Biomaterial Database

Pathogenesis of follicular thymic hyperplasia associated with rheumatoid arthritis. 2022

Rintaro Ohe, and Suran Yang, and Daisuke Yamashita, and Chihiro Ichikawa, and Akihisa Saito, and Takanobu Kabasawa, and Aya Utsunomiya, and Naing Ye Aung, and Yuka Urano, and Takumi Kitaoka, and Kazushi Suzuki, and Daiichiro Takahara, and Akiko Sasaki, and Yuya Takakubo, and Michiaki Takagi, and Mitsunori Yamakawa, and Mitsuru Futakuchi

Department of Pathology, Faculty of Medicine, Yamagata University, Yamagata, Japan.

Lymphoproliferative disorders may occur in patients with rheumatoid arthritis (RA) who are treated with methotrexate. However, follicular thymic hyperplasia (FTH) associated with RA (FTH-RA) is generally not considered a lymphoproliferative disorder. To investigate the pathogenesis of FTH-RA, we examined 12 cases of FTH involving thymic enlargement, four of FTH involving RA and eight of FTH involving myasthenia gravis (MG). Increased numbers and larger germinal center (GC) size were observed in FTH-RA group. The percentage of distorted GCs was 13.3% in FTH-RA group and 3.25% in FTH associated with MG (FTH-MG) group. A greater meshwork of follicular dendritic cells was observed in the GCs of FTH-RA group. Positive indices of CD27+ cells and PD-1+ cells per GC in FTH-RA group were significantly higher than those in FTH-MG group, though positive indices of CD68+ cells and CD163+ cells were similar. Myoid cell proliferation, as evaluated by α-SMA, tenascin-C, and l-caldesmon expression, was significantly increased in the FTH-RA group compared with the FTH-MG group. These results suggest that FTH should be considered in patients with RA treated with methotrexate. The pathogenesis of FTH-RA includes GC expansion and increased numbers of memory B cells, follicular helper T cells, and myoid cells, indicating humoral immunity activation.

UI	MeSH Term	Description	Entries
D008206	Lymphatic Diseases	Diseases of LYMPH; LYMPH NODES; or LYMPHATIC VESSELS.	Lymphatism,Status Lymphaticus,Disease, Lymphatic,Diseases, Lymphatic,Lymphatic Disease
D008727	Methotrexate	An antineoplastic antimetabolite with immunosuppressant properties. It is an inhibitor of TETRAHYDROFOLATE DEHYDROGENASE and prevents the formation of tetrahydrofolate, necessary for synthesis of thymidylate, an essential component of DNA.	Amethopterin,Methotrexate Hydrate,Methotrexate Sodium,Methotrexate, (D)-Isomer,Methotrexate, (DL)-Isomer,Methotrexate, Dicesium Salt,Methotrexate, Disodium Salt,Methotrexate, Sodium Salt,Mexate,Dicesium Salt Methotrexate,Hydrate, Methotrexate,Sodium, Methotrexate
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D001172	Arthritis, Rheumatoid	A chronic systemic disease, primarily of the joints, marked by inflammatory changes in the synovial membranes and articular structures, widespread fibrinoid degeneration of the collagen fibers in mesenchymal tissues, and by atrophy and rarefaction of bony structures. Etiology is unknown, but autoimmune mechanisms have been implicated.	Rheumatoid Arthritis
D013952	Thymus Hyperplasia	Enlargement of the thymus. A condition described in the late 1940's and 1950's as pathological thymic hypertrophy was status thymolymphaticus and was treated with radiotherapy. Unnecessary removal of the thymus was also practiced. It later became apparent that the thymus undergoes normal physiological hypertrophy, reaching a maximum at puberty and involuting thereafter. The concept of status thymolymphaticus has been abandoned. Thymus hyperplasia is present in two thirds of all patients with myasthenia gravis. (From Segen, Dictionary of Modern Medicine, 1992; Cecil Textbook of Medicine, 19th ed, p1486)	Hyperplasia of Thymus Gland,Thymic Hyperplasia,Gland Hyperplasia, Thymus,Gland Hyperplasias, Thymus,Hyperplasia, Thymic,Hyperplasia, Thymus,Hyperplasias, Thymic,Thymic Hyperplasias,Thymus Gland Hyperplasia,Thymus Gland Hyperplasias
D020566	Dendritic Cells, Follicular	Non-hematopoietic cells, with extensive dendritic processes, found in the primary and secondary follicles of lymphoid tissue (the B cell zones). They are different from conventional DENDRITIC CELLS associated with T-CELLS. They are derived from MESENCHYMAL STEM CELLS and are negative for class II MHC antigen and do not process or present antigen like the conventional dendritic cells do. Instead, follicular dendritic cells have FC RECEPTORS and C3B RECEPTORS that hold antigen in the form of ANTIGEN-ANTIBODY COMPLEXES on their surfaces for long periods for recognition by B-CELLS.	Follicular Dendritic Cells,Dendritic Reticulum Cells, Follicular,Dendritic Cell, Follicular,Follicular Dendritic Cell