Molecular profiling of thymoma with myasthenia gravis: Risk factors of developing myasthenia gravis in thymoma patients

Thymic gene expression analysis reveals a potential link between HIF-1A and Th17/Treg imbalance in thymoma associated myasthenia gravis

Myasthenia gravis (MG) is an immune-mediated disease frequently associated with thymic changes. Increased T helper 17 (Th17) cell activity and dysfunctional regulatory T (Treg) cells have been demonstrated in subgroups of MG. On the other hand, hypoxia-inducible factor 1 (HIF-1) has been shown to regulate the Th17/Treg balance by inducing Th17 differentiation while attenuating Treg development. To identify the underlying mechanisms of different thymic pathologies in MG development, we evaluated thymic samples from thymoma-associated myasthenia gravis (TAMG), MG with hyperplasia (TFH-MG) and thymoma without MG (TOMA) patients. Differential gene expression analysis revealed that TAMG and TFH-MG cells are associated with different functional pathways. A higher RORC/FOXP3 ratio provided evidence for Th17/Treg imbalance in TAMG potentially related to increased HIF1A. The hypoxic microenvironment in thymoma may be a driver of TAMG by increasing HIF1A. These findings may lead to new therapeutic approaches targeting HIF1A in the development of TAMG.

Clinicodemographic characteristics and prognostic role of myasthenia gravis in thymoma: Experience from a Saudi population

OBJECTIVES

The objectives of the study were to determine the clinicodemographic characteristics and the prognostic role of myasthenia gravis (MG) in thymoma.

METHODS

The records of patients who underwent surgical resection of thymoma at King Faisal Specialist Hospital and Research Center in the past 23 years were reviewed. Seventy thymoma patients were finally included and were then categorized based on MG status into the MG group (39 patients) and the non-MG group (31 patients). Collected data included patients' demographic characteristics, tumor characteristics, and postoperative clinical outcomes. All analyses were conducted using SPSS. The comparison between both groups was tested using the Student t-test and Chi-square test for continuous and categorical variables, respectively. A P = 0.05 or less indicated statistical significance.

RESULTS

Patients' age ranged from 11 to 76 years, and female predominance was observed (55.7%). Compared to the non-MG group, no difference in patients' gender was observed (P = 0.058); however, MG patients had a younger age (39.30 vs. 48.77, P = 0.0095). No difference was noted between both groups based on the World Health Organization classification (P = 0.398), but MG patients tended to present with less-advanced tumors based on the TNM classification (P = 0.039) and lower stage based on the MASAOKA staging system (P = 0.017). No significant change in tumor size (P = 0.077), resectability (P = 0.507), and adjuvant therapy (P = 0.075) were observed. MG was not significantly associated with postoperative complications, morbidity, or mortality. However, it exhibited a prognostic protective role in terms of lower recurrence (2.56% vs. 35.48%, P = 0.0001) and longer survival duration (18.62 vs. 10.21 years, P < 0.001) as compared to non-MG patients.

CONCLUSIONS

MG occurrence in thymoma patients is more likely to occur at a younger age, higher TNM classification, and advanced MASAOKA stage. Although no significant association was noted between MG and complications and mortality, MG exhibited a protective role in thymoma by providing a lower recurrence rate and longer survival duration.

Analysis on the Clinical Effect of High-Dose Glucocorticoids Combined with Immunosuppressants on Patients with Myasthenia Gravis Undergoing Video-Assisted Thoracoscopic Surgery

Objective

The purpose of the study was to investigate the clinical effect of high-dose glucocorticoids (GCS) combined with immunosuppressants on the treatment of myasthenia gravis (MG) with video-assisted thoracoscopic surgery (VATS).

Methods

A total of 106 MG patients admitted to the neurology department of our hospital from February 2016 to February 2020 were selected as the study subjects and divided into experimental group (n = 53) and control group (n = 53). The patients in the control group underwent VATS, while the patients in the experimental group were treated with high-dose GCS combined with immunosuppressants on the basis of VATS treatment. The clinical efficacy of different MG treatment methods was analyzed.

Results

No significant differences were observed in visual analogue score (VAS) at T1 between the two groups (P > 0.05), while VAS scores at T2, T3, and T4 in the experimental group were significantly lower than those in the control group (P < 0.001). In the experimental group, the overall response rate was significantly higher than the control group (P < 0.05). Cytotoxic T-lymphocyte-associated protein 4 (CTLA4) level in regulatory T (Treg) cells in experimental groups after treatment was significantly higher, compared to that in before treatment and the control group (P < 0.05). Similar results of each quantitative MG score were displayed in both groups after treatment, compared to before treatment and the control group (P < 0.05). Clinical performance of patients with lower incidence of adverse reactions in the experimental groups after treatment was significantly higher than those in the control group (P < 0.001).

Conclusion

GCS combined with immunosuppressants can effectively relieve patients' clinical symptoms and improve their quality of life, with significant clinical efficacy and high safety, which is worthy of application and promotion.

A Large Thymoma Resected via Left Antero-lateral Thoracotomy

BACKGROUND/AIM

Thymomas are a rare type of mediastinal tumors with a slow growth rate. Because of this, they are well tolerated and patients usually present with large masses, which can extend in either of the thoracic cavities. The surgical approach for such tumors is dictated by the size and localization of the mass.

CASE REPORT

We present the case of a patient with a large thymoma, resected through surgery performed by left antero-lateral thoracotomy. The patient presented in our clinic with a persistent cough, dyspnea, chest pain and tightness. Standard thoracic X-ray revealed a bilateral increase in size of the mediastinal shadow, mainly on the left side, with well-defined margins and subcostal intensity. A thoracic computed tomography (CT) scan discovered a tumoral mass within the antero-superior mediastinum, with compression of the mediastinal organs; presentation being suggestive for a thymoma. Surgery was performed, removing a 15/13/10 cm thymoma with a weight of 1126 g. Pathological examination as well as immunohistochemistry confirmed our diagnosis of type AB thymoma, stage I Masaoka-Koga.

CONCLUSION

In conclusion, surgical treatment remains the main therapeutic option in thymomas, but it is often difficult to perform due to tumor size and local invasion. However, even in large thymomas of stages I and II, surgery can be performed using an antero-lateral thoracotomy.

Narrative review of immunotherapy in thymic malignancies

Thymomas and thymic carcinomas (TCs) (also known as Thymic Epithelial Tumors or TETs) are rare cancers and the most frequent masses of the anterior mediastinum. These tumors appear in the epithelial component of the thymus, a primary lymphoid organ, and they have reported a high risk of auto-immunity due to a unique biology. Indeed, up to 30% of patients with TETs could present an autoimmune disorder (AID), the most frequent being Myasthenia Gravis (MG). Moreover, AIDs have been reported not only at tumor diagnosis but before and during the follow-up. These tumors have a lack of specific therapeutic targets for metastatic setting. Immune checkpoint inhibitors (ICI) may defeat cancer cells' capacity to evade the immune system and proliferate. The long-term benefit of ICIs in the metastatic setting in several tumors, such as melanoma or non-small cell lung cancer (NSCLC), let to evaluate ICI approaches in TETs. The high rate of AIDs and distribution of autoimmune events among TET's histological subtypes may have an influence on the decision regarding a treatment based on ICI due to the increased risk of toxicity. We summarize the current evidence for the efficacy of ICI in thymoma and TC and discuss several unresolved challenges and concerns for the use of this agents in TETs.

MiR-522-3p inhibits proliferation and activation by regulating the expression of SLC31A1 in T cells

We investigated the role of miR-522-3p in thymoma-associated myasthenia gravis (TAMG), and the mechanism of action in T cells. The miR-522-3p expression in normal serum, non-thymoma MG patient serum and TAMG patient serum and tissues was detected by quantitative real-time PCR (qRT-PCR), respectively. We assessed miR-522-3p expression in Jurkat cells and human CD4⁺ T cells after activation by anti-CD3 and anti-CD28 using qRT-PCR. The viability, proliferation, cycle distribution and the levels of CD25, CD69, interleukin-2 (IL-2) and IL-10 in transfected Jurkat cells were detected by Cell counting kit-8, 5-ethynyl-2'-deoxyuridine (EdU), flow cytometry, qRT-PCR, respectively. Targeting relationships of miR-522-3p and SLC31A1 were predicted and validated by bioinformatics analysis and dual-luciferase reporter. The viability, proliferation, cycle distribution and the levels of SLC31A1, CD25, CD69, IL-2 and IL-10 in transfected Jurkat cells were detected by above methods and western blot. The miR-522-3p expression was declined in TAMG and activated T cells. MiR-522-3p inhibitor promoted cell viability, EdU positive cells, cycle progression, and the level of CD25, CD69, IL-2 and IL-10 in Jurkat cells, while the effect of miR-522-3p mimic was the opposite. SLC31A1 was targeted by miR-522-3p, and miR-522-3p inhibited SLC31A1 expression. Overexpressed SLC31A1 reversed the inhibitory effects of miR-522-3p mimic on cell viability, EdU positive cell, cycle progression, and the levels of IL-2 and IL-10 in transfected Jurkat cells. MiR-522-3p expression was down-regulated in TAMG, and miR-522-3p inhibited proliferation and activation by regulating SLC31A1 expression in T cells.

What Is in the Neuromuscular Junction Literature?

ABSTRACT

This update covers recommendations for myasthenia gravis (MG) in patients with coronavirus 2019 disease as well as reports of the clinical features of patients with MG and coronavirus 2019. Updated advisory committee recommendations for the use of thymectomy in generalized MG are also provided. Other MG topics include lipoprotein receptor-4 and agrin antibody associations, factors influencing conversion of ocular to generalized MG, the use of rituximab for more recent onset disease, immunoglobulins for maintenance therapy, and fatigue and depression.

Immunobiology of Thymic Epithelial Tumors: Implications for Immunotherapy with Immune Checkpoint Inhibitors

Thymic epithelial tumors (TETs) are a group of rare thoracic malignancies, including thymic carcinomas (TC) and thymomas (Tm). Autoimmune paraneoplastic diseases are often observed in TETs, especially Tms. To date, chemotherapy is still the standard treatment for advanced disease. Unfortunately, few therapeutic options are available for relapsed/refractory TETs. In the last few years, the deepening of knowledge on thymus' immunobiology and involved altered genetic pathways have laid the foundation for new treatment options in these rare neoplasms. Recently, the immunotherapy revolution has landed in TETs, showing both a dark and light side. Indeed, despite the survival benefit, the occurrence of severe autoimmune treatment-related adverse events has risen crescent uncertainty about the feasibility of immunotherapy in these patients, prone to autoimmunity for their cancer biology. In this review, after summarizing immunobiology and immunopathology of TETs, we discuss available data on immune-checkpoint inhibitors and future perspectives of this therapeutic strategy.