four tag SNPs of CTLA4 and nine tag SNPs of PTPN22 were selected using Haploview. Genotyping was performed with the Sequenom MassArray® iPLEX GOLD Assay. Genotype and allele frequency differences were analyzed by χ2 test and Bonferroni correction. Haplotype analysis was performed to further evaluate the association of these two genes with scleritis. In this study, CTLA4/rs3087243 G allele frequency and GG genotype frequency were significantly increased in scleritis patients compared to healthy controls [corrected P-value (Pc) = 0·02, odds ratio (OR) = 1·475, 95% confidence interval (CI) = 1·175-1·851; Pc = 0·04, OR = 1·546, 95% CI = 1·190-2·008, respectively]. None of the tested SNPs in the PTPN22 gene showed an association with scleritis. Haplotype analysis revealed a lower frequency of a CTLA4 TCAA haplotype (order of SNPs: rs733618, rs5742909, rs231775, rs3087243) (Pc = 4·26 × 10-3 , OR = 0·618, 95% CI = 0·540-0·858) and a higher frequency of a PTPN22 TTATACGCG haplotype (order of SNPs: rs3789604, rs150426536, rs1746853, rs1217403, rs1217406, rs3789609, rs1217414, rs3789612, rs2488457) (Pc = 2·83 × 10-4 , OR = 1·457, 95% CI = 1·210-1·754) in scleritis patients when compared to healthy controls. In conclusion, our findings indicate that CTLA4 and PTPN22 might confer genetic susceptibility to scleritis in a Chinese Han population.

Ocular involvement in patients with spondyloarthritis.

Ocular inflammatory diseases can present as isolated conditions but also as part of systemic inflammatory diseases. Anterior uveitis is closely related to SpA and shares the common genetic background of HLA-B27. Other ocular manifestations, such as episcleritis and scleritis, may also occur, although less frequently. Therefore, ocular involvement has been included as one of the important clinical features of SpA in the recently published classification criteria for axial and peripheral disease. However, there are a wide variety of aetiologies for ocular diseases and this must be considered in assessment of SpA.

Ocular Manifestations of Inherited Phospholipase-Cγ2-Associated Antibody Deficiency and Immune Dysregulation.

PURPOSE: To report the ocular manifestations of phospholipase-Cγ2-associated antibody deficiency and immune dysregulation (PLAID). METHODS: Case report and literature review. RESULTS: A 21-year-old woman diagnosed with PLAID was referred for evaluation of repeated episodes of ocular inflammation resulting in bilateral peripheral corneal pannus with episcleritis and corneal scarring accompanied by systemic manifestations including epidermolysis bullosa and interstitial lung disease. Systemic immunosuppression with corticosteroids and interleukin-1 (IL-1) receptor antagonist (anakinra) was supplemented with topical anakinra to avoid systemic side effects, which resulted in partial improvement of the ocular symptoms. Oral prednisone was restarted to treat active lesions during bouts of inflammation. CONCLUSIONS: Ocular PLAID is a bilateral chronic or recurrent inflammatory disease of the ocular surface leading to severe and early cicatricial ocular surface and corneal involvement because of high IL-1 production. Management of PLAID may require both topical and systemic immunomodulatory treatments, potentially including targeted local anti-IL-1 therapy.

Pharmacogenetics of drugs used in the treatment of ocular inflammatory diseases.

INTRODUCTION: Ocular inflammatory diseases comprise uveitis, scleritis, and inflammation of adjacent structures of the eye. Therapy may be challenging and often involves corticosteroids and immunomodulatory agents. AREAS COVERED: This review describes the genes involved in noninfectious ocular inflammatory diseases and focuses on pharmacogenetic studies regarding different classes of anti-inflammatory drugs used in the management of uveitis, including corticosteroids, antimetabolites, calcineurin inhibitors, alkylating agents, and biological agents. EXPERT OPINION: Pharmacogenetics holds the promise of a personalized medicine with potential to customize treatment that can achieve the best clinical response and avoid toxicity. Several polymorphisms in various genes involved in the metabolism of drugs commonly utilized in the treatment of ocular inflammatory diseases have been described. Most promising is the polymorphism in thiopurinemethyltransferase gene for which a genotype analysis can reveal slow metabolizers of azathioprine and help avoid serious drug toxicity. Although pharmacogenetic studies with specific focus on ocular inflammatory diseases are lacking, knowledge from studies in rheumatologic diseases and transplant medicine can provide a platform for future research. Prospective clinical studies are needed to determine the clinical significance of such polymorphisms and their true effect on drug metabolism and side effects.

Association of PDGF-BB-induced thrombomodulin with the regulation of inflammation in the corneal and scleral stroma.

PURPOSE: The responses of corneal and scleral stromal cells to platelet-derived growth factor (PDGF)-BB were assessed and inflammatory reactions in the cornea and sclera were investigated. METHODS: Primary cultures of cells obtained from human subjects and strains derived from human corneal or scleral stromal cells (Cs3 and Sc1, respectively) were used. Changes in gene expression after 24 hours of exposure to 10 ng/mL PDGF-BB were analyzed with an Sc1 DNA microarray. The upregulation of several genes in Cs3 and Sc1 was confirmed by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis. The expression of bioactive factors was detected immunohistochemically in nine different clinical specimens. RESULTS: DNA microarray analysis revealed that the gene encoding thrombomodulin (TM) was induced in Sc1 by PDGF-BB. RT-PCR confirmed that TM expression at the mRNA level was increased in both corneal and scleral stromal cells. At the protein level, TM expression was increased in scleral stromal cells, but not in corneal cells, and TM was detected in both the membrane and cytoplasmic compartments. TM was detected immunohistochemically in inflamed scleral and several corneal specimens. After TM stimulation, interleukin (IL)-18 transcription was increased in Sc1. CONCLUSIONS: PDGF-BB induced TM mRNA expression in scleral and corneal stromal cells, but Western blot analysis revealed the increase in TM expression only in the scleral cells. TM induced IL-18 in scleral stromal cells. A cascade involving these biologically active factors may regulate scleral and corneal inflammation. The results also reveal differences in the biological response of scleral and corneal stromal cells.

Posterior scleritis and its association with HLA B27 haplotype.

BACKGROUND: Posterior scleritis is most commonly idiopathic but is also found in association with systemic disorders like rheumatoid arthritis. HLA B27 spondyloarthropathy manifests itself mainly in the form of anterior uveitis and anterior scleritis. Posterior scleritis has not been previously reported in patients with HLA B27 haplotype. We document the likely association between posterior scleritis and HLA B27 haplotype in a series of 5 patients who presented to the Ocular Inflammation and Immunology Services of the Singapore National Eye Centre. METHODS: Retrospective observational case series. The medical records and ultrasound B scans of 5 patients with a diagnosis of posterior scleritis were reviewed. RESULTS: The medical records of 5 patients (4 Chinese and 1 Malay) in the age range of 22-64 years were reviewed. All had unilateral disease (4 in the left eye and 1 in the right eye) at presentation. The most common presenting symptoms were pain (5) and blurring of vision (5); diplopia and proptosis was present in 2 patients. Two patients had anterior scleritis and all had an associated anterior uveitis. Posterior segment findings included optic disc edema (5), macular edema (5), choroidal folds (3), exudative retinal detachment (2) and choroidal effusion (1). All patients had a thickened sclera on serial ultrasound B scan. 2 patients had joint involvement preceding ocular signs and symptoms and were diagnosed to have ankylosing spondylitis. HLAB27 was positive in all our patients. Systemic workup for other diseases was negative. The ocular inflammation responded to a varying combination of topical, periocular and systemic steroids. One of them developed a recurrence of posterior scleritis which resolved with oral steroids. Visual outcome was satisfactory in all but 1 patient who had retinal pigment epithelium atrophy at the macula. CONCLUSION: Although posterior scleritis has been reported in association with ankylosing spondylitis, it is not clear whether it is the HLAB27 haplotype that is associated with posterior scleritis or ankylosing spondylitis. All our patients were HLAB27 positive but 2 of them did not have an underlying spondyloarthropathy. This suggests the possible association of posterior scleritis with HLAB27 haplotype.

Immunogenetics of episcleritis in leprosy.

Human leukocyte antigens (HLA) were analyzed among Japanese leprosy patients to identify any possible determinants in the development of episcleritis in leprosy patients. Seventy-nine Japanese leprosy patients (33 patients with history of episcleritis and 46 patients without episcleritis) and 114 healthy control subjects were investigated. Human leukocyte antigen-class I and class II specificities were determined serologically by the standard microcytotoxicity test. The HLA-DRB1, -DRB5, -DQA1, and -DQB1 genotypings were performed by using the polymerase chain reaction (PCR)-single strand conformation polymorphism and PCR-restriction fragment length polymorphism analyses. The frequency of HLA-Cw3 was significantly increased among the patients with episcleritis (66.7%) compared to patients without episcleritis (43.5%; odds ratio = 2.6, P < 0.05). The frequency of HLA-DR4 was significantly decreased among the patients with episcleritis (15.2%) compared to patients without episcleritis (39.1%; odds ratio = 0.28, P < 0.05) and the controls (46.5%; odds ratio = 0.21, P < 0.001). At the genomic level, frequencies of the HLA-DRB1*0405, -DQB1*0401, and -DQB1*0302 alleles were significantly decreased among the patients with episcleritis (0%, 0%, and 6.1%, respectively) compared to patients without episcleritis (15.2%, 13.0%, and 26.1%, respectively; odds ratio = 0.07, 0.09, and 0.18, P < 0.05). HLA-DRB1*0405 and -DQB1*0401 were also significantly decreased among the patients with episcleritis compared to the controls (29.8% and 29.8%; odds ratio = 0.04, P < 0.0001). Our results suggest that HLA-Cw3 antigen confers the susceptibility to the development of episcleritis among Japanese leprosy patients. Concurrently, the DRB1 (the -DBR1*0405), and/or DQB1 (the -DQB1*0401 and -DQB1*0302) alleles might provide protection against leprous episcleritis.