Clinical Usefulness of Simultaneous Measurement of the Tear Levels of CCL17, CCL24, and IL-16 for the Biomarkers of Allergic Conjunctival Disorders

CCR1 mediates Müller cell activation and photoreceptor cell death in macular and retinal degeneration

Mononuclear cells are involved in the pathogenesis of retinal diseases, including age-related macular degeneration (AMD). Here, we examined the mechanisms that underlie macrophage-driven retinal cell death. Monocytes were extracted from patients with AMD and differentiated into macrophages (hMdɸs), which were characterized based on proteomics, gene expression, and ex vivo and in vivo properties. Using bioinformatics, we identified the signaling pathway involved in macrophage-driven retinal cell death, and we assessed the therapeutic potential of targeting this pathway. We found that M2a hMdɸs were associated with retinal cell death in retinal explants and following adoptive transfer in a photic injury model. Moreover, M2a hMdɸs express several CCRI (C-C chemokine receptor type 1) ligands. Importantly, CCR1 was upregulated in Müller cells in models of retinal injury and aging, and CCR1 expression was correlated with retinal damage. Lastly, inhibiting CCR1 reduced photic-induced retinal damage, photoreceptor cell apoptosis, and retinal inflammation. These data suggest that hMdɸs, CCR1, and Müller cells work together to drive retinal and macular degeneration, suggesting that CCR1 may serve as a target for treating these sight-threatening conditions.

Modulation of the immune response by the host defense peptide IDR-1002 in chicken hepatic cell culture

IDR-1002, a synthetic host defense peptide (HDP), appears to be a potential candidate for the treatment of bacterial infections and the consequent inflammatory response due to its potent immunomodulatory activity. This is of relevance to the emerging issue of antimicrobial resistance in the farming sector. In this study, the effects of IDR-1002 were investigated on a chicken hepatocyte‒non-parenchymal cell co-culture, and the results revealed that IDR-1002 had complex effects on the regulation of the hepatic innate immunity. IDR-1002 increased the levels of both RANTES (Regulated on Activation, Normal T cell Expressed and Secreted) and Macrophage colony stimulating factor (M-CSF), suggesting the peptide plays a role in the modulation of macrophage differentiation, also reflected by the reduced concentrations of interleukin (IL)-6 and IL-10. The pro-inflammatory cytokine release triggered by the bacterial cell wall component lipoteichoic acid (LTA) was ameliorated by the concomitantly applied IDR-1002 based on the levels of IL-6, chicken chemotactic and angiogenic factor (CXCLi2) and interferon (IFN)-γ. Moreover, the production of nuclear factor erythroid 2-related factor 2 (Nrf2), an essential transcription factor in the antioxidant defense pathway, was increased after IDR-1002 exposure, while protein carbonyl (PC) levels were also elevated. These findings suggest that IDR-1002 affects the interplay of the cellular immune response and redox homeostasis, thus the peptide represents a promising tool in the treatment of bacterially induced inflammation in chickens.

CCL17/TARC in autoimmunity and inflammation-not just a T-cell chemokine

Chemokine (C-C) ligand 17 (CCL17) was first identified as thymus- and activation-regulated chemokine when it was found to be constitutively expressed in the thymus and identified as a T-cell chemokine. This chemoattractant molecule has subsequently been found at elevated levels in a range of autoimmune and inflammatory diseases, as well as in cancer. CCL17 is a C-C chemokine receptor type 4 (CCR4) ligand, with chemokine (C-C) ligand 22 being the other major ligand and, as CCR4 is highly expressed on helper T cells, CCL17 can play a role in T-cell-driven diseases, usually considered to be via its chemotactic activity on T helper 2 cells; however, given that CCR4 is also expressed by other cell types and there is elevated expression of CCL17 in many diseases, a broader CCL17 biology is suggested. In this review, we summarize the biology of CCL17, its regulation and its potential contribution to the pathogenesis of various preclinical models. Reference is made, for example, to recent literature indicating a role for CCL17 in the control of pain as part of a granulocyte macrophage-colony-stimulating factor/CCL17 pathway in lymphocyte-independent models and thus not as a T-cell chemokine. The review also discusses the potential for CCL17 to be a biomarker and a therapeutic target in human disorders.

Vernal keratoconjunctivitis: Current immunological and clinical evidence and the potential role of omalizumab

Vernal keratoconjunctivitis (VKC) is a severe ocular allergic disease characterized by chronic inflammation of the cornea and conjunctiva that may lead to loss of visual acuity and blindness. The disease occurs primarily in children and is more common in geographical regions characterized by warm temperatures and high humidity. The clinical manifestations of VKC, when inadequately treated, may lead to severe complications and corneal damage. The prevalence of allergen sensitization, specific serum immunoglobulin E (IgE), and specific tear IgE was reported in approximately 55%-60% of patients with VKC, confirming the involvement of IgE-mediated and non-IgE-mediated mechanisms in the pathophysiology of the condition. This article explores current knowledge on the immunological pathways of VKC and the role of the monoclonal anti-IgE antibody, omalizumab, in its management. The review evaluated the effects of omalizumab beyond the direct IgE-mediated reactions and discusses its potential as a therapeutic target for VKC. Multiple retrospective analyses, case series, and case reports have reported the effectiveness of omalizumab in the management of VKC. A summary of the clinical data from these studies revealed that in children with VKC omalizumab treatment was well tolerated with improvement or resolution of ocular symptoms, reduction in steroid use, and enhancement of quality of life. Omalizumab may serve as a promising treatment option for VKC due to its ability to target both IgE-mediated and non-IgE-mediated pathophysiological pathways. Larger, controlled clinical trials are needed to support these findings.

Pre-analytical sample handling effects on tear fluid protein levels

Tear fluid is emerging as a source of non-invasive biomarkers, both for ocular and systemic conditions. Accurate quantification of tear proteins can be improved by standardizing methods to collect and process tear fluid. The aim of this study was to determine sample handling factors that may influence the tear protein biomarker profile. Tear fluid was collected using Schirmer's strips. Tear proteins were extracted by elution through centrifugation. Total protein content was determined using the bicinchoninic acid assay. Key concepts that apply to the entire sample processing cycle are tear sampling, tear storage, protein extraction and data normalization. Differences in wetting or migration length were observed between Schirmer's strips from different manufacturers, and between protein-free and protein-rich solutions. One unit of migration length (mm) did not correspond to one unit of volume (µL). A positive correlation (r = 0.6671, p < 0.0001) was observed between migration length and total tear protein content. The most beneficial storage conditions were strips that were not stored (+ 21.8%), or underwent 'wet' storage (+ 11.1%). Protein recovery was the highest in 400 µL extraction buffer and independent of protein molecular weight. This study helps to explain inter- and intra-variability that is often seen with tear biomarker research. This information is critical to ensure accuracy of test results, as tear biomarkers will be used for patient management and in clinical trials in the near future. This study also highlights the need for standardization of Schirmer's strip manufacturing, tear fluid processing and analyte concentration normalization.

Management of Vernal Keratoconjunctivitis in Children in the United Kingdom: A Review of the Literature and Current Best Practice Across Six Large United Kingdom Centers

Vernal keratoconjunctivitis (VKC) is a form of ocular allergy primarily affecting children. Considered a rare disease in Europe, its prevalence varies by geographic region and is poorly studied in the United Kingdom. There is considerable national variation in the management of VKC within the United Kingdom, risking misdiagnosis and delays to treatment for some children. This can significantly impact their quality of life, with the potential for lasting negative consequences. Based on discussions between experienced clinicians from six large centers across the United Kingdom, this article describes best practice recommendations for United Kingdom settings, including principles for diagnosis, referral, initial and long-term management, and supportive care. Recommendations include guidance on referral timing, which should depend on VKC severity, and a stepwise approach to treatment. Joint management by primary care and secondary care is recommended and the importance of supportive care, including emotional support and outreach to schools, is highlighted. Because frequent flareups are common in VKC, it is essential that families have access to the information they need to manage the disease and routes to access rapid care if needed. A thorough understanding of the nature of VKC, its triggers, and how best to manage it, by both patients and their families, is critical to ensuring appropriate management and to improving patient outcomes. [J Pediatr Ophthalmol Strabismus. 2023;60(1):6-17.].

Emerging therapies targeting eosinophil-mediated inflammation in chronic allergic conjunctivitis

Ocular allergy remains a significant burden to the population while the treatment for the severe, chronic forms of allergic conjunctivitis remains largely limited to non-specific immunosuppressants. Eosinophils are central to the pathophysiology and sustaining the immunologic response found in the chronic forms of ocular allergy such as vernal keratoconjunctivitis and atopic keratoconjunctivitis. Several mediators of eosinophil recruitment, chemotaxis, adhesion, activation, and survival have been identified that offer potential therapeutic targets for ocular allergy. Based on preclinical and clinical data available in both ocular and non-ocular allergy studies, these emerging therapies warrant further investigation in reducing the severity of disease in patients with chronic ocular allergy.

Tear and ocular surface disease biomarkers: A diagnostic and clinical perspective for ocular allergies and dry eye disease

Validated biomarkers to be used as biological tools for managing ocular surface diseases (OSDs) are still an unmet need in daily clinical practice. Many studies have contributed to the already extensive list of candidate biomarkers for these disorders. Dry eye (DE) and ocular allergy (OA) are complex and multifactorial diseases, often coexisting and with overlapping symptoms. The purpose of this review is to present a comprehensive updated revision of the most relevant biomarkers of DE and OA, with an emphasis on quantitative analyses and correlations with clinical parameter data. Analysis of biomarkers common for these pathologies has highlighted an important physiological process. Namely, the interleukin proteins (IL-1α, IL-1β and IL-17), tumour necrotic factor (TNFα) and interferon gamma (IFNγ; Th1-Th7 pathway) and IL-4, IL-5 and IL-13 (Th2 pathway) seem to represent similar inflammatory mechanisms. Moreover, changes in the levels of mucins (MUC1, MUC2, MUC4, MUC5 and MUC16) are common alterations in the tear film mucous layer. We also examine the current state of medical devices and the main limitations to their use in clinical practice. Translational research in biomarkers for clinical practice depends on a feasible transition from the laboratory to the point-of-care. This requires large-scale, coordinated clinical validation campaigns to select the biomarkers with the highest specificity and sensitivity and significant correlation with clinical parameters. Moreover, technical limitations of multiplexed quantitation systems must be overcome to detect and measure the levels of several biomarkers in very small samples. To ensure the future of biomarker research, significant progress is necessary in a number of fields. There is an urgent need for global unification of clinical classification and diagnostics criteria. Widespread integration of proteomic and transcriptomic data is paramount for performing meaningful analyses using appropriate bioinformatics tools and artificial intelligence systems.

Sulforaphane inhibits cytokine-stimulated chemokine and adhesion molecule expressions in human corneal fibroblasts: Involvement of the MAPK, STAT, and NF-κB signaling pathways

Chemokines and adhesion molecules are major inflammatory mediators of chronic and recurrent vernal keratoconjunctivitis (VKC). Sulforaphane (SFN) is a natural plant extract that is known to have anti-inflammatory and antioxidant properties. SFN is demonstrated to be effective against a variety of human diseases. The current investigation examines the effects and the molecular mechanisms of SFN on cytokine-induced human corneal fibroblasts (HCFs) expression of adhesion molecules and chemokines. HCFs were exposed to both interleukin (IL)-4 and tumor necrosis factor (TNF)-α in the absence or presence of SFN treatment. The levels of thymus- and activation-regulated chemokine (TARC) and eotaxin-1 in culture supernatants were evaluated using enzyme-linked immunosorbent assay (ELISA). Reverse transcription-polymerase chain reaction analysis (RT-PCR) enabled quantification of mRNA levels of vascular cell adhesion molecule (VCAM)-1, eotaxin-1, and TARC along with cytokine receptors. An immunoblotting assay was used to evaluate the activities of VCAM-1, nuclear factor-kappa B (NF-κB), mitogen-activated protein kinases (MAPKs), signal transducer and activator of transcription factor (STAT)6 pathways, along with the expression of the cytokine receptors including IL-4 receptor (R)α, IL-13Rα1, TNFRI, as well as TNFRII. SFN inhibited TARC and eotaxin-1 release in HCFs stimulated by TNF-α and IL-4 in a manner dependent on dose and time. SFN suppressed transcriptions of TARC, eotaxin-1, and VCAM-1. Furthermore, the mRNA and protein expression levels of IL-4Rα, TNFRI, and TNFRII were also attenuated by SFN exposure, however, those of IL-13Rα1 remained unaffected. In addition, SFN downregulated the expression of VCAM-1 and the phosphorylation of MAPKs, IκBα, and STAT6. These results suggest that SFN inhibited cytokine-stimulated TARC, eotaxin-1 secretion as well as VCAM-1 expression in HCFs, with these effects likely occurring as a result of cytokine receptor inhibition and attenuation of MAPK, NF-κB, and STAT6 signaling. SFN may therefore have therapeutic potential in VKC treatment.

Alterations in Mucin-Associated Gene Expression on the Ocular Surface in Active and Stable Stages of Atopic and Vernal Keratoconjunctivitis

Purpose

To evaluate the presence of ocular surface mucin in patients with atopic and vernal keratoconjunctivitis (AKC/VKC), we investigated the mRNA expression levels of SAM-pointed domain-containing ETS-like factor (SPDEF) and mucin-related genes on the ocular surface.

Methods

Nineteen patients with AKC or VKC were divided into two groups based on the severity of the disease as determined by their clinical scores for AKC/VKC: the stable group and the active group. Impression cytology was performed in all patients using filter paper, and the expression levels of SPDEF, MUC1, MUC4, MUC5AC, MUC16, and eotaxin-2 mRNA were determined by real-time reverse-transcription polymerase chain reaction.

Results

The results showed that the expression levels of SPDEF and MUC5AC mRNA in the active group were significantly decreased compared with those in the stable group. Furthermore, clinical scores were significantly negatively correlated with the expression levels of SPDEF mRNA and significantly positively correlated with the expression levels of eotaxin-2, which is a biomarker for eosinophilic inflammation on the ocular surface. Cluster analysis classified the patients with AKC/VKC into three clusters, and the stable group was divided into two clusters according to the condition of ocular surface mucin.

Conclusions

Ocular surface mucin in patients with AKC/VKC is altered in accordance with the clinical severity of the disease.

Impact of diurnal variation, sex, tear collection method, and disease state on tear protein levels in dogs

OBJECTIVE

To investigate the effects of various biological factors on total protein concentration (TPC) and serum albumin levels in canine tears.

ANIMALS STUDIED

10 healthy beagles (5 female, 5 male) were used.

PROCEDURES

Experiments were conducted on separate days, collecting tears with either capillary tubes or Schirmer strips, as follows: (i) Tear collection at 3 hours intervals (from 6 am to 12 am); and (ii) Tear collection before and 20 minutes following topical histamine application (1, 10, 375 mg/mL) to induce mild, moderate, and severe conjunctivitis, respectively. TPC and serum albumin were measured with infrared spectroscopy and ELISA, respectively.

RESULTS

Tear film TPC and serum albumin ranged from 9.7-26.1 mg/mL and 6.4-1662.6 µg/mL, respectively. Protein levels did not differ significantly among time points (P ≥ .080). Median coefficient of variation (CV%) was lower with Schirmer strips compared to capillary tubes for both TPC (12% vs 15%, P = .020) and serum albumin (57% vs 78%, P = .232). TPC (P < .001), but not serum albumin was greater in male vs. female dogs. Serum albumin, but not TPC (P ≥ .099), increased significantly with each grade of conjunctivitis severity (P < .001), with no differences between collection devices (P ≥ .322); median increase was 106%, 1389%, and 2871% in eyes with mild, moderate, and severe conjunctivitis, respectively.

CONCLUSIONS

There is no apparent diurnal variation in canine tear protein levels. Blood-tear barrier breakdown with conjunctivitis allows serum albumin to leak into the tear film at high concentrations. Schirmer strips compare well with capillary tubes for bioanalytical purposes in healthy and diseased eyes, and this collection method may offer improved reproducibility for protein quantification.

Ocular allergy test and biomarkers on the ocular surface: Clinical test for evaluating the ocular surface condition in allergic conjunctival diseases

Allergic conjunctival diseases (ACDs) are inflammatory diseases of the conjunctiva and cornea caused predominantly by the IgE-mediated immediate hypersensitivity response. Allergic conjunctival diseases include allergic conjunctivitis, vernal keratoconjunctivitis (VKC), atopic keratoconjunctivitis (AKC), and giant papillary conjunctivitis. In clinical practice of ACDs, an ocular allergy test using biomarker measurement is a crucial examination technique for diagnosing, evaluating severity, and determining the efficacy of medical treatment. The ocular allergy test includes the tear test for evaluating the concentration of biomarkers in tears and an ocular surface test for assessing the expression levels of messenger ribonucleic acid (mRNA) biomarkers on the ocular surface. The clinical usefulness of several biomarkers has been demonstrated in patients with ACDs; specifically, eosinophil cationic protein and eotaxin-2 as eosinophilic inflammation biomarkers; interleukin-4 and thymus and activation regulated chemokine (CCL17/TARC) as Th2 inflammation biomarkers; eotaxin, tumor necrosis factor-alpha and soluble IL-6 receptor as giant papillae biomarkers; and osteopontin and periostin as allergic inflammation and remodeling biomarkers. Furthermore, the ocular allergy test, quantitative evaluation methods using biomarkers have allowed for better understanding of the immunological and pathophysiological mechanisms of ACDs. Therefore, the search for a biomarker is important to make an ocular allergy test useful. In previous ocular allergy tests, the biomarkers for allergic inflammation in patients with chronic ACDs including VKC and AKC were substantial. However, the selection of biomarkers associated with the early phase reaction of immediate hypersensitivity and innate immunity responses needs to be addressed in future investigations.

Chemokines in allergic conjunctivitis

PURPOSE OF REVIEW

Chemokines are a large group of low molecular weight cytokines that attract and activate leukocytes throughout the body and therefore have a key role in the framework of late-phase allergic responses. The purpose of this article is to provide an overview of the main chemokines involved in allergic conjunctivitis, their primary functions and their physiological roles, and therapies targeted at chemokines and their receptors for ocular allergic diseases.

RECENT FINDINGS

In recent years, there have been considerable advances in the understanding of ocular pathophysiology of ocular surface inflammatory diseases including both allergic eye diseases and dry eye syndrome. Several therapies being developed for dry eye inflammation are recognized as possible therapies for ocular allergic diseases as there are often common chemokines involved in both disease spectra.

SUMMARY

Chemokines represent an integral part of the late-phase cascade of ocular allergic inflammation. A deep understanding of specific chemokines and their interactions will help in targeting therapies to effectively manage ocular clinical findings and symptoms of allergic eye disease.

Potential Biomarkers for Allergic Conjunctival Diseases

Allergic conjunctival diseases (ACDs) are a group of ocular allergies that include allergic conjunctivitis, atopic keratoconjunctivitis, vernal keratoconjunctivitis, and giant papillary conjunctivitis. Although a large body of information exists on the pathophysiology of ACDs, this has not yet lead to the development of clear recommendations and guidelines for the diagnosis of ACDs or development of conclusive and objective diagnostic tools. Identification of objectively measurable biomarkers that represent the molecular and cellular mechanisms associated with ACDs will be an important step toward achieving these aims. This is a comprehensive review of biological markers that have the potential to become "biomarker(s)" for ACDs and aid in the classification, diagnosis, and development of new therapeutic strategies for these group of allergic conditions.

Kinetics of Tear Fluid Proteins after Endothelial Keratoplasty and Predictive Factors for Recovery from Corneal Haze

Endothelial keratoplasty (EK) is less invasive with faster recovery as compared to conventional penetrating keratoplasty, however, it relies on the clarity of the host corneal stroma. Corneal transplantation involves the induction of immune tolerance for allogeneic tissues as well as the corneal wound healing process, in which coordinated interactions between cytokines and growth factors are critical. In this study, we profiled the expression of 51 soluble factors in the tear fluid over the course of EK and have provided evidence of dynamic changes in cytokine expression in the ipsilateral and contralateral eyes. Cluster analyses classified the cytokine expression kinetics into five groups. Group 1 proteins included TGF-b1, IL-1b, and innate proinflammatory cytokines, which bilaterally increased after surgery, despite the use of topical corticosteroid in the transplanted eyes. Local corticosteroids suppressed cytokines involved in adaptive immunity in the transplanted eyes but not in the contralateral eyes. We found tear protein expression at baseline and one week post-surgery to be a potential predictive biomarker of delayed recovery after EK in terms of the corneal haze and visual acuity. Furthermore, Group 1 tear proteins were most associated with persistent corneal haze pre-surgery as well as visual acuity at one month-post transplant.

Evaluation of Chemokine mRNA Expression to Assess Allergic Inflammation of the Ocular Surface in Chronic Allergic Conjunctival Diseases

Purpose:

We validated the use of chemokine messenger RNA (mRNA) expression analysis for the assessment of ocular surface allergic inflammation in chronic allergic conjunctival diseases (ACDs) with proliferative lesions, including giant papillae and gelatinous infiltration of the limbus.

Methods:

This prospective sectional study included 19 patients with chronic ACDs and 10 healthy volunteers as controls. Patients with chronic ACDs were divided into 2 subgroups according to the severity of the clinical score: active stage ACD subgroup (n = 9) and stable stage ACD subgroup (n = 10). Impression cytology using a filter paper for each upper tarsal conjunctiva of the patients with chronic ACDs and control subjects was performed, and the expression levels of IL1A, CXCL8, IL16, and CCL24 mRNAs encoding interleukin (IL)-1α, CXCL8/IL-8, IL-16, and CCL24/eotaxin-2, respectively, were determined by quantitative real-time polymerase chain reaction using impression cytology specimens.

Results:

CCL24 and IL16 mRNA levels in the active ACD subgroup were significantly higher than those in the control group (P = 0.003 and 0.004, respectively). IL1A and CXCL8 expression levels in the active ACD subgroup were significantly higher than those in the stable ACD (P = 0.008 and 0.029, respectively) and control (P = 0.008 and 0.014, respectively) subgroups. Furthermore, significant correlations were detected between IL16 and CCL24 mRNA levels (r = 0.76, P = 0.0001) and between IL1A and CXCL8 (r = 0.67, P = 0.0004).

Conclusions:

At least 2 kinds of inflammatory reactions, IL-1α- and CXCL8-associated inflammation and CCL24- and IL-16-associated inflammation, may be involved in the exacerbation of chronic ACDs.

Vernal Keratoconjunctivitis: an update focused on clinical grading system

INTRODUCTION

Vernal keratoconjunctivitis (VKC) is a severe disease with a prevalence of < 1 case out of 10,000 in Europe, which occurs mainly in pediatric age and is characterized by a severe and often bilateral chronic inflammation of the ocular surface. The diagnosis is generally confirmed by the finding at the ocular examination of conjunctival hyperemia, papillary hypertrophy in the tarsal conjunctiva, giant papillae, papillae in the limbus region.

OBJECTIVE

Aim of this review is to provide an updated overview on the disease focused on clinical grading system, searching papers published in the last decade on VKC in scientific databases.

RESULTS

Currently there are no standardized criteria for diagnosis of VKC and there is no uniformity to define disease severity, which makes difficult to diagnose and treat the disease.

CONCLUSIONS

Given the wide overlap of the symptoms of VKC with the allergic conjunctivitis, criteria of probable, possible or improbable diagnosis are needed, providing pediatricians with parameters useful for deciding whether to drive the patient to the ophthalmologist for diagnostic confirmation.

Synovial fluid interleukin-16, interleukin-18, and CRELD2 as novel biomarkers of prosthetic joint infections

Objectives

Prosthetic joint infection (PJI) diagnosis is a major challenge in orthopaedics, and no reliable parameters have been established for accurate, preoperative predictions in the differential diagnosis of aseptic loosening or PJI. This study surveyed factors in synovial fluid (SF) for improving PJI diagnosis.

Methods

We enrolled 48 patients (including 39 PJI and nine aseptic loosening cases) who required knee/hip revision surgery between January 2016 and December 2017. The PJI diagnosis was established according to the Musculoskeletal Infection Society (MSIS) criteria. SF was used to survey factors by protein array and enzyme-linked immunosorbent assay to compare protein expression patterns in SF among three groups (aseptic loosening and first- and second-stage surgery). We compared routine clinical test data, such as C-reactive protein level and leucocyte number, with potential biomarker data to assess the diagnostic ability for PJI within the same patient groups.

Results

Cut-off values of 1473 pg/ml, 359 pg/ml, and 8.45 pg/ml were established for interleukin (IL)-16, IL-18, and cysteine-rich with EGF-like domains 2 (CRELD2), respectively. Receiver operating characteristic curve analysis showed that these factors exhibited an accuracy of 1 as predictors of PJI. These factors represent potential biomarkers for decisions associated with prosthesis reimplantation based on their ability to return to baseline values following the completion of debridement.

Conclusion

IL-16, IL-18, and CRELD2 were found to be potential biomarkers for PJI diagnosis, with SF tests outperforming blood tests in accuracy. These factors could be useful for assessing successful debridement based on their ability to return to baseline values following the completion of debridement.Cite this article: M-F. Chen, C-H. Chang, L-Y. Yang, P-H. Hsieh, H-N. Shih, S. W. N. Ueng, Y. Chang. Synovial fluid interleukin-16, interleukin-18, and CRELD2 as novel biomarkers of prosthetic joint infections. Bone Joint Res 2019;8:179-188. DOI: 10.1302/2046-3758.84.BJR-2018-0291.R1.

The proteolytic effect of mast cell tryptase to eotaxin-1/CCL11·eotaxin-2/CCL24 and eotaxin-3/CCL26 produced by conjunctival fibroblasts

PURPOSE

To investigate the proteolytic effect of mast cell tryptase on eotaxin-1/CCL11, eotaxin-2/CCL24 and eotaxin-3/CCL26 produced by conjunctival fibroblasts.

STUDY DESIGN

Experimental.

METHODS

The production of eotaxin-1, -2 and -3 by conjunctival fibroblasts stimulated both with and without IL-4/IL-13 or/and TGF-β₁ was assessed by ELISA. The proteolytic activity of tryptase on eotaxins derived from conjunctival fibroblasts and recombinant eotaxins was also estimated by enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR).

RESULTS

Conjunctival fibroblasts produced eotaxin-1 and -3, but not eotaxin-2. Stimulation with IL-4/IL-13 and TGF-β₁ synergistically increased eotaxin-1 and -3 production. Tryptase reduced the immunoreactivity of eotaxin-1 and -3 but not of eotaxin-2, due to the proteolysis of these eotaxins but not the inhibition of their m-RNA expression.

CONCLUSION

Mast cell tryptase may exercise proteolytic activity on eotaxin-1 and -3 produced by conjunctival fibroblasts, resulting in partial suppression of the ability of eotaxin-1 and -3 to accumulate eosinophils in the conjunctiva. Eotaxin-2 in the tears may be a suitable biomarker of severity of allergic conjunctival disease.

Comprehensive analysis of vitreous chemokines involved in ischemic retinal vein occlusion

PURPOSE

To investigate vitreous levels of chemokines in eyes with ischemic retinal vein occlusion (RVO).

METHODS

The vitreous humor was collected at the start of 23-gauge pars plana vitrectomy from patients with ischemic RVO and patients with idiopathic preretinal membranes (PRMs) and idiopathic macular holes (IMHs). The levels of 40 different chemokines were measured using magnetic color-bead-based multiplex assay. The chi-square test was performed for clinical variables such as sex, and the Mann-Whitney U test was performed to evaluate the differences in the chemokine levels between the RVO group and the control group.

RESULTS

Vitreous humor was collected from 20 controls and 25 subjects with ischemic RVO. C-C motif ligand 17 (CCL17) was unmeasurable in more than 70% of the samples. The levels of 29 of 39 chemokines were statistically significantly elevated in the RVO group compared with the control group, including CCL21, C-X-C motif ligand (CXCL) 13, CCL27, CCL24, CX3CL1, CXCL6, interferon-gamma (IFN-γ), interleukin (IL) 1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-16, CXCL10, CXCL11, CCL8, CCL7, CCL13, CCL22, macrophage migration inhibitory factor (MIF), CXCL9, CCL3, CCL15, CCL20, CCL19, CCL23, CCL25, and tumor necrosis factor-alpha (TNF-α). Among the 29 elevated chemokines, we found that the levels of three chemokines (IL-8, CXCL9, and TNF-α) showed a more than six-fold increase in the RVO eyes versus controls, and CXCL9 expression showed the greatest change of all tested chemokines.

CONCLUSIONS

Dozens of chemokines were found to be elevated in the vitreous of RVO eyes complicated with vitreous hemorrhage, suggesting that inflammation is severe in the ischemic retina. The knowledge of specific upregulation of chemokines in ischemic RVO could allow more targeted future therapies.