Serum anti-carbonic anhydrase antibodies and oxidant-antioxidant balance in patients with acute anterior uveitis

SER recommendations for the treatment of uveitis

OBJECTIVE

To develop evidence-based expert-consensus recommendations for the management of non-infectious, non-neoplastic, non-demyelinating disease associated uveitis.

METHODS

Clinical research questions relevant to the objective of the document were identified, and reformulated into PICO format (patient, intervention, comparison, outcome) by a panel of experts selected based on their experience in the field. A systematic review of the available evidence was conducted, and evidence was graded according to GRADE (Grading of Recommendations Assessment, Development, and Evaluation) criteria. Subsequently, recommendations were developed.

RESULTS

Three PICO questions were constructed referring to uveitis anterior, non-anterior and complicated with macular edema. A total of 19 recommendations were formulated, based on the evidence found and/or expert consensus.

CONCLUSIONS

Here we present the first official recommendations of the Spanish Society of Rheumatology for the treatment of non-infectious and non-demyelinating disease associated uveitis. They can be directly applied to the Spanish healthcare system as a tool for assistance and therapeutic homogenisation.

Recent advances in drug treatments for dry eye disease

INTRODUCTION

Dry eye disease (DED) is a common ocular condition with a significant impact on patients' quality of life. Conventional treatments include behavioral changes, tear substitutes, and anti-inflammatory agents; however, recent advances in the understanding of DED pathogenesis have opened the way to the development of novel treatment strategies able to target several pathways involved in the onset and persistence of DED.

AREAS COVERED

Literature search was conducted on PubMed and Scopus around the term 'dry eye disease' and others involving its pathophysiology and therapeutic strategy. The primary focus was on recent drugs approved by FDA or under investigation in phase 3 clinical trials. Google and ClinicalTrials.gov were used for obtaining information about the status of FDA approval and ongoing clinical trials.

EXPERT OPINION

Due to its multifaced pathogenesis, DED management is often challenging, and patients' needs are frequently unmet. Recently, several novel treatments have been either FDA-approved or studied in late-phase trials. These novel drugs target-specific biological components of the ocular surface and reduce inflammation and ocular pain. Additionally, new drug delivery systems allow for increased bioavailability, improve effective dosing, and minimize ocular side effects. These advances in drug therapies show real promise for better management of DED patients.

Early Onset and Broad Activity of Reproxalap in a Randomized, Double-Masked, Vehicle-Controlled Phase 2b Trial in Dry Eye Disease

PURPOSE

To assess the activity of reproxalap, a novel reactive aldehyde species (RASP) inhibitor, relative to vehicle in patients with dry eye disease (DED) DESIGN: Randomized, double-masked, vehicle-controlled Phase 2b trial METHODS: Three hundred patients with DED were randomly assigned 1:1:1 at multiple US sites to receive 0.1% topical ocular reproxalap, 0.25% topical ocular reproxalap, or vehicle. Eyes were treated bilaterally 4 times daily for 12 weeks. Standard signs and symptoms of DED were assessed at baseline and at Weeks 2, 4, 8, and 12.

RESULTS

A dose response was observed for signs and symptoms of DED. Relative to vehicle over 12 weeks of therapy, the largest symptomatic improvement was observed in ocular dryness (0.25%, P = .047), and the largest objective sign improvement was observed in nasal region fluorescein staining (0.25%, P = .030). A greater proportion of patients receiving 0.25% reproxalap vs. vehicle reported dryness scores of 0 (P = .012). Improvements in combined DED symptoms were evident by the first post-baseline visit (Week 2, 0.25%, P < .0001) in patients with baseline scores greater than or equal to median values. No significant changes in safety measures were observed.

CONCLUSION

The novel RASP inhibitor reproxalap demonstrated rapid, broad, and clinically relevant symptomatic control, in conjunction with statistically significant improvement over vehicle in signs of DED as demonstrated by fluorescein staining, in DED patients over 12 weeks of therapy. The results represent the first vehicle-controlled evidence for the therapeutic potential of RASP inhibition to mitigate the signs and symptoms of dry eye disease.

A Randomized Double-Masked Phase 2a Trial to Evaluate Activity and Safety of Topical Ocular Reproxalap, a Novel RASP Inhibitor, in Dry Eye Disease

Purpose: To determine whether reproxalap, a novel reactive aldehyde species (RASP) inhibitor, is safe and effective for the treatment of the signs and symptoms of dry eye disease (DED).

Methods: In a randomized double-masked parallel-group Phase 2a trial of 3 topical ocular reproxalap formulations (0.1% ophthalmic solution, 0.5% ophthalmic solution, and 0.5% lipid ophthalmic solution), 51 patients with DED were randomly assigned 1:1:1 at a single US site. Eyes were treated bilaterally 4 times daily for 28 days, and standard DED signs and symptoms were assessed at baseline and after 7 and 28 days of dosing. Tear RASP levels were assessed at baseline and at day 28.

Results: The effect of treatment on DED signs and symptoms was similar across the treatment arms, and pooled data from the 28-day treatment period demonstrated significant improvement from baseline in Symptom Assessment in Dry Eye Disease score (P = 0.003), Ocular Discomfort Scale score (P < 0.0001), Ocular Discomfort Score and 4-Symptom Questionnaire overall score (P = 0.0004), Schirmer's test (P = 0.008), tear osmolarity (P = 0.003), and lissamine green total staining score (P = 0.002). Improvements in DED symptoms were evident within 1 week of therapy, and effect sizes generally approached or exceeded 0.5. No significant changes in safety measures were observed.

Conclusion: The results suggest that the novel RASP inhibitor reproxalap has the potential to mitigate the signs and symptoms of DED, and may represent a new, rapidly and broadly active treatment approach for DED (NCT03162783).

Protein Biomarkers in Uveitis

The diseases affecting the retina or uvea (iris, ciliary body, or choroid) generate changes in the biochemical or protein composition of ocular fluids/tissues due to disruption of blood-retinal barrier. Ocular infections and inflammations are sight-threatening diseases associated with various infectious and non-infectious etiologies. Several etiological entities cause uveitis, a complex intraocular inflammatory disease. These causes of uveitis differ in different populations due to geographical, racial, and socioeconomic variations. While clinical appearance is sufficiently diagnostic in many diseases, some of the uveitic entities manifest nonspecific or atypical clinical presentation. Identification of biomarkers in such diseases is an important aid in their diagnostic armamentarium. Different diseases and their different severity states release varying concentrations of proteins, which can serve as biomarkers. Proteomics is a high throughput technology and a powerful screening tool for serum biomarkers in various diseases that identifies proteins by mass spectrometry and helps to improve the understanding of pathogenesis of a disease. Proteins determine the biological state of a cell. Once identified as biomarkers, they serve as future diagnostic and pharmaceutical targets. With a potential to redirect the diagnosis of idiopathic uveitis, ocular proteomics provide a new insight into the pathophysiology and therapeutics of various ocular inflammatory diseases. Tears, aqueous and vitreous humor represent potential repositories for proteomic biomarkers discovery in uveitis. With an extensive proteomics work done on animal models of uveitis, various types of human uveitis are being subjected to proteome analysis for biomarker discovery in different ocular fluids (vitreous, aqueous, or tears).

Randomized Phase 2 Trial of Reproxalap, a Novel Reactive Aldehyde Species Inhibitor, in Patients with Noninfectious Anterior Uveitis: Model for Corticosteroid Replacement

Purpose: Topical corticosteroids used to treat ocular inflammation are associated with a high risk of clinically significant toxicities. Therefore, corticosteroid-sparing medications to treat ocular inflammation are needed. Noninfectious anterior uveitis (NAU) is a sight-threatening ocular inflammatory condition typically treated with topical corticosteroids. This corticosteroid-controlled comparator trial examines the safety and efficacy of reproxalap, a novel inhibitor of reactive aldehyde species (RASP), for the treatment of ocular inflammation, by using NAU as a model. Methods: Forty-five patients with mild-to-moderate acute NAU were randomly assigned 1:1:1 to receive reproxalap 0.5% ophthalmic solution (4 times daily for 6 weeks), prednisolone 1% ophthalmic solution (Pred Forte®, 4 times daily taper for 6 weeks), or a combination of reproxalap 0.5% ophthalmic solution (4 times daily for 6 weeks) and prednisolone 1% ophthalmic solution (twice daily taper for 6 weeks). Results: All treatments improved anterior cell count and grade, and no differences were observed in change from baseline between groups. Reproxalap monotherapy and combination therapy were statistically noninferior to prednisolone. The proportion of patients requiring rescue therapy was comparable across treatment groups. No safety issues were identified for reproxalap-treated patients, whereas treatment with prednisolone resulted in an average increase of intraocular pressure of ∼2 mm Hg. Conclusions: Reproxalap may be a safe and effective alternative to topical corticosteroids for patients with NAU and other forms of ocular inflammation. These results represent initial clinical evidence of the importance of RASP in ocular inflammation and the applicability of RASP inhibition to immune modulation in ocular disease. Clinical trial (NCT02406209).

Acute bilateral granulomatous anterior uveitis as an extra-hepatic manifestation of hepatitis A virus (HAV) infection: a case report

Anterior uveitis (AU) is the most common form of uveitis. The differential diagnosis of AU is broad, ranging from infectious etiologies to autoimmune causes. However, approximately half remain idiopathic. Infections are the vision-threatening causes of AU which should be ruled out by history taking and detailed physical examination combined with guided work up. We report a rare case of bilateral granulomatous AU following hepatitis A virus (HAV) infection in an immunocompetent patient. A 35-year-old male presented to our center with a chief complaint of pain and redness in both eyes 3 days prior to the presentation. The patient’s medical and drug history was unremarkable. He had a history of river water consumption 20 days prior to presentation. The patient was diagnosed with acute bilateral granulomatous AU. All routine work up to investigate the etiology of the disease was unremarkable, except for the serology of acute HAV infection, which was positive. The patient was managed with the topical steroid and cycloplegic for 2 weeks with no recurrence at one-year follow up. Extra-hepatic complications of HAV were reported in previous studies including arthritis, urticaria, myocarditis, nephritis, and myositis. The mechanism of extra-hepatic complication of hepatitis A is unknown; however, immune-complex deposition is most likely the etiological cause. Our report represents a rare case of sudden onset with limited duration granulomatous AU as a presenting manifestation of HAV infection. Previous studies do not provide a direct evidence of granulomatous AU associated with the HAV infection.

Triosephosphate isomerase, carbonic anhydrase, and creatinine kinase-brain isoform are possible antigen targets in patients with achalasia

BACKGROUND

Idiopathic achalasia is an uncommon esophageal motor disorder. The disease involves interaction between inflammatory and autoimmune responses. However, the antigens related to the disease are still unknown.

AIM

To identify the possible antigen targets in muscle biopsies from lower esophageal sphincter (LES) of achalasia patients.

METHODS

Esophageal biopsies of patients with type I and type II achalasia and esophagogastric junction outflow obstruction (EGJOO) were analyzed. Lower esophageal sphincter muscle biopsy from a Healthy organ Donor (HD) was included as control for two-dimensional gel electrophoresis. Immunoblotting of muscle from LES lysate with sera of type I, type II achalasia, or type III achalasia, sera of EGJOO and sera of healthy subjects (HS) was performed. The target proteins of the serum were identified by mass spectrometry Matrix-assited laser desorption/ionization time-of-flight (MALDI-TOF).

KEY RESULTS

The proteomic map of muscle from LES tissue lysates of type I, and type II achalasia, EGJOO, and HD were analyzed and divided into three important regions. We found a difference in the concentration of certain spots. Further, we observed the serum reactivity of type I achalasia and type II achalasia against 45 and 25 kDa bands of type I achalasia tissue. Serum of type III achalasia and EGJOO mainly recognized 25 kDa band. Bands correspond to triosephosphate isomerase (TPI) (25 kDa), carbonic anhydrase (CA) (25 kDa) and creatinine kinase-brain (CKB) isoform (45 kDa).

CONCLUSIONS AND INFERENCES

We identify three antigen targets, TPI, CA, and CKB isoform, which are recognized by sera from patients with achalasia.

Identification of unique proteins in vitreous fluid of patients with noninfectious uveitis

PURPOSE

Uveitis is a cause for concern in the developing countries like India. Its poor diagnosis and lack of proper therapeutics often cause blindness in children and young adults. Moreover, the exact mechanism of pathogenesis of different types of uveitis is still elusive. Modern proteomic techniques are found to be advantageous for an in-depth understanding of the ocular physiology using proteomic diversity. Our aim was to identify unique proteins involved in the pathogenesis of autoimmune or noninfectious uveitis.

METHODS

Vitreous fluid samples (n = 90) were obtained from infectious (N = 34) and noninfectious (N = 56) uveitis patients, and their protein profiles were compared by analysing sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and 2D electrophoresis. Unique proteins were identified through matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) and further studied for pathway analysis.

RESULTS

Protein spots having different molecular weights were observed in noninfectious vitreous fluid samples. Enzymatic digestion of these spots after MALDI-TOF MS analysis revealed different proteins. We identified 25 different proteins through SDS-PAGE and 22 through 2D electrophoresis. 50% of the proteins from SDS-PAGE were associated with heterotrimeric G-protein signalling pathway-rod outer segment phototransduction. 50% proteins from SDS-PAGE and 20% from 2D electrophoresis revealed association with de novo purine biosynthesis. Carbonic anhydrase 1 and serpin B3 were found to be common in both analyses.

CONCLUSION

High-throughput proteomic and pathway analyses have exposed the potential association of these proteins with autoimmune pathogenesis in uveitis. The exact role of most of the proteins in autoimmune uveitis is yet to be unfurled.

Serum carbonic anhydrase I and II autoantibodies in patients with chronic lymphocytic leukaemia

Cancer is the second most important cause of mortality, and millions of people either have or have had the disease. Leukaemia is one of the most common forms of cancer. Autoantibodies that have developed against the organism's self-antigens are detected in the sera of subjects with cancer. In recent years carbonic anhydrase (CA) autoantibodies have been determined in some autoimmune diseases and carcinomas, but the mechanisms underlying this immune response have not yet been fully explained. The purpose of this study was to determine CA I and II autoantibodies in subjects with chronic lymphocytic leukaemia (CLL) and to provide a novel perspective regarding the autoimmune basis of the disease. Autoantibody levels were investigated using enzyme-linked immunosorbent assay (ELISA) in serum samples from 37 patients with CLL and 37 healthy peers. Anti-CA I titres in the CLL group were significantly higher compared with the control group (p = 0.0001). However, there was no significant difference between CLL and control groups in terms of anti-CA II titres (p = 0.278). The prevalences of CA I and II autoantibodies in patients with CLL in this study were 27% and 24.3%, respectively. Our results suggest that these autoantibodies may be involved in the pathogenesis of CLL. More extensive studies are now needed to reveal the entire mechanism.

Behçet's disease: An immunogenetic perspective

Behçet's disease (BD) is a chronic and rare multisystemic disorder defined by autoimmunity and inflammatory characteristics, manifested by ocular lesions, recurrent genital and oral ulcers, skin symptoms and arthritis as well as neurological, intestinal, and vascular involvement. Despite the unknown cause of BD, there is some strong documentation for immunological, genetic, environmental, and infectious factors playing a role in the pathogenesis of BD. While the nature of the genetic variants remains unidentified, many genetic risk factors are considered to contribute to BD susceptibility. Along with human leukocyte antigen gene encoding B*51 (HLA-B*51) and areas including the major histocompatibility complex class I, genome-wide association studies have recognized numerous other BD susceptibility genes including those encoding interleukin (IL)-10, IL-12 receptor β 2 (IL-12RB2), IL-23 receptor (IL-23R), C-C chemokine receptor 1 gene, signal transducer and activator of transcription 4 (STAT4), endoplasmic reticulum aminopeptidase (ERAP1), and genes encoding killer cell lectin-like receptor family members (KLRC4-KLRK1). It is believed that BD could be considered as a disorder lying in between autoimmune and autoinflammatory syndromes. The positive responses to classical immunosuppressive agents like azathioprine and cyclosporine and involvement of autoantigens in the initiation of the disorder are the main BD features that reflect the autoimmune nature of the disorder. In this review, we address recent findings on the role of common cytokines, antibodies and immunogenetic factors in BD.

Effects of Post-Treatment Hydrogen Gas Inhalation on Uveitis Induced by Endotoxin in Rats

Background

Molecular hydrogen (H₂) has been widely reported to have benefiicial effects in diverse animal models and human disease through reduction of oxidative stress and inflammation. The aim of this study was to investigate whether hydrogen gas could ameliorate endotoxin-induced uveitis (EIU) in rats.

Material/Methods

Male Sprague-Dawley rats were divided into a normal group, a model group, a nitrogen-oxygen (N-O) group, and a hydrogen-oxygen (H-O) group. EIU was induced in rats of the latter 3 groups by injection of lipopolysaccharide (LPS). After that, rats in the N-O group inhaled a gas mixture of 67% N₂ and 33% O₂, while those in the H-O group inhaled a gas mixture of 67% H₂ and 33% O₂. All rats were graded according to the signs of uveitis after electroretinography (ERG) examination. Protein concentration in the aqueous humor (AqH) was measured. Furthermore, hematoxylin-eosin staining and immunostaining of anti-ionized calcium-binding adapter molecule 1 (Iba1) in the iris and ciliary body (ICB) were carried out.

Results

No statistically significant differences existed in the graded score of uveitis and the b-wave peak time in the Dark-adapted 3.0 ERG among the model, N-O, and H-O groups (P>0.05), while rats of the H-O group showed a lower concentration of AqH protein than that of the model or N-O group (P<0.05). The number of the infiltrating cells in the ICB of rats from the H-O group was not significantly different from that of the model or N-O group (P>0.05), while the activation of microglia cells in the H-O group was somewhat reduced (P<0.05).

Conclusions

Post-treatment hydrogen gas inhalation did not ameliorate the clinical signs, or reduce the infiltrating cells of EIU. However, it inhibited the elevation of protein in the AqH and reduced the microglia activation.

Effects of hydrogen-rich saline on endotoxin-induced uveitis

The therapeutic effects of hydrogen-rich saline (HRS) have been reported for a wide range of diseases mainly via selectively reducing the amount of reactive oxygen species. Oxidative stress plays an important role in the pathogenesis of uveitis and endotoxin-induced uveitis (EIU). In this study, we investigated whether HRS can mitigate EIU in rats. Sprague-Dawley rats were randomly divided into Norm group, Model group, HRS group, dexamethasone (DEX) group, and rats in the latter three groups were injected with equal amount of lipopolysaccharide (LPS) to induce EIU of different severities (by 1 mg/kg of LPS, or 1/8 mg/kg of LPS). Rats in HRS group were injected with HRS intraperitoneally at three different modes to purse an ameliorating effect of EIU (10 mL/kg of HRS immediately after injection of 1 mg/kg of LPS, 20 mL/kg of HRS once a day for 1 week before injection of 1 mg/kg of LPS and at 0, 0.5, 1, 2, 6, 8, 12 hours after LPS administration, or 20 mL/kg of HRS once a day for 1 week before injection of 1/8 mg/kg of LPS, and at 0, 0.5, 1, 2, 6, 8, 12, 24 hours and once a day for 3 weeks after LPS administration). Rats of DEX group were injected with 1 mL/kg of DEX solution intraperitoneally immediately after LPS administration. Rats in Norm and Model groups did not receive any treatment. All rats were examined under slit lamp microscope and graded according to the clinical signs of uveitis. Electroretinogram, quantitative analysis of protein in aqueous humor (AqH) and histological examination of iris and ciliary body were also carried out. Our results showed that HRS did not obviously ameliorate the signs of uveitis under slit lamp examination and the inflammatory cells infiltration around iris and cilliary body of EIU induced by 1 mg/kg or 1/8 mg/kg of LPS (P > 0.05), while DEX significantly reduced the inflammation reflected by the above two indicators (P < 0.05). The impaired retinal function of mild EIU induced by 1/8 mg/kg of LPS, showed by delay of peak time of b-wave of Dark adapted 3.0 electroretinogram, was not significantly restored by HRS (P > 0.05), while DEX had an obvious therapeutic effect (P < 0.05). However, HRS exerted an inhibition trend on elevation of protein in AqH of EIU induced by 1 mg/kg of LPS, and significantly reduced the increasing amount of protein in AqH of mild EIU induced by 1/8 mg/kg of LPS (P < 0.05). In conclusion, HRS could not obviously mitigate EIU in rats, while it could inhibit the elevation of AqH protein.

Autoantibodies Against Carbonic Anhydrase I and II in Patients with Acute Myeloid Leukemia

OBJECTIVE

Cancer, one of the principal causes of death, is a global social health problem. Autoantibodies developed against the organism's self-antigens are detected in the sera of subjects with cancer. In recent years carbonic anhydrase (CA) I and II autoantibodies have been shown in some autoimmune diseases and carcinomas, but the mechanisms underlying this immune response have not yet been explained. The aim of this study was to evaluate CA I and II autoantibodies in patients with acute myeloid leukemia (AML) and to provide a novel perspective regarding the autoimmune basis of the disease.

MATERIALS AND METHODS

Anti-CA I and II antibody levels were investigated using ELISA in serum samples from 30 patients with AML and 30 healthy peers.

RESULTS

Anti-CA I and II antibody titers in the AML group were significantly higher compared with the control group (p=0.0001 and 0.018, respectively). A strong positive correlation was also determined between titers of anti-CA I and II antibodies (r=0.613, p=0.0001).

CONCLUSION

Our results suggest that these autoantibodies may be involved in the pathogenesis of AML. More extensive studies are now needed to reveal the entire mechanism.

Serum and aqueous xanthine oxidase levels, and mRNA expression in anterior lens epithelial cells in pseudoexfoliation

PURPOSE

The aim of this study was to determine serum and aqueous xanthine oxidase (XO) levels, and mRNA expression in anterior lens epithelial cells in pseudoexfoliation (PEX).

METHODS

In this prospective study, serum, aqueous and anterior lens capsules were taken from 21 patients with PEX and 23 normal subjects who had undergone routine cataract surgery. Serum and aqueous XO levels were analyzed using the colorimetric method. mRNA expression of XO in anterior lens epithelial cells was evaluated using reverse transcription polymerase chain reaction analysis.

RESULTS

Serum XO levels (means ± standard deviations) were 207.0 ± 86.1 IU/mL and 240.6 ± 114.1 IU/mL in the normal and PEX groups, respectively (p = 0.310). Aqueous XO levels (means ± standard deviations) were 65.5 ± 54.3 IU/mL in the normal group and 130.5 ± 117.4 IU/mL in the PEX group (p = 0.028). There was a 2.9 fold decrease in mRNA expression in anterior lens epithelial cells of PEX, which is significantly lower than the normal group (p = 0.01).

CONCLUSIONS

Higher aqueous XO levels lacking associated different serum XO suggests higher oxidative stress in the aqueous. Higher aqueous XO levels in PEX with decreased mRNA expression in anterior lens epithelial cells indicate possible overexpression of XO in other structures related to the aqueous.