Peizeng Yang

Upregulated IL-23 and IL-17 in Behcet Patients with Active Uveitis

PURPOSEnBehçet disease (BD) is a systemic inflammatory disease presumably caused by an autoimmune response. The interleukin (IL)-23/IL-17 pathway has been demonstrated to be involved in the development and maintenance of certain inflammatory diseases. This study was designed to investigate the role of IL-23 and IL-17 in BD.nnnMETHODSnIL-23p19 mRNA in peripheral blood mononuclear cells (PBMCs) was examined using RT-PCR. The levels of IL-23, IL-17, and IFN-gamma in sera or PBMCs were detected by ELISA. Flow cytometry was used to evaluate the frequencies of IL-17-producing and IFN-gamma-producing T cells and the expression of CD45RO.nnnRESULTSnResults showed that the expression of IL-23p19 mRNA, IL-23, IL-17, and IFN-gamma was markedly elevated in BD patients with active uveitis. The frequencies of IL-17-producing and IFN-gamma-producing T cells from PBMCs were significantly upregulated in BD patients with active uveitis. The increased IL-17 (3.10% +/- 0.53%) in BD patients with active uveitis was primarily produced by CD45RO(+) memory T cells. Recombinant (r) IL-23 could upregulate IL-17 production by polyclonally stimulated PBMCs, whereas interferon (IFN)-gamma downregulated IL-17 production.nnnCONCLUSIONSnThese findings reveal that the levels of IL-23, IL-17, and IFN-gamma are elevated in BD patients with active uveitis, and they suggest that the IL-23/IL-17 pathway together with IFN-gamma is associated with the active intraocular inflammation in BD patients.

Distribution, markers, and functions of retinal microglia

Retinal microglia originate from hemopoietic cells and invade the retina from the retinal margin and the optic disc, most likely via the blood vessels of the ciliary body and iris, and the retinal vasculature, respectively. The microglial precursors that appear in the retina prior to vascularization are major histocompatibility complex (MHC) class I- and II-positive and express the CD 45 marker, but lack specific macrophage markers. They differentiate into ramified parenchymal microglia in the adult retina. A second category of microglial precursors, which do express specific macrophage markers, migrate into the retina along with vascular precursors. They appear around blood vessels in the adult retina and are similar to macrophages or cells of the mononuclear phagocyte series (MPS). Microglia are distributed in the outer plexiform layer (OPL), outer nuclear layer (ONL), inner plexiform layer (IPL), ganglion cell layer (GCL), and nerve fiber layer (NFL) of the primate retina. The pattern of microglial distribution in the avascular retina of the quail indicates that blood vessels are not responsible for the final location of microglia in the retina. In the human retina, microglia express MHC class I, MHC class II, CD 45 , CD68, and S22 markers. In the rat and mouse retina, OX 41 , OX 42 , OX 3 , OX6, OX18, ED1, Mac-1, F 4 /80, 5 D 4 anti-keratan sulfate, and lectins are used to recognize microglia. Microglial cells play an important role in host defense against invading microorganisms, immunoregulation, and tissue repair. During neurodegeneration, activated microglial cells participate in the phagocytosis of debris and facilitate regenerative processes. In autoimmune disease, microglia have dual functions: initiating uveoretinitis, but also limiting subsequent inflammation. Retinal microglia may be associated with vitreoretinopathy, diabetic retinopathy, glaucoma, and age-related macular degeneration. The goal of this article was to review the present knowledge about retinal microglia and the function of retinal microglia in pathological conditions.

Diminished frequency and function of CD4+CD25high regulatory T cells associated with active uveitis in Vogt-Koyanagi-Harada syndrome.

PURPOSEnCD4(+)CD25(high) regulatory T (Treg) cells have been shown to be involved in the pathogenesis of autoimmune diseases. Vogt-Koyanagi-Harada (VKH) syndrome is an organ-specific autoimmune disease. This study was designed to phenotypically and functionally characterize peripheral blood CD4(+)CD25(high) Treg cells in VKH patients with active uveitis.nnnMETHODSnBlood samples were taken from 30 patients with active VKH, 19 patients with inactive VKH, and 26 healthy controls. Peripheral blood mononuclear cells were subjected to flow cytometry for analysis of phenotypes of the CD4(+)CD25(high) Treg cells. For functional analysis, CD4(+)CD25(high) Treg cells and CD4(+)CD25(-) T cells were separated by means of magnetic-assisted cell sorting and subsequently cocultured for 6 days. The proliferation of CD4(+)CD25(-) T cells was measured by [(3)H] thymidine incorporation assay. The levels of IFN-gamma, IL-17, and IL-13 in the supernatants were determined by enzyme-linked immunosorbent assay.nnnRESULTSnSignificantly decreased frequencies of CD4(+)CD25(high) Treg cells and percentages of FOXP3(+) cells in these Treg cells were shown in patients with active VKH. Treg cells from patients with active VKH showed a significant deficiency in suppressing the proliferation of CD4(+)CD25(-) T cells and inhibiting the production of IFN-gamma and IL-13 by CD4(+)CD25(-) T cells. CD4(+)CD25(high) Treg cells from VKH patients or healthy controls did not markedly inhibit or promote IL-17 production.nnnCONCLUSIONSnA significantly decreased frequency and diminished function of CD4(+)CD25(high) Treg cells is associated with active uveitis in patients with VKH syndrome. These results suggest that these dysfunctional CD4(+)CD25(high) Treg cells may play a role in the pathogenesis of uveitis in VKH syndrome.

Association of the CTLA-4 gene with Vogt-Koyanagi-Harada syndrome ☆

Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4), a critical negative regulator of the T cell response, has been shown to be associated with a variety of autoimmune diseases. In this study, we investigated the association of CTLA-4 gene polymorphisms (- 1661A/G; - 318C/T; + 49G/A, and CT60) with Vogt-Koyanagi-Harada (VKH) syndrome in Chinese Han patients and normal controls. The results showed that the frequency of the G allele at the + 49 site was significantly higher in VKH patients than that observed in healthy controls (71.6% versus 62.8%, P = 0.0046, Pc = 0.037). Three haplotypes were identified from the four SNPs. The frequency of haplotype - 1661A:- 318C:+ 49G:CT60G, the most prevalent haplotype both in patients and controls, was significantly higher in patients than that in controls (70.1% versus 60.0%, P= 0.0013, n= 16, Pc = 0.021). These results suggest that CTLA-4 genetic polymorphisms are associated with the susceptibility to VKH syndrome.

Genome-wide association analysis of Vogt-Koyanagi-Harada syndrome identifies two new susceptibility loci at 1p31.2 and 10q21.3

To identify new genetic risk factors for Vogt-Koyanagi-Harada (VKH) syndrome, we conducted a genome-wide association study of 2,208,258 SNPs in 774 cases and 2,009 controls with follow-up in a collection of 415 cases and 2,006 controls and a further collection of 349 cases and 1,588 controls from a Han Chinese population. We identified three loci associated with VKH syndrome susceptibility (IL23R-C1orf141, rs117633859, Pcombined = 3.42 × 10−21, odds ratio (OR) = 1.82; ADO-ZNF365-EGR2, rs442309, Pcombined = 2.97 × 10−11, OR = 1.37; and HLA-DRB1/DQA1, rs3021304, Pcombined = 1.26 × 10−118, OR = 2.97). The five non-HLA genes were all expressed in human iris tissue. IL23R was also expressed in the ciliary body, and EGR2 was expressed in the ciliary body and choroid. The risk G allele of rs117633859 in the promoter region of IL23R exhibited low transcriptional activation in a cell-based reporter assay and was associated with diminished IL23R mRNA expression in human peripheral blood mononuclear cells.

Longitudinal quantification of aqueous flare and cells in Vogt–Koyanagi–Harada disease

Aims: To quantitatively evaluate the changes of aqueous flare and cells in eyes with Vogt–Koyanagi–Harada (VKH) disease. Methods: This prospective study included 35 initial-onset VKH patients (70 eyes) and 46 recurrent VKH patients (92 eyes) following immunotherapy. Aqueous flare and cells were quantified using the laser flare-cell meter before treatment, 2 weeks, 1, 3, 6 and 9 months after treatment. Results: Before treatment, mean aqueous flare (ph/ms) in initial-onset and recurrent VKH eyes were 8.1 (SD 4.1) vs 43.6 (20.7) (pu200a=u200a0.000). Following treatment, recurrent VKH eyes showed a significantly higher flare value than initial-onset VKH eyes at 2 weeks, 1, 3 and 6 months. Prior to treatment, mean cell counts (cells/0.5 mm3) in initial-onset and recurrent VKH eyes were 2.0 (1.9) vs 39.4 (23.1) (pu200a=u200a0.000). Following treatment, recurrent VKH eyes showed significantly higher cell counts than initial-onset VKH eyes at 2 weeks, 1 and 3 months. Conclusions: Our study shows that recurrent VKH patients displayed a more striking and long-lasting breakdown of the BAB and more severe inflammation than initial-onset VKH patients. Our study also indicates that the disruption of BAB lasted longer than aqueous cells either in initial-onset or in recurrent VKH patients.

Ocular manifestations of syphilitic uveitis in Chinese patients.

Purpose: To present the manifestations of syphilitic uveitis in Chinese patients. Methods: This is a retrospective case series of 35 eyes of 19 patients with syphilitic uveitis. The data of these patients including complaints, ocular and systemic manifestations, human immunodeficiency virus status, results of auxiliary examinations, treatment, and follow-up were reviewed. Results: Nineteen consecutive Chinese patients were diagnosed with syphilitic uveitis by serologic tests. Four patients had circulating human immunodeficiency virus antibodies. Ocular involvement was found in 35 eyes. Posterior segment involvement was found in 30 eyes of 17 patients (85.7%), whereas anterior segment involvement was found in 14 eyes of 8 patients (40.0%). Thirty eyes of 17 patients (85.7%) presented with vitreous opacities and 28 eyes of 16 patients (80.0%) with retinitis. Papillitis and retinal vasculitis were found in 10 eyes of 6 patients (28.6%) and 7 eyes of 4 patients (20.0%), respectively. Multiple precipitates on the retina and posterior vitreous membrane were observed in six eyes of three patients. A large iris granuloma was observed in one eye. Conclusion: Posterior uveitis was the most common ocular finding in these investigated Chinese patients with syphilis. Coinfection of syphilis and human immunodeficiency virus was less common in these patients. Syphilis should be considered in the differential diagnosis of patients presenting with large iris granulomas.

Upregulation of interleukin 21 and promotion of interleukin 17 production in chronic or recurrent Vogt-Koyanagi-Harada disease.

OBJECTIVESnTo analyze the expression and potential role of interleukin (IL) 21 in the pathogenesis of Vogt-Koyanagi-Harada (VKH) disease.nnnMETHODSnBlood samples were obtained from patients with VKH disease and from healthy control subjects. Serum IL-21 level and IL-21 messenger RNA (mRNA) expression by peripheral blood mononuclear cells (PBMCs) were determined by enzyme-linked immunosorbent assay and by reverse transcriptase-polymerase chain reaction, respectively. Interleukin 17 and interferon γ levels in the supernatants of PBMCs and CD4(+) T cells cultured with anti-CD3 and anti-CD28 antibodies in the presence or absence of recombinant IL-21 were detected by enzyme-linked immunosorbent assay.nnnRESULTSnThe results showed a significantly increased serum IL-21 level, as well as higher IL-21 mRNA expression by PBMCs, in patients having chronic or recurrent active VKH disease compared with patients having inactive VKH disease and with controls. In vitro experiments showed that recombinant IL-21 significantly increased IL-17 production by PBMCs and by CD4(+) T cells from patients and from controls. However, recombinant IL-21 did not affect interferon γ expression by PBMCs or by CD4(+) T cells.nnnCONCLUSIONnInterleukin 21 may be involved in the pathogenesis of chronic or recurrent VKH disease, possibly by promoting IL-17 secretion.nnnCLINICAL RELEVANCEnFindings from the present study suggest that IL-21 may be a potential target in the development of therapy for VKH disease.

Leptin increases in Vogt-Koyanagi-Harada (VKH) disease and promotes cell proliferation and inflammatory cytokine secretion

Backgroud/aims: Leptin has recently been found to play an important role in the development of autoimmune diseases. Our study is designed to investigate the expression and possible role of leptin in the pathogenesis of Vogt–Koyanagi–Harada (VKH) disease, one of the common types of autoimmune uveitis in China. Methods: Leptin levels in serums of 20 active, 16 inactive VKH patients and 20 healthy controls were measured using ELISA. Peripheral blood mononuclear cells (PBMCs) separated from active VKH patients and healthy controls were cultured with recombinant human leptin, and cell proliferation was assayed by [3H]-TdR incorporation. Cytokine levels in the supernatant of PBMCs cultured in mixed lymphocyte reaction (MLR) upon stimulation with leptin were assayed by ELISA. Results: Our results showed that leptin was significantly increased in the serum of active VKH patients compared with that in inactive VKH patients and healthy controls. Leptin levels in active VKH patients remained markedly higher when divided by body mass index (BMI). PBMCs cultured with leptin induced a marked cell proliferation and profound secretion of IFN-γ and IL-17. Conclusion: These findings suggest that leptin may be involved in the development of VKH disease possibly by promoting an immune response.

Polymorphisms of IL23R and Vogt-Koyanagi-Harada syndrome in a Chinese Han population.

Polymorphisms of interleukin-23 receptor (IL23R) gene have recently been reported to be associated with the susceptibility to several immune-related diseases. The aim of this study was to determine the association of IL23R polymorphisms with Vogt-Koyanagi-Harada (VKH) syndrome, a disease presumably mediated by autoimmune response. A total of 382 Chinese Han patients with VKH syndrome and 407 healthy controls were genotyped by the polymerase chain reaction-restriction fragment length polymorphism method. Data were analyzed by chi(2) analysis. All genotype distributions in healthy controls were in Hardy-Weinberg equilibrium. There was no difference among the investigated four single nucleotide polymorphisms concerning the linkage disequilibrium between the tested samples and those available in the international HapMap. The genotype and allele frequencies of rs17375018, rs7517847, rs11209032, and rs1343151 were not different between patients with VKH syndrome and healthy controls. Analysis according to gender and clinical findings did not show any association of the four polymorphisms with these parameters. In conclusion, the tested IL23R gene polymorphisms are not associated with the susceptibility to VKH syndrome in the Chinese Han population.