OBJECTIVETo explore the clinical significance of serum anti-ryanodine receptor (RyR) antibody in the diagnosis of myasthenia gravis (MG).

METHODSThe crude sarcoplasmic reticulum was prepared from rabbit skeletal muscle, and then purified by differential centrifugation to produce the antigen. The serum anti-RyR antibody levels in 74 patients with MG (including 21 patients with comorbidic thymomas) were determined with ELISA.

RESULTSWestern blot demonstrated the presence of RyR in purified crude sarcoplasmic reticulum. The positive rate of anti-RyR antibody was significantly higher in MG patients who had comorbidic thymoma compared with those who had no such comorbidity (P < 0.01). Also, the positive rate was closely correlated with the severity of MG.

CONCLUSIONSerum anti-RyR antibody test is helpful in the diagnosis of MG associated with thymoma and can be used to judge the outcome of MG.

Autoantibodies ; blood ; Humans ; Myasthenia Gravis ; blood ; complications ; immunology ; Ryanodine Receptor Calcium Release Channel ; immunology ; Thymoma ; complications ; Thymus Neoplasms ; complications

For the purpose of investigating the pattern of E-cadherin (E-CD) expression in thymomas, 72 cases were immunostained using monoclonal antibody (HECD-1) and microwave-enhanced immunohistochemical method on formalin-fixed, paraffin-embedded tissue sections. The thymomas were classified according to modified Muller-Hermelink classification. The spindle-shaped, medullary type tumor epithelial cells in medullary (3 cases) and composite type (20 cases) thymomas rarely expressed E-CD except in focal areas showing microcystic change observed in 8 cases. Meanwhile, the cohesive epithelioid tumor cells in every case of well-differentiated thymic carcinomas (WDTC) (29 cases) expressed E-CD. The epithelial cells in cortical type (13 cases) expressed stronger E-CD compared with those of organoid type (7 cases). In cases of WDTC admixed with cortical type, we observed increasing expression of E-CD as the tumor epithelium forms cohesive sheets. We could not find any loss of E-CD expression in invasive foci of the 11 cases of high-staged WDTC examined. Since the results of our study show a strong correlation between E-CD expression and epithelioid morphology of the tumor, E-CD seems to play a major role as a morpho-regulatory factor rather than as a suppressor of invasion in organotypic thymomas.
Adolescence ; Adult ; Aged ; Cadherins/immunology ; Cadherins/analysis* ; Female ; Human ; Immunohistochemistry ; Male ; Middle Age ; Neoplasm Staging ; Thymoma/pathology ; Thymoma/classification ; Thymoma/chemistry* ; Thymus Neoplasms/pathology ; Thymus Neoplasms/classification ; Thymus Neoplasms/chemistry*

The cell surface molecule identified by a monoclonal antibody(TE-1) to human thymic epithelial cell showed the specificity for thymic epithelial cells of both the cortex and medulla. TE-1 reacted with the epithelial cells of normal thymus and thymoma in fresh frozen tissues. The antigen recognized by TE-1 was mostly confined to the cell surface membrane and arranged in reticular network with long processes between thymocytes. On immunohistochemical analysis, TE-1 did not recognize normal epithelial cells of the uterine cervix, skin and stomach, and neoplastic cells of squamous cell carcinoma and gastric adenocarcinoma, all of which were stained with anti-cytokeratin monoclonal antibody. Among the tumor cell lines tested with flow cytometry, most of epithelial and all of hematopoietic cell origin were not labeled with TE-1. In summary, TE-1 appears to be a monoclonal antibody against a surface antigen of human thymic epithelial cell that is immunohistologically different from known epithelial cell surface antigens reported so far.
Animals ; Antibodies, Monoclonal/biosynthesis/*immunology ; Antibody Specificity ; Antigens, Surface/*immunology ; Epithelium/immunology ; Fluorescent Antibody Technique ; Humans ; Immunoenzyme Techniques ; Immunoglobulin G/immunology ; Immunoglobulin Isotypes/immunology ; Mice ; Mice, Inbred BALB C ; Neoplasms/immunology ; Thymoma/immunology ; Thymus Gland/*immunology ; Thymus Neoplasms/immunology ; Tumor Cells, Cultured

For a long time, thymic function could not be monitored, as a consequence of the absence of adequate technology to detect recent thymic emigrants from naive T cells. T cell differentiation in the thymus is characterized by T cell receptor (TCR) rearrangement. During the rearrangement of TCRalpha gene segments, the deltaRec and psiJalpha rearrange to each other to delete the TCRdelta gene and form an extrachromosomal DNA circles, referred to as signal joint T cell receptor excision DNA circles (sjTRECs) or TRECs. TRECs are assumed to have a high stability, they can not multiply and consequently are diluted during T cell proliferation. It was recently suggested that quantitative detection of TRECs would allow for direct measurement of thymic output. In this review TRECs quantification is a powerful method to evaluate the thymic output function in both health and disease, including hematopoietic stem cell transplantation, hematopoietic malignancies, HIV infection and autoimmune disease, and so on is described.
Animals ; Cell Differentiation ; Cell Movement ; Gene Rearrangement, T-Lymphocyte ; HIV Infections ; immunology ; Humans ; Immunity ; Neoplasms ; immunology ; T-Lymphocytes ; physiology ; Thymus Gland ; physiology

OBJECTIVETo study the clinical significance of serum anti-titin antibody level in the diagnosis of myasthenia gravis (MG) with thymoma.

METHODThe serum anti-titin antibody was analysed by ELISA method in 40 cases of health control group, 90 cases of MG, 17 cases of MG with thymoma and 7 cases of no-MG thymoma. The positive rate was compared among these groups.

RESULTSThe positive rate of anti-titin antibody was significantly higher in MG with thymoma patients than MG patients (94% and 3%, P < 0.01). According to the Osserman's classification, anti-titin antibody was present mostly in patients (43%) in IV stage, and also present in 2 cases of 7 who with no-MG thymoma.

CONCLUSIONSerum anti-titin antibody test is helpful in the diagnosis of MG with thymoma.

Adolescent ; Adult ; Aged ; Antibodies ; blood ; Connectin ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Male ; Middle Aged ; Muscle Proteins ; immunology ; Myasthenia Gravis ; complications ; diagnosis ; immunology ; Protein Kinases ; immunology ; Thymoma ; complications ; diagnosis ; immunology ; Thymus Neoplasms ; complications ; diagnosis ; immunology

Germ-line mutations in BRCA2 predispose to early-onset cancer. Homozygous mutant mouse, which has Brca2 truncated in exon 11 exhibit paradoxic occurrence of growth retardation and development of thymic lymphomas. However, due to its large embryonic lethality, cohort studies on the thymic lymphomas were not feasible. With the aid of Cre-loxP system, we demonstrate here that thymus-specific disruption of Brca2 allele without crossing it to p53-mutant background leads to the development of thymic lymphomas. Varying from 16 weeks to 66 weeks after birth, 25% of mice disrupted of Brca2 in the thymus died of thymic lymphomas, whereas previous report did not observe lymphomagenesis using similar Cre-loxP system. Future analysis of thymic lymphomas from these mice presented here will provide information on the cooperative mutations that are required for the BRCA2-associated pathogenesis of cancer.
Animals ; BRCA2 Protein/deficiency/*genetics ; CD4-CD8 Ratio ; Cell Separation ; Flow Cytometry ; Integrases/*genetics/immunology ; Lymphoma/*genetics/immunology/metabolism/pathology ; Mice ; Mice, Knockout ; Organ Specificity ; *Sequence Deletion ; T-Lymphocytes/enzymology/*immunology ; Thymus Gland/immunology/metabolism/pathology ; Thymus Neoplasms/*genetics/immunology/metabolism/pathology ; Tumor Suppressor Protein p53/deficiency/genetics/immunology

OBJECTIVETo investigate the clinical significance of the serum anti-titin, anti-ryanodine receptor (RyR) antibody level and thymus CT scan in the diagnosis of myasthenia gravis with thymoma.

METHODSTotally 32 patients with myasthenia gravis who had received thymectomy were included in the study. Abnormalities were shown under CT scan of thymus in all these patients. The relationships were studied among the pathological diagnosis, CT findings, and serum level of thymoma associated antibodies: anti-titin and anti-RyR antibodies.

RESULTSThe pathological diagnosis of thymoma was made in 21 patients and thymus hyperplasia in 11 patients after operation. The sensitivity of CT scan in the diagnosis of thymomas was 90.5%, the specificity of serum thymoma associated antibodies in the diagnosis of thymoma was 100%.

CONCLUSIONThe thymoma-associated antibodies test is helpful in the differential diagnosis of thymomas and thymus hyperplasia; when combined with CT scan, it may achieve high sensitivity in the diagnosis of the thymoma.

Adult ; Antibodies, Neoplasm ; blood ; immunology ; Autoantibodies ; blood ; Biomarkers, Tumor ; blood ; Female ; Humans ; Male ; Myasthenia Gravis ; complications ; diagnostic imaging ; immunology ; Ryanodine Receptor Calcium Release Channel ; immunology ; Thymoma ; complications ; diagnostic imaging ; immunology ; Thymus Hyperplasia ; diagnostic imaging ; immunology ; Thymus Neoplasms ; complications ; diagnostic imaging ; immunology ; Tomography, X-Ray Computed

Primary thymic marginal zone B-cell lymphoma (MZBL) of mucosa-associated lymphoid tissue (MALT)-type is a very rare disease with distinct clinicopathologic features. I herein report a rare case of primary thymic MZBL of MALT-type arising in the thymus in a patient with Sjogren's syndrome and rheumatoid arthritis. A mediastinal mass was detected by computerized tomography in a 43-yr-old Korean woman with a history of Sjogren's syndrome and rheumatoid arthritis and the thymus was resected through median sternotomy. The solid and nodular tumor (7x6x3cm) was confined in the thymus. Histologically, the lymphoid infiltrate comprised monotonous centrocyte-like cells with monocytoid cells, small lymphocytes, and plasma cells. Prominent lymphoepithelial lesions were formed by centrocyte-like cells infiltrating the Hassall's corpuscles. Immunohistochemically, the tumor cells were positive for CD20, CD79a, and bcl-2 and negative for CD3, CD5, CD10, CD23, and bcl-6. IgA and kappa light chain restriction were also found in plasma cells in the tumor. Sjogren's syndrome and rheumatoid arthritis are known to be associated with MALT lymphoma and were considered to play an important role in the development of malignant lymphoma in this patient.
Adult ; Arthritis, Rheumatoid/*complications/immunology ; B-Lymphocytes/metabolism ; Female ; Human ; Lymphoma, Mucosa-Associated Lymphoid Tissue/diagnosis/*etiology/immunology ; Sjogren's Syndrome/*complications/immunology ; Thymus Neoplasms/immunology/*pathology ; Tumor Markers, Biological

Adult ; Antibodies, Monoclonal ; analysis ; DNA Nucleotidylexotransferase ; metabolism ; Female ; Follow-Up Studies ; Humans ; Keratins ; immunology ; Male ; Middle Aged ; Prognosis ; Thymoma ; metabolism ; pathology ; surgery ; Thymus Neoplasms ; metabolism ; pathology ; surgery

Good's syndrome is extremely rare. This adult-onset condition is characterized by a thymoma with immunodeficiency, low B- and T-cell counts, and hypo-gammaglobulinemia. The initial clinical presentation is either a mass-lesion thymoma or a recurrent infection. Patients with Good's syndrome are very susceptible to infections; common respiratory and opportunistic infections can be life-threatening. There are no reports of granulomatous lung disease in patients with Good's syndrome, although it has been observed in patients with common variable immunodeficiency, of which Good's syndrome is a subset. We describe a 53-year-old male thymoma patient who presented with respiratory symptoms caused by granulomatous lung disease and an opportunistic infection. He died of uncontrolled fungal infection despite repeated intravenous immunoglobulin and supportive care. Clinicians should look for evidence of immunologic dysfunction in thymoma patients presenting with severe recurrent infections, especially opportunistic infections.
Fatal Outcome ; Granuloma, Respiratory Tract/diagnosis/*etiology/therapy ; Humans ; Immunologic Deficiency Syndromes/*complications/immunology/pathology ; Lung Diseases/diagnosis/*etiology/therapy ; Male ; Middle Aged ; Thymoma/*complications/immunology/pathology ; Thymus Neoplasms/*complications/immunology/pathology