Eosinophil cationic protein in tears in allergic conjunctivitis

The multifaceted aspects of ocular allergies: Phenotypes and endotypes

Like the lung, skin, and nose, the external eye is a common target of allergic inflammation. Ocular allergy (OA) represents a collection of underestimated diseases of the eye observed in children and adults. The ocular manifestations are the expression of multifactorial immune mechanisms that generally have a good prognosis, but for a few patients, long term inflammation may remarkably reduce the visual function. Evidence suggests that other co-participant systems, including epigenetic, genetic, environmental, individual factors, sex hormones, and the central and autonomic nervous systems may influence the ocular response from distant sites. This is consistent with the concept that the eye is an organ fully integrated with the rest of the body and that the therapeutic approach should be holistic, dynamic, and personalized. For instance, androgens and estrogens binding to receptors on the ocular surface and the continuous cross-talking of neuromediators and growth factors with immune cells act to maintain the ocular surface homeostasis in response to environmental challenges. The immune system links and regulates the response of the ocular surface. Complex and incompletely understood mechanisms influence the innate and adaptive immune responses and generate different OA phenotypes and endotypes discussed in the present review.

A Population-Based Study of Social Demographic Factors, Associated Diseases and Recurrent Corneal Erosion in Taiwan

Purpose

To investigate the association of recurrent corneal erosion (RCE) with sociodemographic factors and associated ocular conditions or systemic diseases.

Methods

This nationwide, population-based, retrospective, matched case-controlled study included 98,895 RCE patients, identified by the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code 371.42, were selected from the Taiwan National Health Insurance Research Database. The age-, sex-, and index date- matched control group included 98,895 non-RCE control group also selected from the Taiwan Longitudinal Health Insurance Database 2000. Sociodemographic factors and associated ocular conditions or systemic diseases were examined using univariate logistic regression analyses, and continuous variables were analyzed using paired t-test. The odds ratio (OR) of developing RCE were compared using adjusted logistic regression analysis.

Results

Patients with ocular conditions including corneal abrasion, ocular allergic conditions, and corneal dystrophy were more likely to have RCE than the control group (adjusted OR = 63.56, 95% CI = 42.06-96.06, p < 0.0001; adjusted OR = 24.27, 95% CI = 20.51-28.72, p < 0.0001; adjusted OR = 17.10, 95% CI = 5.14-59.93, p < 0.0001, respectively). Patients with systemic diseases such as diabetes mellitus, hyperlipidaemia, and atopy trait have significantly higher ORs for RCE development. Patients residing in either Northern Taiwan or a metropolis city had higher odds of developing RCE; however, there were no significant differences in income or occupation on the probability to develop RCE.

Conclusion

RCE is strongly associated with corneal abrasion, ocular allergic conditions, corneal dystrophy, diabetes mellitus, hyperlipidaemia, and atopy trait.

Novel Insight of Histamine and Its Receptor Ligands in Glaucoma and Retina Neuroprotection

Glaucoma is a multifactorial neuropathy characterized by increased intraocular pressure (IOP), and it is the second leading cause of blindness worldwide after cataracts. Glaucoma combines a group of optic neuropathies characterized by the progressive degeneration of retinal ganglionic cells (RGCs). Increased IOP and short-term IOP fluctuation are two of the most critical risk factors in glaucoma progression. Histamine is a well-characterized neuromodulator that follows a circadian rhythm, regulates IOP and modulates retinal circuits and vision. This review summarizes findings from animal models on the role of histamine and its receptors in the eye, focusing on the effects of histamine H3 receptor antagonists for the future treatment of glaucomatous patients.

Association Between Atopic Keratoconjunctivitis and the Risk of Recurrent Corneal Erosion

Purpose: To investigate the risk of recurrent corneal erosion (RCE) in patients with atopic keratoconjunctivitis (AKC).

Methods: This national, retrospective, matched cohort study enrolled 184,166 newly-diagnosed AKC patients, selected from the Taiwan National Health Insurance Research Database and identified by the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code 372.05. The control group comprised 184,166 non-AKC patients matched by age, sex, and potential comorbidities and they were selected from the Taiwan Longitudinal Health Insurance Database, 2000. Information from patients was gathered from 1 January 2004 to 31 December 2011, and both groups were traced from the index date until December 2013. The incidence and risk of RCE (ICD-9-CM code 361.42) was compared between the groups. The adjusted hazard ratio (HR) for RCE was obtained by a Cox proportional hazard regression analysis. The Kaplan–Meier analysis was performed to calculate the cumulative incidence of RCE.

Results: In total, 564 AKC patients and 406 non-AKC controls developed RCE during the follow-up span. The incidence of RCE was 1.45 times higher in AKC patients than in controls (95% confidence interval [CI] = 1.27–1.64; P < 0.0001). After adjusting for potential confounders, including diabetes mellitus, keratoconjunctivitis sicca, corneal transplantation, ocular blunt trauma, corneal dystrophy, and band keratopathy, AKC patients were 1.36 times more likely to develop RCE than controls (adjusted HR, 1.36; 95% CI = 1.19–1.54; p < 0.05).

Conclusions: AKC Patients had an increased risk of developing RCE and should be informed of this risk.

Association between atopic keratoconjunctivitis and the risk of corneal ulcer

AIMS

To investigate the risk of corneal ulcer in patients with atopic keratoconjunctivitis (AKC).

METHODS

The nationwide, population-based, retrospective, matched cohort study included 171 019 newly diagnosed patients with AKC who were identified by the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM), code 372.05, and selected from the Taiwan National Health Insurance Research Database. The age-, sex- and potential comorbidities-matched control group included 171 019 patients with non-AKC selected from the Taiwan Longitudinal Health Insurance Database 2000. Patient information was collected between 1 January 2004 and 31 December 2011, and both groups of patients were tracked from the index date until December 2013. The incidence and risk of corneal ulcer (ICD-9-CM code 370.0 except for 370.07) was compared between the groups. A Cox proportional hazard regression analysis was performed to obtain the adjusted HR for corneal ulcer. The cumulative corneal ulcer incidence rate was calculated with the Kaplan-Meier analysis.

RESULTS

In total, 2018 patients with AKC and 1481 controls developed a corneal ulcer during the follow-up period. The incidence rate of corneal ulcer was 1.42 times (95% CI1.33 to 1.52; p<0.0001) higher in patients with AKC than in controls. After adjusting for potential confounders, including diabetes mellitus, chronic renal disease, topical steroid ophthalmic agent use, lid margin disease, keratoconjunctivitis sicca, ocular blunt trauma and post-corneal transplantation, patients with AKC were 1.26 times more likely to develop a corneal ulcer than controls (adjusted HR, 1.26; 95% CI 1.14 to 1.39; p<0.05).

CONCLUSIONS

Patients with AKC had an increased risk of developing a corneal ulcer and should be advised of this risk.

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.

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.

Immune Modulation by Human Secreted RNases at the Extracellular Space

The ribonuclease A superfamily is a vertebrate-specific family of proteins that encompasses eight functional members in humans. The proteins are secreted by diverse innate immune cells, from blood cells to epithelial cells and their levels in our body fluids correlate with infection and inflammation processes. Recent studies ascribe a prominent role to secretory RNases in the extracellular space. Extracellular RNases endowed with immuno-modulatory and antimicrobial properties can participate in a wide variety of host defense tasks, from performing cellular housekeeping to maintaining body fluid sterility. Their expression and secretion are induced in response to a variety of injury stimuli. The secreted proteins can target damaged cells and facilitate their removal from the focus of infection or inflammation. Following tissue damage, RNases can participate in clearing RNA from cellular debris or work as signaling molecules to regulate the host response and contribute to tissue remodeling and repair. We provide here an overall perspective on the current knowledge of human RNases’ biological properties and their role in health and disease. The review also includes a brief description of other vertebrate family members and unrelated extracellular RNases that share common mechanisms of action. A better knowledge of RNase mechanism of actions and an understanding of their physiological roles should facilitate the development of novel therapeutics.

Tear and Serum Eosinophil Cationic Protein Levels in Seasonal Allergic Conjunctivitis

PURPOSE

Eosinophil cationic protein (ECP) levels in tear fluid and sera of patients with seasonal allergic conjunctivitis (SAC) were measured to assess local and systemic eosinophilic activity in SAC. The correlation between ECP levels and disease activity was evaluated.

METHODS

Tears and sera were collected from 21 patients with SAC and 13 healthy control subjects. ECP levels in tears and sera were measured before and 4 weeks after treatment with 0.1% lodoxamide eyedrops. Clinical signs and symptoms of SAC were scored and the correlation of ECP levels with the clinical scores was evaluated.

RESULTS

Tear and serum levels of ECP were significantly increased (p = 0.01, p = 0.02, respectively) in patients with SAC compared with the control subjects, but ECP levels were not correlated with the severity of the disease. Following treatment with topical 0.1% lodoxamide eyedrops, the mean level of ECP in tears decreased significantly (p = 0.02), whereas no significant change was observed in serum ECP levels. Furthermore, a significant decrease in clinical signs and symptoms scores was found after treatment (both p < 0.0001).

CONCLUSIONS

Increased serum and tear ECP levels in patients with SAC confirms that both local and systemic eosinophil activation occurs in SAC. However, clinical signs and symptoms of SAC were not found to be correlated with the degree of eosinophilic activity. Thus ECP does not seem to have an important role in clinical manifestations of SAC.

Elevated serum levels of TNF-α, IL-8, and ECP can be involved in the development and progression of bronchial asthma

OBJECTIVE

This study aimed to explore the value of elevated serum levels of tumor necrosis factor-α (TNF-α), interleukin-8 (IL-8), and eosinophil cationic protein (ECP) in the diagnosis of bronchial asthma (BA).

METHODS

A total of 170 patients with BA (case group, 85 patients in acute attack and 85 patients in clinical remission) and 150 healthy individuals (control group) were enrolled in this study. Enzyme-linked immunosorbent assay and receiver operating characteristic (ROC) curves were calculated for the contents and diagnostic values of serum TNF-α, IL-8, and ECP in BA.

RESULTS

Compared with the control group, patients in acute attack and clinical remission had higher TNF-α, IL-8, and ECP levels (p < 0.05). The serum level of TNF-α was positively correlated with IL-8 and ECP (p < 0.05). ROC curves showed that the diagnostic threshold value of IL-8 was 13.53 ng/ml, its area under the curve (AUC) was 0.87, its specificity was 99.3%, and its sensitivity was 57.6%. The diagnostic threshold value of TNF-α was 1.29 ng/ml with AUC being 0.94, specificity was 89.3%, and sensitivity was 83.5%. ECP showed 7.22 ng/ml diagnostic threshold value (AUC = 0.88, specificity = 74.0%, sensitivity = 86.5%). The FEV₁/pre(%) and FEV₁/FVC were negatively correlated and the Z5/pre(%) and resonance frequency (Fres) were positively correlated with the serum levels of TNF-α, IL-8, and ECP in patients in acute attack and in clinical remission (all p < 0.05).

CONCLUSION

Our findings reveal that elevated serum levels of TNF-α, IL-8, and ECP can be involved in the development and progression of BA.

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

PURPOSE

This study investigated the clinical usefulness of a multiple tear cytokine/chemokine test by simultaneously determining tear levels of CC chemokine ligand 17 (CCL17)/thymus and activation-regulated chemokine (TARC), CCL24/eotaxin-2, and interleukin-16 (IL-16) for assessing acute and chronic allergic inflammation in allergic conjunctival disorders (ACDs).

SUBJECTS AND METHODS

This study included 37 patients with ACD and 11 healthy adults (controls). Patients with ACDs were divided into the following three groups; patients with allergic conjunctivitis (AC group, n = 17), patients with atopic keratoconjunctivitis (AKC group, n = 6), and patients with vernal keratoconjunctivitis (VKC group, n = 14). Tear samples were collected using the Schirmer I method with a filter paper. Tear levels of CCL17/TARC, CCL24/eotaxin-2, and IL-16 were determined by performing a magnetic bead assay (tear cytokine/chemokine test). Tear levels of eosinophil cationic protein (ECP) were determined by performing enzyme immunoassay. In patients with AC, clinical scores of objective findings and results of the tear cytokine/chemokine test at baseline were compared with those at 7 days after treatment with the histamine H₁ receptor antagonist (epinastine) ophthalmic solution.

RESULTS

Tear positive rates of CCL17/TARC, CCL24/eotaxin-2, and IL-16 were higher in patients with AC, AKC, and VKC compared with controls. Tear levels of CCL17/TARC, CCL24/eotaxin-2, and IL-16 in patients with AKC and VKC were significantly higher than those in patients with AC. Moreover, tear levels of IL-16 in patients with AC that showed improvement of their clinical score by treatment with epinastine ophthalmic solution decreased significantly after 7 days of the treatment compared with those at baseline. In patients with AKC and VKC, a significant correlation was observed between the tear levels of CCL24/eotaxin-2 and ECP.

CONCLUSION

Simultaneous measurement of the tear levels of CCL17/TARC, CCL24/eotaxin-2, and IL-16 may be a useful test for assessing acute and chronic allergic inflammation in ACDs.

Clinical Usefulness of Monitoring Expression Levels of CCL24 (Eotaxin-2) mRNA on the Ocular Surface in Patients with Vernal Keratoconjunctivitis and Atopic Keratoconjunctivitis

Purpose. This study aimed to evaluate the clinical efficacy of using expression levels of CCL24 (eotaxin-2) mRNA on the ocular surface as a biomarker in patients with vernal keratoconjunctivitis (VKC) and atopic keratoconjunctivitis (AKC). Methods. Eighteen patients with VKC or AKC (VKC/AKC group) and 12 control subjects (control group) were enrolled in this study. The VKC/AKC clinical score was determined by objective findings in patients by using the 5-5-5 exacerbation grading scale. All subjects underwent modified impression cytology and specimens were obtained from the upper tarsal conjunctiva. Expression levels of CCL24 (eotaxin-2) mRNA on the ocular surface were determined using real-time reverse transcription polymerase chain reaction. Results. The VKC group was divided into two subgroups, depending on the clinical score: the active stage subgroup with 100 points or more of clinical scores and the stable stage subgroup with 100 points or less. CCL24 (eotaxin-2) mRNA expression levels in the active VKC/AKC stage subgroup were significantly higher than those in the stable VKC/AKC subgroup and the control group. Clinical scores correlated significantly with CCL24 (eotaxin-2) mRNA expression levels in the VKC group. Conclusions. CCL24 (eotaxin-2) mRNA expression levels on the ocular surface are a useful biomarker for clinical severity of VKC/AKC.

Tear fluid biomarkers in ocular and systemic disease: potential use for predictive, preventive and personalised medicine

In the field of predictive, preventive and personalised medicine, researchers are keen to identify novel and reliable ways to predict and diagnose disease, as well as to monitor patient response to therapeutic agents. In the last decade alone, the sensitivity of profiling technologies has undergone huge improvements in detection sensitivity, thus allowing quantification of minute samples, for example body fluids that were previously difficult to assay. As a consequence, there has been a huge increase in tear fluid investigation, predominantly in the field of ocular surface disease. As tears are a more accessible and less complex body fluid (than serum or plasma) and sampling is much less invasive, research is starting to focus on how disease processes affect the proteomic, lipidomic and metabolomic composition of the tear film. By determining compositional changes to tear profiles, crucial pathways in disease progression may be identified, allowing for more predictive and personalised therapy of the individual. This article will provide an overview of the various putative tear fluid biomarkers that have been identified to date, ranging from ocular surface disease and retinopathies to cancer and multiple sclerosis. Putative tear fluid biomarkers of ocular disorders, as well as the more recent field of systemic disease biomarkers, will be shown.

Vernal Keratoconjunctivitis in Kashmir: A temperate zone

The objective of this study was to observe the clinical features of patients with vernal keratoconjunctivitis attending the Outpatient Department of a mobile eye unit, Directorate of Health Services, Jammu and Kashmir over a period of 1 year. The greater prevalence of VKC is seen in the regions with hot, humid climate, and higher load of airborne allergens. The clinical profile of this disease seems to have geographical variation. The study was conducted in the mobile eye unit, Directorate of Health Services, Kashmir, a comparatively cooler area. All the patients with vernal keratoconjunctivitis who presented to the OPD during this period were examined. The diagnosis of vernal keratoconjunctivitis was based on typical history, clinical features, and examination. All the patients with the complaints of itching, watering, and photophobia were examined. After proper history, clinical features, and ocular examination under slit lamp, the data were recorded for patients who were diagnosed with vernal keratoconjunctivitis. Of all the patients who had allergic ocular disorders, a total of 212 patients were diagnosed as cases with vernal keratoconjunctivitis. This is a non-interventional study, and the ethical clearance was obtained from the regulatory board of the hospital. The study abides by the tenets laid down in the declaration of Helsinki. During this 1-year period, 212 vernal keratoconjunctivitis patients were examined, of whom 155 (73 %) were males and 57 (27 %) were females. As per the age group, 40 % (85) of patients were in the age group of 11-15 years. 93 % (197) of patients had bilateral disease, and 7 % (15) had unilateral. It was seen that 75 % (159) had seasonal attack. Different types of disease were observed: 77 % (163) had bulbar disease, 7 % (15) had palpebral, and 16 % (34) had mixed disease. During this period, we noticed that VKC led to complications also. It was seen that 3 % (6) of patients had steroid induced glaucoma, 5 % (11) had developed cataract, 6 % (13) of patients had keratoconus, and 6 % (13) of patients had corneal scarring. Other complications were also seen. VKC is a bilateral disease. Males are affected more than females. Ocular complications were seen in around 30 % of patients. Visual impairment ranging from severe visual impairment to blindness was observed in 2 % of patients. VKC patients should be instructed to use medication under the supervision of an ophthalmologist. There is a need to assess disease severity in order to develop standardized guidelines based on the stage of vernal keratoconjunctivitis.

Long-term follow-up of tacrolimus ointment for treatment of atopic keratoconjunctivitis

PURPOSE

To evaluate the long-term clinical outcomes of 0.1% tacrolimus dermatologic ointment (Protopic) in cases of refractory atopic keratoconjunctivitis (AKC).

DESIGN

Prospective, nonrandomized, noncontrolled case series.

METHODS

Twenty-two eyes from 11 patients with severe AKC who were treated with 0.1% tacrolimus ointment were followed prospectively. The mean age of the patients was 32.27 ± 12.7 years (range, 19-61 years). Each patient completed a follow-up period of at least 48 months, during which the signs and symptoms of AKC were assessed. Changes in the total scores of signs and symptoms from baseline were recorded at each visit, and the main outcome measure was the clinical response to topical tacrolimus treatment.

RESULTS

Dramatic improvements in clinical signs and symptoms were achieved 1 week after starting topical tacrolimus treatment, and complete clinical resolution was observed in almost all patients 6 weeks after starting treatment. Treatment was gradually reduced, with increasing intervals between applications. Eight patients remained asymptomatic for up to 3 years, although recurrence occurred in 3 patients who attempted to discontinue treatment. All patients complained of a mild burning sensation upon application of the ointment. No additional medications were required to provide relief, and no patient discontinued treatment because of adverse drug effects. No drug-related ocular complications were encountered, and no significant changes in visual acuity or refraction were documented.

CONCLUSIONS

Tacrolimus dermatologic ointment is a potentially safe and effective treatment for AKC cases refractory to standard treatment and may substitute for steroid treatments aimed at controlling disease activity.

Tear analysis in ocular surface diseases

The thin layer of tears covering the ocular surface are a complex body fluid containing thousands of molecules of varied form and function of several origins. In this review, we have discussed some key issues in the analysis of tears in the context of understanding and diagnosing eye disease using current technologies of proteomics and metabolomics, and for their potential for clinical application. In the last several years, advances in proteomics/metabolomics/lipidomics technologies have greatly expanded our knowledge of the chemical composition of tear fluid. The quickened pace of studies has shown that tears as a complex extra-cellular fluid of the ocular surface contains a great deal of molecular information useful for the diagnosis, prognosis, and treatment of ocular surface diseases that has the ability to addresses the emphasis on personalized medicine and biomarkers of disease. Future research directions will likely include (1) standardize tear collection, storage, extraction, and sample preparation; (2) quantitative proteomic analysis of tear proteins using multiple reaction monitoring (MRM)-based mass spectrometry; (3) population based studies of human tear proteomics/metabolomics; (4) tear proteomics/metabolomics for systemic diseases; and (5) functional studies of tear proteins.

Eosinophil cationic protein as a marker for assessing the efficacy of tacrolimus ophthalmic solution in the treatment of atopic keratoconjunctivitis

PURPOSE

To examine the clinical efficacy and anti-inflammatory effects of tacrolimus eye drops; we studied the changes in clinical ocular findings and measured tear eosinophil cationic protein (ECP) levels of atopic keratoconjunctivitis (AKC) patients before and after the treatment.

METHODS

Nine eyes of 9 patients (8 males, 1 female; mean age: 16.9 ± 11.4 years; range: 6-44 years) diagnosed with moderate or severe AKC disease were enrolled in this prospective study and treated with tacrolimus. All patients received 0.1% tacrolimus eye drops 2 times a day for 1 month. Tear samples were taken before and after treatment and ECP concentrations were obtained. Corneal fluorescein staining and conjunctival injection, edema, and papillary formation were graded on the recruitment day and one month later. Analysis of pre- and post-treatment findings was done using the Wilcoxon signed test. The ECP concentrations were correlated with the clinical signs using Spearman correlation tests.

RESULTS

Post-treatment tear ECP levels were significantly reduced compared to the pre-treatment level. Clinical corneal scores also improved significantly after one month treatment with tacrolimus eye-drops. The mean conjunctival injection and conjunctival edema scores were significantly (p<0.05) decreased after the drug therapy. Strong positive linear correlations between ECP values and clinical signs were observed. Patients did not present side effects during the treatment with tacrolimus.

CONCLUSIONS

In this pilot study, tacrolimus eye drops were found to reduce signs of AKC. ECP proved to correlate well with clinical signs of AKC.

Atopic dermatitis and keratoconjunctivitis

Atopic dermatitis, a chronic disease seen by allergist-immunologists, has both dermatologic and ocular manifestations. The ocular component is often disproportionately higher than the dermatologic disease. Even if skin abnormalities seem well controlled, these patients require ophthalmic evaluation. Atopic keratoconjunctivitis in atopic dermatitis patients is characterized by acute exacerbations and requires maintenance therapy for long-term control. Future studies will continue to emphasize the use of steroid-sparing, immunomodulating agents that have the potential to provide long-lasting anti-inflammatory control with a more favorable side-effect profile.

Analysing the eosinophil cationic protein--a clue to the function of the eosinophil granulocyte

Eosinophil granulocytes reside in respiratory mucosa including lungs, in the gastro-intestinal tract, and in lymphocyte associated organs, the thymus, lymph nodes and the spleen. In parasitic infections, atopic diseases such as atopic dermatitis and asthma, the numbers of the circulating eosinophils are frequently elevated. In conditions such as Hypereosinophilic Syndrome (HES) circulating eosinophil levels are even further raised. Although, eosinophils were identified more than hundred years ago, their roles in homeostasis and in disease still remain unclear. The most prominent feature of the eosinophils are their large secondary granules, each containing four basic proteins, the best known being the eosinophil cationic protein (ECP). This protein has been developed as a marker for eosinophilic disease and quantified in biological fluids including serum, bronchoalveolar lavage and nasal secretions. Elevated ECP levels are found in T helper lymphocyte type 2 (atopic) diseases such as allergic asthma and allergic rhinitis but also occasionally in other diseases such as bacterial sinusitis. ECP is a ribonuclease which has been attributed with cytotoxic, neurotoxic, fibrosis promoting and immune-regulatory functions. ECP regulates mucosal and immune cells and may directly act against helminth, bacterial and viral infections. The levels of ECP measured in disease in combination with the catalogue of known functions of the protein and its polymorphisms presented here will build a foundation for further speculations of the role of ECP, and ultimately the role of the eosinophil.

Quantification of tear proteins and sPLA2-IIa alteration in patients with allergic conjunctivitis

PURPOSE

Allergic conjunctivitis (AC) has been reported to induce the instability of the tear film. The tear protein and the lipid layer play important roles in maintaining the tear film. The aim of this study was to quantify the alteration of the major tear protein components and a lipid related protein secretory type IIa phospholipase A2 (sPLA2-IIa) in tears of seasonal allergic conjunctivitis (SAC) and perennial allergic conjunctivitis (PAC) patients.

METHODS

Twenty-one SAC and PAC patients and thirteen normal controls completed a symptom questionnaire and underwent regular ocular examination. SAC and PAC patients were diagnosed based on the clinical presentation and elevated serum IgE levels. Schirmer test paper was used to collect tear samples from SAC and PAC patients and normal controls. Soybean trypsin inhibitor (SBTI) was used as an internal standard to analyze tear samples in 15% SDS-PAGE gel. Total tear protein and its major components from the SAC and PAC patients and normal controls were quantified by band densitometry. The major tear protein bands were determined by MALDI-TOF/TOF spectrum analysis. Western blot was used to detect the content of sPLA2-IIa in tears of allergic conjunctivitis patients and normal controls.

RESULTS

Schirmer test scores were more than 10 mm in all the SAC and PAC patients and control subjects. The tear film breakup time of SAC and PAC patients was much shorter than that of the normal controls. We obtained 15 bands of tear protein by one dimensional SDS-PAGE, in which 14 bands were determined by mass-spectrum analysis. The band densitometry analysis revealed that the total tear protein concentration was much higher in SAC and PAC patients than in normal controls (p<0.05). The quantity of tear protein band 4 (serum albumin precursor), band 6 (Ig gamma-2), band 9 (leukocyte elastase inhibitor) were also significantly higher in AC patients (p<0.05). Content of sPLA2-IIa, as shown by western blot, was much higher in AC patients than in controls.

CONCLUSIONS

The total tear protein concentration and some of the major tear protein components was increased in tears of SAC and PAC patients. In addition, the content of sPLA2-IIa in tears of SAC and PAC patients was elevated. The tear protein changes in SAC and PAC patients may contribute to instability of tear film.

Corneal and conjunctival fibroblasts are major sources of eosinophil-recruiting chemokines

BACKGROUND

Differential expression of chemokine genes were investigated in various types of ocular surface cells.

METHODS

Primary cultures of human corneal epithelial cells (n = 3), corneal fibroblasts (n = 2), conjunctival epithelial cells (n = 2) and conjunctival fibroblasts (n = 2) were established and incubated with or without interleukin (IL)-4 (30ng/ml) and tumor necrosis factor (TNF)-alpha(30ng/ml) for 24 hours. Gene transcription levels of 33 chemokines and production of 4 chemokines were analyzed.

RESULTS

After stimulation, chemokine expression increased for 18 of 33 coded chemokine gene transcripts. In stimulated conjunctival and corneal cells, CC chemokine genes increased in fibroblasts (expression of 6 out of 8 genes), while CXC chemokine genes increased in both epithelial cells (expression of 4 out of 9 genes in conjunctival epithelial cells and 7 out of 9 genes in corneal epithelial cells) and in fibroblasts (expression of 8 out of 9 genes in conjunctival and corneal fibroblasts). Except for MCP-1, gene transcription levels for most CC chemokines were inducible and, except for IP-10 and I-TAC, most CXC chemokines were constitutively expressed. Corneal epithelial cell and fibroblast production patterns for eotaxin-1, MCP-1 and IP-10 were comparable to the mRNA expression pattern.

CONCLUSIONS

Corneal and conjunctival fibroblasts exhibited marked increases in the expression of chemokines upon stimulation with TNF-alpha and IL-4, suggesting that fibroblasts may be one of the primary sources of chemokines in allergic conjunctival diseases. Therefore, regulation of chemokine production from these cells may be an effective strategy for treating such diseases.

Evaluation of novel scoring system named 5-5-5 exacerbation grading scale for allergic conjunctivitis disease

BACKGROUND

The objective of this study is to evaluate the practical usefulness of a scoring system using the 5-5-5 exacerbation grading scale for allergic conjunctivitis disease (ACD).

METHODS

Subjects were 103 patients with ACD including 40 patients with vernal keratoconjunctivitis (VKC), 20 patients with atopic keratoconjunctivitis (AKC), and 43 patients with allergic conjunctivitis (AC). The 5-5-5 exacerbation grading scale consists of the following 3 graded groups of clinical observations: the 100-point-grade group (100 points for each observation) includes active giant papillae, gelatinous infiltrates of the limbus, exfoliative epithelial keratopathy, shield ulcer and papillary proliferation at lower palpebral conjunctiva; the 10-point-grade group (10 points for each observation) includes blepharitis, papillary proliferation with velvety appearance, Horner-Trantas spots, edema of bulbal conjunctiva, and superficial punctate keratopathy; and the 1-point-grade group (1 point for each observation) includes papillae at upper palpebral conjunctiva, follicular lesion at lower palpebral conjunctiva, hyperemia of palpebral conjunctiva, hyperemia of bulbal conjunctiva, and lacrimal effusion. The total points in each grade group were determined as the severity score of the 5-5-5 exacerbation grading scale.

RESULTS

The median severity scores of the 5-5-5 exacerbation grading scale in VKC, AKC and AC were 243 (range: 12-444), 32.5 (11-344), and 13 (2-33), respectively. The severity score of each ACD disease type was significantly different (P < 0.001, Kruskal-Wallis test). The severity of each type of ACD was classified as severe, moderate, or mild according to the severity score.

CONCLUSIONS

The 5-5-5 exacerbation grading scale is a useful clinical tool for grading the severity of each type of ACD.

Evaluation of eotaxin-1, -2, and -3 protein production and messenger RNA expression in patients with vernal keratoconjunctivitis

PURPOSE

To evaluate the in vivo expression of members of the eotaxin subfamily, eotaxin-1, -2, and -3, at the ocular surface, we analyzed the messenger RNA (mRNA) expression of the eotaxin subfamily in conjunctival epithelium and the protein expression of the eotaxin subfamily in tears of patients with vernal keratoconjunctivitis (VKC) and in those of healthy individuals.

METHODS

The subjects were 25 patients with VKC (25 eyes) and 11 healthy volunteers (11 eyes) as a control. Tear samples were collected using the Schirmer strip method. Tear samples were eluted, and concentrations of eotaxin-1, -2, and -3 in the tear samples were determined by enzyme-linked immunosorbent assay (ELISA). Concentration of eosinophil cationic protein (ECP) in tears was also determined by chemiluminescent enzyme immunoassay. Conjunctival epithelial cells were obtained from upper tarsal conjunctiva by impression cytology, and eotaxin-1, -2, and -3 mRNA extracted from the impression cytology membrane were analyzed by reverse transcriptase polymerase chain reaction (RT-PCR). Conjunctival smears, which were obtained by tarsal conjunctival scraping, were stained for eotaxin-2 using immunohistochemical methods.

RESULTS

In the ELISA analysis, the expression ratio of eotaxin-1 (P < 0.01) and -2 (P < 0.001) in tears was significantly higher in the VKC group than in the control group. Concentrations of eotaxin-1 and -2 in tears in the VKC group were 0.7 and 1440.5 (median values) pg/ml, respectively. In the VKC group, the concentration of eotaxin-2 in tears was higher than that of eotaxin-1. There was a significant correlation between the concentration of eotaxin-2 and that of ECP in tears in the VKC group (r = 0.53, P < 0.01). Expression of eotaxin-3 protein in tears was not detected in the VKC group or the controls. In the RT-PCR analysis, the positive ratio of eotaxin-1, -2, and -3 mRNA expression in the VKC group was significantly higher than that in the control group (P < 0.01, P < 0.01, P < 0.05, respectively). In the immunohistochemical analysis, positive staining was detected in epithelial-like cells in conjunctival smears obtained from the patients with VKC.

CONCLUSIONS

We showed that the mRNA expression and the protein production of the eotaxin subfamily at the ocular surface are critical biomarkers when investigating the pathophysiology of eosinophilic inflammation and the effect of antiallergic treatment in patients with VKC.

Vernal keratoconjunctivitis: a major review

Vernal keratoconjunctivitis (VKC) is a chronic, bilateral, at times asymmetrical, seasonally exacerbated, allergic inflammation of the ocular surface, involving tarsal and/or bulbar conjunctiva. Though the allergic nature of this entity has been accepted for a long time, the accumulation of a large amount of immunological data has proved that the pathogenesis of VKC is much more complex than a mere type 1 hypersensitivity reaction. In the past several years, many clinical and experimental studies about the cells and mediators involved in initiating and perpetuating the ocular allergic inflammation have shown that T helper type 2 cells and their cytokines, corneal fibroblasts and epithelium along with various growth factors play an important role in the pathogenesis of VKC. Based on this information about the pathogenesis of VKC newer, more selective drugs like anti-chemokine receptor antibodies and leukotriene receptor antagonists are under evaluation. Cyclosporine has been shown to be effective in the treatment of VKC but further randomized control trials are required to establish the minimum effective concentration.

Clinical and biological efficacy of preservative-free NAAGA eye-drops versus levocabastine eye-drops in vernal keratoconjunctivitis patients

AIMS

This comparative and randomised pilot study assessed the clinical and biological efficacy of Naaxia Sine(R) eye-drops versus levocabastine eye-drops in the treatment of vernal keratoconjunctivitis (VKC).

METHODS

Twenty-three VKC patients were randomised and treated bilaterally for 28 days with N-acetyl-aspartyl-glutamate (NAAGA) or levocabastine (LEVO) eye-drops. The primary efficacy variable, overall evolution of eosinophil cationic protein (ECP) tear concentrations, was assessed in a masked fashion on D0, D7 and D28. Clinical symptoms and signs were reported at the same time points. Biological parameters were analysed with a non-parametric rank-based approach. Global tolerance was assessed by the investigator and patient.

RESULTS

At all time points, ECP tear levels were significantly reduced in the NAAGA compared with the LEVO group (p = 0.023). Reduction of eosinophil leucocytes and tear lymphocytes was higher not significant in the NAAGA group. The same trend was observed for the evolution of total ocular symptom score. There were no significant differences between treatment groups in the occurrence of adverse effects, except for burning which was more frequent in the LEVO group (p = 0.002).

CONCLUSION

The anti-eosinophilic actions of NAAGA were shown by a significant reduction of ECP tear concentrations. A decreased lymphocyte count and an overall improvement of the symptomatology were also noted. Moreover, the tolerability of NAAGA appeared to be better.

Immunohistochemical findings in prosthesis-associated giant papillary conjunctivitis

PURPOSE

To identify functional subsets of inflammatory cells and expression of cytokines in the conjunctiva of patients with ocular prosthesis-associated giant papillary conjunctivitis (P-GPC).

METHODS

Specific immunohistochemical staining using monoclonal antibodies was performed on biopsy specimens obtained from superior tarsal conjunctiva of 18 patients with P-GPC. The prosthetic eyes were taken as the study group, whereas their fellow eyes were used as matched controls.

RESULTS

In normal conjunctiva, mast cells (MCs) were located only in the substantia propria (SP), whereas in P-GPC eyes MCs were also notable in the epithelium in five specimens. Tryptase-chymase-positive MCs (MC(TC)) were predominant both in P-GPC (79%) and in fellow (72%) eyes. MC(TC), CD4(+) lymphocyte, CD8(+) lymphocyte and eosinophil numbers were higher in P-GPC specimens compared with the fellow eyes (P = 0.005, 0.074, 0.012 and 0.025, respectively). Eosinophils were detected in 58.8% of P-GPC specimens and 16.7% of control specimens (P = 0.053). The number of inflammatory cells expressing eotaxin and interleukin (IL)-4 was higher in P-GPC group (P = 0.050 and 0.048, respectively). Nine out of 17 giant papillary conjunctivitis specimens (52.9%) showed eotaxin and IL-4 immunoreactivity, which was considerably higher than the fellow eyes (16.7%) (P = 0.064).

CONCLUSION

These findings suggest that P-GPC is an allergic disease of the eye associated with increased numbers of MC, eosinophils and lymphocytes in the conjunctiva and a remarkable expression of IL-4 and eotaxin both by the conjunctival epithelium and by the inflammatory cells in the SP.

Antibodies to T-cell Ig and mucin domain-containing proteins (Tim)-1 and -3 suppress the induction and progression of murine allergic conjunctivitis

The T cell Ig and mucin domain-containing proteins (Tim) regulate Th1- and Th2-mediated immune responses. We investigated the ability of Abs blocking Tim-1 or Tim-3 ligand-binding activity to prevent and treat murine experimental allergic conjunctivitis (EC), a Th2-mediated disease. Treatment with either Ab during the induction phase of EC in actively immunized wild-type mice suppressed EC and upregulated Th1 and Th2 immune responses. In contrast, both Abs exacerbated EC in actively immunized IFN-gamma-knockout mice. Thus, both anti-Tim Abs suppress the pathogenic immune responses generated in the induction phase by upregulating systemic IFN-gamma production. Treatment of actively immunized mice and passively immunized mice with either anti-Tim Ab just prior to RW challenge also suppressed EC. Thus, treatment with anti-Tim-1 or anti-Tim-3 Ab can suppress both the induction and progression of EC, which could indicate potential preventive and/or therapeutic approaches for allergic diseases such as allergic conjunctivitis.

Quantitative Evaluation of the Early Changes in Ocular Surface Inflammation Following MMC-Aided Papillary Resection in Severe Allergic Patients With Corneal Complications

BACKGROUND

Atopic keratoconjunctivitis (AKC) and vernal keratoconjunctivitis (VKC) are chronic inflammatory allergic diseases that are associated with some common conjunctival and corneal complications.1 The clinical corneal manifestations of both entities may include superficial punctate keratitis, macroerosions, corneal ulceration, plaque formation, corneal neovascularization, and lipid infiltration.

PURPOSE

To quantitatively evaluate the early ocular surface inflammation before and after mitomycin C (MMC)-aided papillary resection in severe allergy patients with corneal complications.

METHODS

Three eyes with VKC and 5 eyes with AKC were included in this study. All eyes had cobblestone-like papillae on the upper tarsal conjunctiva and corneal complications such as corneal ulcers, defect, or erosions that were refractory to conventional treatment of more than 2 weeks. Papillary resection with intraoperative 0.05% MMC application for 5 minutes on the palpebral conjunctiva was carried out in all eyes. Corneal and conjunctival findings were evaluated before and 1 week and 2 weeks after surgery. Brush cytology (BC) and evaluation of tear eosinophilic cationic protein (ECP) levels by radioimmunoassay techniques were performed as well pre- and postoperatively.

RESULTS

Corneal and conjunctival complications resolved in all patients within 7 days after resection. Postoperative tear ECP levels decreased significantly with papillary resection (P< 0.05). Concomitant brush cytology showed a significant decrease in the number of eosinophils and neutrophils following papillary resection (P < 0.05).

CONCLUSION

MMC-aided papillary resection provided a dramatic decrease in ocular surface inflammation as evidenced by decrease in the number of inflammatory cells as well as tear ECP levels with a rapid improvement of clinical corneal and conjunctival findings.

Atopic ocular surface disease: implications on tear function and ocular surface mucins

PURPOSE

To describe tear function, mucin alterations, and ocular surface disorder in patients with atopic diseases.

METHODS

Subjects underwent corneal sensitivity measurements, Schirmer test, tear film break-up time (BUT) assay, and fluorescein and rose Bengal staining of the ocular surface. Conjunctival impression cytology and brush cytology were also conducted. Impression cytology samples underwent PAS and immunohistochemical staining for MUC5AC. Brush cytology specimens underwent evaluation for inflammatory cell expression and RT-PCR for MUC5AC mRNA expression. Differences related to tear function and ocular surface examination parameters among patients with and without corneal ulceration and healthy control subjects were studied.

RESULTS

Mean corneal sensitivity and BUT values were significantly lower in atopic patients with corneal ulcers compared with patients without ulcers and controls (P<0.001). Brush cytology specimens from patients with corneal ulcers revealed significantly higher expression of inflammatory cells compared with patients without ulcers and controls (P<0.001). Impression cytology samples from eyes with corneal ulcers showed significant squamous metaplasia and reduction of goblet cell density compared with eyes without ulcers and control subjects. Specimens from eyes with corneal ulcers showed PAS (+) mucin pick up and did not stain positive for MUC5AC. MUC5AC mRNA expression was significantly lower in eyes with corneal ulcers compared with in eyes without ulcers and control subjects.

CONCLUSIONS

Ocular surface inflammation, tear film instability, and decreased conjunctival MUC5AC mRNA expression are important in the pathogenesis of noninfectious corneal shield ulcers in atopic ocular surface disease.

In-vivo diagnostic measurements of ocular inflammation

PURPOSE OF REVIEW

The diagnosis of allergic conjunctival inflammation is usually made on the basis of clinical signs and symptoms; however, in-vivo and in-vitro tests are indicated when patient management requires identification of the specific allergic sensitization. The purpose of this review is to describe recent and less recent methods to assess ocular allergic inflammation.

RECENT FINDINGS

In the non-active phase of the disease, the specific conjunctival provocation test can be used to identify local sensitivities to allergens. Although not highly specific, total IgE in tears may be measured with a simple local test by inserting a paper strip in the lower meniscus. Limited tear volume prohibits the use of specific IgE tests. The measurement of tear-specific inflammatory markers, such as eosinophil cationic protein, IL-4, IL-5 and eotaxin, may also be useful for the diagnosis of ocular allergy. Multiple cytokine assays of tear samples and new imaging techniques are exciting advances that might provide the in-vivo diagnosis of ocular surface inflammation.

SUMMARY

Whereas chronic, severe ocular allergic conditions have uniquely diagnostic signs and symptoms, the most common diseases, seasonal and perennial allergic conjunctivitis, have no specific pathognomonic signs. The diagnostic measurements of local inflammation may help in the management of ocular allergy.

[Ocular allergies]

Recent developments indicate that ocular allergy is more than an IgE-mediated allergic conjunctivitis. Ocular allergy is a disease affecting the entire ocular surface including conjunctiva, lids, cornea, lacrimal gland and tear film. Besides an IgE-mediated reaction, a complex chronic inflammation is involved in the pathogenesis of many ocular allergies. According to their pathogenesis and clinical picture, ocular allergies are classified into mild forms, such as seasonal and perennial allergic conjunctivitis as well as giant papillary conjunctivitis, and chronic, potentially blinding forms such as atopic keratoconjunctivitis and vernal keratoconjunctivitis. New therapeutics act on the entire inflammatory process or try to modulate the allergic reaction early and specifically. The association with non-ocular allergic symptoms requires an interdisciplinary approach.

Basic science and pathophysiology of ocular allergy

Ocular allergy includes several clinical subtypes ranging from the mild seasonal allergic conjunctivitis to the potentially sight-threatening atopic keratoconjunctivitis. Current therapies, particularly for the severe forms of disease, need to be more localized and with fewer side effects. For this to be achieved, it requires a better understanding of the basic mechanisms involved. In this chapter, recent findings are discussed that suggest that it is important to take an integrated approach, including both immune and structural elements of the eye. This provides potential new strategies for therapy, addressing the influence of structural cells in disease. These might influence the immune processes that take place and, as the structural cells are precisely localized, topical application is likely to be effective.

Inflammatory cells in brush cytology samples correlate with the severity of corneal lesions in atopic keratoconjunctivitis

BACKGROUND

Inflammatory cells infiltrating to the tarsal conjunctiva are thought to be involved in the pathogenesis of corneal lesions in severe allergic conjunctival diseases. The relation between such cells and the severity of corneal lesions was studied.

METHODS

Six patients with atopic keratoconjunctivitis (AKC) were enrolled in this study. Tarsal brush cytology findings and the severity of corneal damage at that point were recorded and analysed for correlation.

RESULTS

Four out of six patients exhibited correlation between eosinophils and corneal damage. Three out of six patients exhibited correlation between neutrophils and corneal damage. Two out of six patients exhibited correlation between both eosinophils and neutrophils and corneal damage. Analysis of all data from all patients taken together revealed that both eosinophils and neutrophils in brush cytology samples significantly correlated with corneal damage.

CONCLUSIONS

Inflammatory cells in brush cytology samples correlated with corneal damage. Evaluation of the relative percentages of inflammatory cells in brush cytology samples is a useful method of assessing disease activity in allergic conjunctival disease.

Provocation testing with recombinant allergens

In the past few decades, DNA technology has enabled the production of defined recombinant allergen molecules for diagnostic and therapeutic purposes. Recombinant allergens containing most of the relevant IgE epitopes present in natural allergen sources are now available and allergen proteins can be produced that are identical, without biological or batch-to-batch variation. A great advantage of recombinant allergens is that they can be used for component-resolved diagnostics, which makes it possible to establish the patient's individual IgE reactivity profile before therapy is selected. However, before recombinant allergens can be applied in clinical practice their biological activity has to be carefully investigated in vivo. We here describe the most commonly used provocation methods (skin tests (prick and intradermal), nasal, bronchial, and conjunctival provocations) and how they can be performed. We also discuss the results so far obtained with in vivo testing using recombinant allergens and envisage their future use for immunotherapy.

Vernal keratoconjunctivitis

Vernal keratoconjunctivitis (VKC) is an allergic eye disease that especially affects young boys. The most common symptoms are itching, photophobia, burning, and tearing. The most common signs are giant papillae, superficial keratitis, and conjunctival hyperaemia. Patients with VKC frequently have a family or medical history of atopic diseases, such as asthma, rhinitis, and eczema. However, VKC is not associated with a positive skin test or RAST in 42-47% of patients, confirming that it is not solely an IgE-mediated disease. On the basis of challenge studies as well as immunohistochemical and mediator studies, a Th2-driven mechanism with the involvement of mast cells, eosinophils, and lymphocytes has been suggested. Th2 lymphocytes are responsible for both hyperproduction of IgE (interleukin 4, IL-4) and for differentiation and activation of mast cells (IL-3) and eosinophils (IL-5). Other studies have demonstrated the involvement of neural factors such as substance P and NGF in the pathogenesis of VKC, and the overexpression of oestrogen and progesterone receptors in the conjunctiva of VKC patients has introduced the possible involvement of sex hormones. Thus, the pathogenesis of VKC is probably multifactorial, with the interaction of the immune, nervous, and endocrine systems. The clinical management of VKC requires a swift diagnosis, correct therapy, and evaluation of the prognosis. The diagnosis is generally based on the signs and symptoms of the disease, but in difficult cases can be aided by conjunctival scraping, demonstrating the presence of infiltrating eosinophils. Therapeutic options are many, in most cases topical, and should be chosen on the basis of the severity of the disease. The most effective drugs, steroids, should however be carefully administered, and only for brief periods, to avoid secondary development of glaucoma.A 2% solution of cyclosporine in olive oil or in castor oil should be considered as an alternative. The long-term prognosis of patients is generally good; however 6% of patients develop corneal damage, cataract, or glaucoma.

The promotion of eosinophil degranulation and adhesion to conjunctival epithelial cells by IgE-activated conjunctival mast cells

BACKGROUND

Allergen-mediated mast cell activation is a key feature of ocular allergic diseases. Evidence of eosinophil-derived mediators in tears and conjunctival biopsy specimens has been associated with chronic ocular allergic inflammation.

OBJECTIVE

To examine the role of conjunctival mast cell mediators in eosinophil adhesion to conjunctival epithelial cells and eosinophil degranulation.

METHODS

Conjunctival cells were obtained by enzymatic digestion of cadaveric conjunctival tissues. Eosinophils were obtained from peripheral blood samples using negative magnetic bead selection. The effect of IgE-activated mast cell supernates on eosinophil degranulation and adherence to epithelial cells was compared with supernates obtained from mast cells pretreated with a degranulation inhibitor (olopatadine). Eosinophil adhesion was measured by eosinophil peroxidase assay, and eosinophil degranulation was measured by eosinophil-derived neurotoxin radioimmunoassay.

RESULTS

IgE-activated conjunctival mast cell supernates stimulated adhesion of eosinophils to epithelial cells (20.4% +/- 6.3% vs 3.1% +/- 1.0%; P = .048). Degranulation was not required for this process (no effect of olopatadine). IgE-activated mast cell supernates stimulated eosinophil-derived neurotoxin release (108.89 +/- 8.27 ng/10(6) cells vs 79.45 +/- 5.21 ng/10(6) cells for controls, P = .02), which was significantly inhibited by pretreatment of mast cells with a degranulation inhibitor (79.22 +/- 4.33 ng/10(6) cells vs 61.09 +/- 5.39 ng/10(6) cells for olopatadine pretreated and untreated, respectively, P = .02).

CONCLUSIONS

Mediators released from conjunctival mast cells promote eosinophil adhesion to conjunctival epithelial cells and eosinophil degranulation. Degranulation inhibition studies suggest that different mast cell mediators are involved in regulation of these events.

Allergic chronic inflammation of the ocular surface in vernal keratoconjunctivitis

PURPOSE OF REVIEW

The purpose of this review is to describe the new immunopathologic features of vernal keratoconjunctivitis: the involvement of cytokines, growth factors, cells, mediators and neurotransmitters, as well as the mechanism leading to tissue remodelling.

RECENT FINDINGS

Vernal keratoconjunctivitis is an allergic eye disease affecting young boys living in a warm climate. It is characterized by conjunctival giant papillae, hyperemia and frequent involvement of the cornea. Approximately 50% of the patients with vernal keratoconjunctivitis do not have a family or medical history of atopic diseases, and do not show IgE sensitization, suggesting that this disease is not solely IgE mediated. Vernal keratoconjunctivitis is a Th2 lymphocyte driven disease with a Th2 cytokine derived pattern, increased levels of mRNA for IL-3, IL-4, IL-5 and IL-13. Th2 lymphocytes induce IgE hyperproduction, activation of mast cells, eosinophils, neutrophils and their toxic products. An overexpression of adhesion molecules, RANTES, eotaxin and metalloproteinases contribute to chronic inflammation. A role for substance P and nerve growth factor has been postulated, as well as for other growth factors (epidermal growth factor, fibroblast growth factor and transforming growth factor beta 1) that induce fibroblast growth and new collagen production. Recent studies have also pointed out the role of resident conjunctival cells, such as epithelial cells and fibroblasts, in the inflammatory and remodelling process of vernal keratoconjunctivitis. The pathogenesis of the condition is probably multifactorial, with the interaction of the immune, nervous and endocrine systems.

SUMMARY

Vernal keratoconjunctivitis is a chronic inflammatory and potentially blinding disease. Understanding of the complex interactions and cross talk between cells, cytokines and other mediators is relevant for new therapeutic approaches.

Ocular Allergic Disease: Mechanisms, Disease Sub-types, Treatment

Ocular allergy refers to a variety of hypersensitivity disorders that affect the lid, conjunctiva, and/or cornea. Its incidence is estimated at over 20% of the general population in the United States. This review will discuss the various forms of ocular allergy, their pathophysiology, clinical presentation, and treatment. New frontiers in mechanisms, therapy, and management in the office are emphasized throughout.

T-cell characterization in chronic allergic eye disease

Chronic allergic eye disease encompasses several disorders, but it is vernal keratoconjunctivitis (VKC) and atopic keratoconjunctivitis (AKC) that have sight-threatening sequelae. T cells, eosinophils, and mast cells are all found in the conjunctiva, and are thought to play a role in disease pathogenesis. Recently, the conjunctival epithelium has also been considered to play a key role. New and effective therapeutic strategies for the future for these patients depend on achieving a greater understanding of the roles and interactions of the cell populations in these sight-threatening disorders.

Ocular allergy: implications for the clinical immunologist

BACKGROUND

Allergic diseases of the eye are the most common conditions affecting the external ocular adnexa. The most common forms are primarily IgE-mediated and share features in common with other atopic conditions. Mast cell activation and release of mediators, particularly histamine, are central to the pathogenesis of seasonal and perennial allergic conjunctivitis. These conditions are self-limited without the occurrence of ocular surface damage. In contrast, vernal keratoconjunctivitis and atopic keratoconjunctivitis are complex diseases, involving both early- and late-phase allergic responses. They are characterized by severe chronic immune inflammation with T cell infiltration in the conjunctiva and may be sight-threatening.

OBJECTIVES

To provide a brief overview of the ocular allergic conditions and summarize the current knowledge of immunopathogenetic mechanisms involved in initiating and driving these conditions.

DATA SOURCES

English-language articles were sought from a MEDLINE search from 1995. This yielded a number of scientific and review papers exploring recent advances in the understanding of the pathogenesis of the ocular allergic conditions.

CONCLUSIONS

Recent advances in knowledge about the pathogenetic mechanisms involved in ocular allergy have led to a better understanding of treatment options and to the development of new treatment modalities, resulting in improved control of symptoms for patients.

Modulation of IL-8 and RANTES release in human conjunctival epithelial cells: primary cells and cell line compared and contrasted

PURPOSE

Recent research indicates that epithelial cells of the ocular surface can contribute to the allergic reaction by the release of inflammatory and/or chemotactic mediators. In this study, the role of two inflammatory mediators, previously identified in the tear film of ocular allergy subjects, TNF-alpha and IFN-gamma, were evaluated for their effect on the release of two chemotactic mediators, IL-8 and RANTES, from cultured human conjunctival epithelial cells.

METHODS

Human conjunctival epithelial cells (primary cells or HC0597 cell line) were grown to confluence and stimulated with various concentrations of TNF-alpha, IFN-gamma, or a combination of both. Supernatants were collected at 6, 24, and 48 hours and stored frozen for subsequent ELISA analyses of RANTES and IL-8.

RESULTS

RANTES and IL-8 release from HC0597 cells was stimulated in a dose- and time-dependent manner following treatment with TNF-alpha. However, only RANTES release was modulated by IFN-gamma treatment. Treatment of HC0597 cells with both TNF-alpha and IFN-gamma resulted in a synergistic increase in the release of RANTES. This synergistic effect was confirmed using primary cultures of human conjunctival epithelial cells.

CONCLUSIONS

Stimulation of conjunctival epithelium with proinflammatory mediators, TNF-alpha and/or IFN-gamma, generated the release of the chemotactic factors IL-8 and RANTES, which could act to prolong inflammation. These two chemokines may prolong inflammation by recruiting eosinophils to the ocular surface. This is the first study to compare chemokine release in a cell line and primary cells; similar chemokine release after mediator stimulation was demonstrated, indicating that the two cell types are phenotypically similar.