Novel Cytokine Multiplex Assay for Tear Fluid Analysis in Sjogren’s Syndrome

Ocular manifestations of juvenile Sjögren's disease

PURPOSE OF REVIEW

This review aims to enhance understanding of juvenile Sjögren's disease (jSjD) by exploring diagnostic criteria, ocular clinical features, ancillary ophthalmic testing, and management strategies specific to this rare pediatric condition.

RECENT FINDINGS

Unlike adults, children with jSjD often present with recurrent parotitis and extra-glandular symptoms before developing sicca symptoms. Adult SjD classification criteria do not consider pediatric-specific symptoms and physiological differences. Underutilization of diagnostic tests such as the ocular staining score (OSS) and Schirmer I may result in an incomplete understanding of the prevalence of keratoconjunctivitis sicca in jSjD.

SUMMARY

Timely referral to an ophthalmologist can address perceived feasibility issues with respect to ocular features in jSjD. Management of keratoconjunctivitis sicca in jSjD includes improving ocular surface lubrication and decreasing inflammation. Recognition of pediatric-specific clinical features and development of universally accepted jSjD classification criteria will allow for better identification of potential participants for future jSjD studies.

Complement activation products in tears of dry eye and meibomian gland dysfunction

Sixty-seven patients (38 woman; median age, 69 years) were enrolled to assess complement activation products (CAPs) in tear fluid with/without dry eye (DE) and with/without meibomian gland dysfunction (MGD). Patients were divided into four groups based on the presence/absence of DE and MGD: group DM had both DE and MGD, group DN had DE without MGD, group NM had MGD without DE, and group NN had neither DE nor MGD. The levels of C3a and C5a in the collected tears were analyzed using a cytometric bead array. The C3a concentrations in the DM, DN, NM, and NN groups were 2326 pg/ml, 1411 pg/ml, 1821 pg/ml, and 978 pg/ml, respectively. The C5a concentrations in the DM, DN, NM, and NN groups were 24.7 pg/ml, 15.3 pg/ml, 24.1 pg/ml, and 12.9 pg/ml, respectively. The concentrations of C3a and C5a in the DM and NM groups were significantly higher than in the NN group (P < 0.05 for both comparisons). The CAPs in the tear fluid in MGD and DE increased. Local dysregulation of the innate immune system can be associated with the development of MGD and DE in elderly patients.

Quantum molecular resonance electrotherapy (Rexon-Eye) for recalcitrant dry eye in an Asian population

Objectives

To assess the safety, efficacy, patients' satisfaction and acceptability of Rexon-Eye electrotherapy in treating Asian severe dry eye disease (DED) patients.

Methods

Prospective parallel-arm pilot study recruiting 40 DED Chinese patients with >moderate recalcitrant DED (Contact Lens Research Unit [CCLRU] > grade 2). Subjects were randomized into 2 groups, undergoing four weekly treatment sessions each: group 1 received full treatment power; group 2 received control treatment (power 1 treatment). Non-invasive tear break-up time (NIBUT), cornea fluorescein staining graded via CCLRU and Schirmer's I test were compared pre- and 2 months post-treatment. The SPEED and QUEST questionnaires that evaluated subjective symptoms and treatment satisfaction, respectively, at baseline and 2 weeks post-treatment were carried out. Tear cytokine levels in both groups were examined at 2 weeks post-treatment.

Results

The amount of improvement in post-treatment corneal staining in the inferior corneal zone was significant in Group 1 (p = 0.038) but not in Group 2 (p = 0.832). Group 1 eyes with worse baseline staining (total score >9.8) had a significantly greater reduction of corneal staining than those with better baseline staining (-11.7 ± 1.98 vs. -4.6 ± 2.89, p < 0.001). There were no other significant differences in NIBUT, Schirmer's 1 and cornea fluorescein staining grading within or between the groups.: Group 1 (n = 24) had improved subjective dryness scores compared to Group 2 (n = 16) (SPEED score: 6.38 + 4.16 vs. 10.0 + 6.36, p = 0.04). No significant differences were seen in 11 tear cytokine levels at 2 weeks post-treatment between the 2 groups.

Conclusion

In Asian DED patients treated with Rexon-Eye, inferior cornea staining showed significant improvement compared to placebo, and eyes with greater cornea staining at baseline achieved a greater improvement in staining. There were no other significant improvements in NIBUT and Schirmer's 1. Rexon-Eye also improved subjective DED scores in 41.7% of eyes without any adverse effects.

Multi-Omic Biomarkers for Patient Stratification in Sjogren's Syndrome-A Review of the Literature

Sjögren's syndrome (SS) is a heterogeneous autoimmune rheumatic disease (ARD) characterised by dryness due to the chronic lymphocytic infiltration of the exocrine glands. Patients can also present other extra glandular manifestations, such as arthritis, anaemia and fatigue or various types of organ involvement. Due to its heterogenicity, along with the lack of effective treatments, the diagnosis and management of this disease is challenging. The objective of this review is to summarize recent multi-omic publications aiming to identify biomarkers in tears, saliva and peripheral blood from SS patients that could be relevant for their better stratification aiming at improved treatment selection and hopefully better outcomes. We highlight the relevance of pro-inflammatory cytokines and interferon (IFN) as biomarkers identified in higher concentrations in serum, saliva and tears. Transcriptomic studies confirmed the upregulation of IFN and interleukin signalling in patients with SS, whereas immunophenotyping studies have shown dysregulation in the immune cell population frequencies, specifically CD4+and C8+T activated cells, and their correlations with clinical parameters, such as disease activity scores. Lastly, we discussed emerging findings derived from different omic technologies which can provide integrated knowledge about SS pathogenesis and facilitate personalised medicine approaches leading to better patient outcomes in the future.

Response of tear cytokines following intense pulsed light combined with meibomian gland expression for treating meibomian gland dysfunction-related dry eye

PURPOSE

This study compared the changes in tear inflammatory cytokine levels after intense pulsed light (IPL) combined with meibomian gland expression (MGX) (IPL group) and instant warm compresses combined with MGX (physiotherapy group) as treatments for meibomian gland dysfunction (MGD)-related dry eye disease (DED) to explore their similarities and differences in therapeutic mechanisms.

METHODS

This study was a post-hoc analysis of a randomized controlled trial. Thirteen patients with MGD-related DED were enrolled in each group and received three treatments correspondingly with 3-week intervals. The levels of 20 tear cytokines, namely, TNF-α, IL-6, MMP-9, CXCL8/IL-8, CXCL10/IP-10, IL-10, EGF, IL-6R, IL-1β, IFN-γ, lactoferrin, Fas ligand, IL-17A, LT-α, S100A9, LCN2/NGAL, IL-13, IL-12/IL-23p40, Fas, and CCL11/Eotaxin, were measured at baseline, before the second and third treatments, and 3 weeks after the third treatment. The primary outcome was the difference in cytokine levels between baseline and the last measurement, and the trends were analyzed at each measurement point.

RESULTS

At the last measurement, a significant decrease was observed in all tear cytokines for both IPL and physiotherapy groups compared with baseline. The IPL group showed greater reductions in IL-6, IL-6R, IL-1β, IL-13, and CCL11/Eotaxin than the physiotherapy group. TNF-α, CXCL8/IL-8, CXCL10/IP-10, IL-10, EGF, IL-1β, IFN-γ, and Lipocalin-2/NGAL levels continued to decrease with treatment time. Important interactions were found in the changes of IL-6 and IL-13 levels, where the levels first decreased and then slightly increased in the physiotherapy group after treatment, while they continued to decrease in the IPL group.

CONCLUSIONS

The mechanisms of IPL and physiotherapy in treating MGD-related DED were both associated with reducing inflammation, and the superiority of IPL could be attributed to its better inhibitory effect on inflammatory cytokines like IL-6. In addition, several cytokines were on a downward trend during treatment, suggesting that the vicious cycle of DED was suppressed.

Uncovering the Depths of the Human Proteome: Antibody-based Technologies for Ultrasensitive Multiplexed Protein Detection and Quantification

Probing the human proteome in tissues and biofluids such as plasma is attractive for biomarker and drug target discovery. Recent breakthroughs in multiplex, antibody-based, proteomics technologies now enable the simultaneous quantification of thousands of proteins at as low as sub fg/ml concentrations with remarkable dynamic ranges of up to 10-log. We herein provide a comprehensive guide to the methodologies, performance, technical comparisons, advantages, and disadvantages of established and emerging technologies for the multiplexed ultrasensitive measurement of proteins. Gaining holistic knowledge on these innovations is crucial for choosing the right multiplexed proteomics tool for applications at hand to critically complement traditional proteomics methods. This can bring researchers closer than ever before to elucidating the intricate inner workings and cross talk that spans multitude of proteins in disease mechanisms.

Tear metabolomics highlights new potential biomarkers for differentiating between Sjögren's syndrome and other causes of dry eye

PURPOSE

The lacrimal exocrinopathy of primary Sjögren's syndrome (pSS) is one of the main causes of severe dry eye syndrome and a burden for patients. Early recognition and treatment could prevent irreversible damage to lacrimal glands. The aim of this study was to find biomarkers in tears, using metabolomics and data mining approaches, in patients with newly-diagnosed pSS compared to other causes of dry eye syndrome.

METHODS

A prospective cohort of 40 pSS and 40 non-pSS Sicca patients with dryness was explored through a standardized targeted metabolomic approach using liquid chromatography coupled with mass spectrometry. A metabolomic signature predictive of the pSS status was sought out using linear (logistic regression with elastic-net regularization) and non-linear (random forests) machine learning architectures, after splitting the studied population into training, validation and test sets.

RESULTS

Among the 104 metabolites accurately measured in tears, we identified a discriminant signature composed of nine metabolites (two amino acids: serine, aspartate; one biogenic amine: dopamine; six lipids: Lysophosphatidylcholine C16:1, C18:1, C18:2, sphingomyelin C16:0 and C22:3, and the phoshatidylcholine diacyl PCaa C42:4), with robust performances (ROC-AUC = 0.83) for predicting the pSS status. Adjustment for age, sex and anti-SSA antibodies did not disrupt the link between the metabolomic signature and the pSS status. The non-lipidic components also remained specific for pSS regardless of the dryness severity.

CONCLUSION

Our results reveal a metabolomic signature for tears that distinguishes pSS from other dry eye syndromes and further highlight nine key metabolites of potential interest for early diagnosis and therapeutics of pSS.

Applications of Protein Microarrays in Biomarker Discovery for Autoimmune Diseases

Dysregulated autoantibodies and cytokines were deemed to provide important cues for potential illnesses, such as various carcinomas and autoimmune diseases. Increasing biotechnological approaches have been applied to screen and identify the specific alterations of these biomolecules as distinctive biomarkers in diseases, especially autoimmune diseases. As a versatile and robust platform, protein microarray technology allows researchers to easily profile dysregulated autoantibodies and cytokines associated with autoimmune diseases using various biological specimens, mainly serum samples. Here, we summarize the applications of protein microarrays in biomarker discovery for autoimmune diseases. In addition, the key issues in the process of using this approach are presented for improving future studies.