Clinical and Genetic Characteristics of Thymoma Patients With Autoimmune Hepatitis and Myocarditis

Novel modulation of T effector memory cells-expressing CD45RA by prednisone in inoperable advanced type B thymoma patients

Due to the covert onset of thymoma, nearly 30% of patients are diagnosed at stage III or IV, losing the opportunity for surgical treatment. We have initiated the application of prednisone in treating refractory thymoma and explored biomarkers to identify potential cases that might benefit from prednisone treatment. In a study involving 96 patients with thymoma, we confirmed a significant tumor shrinkage with prednisone acetate treatment. A reduced diameter ratio indicated that type B1 and B2 thymomas exhibited the most obvious response to prednisone acetate, especially type B2 thymoma. However, the reduced diameter ratio was < 30% in type A, AB, and B3 thymomas. Immunofluorescence and flow cytometry of tumor tissues indicated that TEMRA (T Effector Memory-Expressing CD45RA) cells primarily exist in type B thymoma. However, the percentage of interleukin-8 + TEMRA cells decreased only in B1 and B2 thymoma tissues after prednisone acetate treatment. These findings are particularly significant for patients with type B thymoma with stage III or IV.

Prenatal toxicity of L-mimosine in Wistar rats

L-Mimosine is the main active component of the plant Leucaena leucocephala. Due to its metal-chelating mechanism, it interacts with various metabolic pathways in living organisms, making it a potential pharmacological target, although it also leads to toxicity. The present study aimed to investigate the transplacental passage of L-mimosine and its effects on embryofetal development. Pregnant Wistar rats were divided into control groups (CO2; n = 8 or CO3; n = 6, according to experimental design 2 or 3) that received only the vehicle, and groups that received doses of 60 (n = 9), 100 (n = 8), 140 (n = 9), and 240 (n = 7) mg/kg of L-mimosine from gestational day (GD) 6-19. For the transplacental analysis, five rats were used: two as controls and three treated with a dose of 140 mg/kg L-mimosine from GD12 to 14. All the animals received food and water ad libitum. The parameters analyzed were body weight gain; water and food consumption; serum biochemistry; blood cell counts; reproductive indices; and histopathological, visceral and skeletal analyses of the fetuses. In the groups that received doses of 60, 100, and 140 mg/kg, alterations (P < 0.05) in the skeletal development of the fetuses were observed. In the 240 mg/kg group, a decrease (P < 0.05) in total food consumption; a decrease (P < 0.05) in absolute leukocyte and neutrophil counts; alterations (P < 0.05) in the levels of ALT, GGT, and creatinine enzymes; a decrease (P < 0.05) in the relative weight of the thymus along with a loss of the corticomedullary distinction; coalescence of lymphoid follicles in the spleen; and skeletal and visceral alterations and alopecia were observed. L-Mimosine was detected in the amniotic fluid of the rats. These results demonstrate the complex action of L-mimosine, leading to toxic effects on both dams and fetuses, highlighting the risk of exposure to this substance during the perinatal period, which negatively impacts embryo/fetal and neonatal growth and development.

An unusual ectopic thymoma clonal evolution analysis: A case report

Thymomas and thymic carcinomas are rare and primary tumors of the mediastinum which is derived from the thymic epithelium. Thymomas are the most common primary anterior mediastinal tumor, while ectopic thymomas are rarer. Mutational profiles of ectopic thymomas may help expand our understanding of the occurrence and treatment options of these tumors. In this report, we sought to elucidate the mutational profiles of two ectopic thymoma nodules to gain deeper understanding of the molecular genetic information of this rare tumor and to provide guidance treatment options. We presented a case of 62-year-old male patient with a postoperative pathological diagnosis of type A mediastinal thymoma and ectopic pulmonary thymoma. After mediastinal lesion resection and thoracoscopic lung wedge resection, the mediastinal thymoma was completely removed, and the patient recovered from the surgery and no recurrence was found by examination until now. Whole exome sequencing was performed on both mediastinal thymoma and ectopic pulmonary thymoma tissue samples of the patient and clonal evolution analysis were further conducted to analyze the genetic characteristics. We identified eight gene mutations that were co-mutated in both lesions. Consistent with a previous exome sequencing analysis of thymic epithelial tumor, HRAS was also observed in both mediastinal lesion and lung lesion tissues. We also evaluated the intratumor heterogeneity of non-silent mutations. The results showed that the mediastinal lesion tissue has higher degree of heterogeneity and the lung lesion tissue has relatively low amount of variant heterogeneity in the detected variants. Through pathology and genomics sequencing detection, we initially revealed the genetic differences between mediastinal thymoma and ectopic thymoma, and clonal evolution analysis showed that these two lesions originated from multi-ancestral regions.

Concurrent de novo Thymoma-associated Paraneoplastic Type 1 Autoimmune Hepatitis and Pure Red Cell Aplasia after Thymectomy: A Case Report and Literature Review

The precise manipulation of immune tolerance is the holy grail of immunotherapies for both autoimmunity and cancer immunity. Thymomas are well known to be associated with autoimmune diseases. The exact mechanism by which autoreactivity is induced after thymectomy remains to be elucidated. We herein present the case of a 50-year-old lady with concurrent de novo type 1 autoimmune hepatitis (AIH) and pure red cell aplasia (PRCA), 1 month after undergoing a successful total thymectomy for combined squamous cell carcinoma and thymoma (Masaoka stage II). Corticosteroids yielded short-term effects for both AIH and PRCA. Literature on thymoma-associated AIH, an extremely rare immune-related comorbidity, was also reviewed.