Clinical relevance of T lymphocyte subsets in pediatric Graves' disease

Plasma exosomes from patients with active thyroid-associated orbitopathy induce inflammation and fibrosis in orbital fibroblasts

BACKGROUND

The pathogenesis of thyroid-associated orbitopathy (TAO) remains incompletely understand. The interaction between immunocytes and orbital fibroblasts (OFs) play a critical role in orbital inflammatory and fibrosis. Accumulating reports indicate that a significant portion of plasma exosomes (Pla-Exos) are derived from immune cells; however, their impact upon OFs function is unclear.

METHODS

OFs were primary cultured from inactive TAO patients. Exosomes isolated from plasma samples of patients with active TAO and healthy controls (HCs) were utilized for functional and RNA cargo analysis. Functional analysis in thymocyte differentiation antigen-1+ (Thy-1+) OFs measured expression of inflammatory and fibrotic markers (mRNAs and proteins) and cell activity in response to Pla-Exos. RNA cargo analysis was performed by RNA sequencing and RT-qPCR. Thy-1+ OFs were transfected with miR-144-3p mimics/inhibitors to evaluate its regulation of inflammation, fibrosis, and proliferation.

RESULTS

Pla-Exos derived from active TAO patients (Pla-ExosTAO-A) induced stronger production of inflammatory cytokines and hyaluronic acid (HA) in Thy-1+ OFs while inhibiting their proliferation. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and single sample gene set enrichment analysis (ssGSEA) suggested that the difference in mRNA expression levels between Pla-ExosTAO-A and Pla-ExosHC was closely related to immune cells. Differential expression analysis revealed that 62 upregulated and 45 downregulated miRNAs in Pla-ExosTAO-A, with the elevation of miR-144-3p in both Pla-Exos and PBMCs in active TAO group. KEGG analysis revealed that the target genes of differentially expressed miRNA and miR-144-3p enriched in immune-related signaling pathways. Overexpression of the miR-144-3p mimic significantly upregulated the secretion of inflammatory cytokines and HA in Thy-1+ OFs while inhibiting their proliferation.

CONCLUSION

Pla-Exos derived from patients with active TAO were immune-active, which may be a long-term stimulus casual for inflammatory and fibrotic progression of TAO. Our finding suggests that Pla-Exos could be used as biomarkers or treatment targets in TAO patients.

Association of Ocular Surface Immune Cells With Dry Eye Signs and Symptoms in the Dry Eye Assessment and Management (DREAM) Study

Purpose

Dry eye disease (DED) is a multifactorial, heterogeneous disease of the ocular surface with one etiology being ocular surface inflammation. Studies using animal models demonstrate the role of ocular surface immune cells in the inflammatory pathway leading to DED, but few have evaluated humans. This study described the white blood cell population from the ocular surface of patients with DED and assessed its association with DED signs and symptoms in participants of the Dry Eye Assessment and Management (DREAM) study.

Methods

Participants were assessed for symptoms using the Ocular Surface Disease Index, signs via corneal staining, conjunctival staining, tear break-up time, and Schirmer test, and Sjögren's syndrome (SS) based on the 2012 American College of Rheumatology classification criteria. Impression cytology of conjunctival cells from each eye was evaluated using flow cytometry: T cells, helper T cells (Th), regulatory T cells (Tregs), cytotoxic T cells, and dendritic cells.

Results

We assessed 1049 eyes from 527 participants. White blood cell subtype percentages varied widely across participants. Significant positive associations were found for Th and conjunctival staining (mean score of 2.8 for 0% Th and 3.1 for >4.0% Th; P = 0.007), and corneal staining (mean score of 3.5 for 0% Th and 4.3 for >4.0% Th; P = 0.01). SS was associated with higher percent of Tregs (median 0.1 vs. 0.0; P = 0.01).

Conclusions

Th were associated with more severe conjunctival and corneal staining, possibly indicating their role in inflammation leading to damage of the ocular surface. There is no consistent conclusion about Tregs in SS, but these results support that Tregs are elevated in SS.

"Lymphocyte population in peripheral blood in children and adolescents with graves disease. Potential predictive tool for severity of the disease"

PURPOSE

To date, few data are available on the prognostic role of lymphocyte subsets in pediatric Graves' Disease (GD). The aim of this retrospective study is to analyze the role of lymphocyte subtypes in predicting the severity of GD.

METHODS

Data of 10 pediatric subjects aged <18 years with GD onset in the period November 2017-April 2021 were collected. The lymphocyte population was assessed at the onset of GD as well as hormonal and clinical data. The follow-up period was 2.4 ± 0.8 years.

RESULTS

Pearson correlation coefficient between CD4+ /CD8+ ratio and fT3 levels and thyroid volume at diagnosis was 0.72 (p = 0.04) and 0.81 (p = 0.004) respectively; that between CD4+ /CD8+ ratio and the TRAb titer at diagnosis and after 6, 12 and 24 months was 0.89, 0.89, 0.73 and 0.77 respectively (p = 0.02, p = 0.01, p = 0.03 and 0.04). The correlation coefficient of anti-thyroid drug (ATD) dose after 6 and 12 months with CD4+ /CD8 ratio was 0.88 and 0.78 (p = 0.001 and p = 0.02 respectively). Patients with a higher CD4+ /CD8+ ratio at diagnosis displayed higher fT3 levels (28.73 ± 2.18 vs 13.48 ± 2.19 pmol/L, p = 0.03) and higher TRAb titers (28.9 ± 11.2 vs 4.88 ± 0.97, p = 0.01).

CONCLUSION

CD4+/CD8+ ratio appears as a promising predictive tool to be considered together with other prognostic factors to better manage pediatric GD. These preliminary data need to be confirmed over a longer follow-up period and in larger cohorts.

CD8+ T Lymphocytes: Crucial Players in Sjögren's Syndrome

Primary Sjögren's syndrome (pSS) is a chronic autoimmune disease associated with damage to multiple organs and glands. The most common clinical manifestations are dry eyes, dry mouth, and enlarged salivary glands. Currently, CD4+ T lymphocytes are considered to be key factors in the immunopathogenesis of pSS, but various studies have shown that CD8+ T lymphocytes contribute to acinar injury in the exocrine glands. Therefore, in this review, we discussed the classification and features of CD8+ T lymphocytes, specifically describing the role of CD8+ T lymphocytes in disease pathophysiology. Furthermore, we presented treatment strategies targeting CD8+ T cells to capitalize on the pathogenic and regulatory potential of CD8+ T lymphocytes in SS to provide promising new strategies for this inflammatory disease.

Comprehensive Metabolomics Study in Children With Graves' Disease

OBJECTIVE

Graves' disease (GD) related hyperthyroidism (HT) has profound effects on metabolic activity and metabolism of macromolecules affecting energy homeostasis. In this study, we aimed to get a comprehensive understanding of the metabolic changes and their clinical relevance in GD children.

METHODS

We investigated serum substances from 30 newly diagnosed GD children and 30 age- and gender-matched healthy controls. We explored the metabolomics using ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF/MS) analysis, and then analyzed the metabolomic data via multivariate statistical analysis.

RESULTS

By untargeted metabolomic analysis, a total of 730 metabolites were identified in all participants, among which 48 differential metabolites between GD and control groups were filtered out, including amino acids, dipeptides, lipids, purines, etc. Among these metabolites, 33 were detected with higher levels, while 15 with lower levels in GD group compared to controls. Pathway analysis showed that HT had a significant impact on aminoacyl-transfer ribonucleic acid (tRNA) biosynthesis, several amino acids metabolism, purine metabolism, and pyrimidine metabolism.

CONCLUSION

In this study, via untargeted metabolomics analysis, significant variations of serum metabolomic patterns were detected in GD children.