Multiplex bead analysis of vitreous humor of patients with vitreoretinal disorders

PURPOSE: Vitreoretinal disorders are frequently characterized by increased vitreous levels of cellular mediators, including cytokines, chemokines, and growth factors. The study was conducted to investigate whether multiplex bead analysis could identify disease-specific profiles of these mediators in a variety of vitreoretinal diseases. METHODS: Levels of 19 mediators were measured: the cytokines IL-6, IL-10, IL-12, IL-13, IL-15, IL-17, TNF, IFN-gamma, granulocyte-macrophage-colony-stimulating factor (GM-CSF), and granulocyte-stimulating factor (G-CSF); the chemokines CCL2, CCL3, CCL4, CCL5, CCL11, and CXCL8; and the growth factors epidermal growth factor (EGF), FGF, and VEGF, by using multiplex bead analysis of vitreous humor of 58 eyes undergoing vitrectomy for a variety of vitreoretinal disorders. RESULTS: The predominant mediators detected were IL-6, CXCL8, and CCL2. The most complex pattern of mediators was seen in patients with proliferative vitreoretinopathy (PVR) and included a mixture of cytokines, chemokines, and growth factors. Patients with chronic uveitis showed a limited mediator pattern that did not suggest either a Th1 or Th2 response. By comparison, patients with lens-induced uveitis (LIU) showed significantly greater levels of cytokines than did patients with chronic uveitis, including IFN-gamma and IL-12, with a trend toward an acute Th1 inflammatory response. Moreover, in samples from patients with LIU, CXCL8 inversely correlated with time after initial surgery and duration of treatment. CONCLUSIONS: Multiplex bead analysis allows the measurement of multiple mediators from a single vitreous sample. The data confirm patterns of mediators previously described in different vitreoretinal conditions. In addition, LIU mediator levels correlate with duration of treatment and time after cataract surgery.     

Cytokine profile in aqueous humor and sera of patients with infectious or noninfectious uveitis

PURPOSE: To determine the cytokine expression profile at the protein level in aqueous humor (AqH) and sera of patients with uveitis. METHODS: Patients with various clinical entities of strictly diagnosed infectious or noninfectious uveitis were tested. AqH and sera were collected from patients with uveitis. AqH was also collected during surgery from patients with cataract, as control specimens. Interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, and interleukin (IL)-2, -4, -5, and -10 were measured from nondiluted samples simultaneously, with microparticle-based flow cytometric analysis. RESULTS: In AqH IFN-gamma was the most abundant cytokine in both infectious (mean, 3240.5 pg/mL) and noninfectious (mean, 115.6 pg/mL) uveitis, and IL-10 was the second (mean, 402.1 pg/mL, infectious uveitis; 7.5 pg/mL, noninfectious uveitis). The expression level of other cytokines in AqH was generally higher in infectious uveitis than in noninfectious uveitis, but the levels were lower than that of IL-10. There was no remarkable difference, however, in the cytokine expression pattern in AqH of the different clinical entities of uveitis. Sera from patients with noninfectious uveitis contained IFN-gamma (mean, 45.0 pg/mL), but the other serum cytokines in both types of uveitis were low or under the detectable level. CONCLUSIONS: IFN-gamma is the most abundant cytokine in infectious and noninfectious uveitis, with a remarkable difference between the two groups. The data suggest that cytokines in AqH of infectious uveitis are locally produced, whereas in noninfectious uveitis, IFN-gamma is produced both in the eye and the peripheral blood.     

A correlation of pregnancy term, disease activity, serum female hormones, and cytokines in uveitis

BACKGROUND/AIMS: Pregnancy and the postpartum period are associated with the activity of autoimmune diseases including uveitis. Although the exact mechanism is unknown, hormones are reported to alter inflammatory cytokines and influence disease activity. The authors studied ocular inflammation, female hormones, and serum cytokine levels during and after pregnancy. METHODS: A prospective, observational case study was conducted. Four pregnant women in their first trimester with chronic non-infectious uveitis were followed monthly until 6 months after delivery. Serum female hormones (oestrogen, progesterone, prolactin) and various cytokines (IL-2, IL-4, IL-5, IL-6, IL-10, IFN-gamma, and TGF-beta) were measured by ELISA. RESULTS: The four patients had five full term pregnancies. Uveitis activity decreased after the first trimester but flared in the early postpartum period. Serum female hormones, highly elevated during pregnancy, drastically dropped post partum. Cytokine levels except TGF-beta were mostly undetectable. CONCLUSION: Female hormones and TGF-beta may contribute to the activity of uveitis during pregnancy and the postpartum period.     

Multiplex cytokine detection versus ELISA for aqueous humor: IL-5, IL-10, and IFNgamma profiles in uveitis

PURPOSE: The purpose of this study was to determine levels of IL-2, -4, -5, -10, TNF-alpha, and IFN-gamma in aqueous humor (AH) from patients with active panuveitis, anterior uveitis (AU), and noninflammatory controls by using a flow cytometric mutiplex array (CBA) and to compare with results from ELISA. METHODS: Pooled normal AH was spiked with six cytokines at decreasing concentrations for evaluating the CBA. AH was also obtained from 10 controls (cataract patients) and 36 patients with active uveitis. Cell-free supernatants were added to a cocktail of capture beads and detector antibodies or to antibody-coated wells for CBA and ELISA determination, respectively. RESULTS: CBA demonstrated greater sensitivity for detecting IL-4, IL-10, and TNF-alpha than with ELISA. Increased IFN-gamma was detected in both AU and panuveitis groups compared with controls (P < 0.01). IL-10 was higher in the panuveitis group on steroids (P < 0.01). IL-5 was detected in the control (P < 0.01) and AU groups (P < 0.05) but was undetectable in the panuveitis group (n = 10). Correlations between IFN-gamma and IL-10 were found in all uveitis groups (P < 0.01) but not in controls, whereas TNF-alpha correlations with IL-4/IFN-gamma were obtained in controls but not in the uveitis groups (P < 0.01). CONCLUSIONS: It was possible to measure cytokines titrated into normal AH specimens by CBA, and a greater number of cytokines were detected with increased sensitivity than with ELISA. Elevated IFN-gamma in active uveitis and decreased IL-5 in posterior uveitis suggest Th1 polarity is more marked, with greater uveal tract involvement. The increased IL-10 in the steroid treated group suggests glucocorticoid-induced IL-10 upregulation.     

细胞因子对甲状腺相关性免疫眼眶病发病机制的研究

目的探讨细胞因子在甲状腺相关性免疫眼眶病（ｔｈｙｒｏｉｄｒｅｌａｔｅｄｉｍｍｕｎｅｏｒｂｉｔｏｐａｔｈｙ,ＴＲＩＯ）发病机制中的作用。方法体外培养眶成纤维细胞,应用免疫组化,观察细胞因子对眶成纤维细胞人类白细胞表面抗原Ⅱ（ｈｕｍａｎｌｅｕｋｏｃｙｔｅａｎｔｉｇｅｎⅡ,ＨＬＡⅡ）异常表达的诱导作用。结果干扰素γ（ｉｎｔｅｒｆｅｒｏｎγ,ＩＦＮγ）、白细胞介素１（ｉｎｔｅｒｌｅｕｋｉｎ１,ＩＬ１）及肿瘤坏死因子（ｔｕｍｏｒｎｅｃｒｏｓｉｓｆａｃｔｏｒ,ＴＮＦ）对眶成纤维细胞ＨＬＡⅡ抗原异常表达有诱导作用,ＩＦＮγ的诱导作用最强且与时间和浓度呈正相关。结论细胞因子（ＩＦＮγ,ＩＬ１,ＴＮＦ等）可诱导眶成纤维细胞ＨＬＡⅡ抗原异常表达,在启动免疫反应及甲状腺相关性免疫眼眶病发病机制中起重要作用。     

Elevated levels of interleukin 6 in the vitreous fluid of patients with pars planitis and posterior uveitis: the Massachusetts eye & ear experience and review of previous studies

INTRODUCTION: Although the exact mechanisms that lead to uveitis are not entirely known, the role of cytokines in the pathogenesis of this disease has been shown to be important. Prior studies described the presence of an array of cytokines in the intraocular fluid of patients with uveitis. Review of these studies indicate that Interleukin-6 (IL-6) is present, and animal data suggest the important role of IL-6 in the regulation of ophthalmologic immune responses. PURPOSE: We investigated whether IL-6, TNF-alpha, IL-1 alpha, beta, IL-2 are present in the vitreous of patients with active intermediate and posterior uveitis. METHODS: Vitreous specimens were collected from 23 eyes of patients with active intermediate and posterior uveitis who underwent diagnostic or therapeutic vitrectomies. TNF-alpha, IL-1 alpha and beta, IL-2 and IL-6 were measured by enzyme-linked immunosorbent assay. Eight vitreous fluid samples from eye bank eyes were used as control. RESULTS: IL-6 was higher in the vitreous of patients with uveitis compared to control samples (p = 0.0119). No TNF-alpha, IL-2, IL1-alpha or beta was detected. The levels of IL-6 did not correlate with a specific clinical diagnosis, but patients with pars planitis and panuveitis had the highest levels (p = 0.58) CONCLUSIONS: IL-6 is elevated in the vitreous of patients with active intermediate and posterior uveitis.     

Synergistic uveitic effects of tumor necrosis factor-alpha and interleukin-1 beta.

Tumor necrosis factor (TNF) and interleukin-1 (IL-1), cytokines with multiple, overlapping biologic activities, have been shown to interact synergistically in nonocular tissues. To test the hypothesis that coinjection of TNF and IL-1 interact synergistically in the eye, low, marginally inflammatory doses of human recombinant TNF-alpha (4000 U), IL-1 beta (40 U), and TNF-alpha+IL-1 beta (TNF-alpha/IL-1 beta) were injected into the vitreal chamber of the rabbit eye, and inflammation was assessed at 6, 24, 48, and 168 hr post-cytokine injection. TNF-alpha/IL-1 beta induced an anterior uveitis that was barely detectable at 6 hr, increased at 24 hr, peaked at 48 hr, and largely resolved by 168 hr. Synergy was observed for infiltration of inflammatory leukocytes into aqueous humor at 24 and 48 hr and for protein and prostaglandin E levels in aqueous humor at 48 hr. Based upon protein levels in vitreous humor, TNF-alpha/IL-1 beta also induced a posterior uveitis. This posterior uveitis was not apparent until 48 hr and then increased significantly at 168 hr. At 48 and 168 hr, the effects of TNF-alpha/IL-1 beta on protein levels in vitreous humor were consistent with a synergistic interaction. Results of separate experiments using higher dose combinations of TNF-alpha/IL-1 beta and a longer time course suggested that the effects of TNF-alpha/IL-1 beta on the blood vitreous barrier persisted beyond 168 hr. The results of this study support the hypothesis that TNF-alpha and IL-1 beta interact synergistically when injected into the rabbit eye.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pro-inflammatory cytokines increase reactive oxygen species through mitochondria and NADPH oxidase in cultured RPE cells

Reactive oxygen species (ROS) generated during inflammation are believed to play critical roles in various ocular diseases. However, the underlying mechanisms remain poorly understood. We investigated if pro-inflammatory cytokines, tumor necrosis factor (TNF)-alpha, interleukin-1 beta (IL-1 beta), and interferon-gamma (IFN-gamma), induce ROS in human retinal pigment epithelial (RPE) cells. TNF-alpha, IL-1 beta and IFN-gamma increased both intracellular and extracellular ROS production in a time- and dose-dependent manner. Thenoyltrifluoroacetone (TTFA), an inhibitor of mitochondrial respiratory chain, blocked TNF-alpha- and IFN-gamma-, but not IL-1 beta-induced ROS, whereas other two mitochondrial respiratory chain inhibitors, rotenone and antimycin A, had no effect. NADPH oxidase inhibitor (diphenylene iodinium) abolished the ROS production induced by IL-1 beta or IFN-gamma, but not by TNF-alpha, whereas 6-aminonicotinamide (6AN), an inhibitor of the hexose monophosphate shunt (HMS), had no significant effects on the ROS induced by all three cytokines. ROS scavengers, pyrrolidinedithiocarbamate (PDTC) and N-acetyl-cysteine (NAC), reduced the levels of ROS induced by TNF-alpha, IL-1 beta and IFN-gamma (P<0.05). Collectively, these results demonstrate that TNF-alpha, IL-1 beta and IFN-gamma increase mitochondrial- and NADPH oxidase-generated ROS in human RPE cells.     

Elevated Levels of Interleukin 6 in the Vitreous Fluid of Patients with Pars Planitis and Posterior Uveitis: The Massachusetts Eye & Ear Experience and Review of Previous Studies

Introduction: Although the exact mechanisms that lead to uveitis are not entirely known, the role of cytokines in the pathogenesis of this disease has been shown to be important. Prior studies described the presence of an array of cytokines in the intraocular fluid of patients with uveitis. Review of these studies indicate that Interleukin-6 (IL-6) is present, and animal data suggest the important role of IL-6 in the regulation of ophthalmologic immune responses. Purpose: We investigated whether IL-6, TNF-alpha, IL-1 alpha, beta, IL-2 are present in the vitreous of patients with active intermediate and posterior uveitis. Methods: Vitreous specimens were collected from 23 eyes of patients with active intermediate and posterior uveitis who underwent diagnostic or therapeutic vitrectomies. TNF-alpha, IL-1 alpha and beta, IL-2 and IL-6 were measured by enzyme-linked immunosorbent assay. Eight vitreous fluid samples from eye bank eyes were used as control. Results: IL-6 was higher in the vitreous of patients with uveitis compared to control samples (p = 0.0119). No TNF-alpha, IL-2, IL1-alpha or beta was detected. The levels of IL-6 did not correlate with a specific clinical diagnosis, but patients with pars planitis and panuveitis had the highest levels (p = 0.58) Conclusions: IL-6 is elevated in the vitreous of patients with active intermediate and posterior uveitis.     

Multiplex bead immunoassay analysis of aqueous humor reveals distinct cytokine profiles in uveitis

PURPOSE: To extensively characterize the complex network of cytokines present in uveitis aqueous humor (AqH), and the relationships between cytokines and the cellular infiltrate. METHODS: AqH from noninflammatory control subjects and patients with idiopathic, Fuchs' heterochromic cyclitis (FHC), and herpes-viral or Beh?et's uveitis were analyzed for IL-1beta, -2, -4, -5, -7, -8, -10, -12, -13, -15, TNFalpha, IFNgamma, CCL2 (MCP-1), CCL5 (RANTES), CCL11 (Eotaxin), TGFbeta2, and CXCL12 (SDF-1), using multiplex bead immunoassays. The cellular infiltrate was also determined for each sample. RESULTS: Idiopathic uveitis AqH, compared with noninflammatory controls, was characterized by high levels of IL-6, IL-8, CCL2 and IFNgamma, the levels of which correlated with each other. For IL-6 and IL-8 these levels were proportional to the number of neutrophils present. By contrast, the levels of both TGFbeta2 and CXCL12 decreased in idiopathic uveitis AqH with increasing inflammation. Cluster analysis showed a degree of segregation between noninflammatory and idiopathic uveitis AqH. Further examination using random forest analysis yielded a complete distinction between these two groups. The minimum cytokines required for this classification were IL-6, IL-8, CCL2, IL-13, TNFalpha, and IL-2. CONCLUSIONS: Application of multiplex bead immunoassays has allowed us to identify distinct patterns of cytokines that relate to both clinical disease and the cellular infiltrates present. Bioinformatics analysis allowed identification of cytokines that differentiate idiopathic uveitis from noninflammatory control AqH and are likely to be important for the pathogenesis of uveitis.     

Differential expression of retinal pigment epithelium (RPE) IP-10 and interleukin-8

Interferon-gamma induced protein of 10 kDa (IP-10) is a C-X-C chemokine that attracts T lymphocytes and inhibits angiogenesis. In this study, we investigated the expression of IP-10 by human retinal pigment epithelial cells (HRPE) and compared IP-10 expression to that of interleukin-8 (IL-8), which is a leukocytic chemoattractant and pro-angiogenic factor. Cultured HRPE cells were incubated with either IL-1 beta (0.2-20 ng/ml) or tumor necrosis factor (TNF)-alpha (0.2-20 ng/ml) alone or in combination with interferon-gamma (IFN-gamma) (1000 U/ml). HRPE cells were also incubated with: (1) media conditioned by activated human T lymphocytes (CM), or (2) the same CM treated with neutralizing antibodies to IL-1, TNF, and/or IFN-gamma. IL-8 and IP-10 protein levels were measured by ELISA and mRNA levels by Northern blot analysis of HRPE cells. HRPE cells produced very high levels of IP-10 in response to either IL-1 beta/IFN-gamma, TNF-alpha/IFN-gamma or CD3-activated T-lymphocyte CM. The levels of IP-10 were at least tenfold higher (p<.001) than IL-8 measured in the same samples. Neutralizing antibodies to TNF and IFN-gamma, but not to IL-1, abrogated the ability of the CD3-activated T lymphocytes CM to induce HRPE IP-10 (p<.001). HRPE cells produce differential levels of IP-10 and IL-8 in response to various combinations of recombinant and T-lymphocyte-secreted pro-inflammatory cytokines. This may be important in evolving inflammatory and angiogenic ocular responses.     

Effects of pyrrolidine dithiocarbamate, an NF-kappaB inhibitor, on cytokine expression and ocular inflammation in experimental autoimmune anterior uveitis.

AIMS: The aim of this study was to investigate the effects of pyrrolidine dithiocarbamate (PDTC), a nuclear factor (NF)-kappaB inhibitor, on cytokine expression and suppression of anterior chamber inflammation in experimental autoimmune anterior uveitis. Uveitis was induced in the Lewis rats with the injection of a melanin-associated antigen into the peritoneum and footpad. At defined time points, cytokine mRNA expressions in the iris and ciliary body were measured by using a semiquantitative polymerase chain-reaction method. RESULTS: We found that interferon-gamma (IFN-gamma) and tumor necrosis factor (TNF)-alpha mRNA expression peaked during the active phase of uveitis, whereas interleukin (IL)-10 mRNA increased during the disease resolution. In a separate experiment, PDTC (100 and 200 mg/kg/day) was administrated intraperitoneally daily after immunization. We found that PDTC (100 and 200 mg/kg/day) effectively suppressed ocular inflammation, as indicated by reduced clinical scores and inflammatory cells infiltration in aqueous humor and the iris and ciliary body. CONCLUSIONS: The inhibitory effects of PDTC are mainly resulted from inhibiting the expression of proinflammatory cytokines, TNF-alpha and IFN-gamma but augmenting anti-inflammatory cytokines, IL-10 expression. These findings suggest that the application of NF-kappaB inhibitors may be a potential therapeutic method for the treatment of acute anterior uveitis.     

Effect of <Emphasis Type="Italic">N</Emphasis>-Acetylcysteine on Lipopolysaccharide-Induced Uveitis in Rats

Purpose In this study we investigated the in vivo effect of N-acetylcysteine (NAC) on lipopolysaccharide (LPS)-induced uveitis in rats. Methods To induce uveitis, LPS (100 μg) was injected into subcutaneous tissue of Wistar rats (170–190 g). NAC was injected intraperitoneally. Intracameral levels of protein, cells, nitrite, tumor necrosis factor (TNF)-α, and interleukin (IL)-6 were determined by spectrophotometry, hemocytometry, and enzyme-linked immunosorbent assay. Expression of TNF-α, IL-6, endothelial leukocyte adhesion molecule-1 (E-selectin), intercellular adhesion molecule-1 (ICAM-1), and inducible nitric oxide synthase (iNOS) mRNA was examined by real-time polymerase chain reaction. Results LPS injection elevated intracameral protein and cells, and the elevation was inhibited by NAC. LPS injection induced expression of TNF-α, IL-6, E-selectin, and ICAM-1 mRNA in the iris/ciliary body at 3 h, and iNOS mRNA at 6 h. The LPS-induced elevation of the mRNA levels was inhibited by NAC. NAC inhibited LPS-induced intracameral elevation of TNF-α, IL-6, and nitrite. Conclusion NAC decreased LPS-induced uveitis in vivo by reducing the expression of proinflammatory cytokines and adhesion molecules. Jpn J Ophthalmol 2007;51:14–20 ? Japanese Ophthalmological Society 2007     

IL-1 and TNF receptor-deficient mice show decreased inflammation in an immune complex model of uveitis.

PURPOSE: To determine the role of interleukin-1 (IL-1) and tumor necrosis factor-alpha (TNF-alpha) in the induction of uveitis by a reverse passive Arthus reaction (RPAR). METHODS: Human serum albumin (HSA) antiserum was injected into the vitreous of "knockout" or "double knockout" mice genetically deficient in IL-1 receptor type I (IL-1RI-/-), TNF receptors p55 and p75 (TNFR p55-/-/p75-/-), IL-1RI and TNFR p55 (IL-1RI-/-/TNFR p55-/-), and controls. Twenty-four hours later, animals were challenged with intravenous HSA. Eyes were enucleated 4 hours after antigen challenge, and inflammation was quantitated by counting cells on histologic sections. Interleukin-6 in aqueous humor was measured with a B9 cell bioassay. The distribution of immune complexes in eyes was observed by immunohistochemical staining for IgG and complement component C3. RESULTS: Four hours after antigen challenge, immune complexes were localized at the ciliary body and iris of receptor-deficient mice. A transient uveitis was most severe at this time. A significant reduction in the median number of infiltrating cells was found in TNFR p55-/-/p75-/- mice (4.8, n = 15), compared with controls (14.2, n = 20, P < 0.05). The median number of infiltrating cells was significantly reduced in IL-1RI-/- mice (knockout 2.6, n = 11; controls 7.4, n = 8, P < 0.005). Interleukin-1RI-/-/TNFR p55-/- mice had a strong reduction in infiltrating cells (knockout 1.6, n = 11; controls 27.3, n = 12, P = 0.002). Interleukin-6 activity in aqueous humor was reduced in IL-1RI-/-/TNFR p55-/- mice (P = 0.03) but not in TNFR p55-/-/p75-/- (P = 0.40) mice. Most IL-1RI-/-mice had no detectable aqueous humor IL-6, but this group was not statistically different from controls. CONCLUSIONS: In contrast to endotoxin-induced uveitis, both IL-1 and TNF appear to have critical roles in RPAR uveitis. When receptors for these cytokines were deleted, the severity of immune complex-induced uveitis was profoundly reduced.     

Systemic interferon-gamma suppresses the development of endotoxin-induced uveitis in mice

PURPOSE: It has been shown that interferon (IFN)-gamma is involved in the development of endotoxin-induced uveitis (EIU), but its exact role is unclear. We aimed to elucidate the role that endogenous systemic IFN-gamma plays in EIU pathogenesis. METHODS: EIU was induced in wild-type (WT) or IFN-gamma knockout (GKO) mice on the C57BL/6 background by injecting Salmonella typhimurium endotoxin into a hind footpad. Twenty-four hours later, the eyes were harvested for histological analysis, and the serum was collected for cytokine ELISAs. WT and GKO mice were also intraperitoneally injected with 1 microg of recombinant murine IFN-gamma (rmIFN-gamma) just after and 6 h after EIU induction, and their eyes and sera were evaluated 24 h after EIU induction, as above. RESULTS: The GKO mice had significantly more severe EIU as determined by the number of ocular infiltrating cells and lower serum IL-6 levels after EIU induction compared to WT mice. The injection of rmIFN-gamma suppressed the severity of EIU and increased the serum IL-6 levels in both the WT and GKO mice. CONCLUSIONS: Endogenous IFN-gamma suppresses EIU pathogenesis. In addition, the systemic administration of IFN-gamma suppresses EIU. The suppressive mechanism involved is unclear but may relate to the production of IL-6.     

Aqueous humor cytokine profile in patients with chronic uveitis

There is increasing evidence that cytokines play an important role in the pathogenesis of uveitis. The aim of this study was to determine the presence of cytokines in the aqueous humor (AH) of patients with chronic idiopathic uveitis (CU). Patients with uveitis (n=10) were compared to those undergoing cataract surgery (n=1) for non-inflammatory eye diseases. ELISA's for the detection of cytokines (IL-1, IL-2, IL-6, TNF-α) in aqueous humor were developed that allowed the measurement of multiple cytokines present in low concentrations. Interleukin-6 was found to be elevated in the aqueous humor of two patients (20%) with CU, but in none of the controls. Interleukin-1-α, Interleukin-2 and TNF-α were not detected in the AH of patients or controls. TGF-? was detected in the aqueous of all patients and controls, using a bioassay.