Myasthenia gravis (MG) is a prototypical antibody-mediated neurological autoimmune disease with the involvement of humoral immune responses in its pathogenesis. T follicular helper (Tfh) cells have been implicated in many autoimmune diseases. However, whether and how Tfh cells are involved in MG remain unclear. Here, we established and studied a widely-used and approved animal model of human MG, the rat model with acetylcholine receptor alpha (AChRα) subunit (R-AChR)-induced experimental autoimmune myasthenia gravis (EAMG). This model presented mild body-weight loss 10 days after the first immunization (representing the early stage of disease) and more obvious clinical manifestations and body-weight loss 7 days after the second immunization (representing the late stage of disease). AChR-specific pre-Tfh cells and mature Tfh cells were detected in these two stages, respectively. In co-cultures of Tfh cells and B cells, the number of IgG2b-secreting B cells and the level of anti-AChR antibodies in the supernatant were higher in the cultures containing EAMG-derived Tfh cells. In immunohistochemistry and immunofluorescence assays, a substantial number of CD4/Bcl-6 T cells and a greater number of larger germinal centers were observed in lymph node tissues resected from EAMG rats. Based on these results, we hypothesize that an AChR-specific Tfh cell-mediated humoral immune response contributes to the development of EAMG.
Animals ; B-Lymphocytes ; immunology ; Disease Models, Animal ; Female ; Immunity, Humoral ; Lymph Nodes ; immunology ; Myasthenia Gravis, Autoimmune, Experimental ; immunology ; Protein Subunits ; immunology ; Proto-Oncogene Proteins c-bcl-6 ; immunology ; Rats, Inbred Lew ; Receptor Cross-Talk ; Receptors, Cholinergic ; immunology ; T-Lymphocytes, Helper-Inducer ; immunology

A mediastinal mass was incidentally found on chest radiography in a 46-yr-old woman who had had myasthenia gravis (MG) for 2 months. Computed tomography revealed a 4-cm in size, well-defined, and lobulating mass with nodular calcification that was located in the thymus. Microscopically, the mass consisted of diffuse amorphous eosinophilic materials. These deposits exhibited apple-green birefringence under polarized light microscopy after Congo red staining. Immunohistochemical analysis revealed that they were positive for both kappa and lambda light chains and negative for amyloid A. A diagnosis of localized primary thymic amyloidosis was finally made. After thymectomy, the symptoms of MG were controlled with reduced corticosteroid requirements. Localized thymic amyloidosis associated with MG has not been reported to date.
Amyloidosis/complications/*radiography/*surgery ; Calcinosis/*radiography/*surgery ; Female ; Humans ; Immunoglobulin kappa-Chains/immunology ; Immunoglobulin lambda-Chains/immunology ; Mediastinum/radiography/surgery ; Middle Aged ; Myasthenia Gravis/*complications ; Radiography, Thoracic ; Thymectomy ; Thymus Gland/radiography/surgery ; Tomography, X-Ray Computed

OBJECTIVETo observe the efficacy of Yiqi Qushi Recipe (YQR) in treating myasthenia gravis (MG) patients and its effects on their immune functions.

METHODSRecruited were 40 type I and II MG patients from clinics and wards of the Affiliated Hospital of Shandong University of Traditional Chinese Medicine from January 2009 to June 2011. They were randomly assigned to the treatment group (20 cases) and the control group (20 cases). Patients in the treatment group took YQR, one dose daily, while those in the control group took pyridostigmine 60 mg, three times a day. The therapeutic course consisted of eight weeks. The clinical efficacy, immunization indicators before and after treatment were observed. Meanwhile, the safety evaluation was performed.

RESULTSThe cured and effective rate was 75% and the total effective rate was 95% in the treatment group. They were 45% and 85% in the control group. Better results were obtained in the treatment group. Compared with the same group before treatment, IgA, IgG, and CD8 increased, IgM, CD4, and CD4/CD8 decreased in the treatment group, showing statistical difference (P < 0.05). There was no obvious change in each index of the control group after treatment (P > 0.05). Compared with the control group after treatment, IgA, IgG, and CD8 increased, CD4 and CD4/CD8 decreased in the treatment group, showing statistical difference (P < 0.05). During the course of treatment, mild diarrhea, nausea, and vomit occurred in two patients of the control group, while no adverse reaction occurred in those of the treatment group.

CONCLUSIONYQR could significantly improve clinical symptoms of MG patients, regulate their immune functions, with no obvious adverse reaction.

Adult ; CD4-CD8 Ratio ; Drugs, Chinese Herbal ; therapeutic use ; Female ; Humans ; Immunoglobulin A ; immunology ; Immunoglobulin G ; immunology ; Male ; Middle Aged ; Myasthenia Gravis ; drug therapy ; immunology ; Phytotherapy ; Young Adult

OBJECTIVE: To determine the role of miR-155 in the pathogenesis of generalized myasthenia gravis (GMG) and the effect of dexamethasone (DXM) on miR-155. METHODS: The expression of miR-155 in B cells from the GMG patients and healthy controls was analyzed by qPCR. The B cells were cultured with DXM and PBS. The B cell proliferation was examined by MTT; CD80 and CD86 frequencies were detected by flow cytometry; and anti-AChRIgG and isotypes anti-AChR-IgG1, 2, 3 in the supernatant were detected by ELISA. RESULTS: qPCR revealed that the expression of miR-155 in the B cells was much higher than that in the controls, and the miR155 expression decreased after DXM treatment. flow cytometry showed that there was no significant difference in the proliferation and the expressions of CD80 and CD86 in the B cells between the DXM group and the PBS group. The concentration of anti-AChR-IgG1 was obviously lower in the DXM group than in the PBS group, but the concentration of anti-AChRIgG, anti-AChR-IgG2, and anti-AchR-IgG3 was similar. CONCLUSION high expression of miR-155 may be associated with myasthenia gravis progression. DXM may disturb the antibody class switch of B cells by suppressing the expression of miR-155 and improve the symptom of MG patients.
Adult ; B-Lymphocytes ; cytology ; immunology ; metabolism ; B7-1 Antigen ; metabolism ; Cell Proliferation ; Cells, Cultured ; Dexamethasone ; therapeutic use ; Female ; Humans ; Immunoglobulin G ; immunology ; Male ; MicroRNAs ; genetics ; metabolism ; Middle Aged ; Myasthenia Gravis ; drug therapy ; genetics ; immunology ; Receptors, Cholinergic ; immunology ; Tetraspanin 28 ; metabolism ; Young Adult

PURPOSE: To compare the clinical manifestations between patients with ocular myasthenia gravis and those with generalized myasthenia gravis (MG). METHODS: The medical records of 71 patients diagnosed with MG between January 1995 and December 2007 were reviewed. Demographics, sensitivities of diagnostic methods, the presence of systemic autoimmune diseases, ophthalmic complications caused by MG, and treatments were evaluated and compared. RESULTS: Fourteen patients (20%) were diagnosed with ocular MG and 57 patients (80%) with generalized MG. Sensitivities of anti-acetylcholine receptor antibody and repetitive nerve stimulation tests were significantly higher in the generalized MG group (84%, 89%) compared to those in the ocular MG group (50%, 54%) (p = 0.011, p = 0.008). The sensitivity of the neostigmine test was the highest in both groups (98% of generalized MG, 79% of ocular MG), and the difference between the two groups was borderline significant (p = 0.058). The most common symptoms were ptosis and diplopia, and both groups presented with pain, blurred vision, and tearing. Systemic autoimmune disease was more prominent in the generalized MG group (21%) than in the ocular MG group (14%), and steroid therapy was used more frequently in the generalized MG group (82%) than in the ocular MG group (57%). Ophthalmic complications associated with long-term steroid treatment were more profound in the generalized MG (30%) compared to those of the ocular MG (21%). CONCLUSIONS: The generalized MG group was associated with higher sensitivities to diagnostic tests, more systemic steroid use, higher ophthalmic complications caused by systemic autoimmune disease, and long-term steroid treatment compared to those of the ocular MG group.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Autoimmune Diseases/complications ; Child ; Drug Administration Schedule ; Eye Diseases/chemically induced/immunology ; Female ; Humans ; Male ; Middle Aged ; Myasthenia Gravis/complications/*diagnosis/*drug therapy ; Steroids/*administration & dosage/adverse effects ; Young Adult

BACKGROUNDAntibodies against acetylcholine receptor, acetylcholinesterase, ryanodine receptor and titin have been found in patients with myasthenia gravis. However, the relations between these antibodies and character of myasthenia gravis are unknown. This study aimed to detect multiple antibodies in myasthenia gravis and to investigate its clinical significance.

METHODSThese antibodies were detected by enzyme-linked immunoabsorbent assay in 89 cases of myasthenia gravis, 66 cases of other neurological diseases and 66 healthy controls. The incidences of antibodies were compared using the chi-square test.

RESULTSAcetylcholine receptor, acetylcholinesterase, titin and ryanodine receptor antibodies were detected in 53.9%, 20.2%, 64.0% and 55.0% of myasthenia gravis patients respectively, higher than in patients of other neurological diseases and controls groups. The combination of the four antibodies assays provided 94.4% sensitivity and 84.0% specificity for the diagnosis of myasthenia gravis. Acetylcholinesterase antibody occurred more frequently in acetylcholine receptor antibody negative patients with adverse reactions to neostigmine test. Titin antibody provided 82.1% sensitivity and 52.5% specificity for myasthenia gravis with thymoma. Incidences of titin and of ryanodine receptor antibody were higher in late onset myasthenia gravis than in early onset myasthenia gravis. The proportion of titin antibody positive patients increased with the severity of myasthenia gravis as graded by a modified Osserman scale.

CONCLUSIONSTesting for acetylcholine receptor, acetylcholinesterase, titin and ryanodine receptor antibodies can offer a better diagnostic method for myasthenia gravis than each antibody test alone. Titin antibody combined with computed tomography was better for the diagnosis of thymoma. Titin antibody occurred most frequently in severe myasthenia gravis.

Adult ; Age of Onset ; Antibodies ; metabolism ; Case-Control Studies ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Male ; Middle Aged ; Myasthenia Gravis ; immunology ; metabolism ; pathology ; Thymoma ; immunology

OBJECTIVETo study the expression of CD20 in thymomas and its clinical significance.

METHODSOne hundred and seventy-nine cases of thymoma were enrolled into the study. The histologic diagnosis was reviewed by two experienced pathologists on the basis of the 2004 WHO classification. One hundred and two cases were selected for immunohistochemical study for CD20, pancytokeratin, TdT, CD3, CD43, CD99 and S-100 protein. The cases were further categorized into two groups, according to the association with clinical evidence of myasthenia gravis. The immunostaining pattern was then statistically analyzed.

RESULTSAmongst the 102 cases studied, 7 cases belonged to type A thymoma, 32 cases type AB thymoma, 17 cases type B1 thymoma, 15 cases type B2 thymoma, 17 cases type B3 thymoma and 14 cases thymic carcinoma. The expression rates of CD20 in neoplastic epithelial cells of type A, type AB, type B1, type B2 and type B3 thymomas and thymic carcinomas were 3/7, 84.4% (27/32), 1/17, 2/15, 0/17, 0/14, respectively. The proportions of CD20-positive lymphocytes in the background were 3/7, 18.8% (6/32), 14/17, 11/15, 11/17, 6/14, respectively. The proportion of CD20-positive intra-tumoral B lymphocytes in the group of thymomas with myasthenia gravis was 67.5% (22/40), in contrast to 35.5% (22/62) in those without myasthenia gravis.

CONCLUSIONSThe neoplastic epithelial cells in cases of type A and type AB thymoma, as well as few cases of type B1 and B2 thymoma, express CD20. The immunostain highlights the presence of oval, stellate or spindly cells. Thymomas associated with myasthenia gravis contain a significant population of CD20-positive intra-tumoral B lymphocytes. Type AB thymomas may be originated from different populations of cells, rather than a simple admixture of type A and B thymoma cells.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Antigens, CD20 ; metabolism ; B-Lymphocytes ; immunology ; pathology ; Child ; Epithelial Cells ; immunology ; pathology ; Female ; Humans ; Male ; Middle Aged ; Myasthenia Gravis ; complications ; immunology ; pathology ; Thymoma ; classification ; complications ; immunology ; pathology ; Thymus Neoplasms ; classification ; complications ; immunology ; pathology ; Young Adult

OBJECTIVETo study the clinicopathologic characteristics of thymic epithelial tumors and to evaluate the diagnostic reproducibility and clinical relevance of the 2004 WHO histologic classification system.

METHODSThe morphology and immunophenotype of 52 cases of thymic epithelial tumor were reviewed. The tumors were classified according to the new WHO classification system and the clinical data were analyzed.

RESULTSOf the 52 cases studied, 45 were thymomas and 7 were thymic carcinomas. Amongst the 45 cases of thymoma, 6 (13.4%) were type A, 15 (33.3%) were type AB, 4 (8.9%) were type B1, 9 (20.0%) were type B2, 9 (20.0%) were type B3 and 2 (4.4%) were metaplastic thymoma. Amongst the 7 cases of thymic carcinoma, 6 were squamous cell carcinomas and 1 was neuroendocrine carcinoma. The commonest presentations were cough and chest pain. Some cases were incidentally discovered by routine physical examination. Thirteen cases (25.0%) of thymoma were associated with myasthenia gravis. CT scan showed that 49 cases (94.2%) were located in the anterior mediastinum. All cases of type A, AB and B1 thymoma and most cases of B2 thymoma appeared as well-defined homogeneous mass, whereas a few cases of type B2 thymoma and most cases of type B3 thymoma and thymic carcinoma were poorly demarcated and heterogeneous. According to Masaoka staging system, 20 cases (41.7%) belonged to stage I, 15 cases (31.3%) stage II, 11 cases (22.9%) stage III and 2 cases (4.1%) stage IV. The histologic subtypes of thymic epithelial tumors significantly correlated with the clinical stages (chi(2) = 32.5, P < 0.01).

CONCLUSIONSThe 2004 revision of WHO histologic classification system for thymic epithelial tumors shows a high degree of reproducibility. Correlation with the radiologic, clinical and prognostic parameters is helpful in determining the management strategy for individual patients.

Adult ; Aged ; Antibodies, Monoclonal ; analysis ; Antigens, CD20 ; metabolism ; CD5 Antigens ; metabolism ; Carcinoma, Neuroendocrine ; classification ; diagnostic imaging ; metabolism ; pathology ; Carcinoma, Squamous Cell ; classification ; diagnostic imaging ; metabolism ; pathology ; Female ; Follow-Up Studies ; Humans ; Keratins ; immunology ; Male ; Middle Aged ; Myasthenia Gravis ; Neoplasm Recurrence, Local ; Neoplasm Staging ; Prognosis ; Radiotherapy, Adjuvant ; Retrospective Studies ; Thymoma ; classification ; diagnostic imaging ; metabolism ; pathology ; Thymus Neoplasms ; classification ; diagnostic imaging ; metabolism ; pathology ; Tomography, X-Ray Computed

OBJECTIVE: To explore the role of IL-21 in the pathogenesis of myasthenia gravis (MG) and its influence on the the class switch of anti-AChR antibodies. METHODS: Blood was taken from 26 patients and 18 healthy controls, and the expression of IL-21R mRNA in peripheral blood mononuclear cells (PBMCs) was detected by RT-PCR. The expression of IL-21R on B lymphocytes was measured by flow cytometry, while the concentrations of serum IL-21 and the levels of anti-AChR-IgG and its isotype IgG(1), IgG(2), and IgG(3) were tested by ELISA. RESULTS: The serum concentration of IL-21 in the MG group was higher than that in the control group (31.686±8.499 pg/mL, 15.147±6.366 pg/mL) and the difference was significant (P<0.01). IL-21R mRNA expressed on PBMCs in the MG group was higher than that in the control group (0.139±0.052, 0.101±0.022), and the difference was significant (P<0.05). There was no difference between ocular MG and generalized MG subgroup (P>0.05). Compared with the control group, the expression of IL-21R on B lymphocytes also increased in the MG group (P<0.05). In the anti-AChR-Ab positive MG group, the serum concentration of IL-21 showed positive correlation with anti-AChR-IgG(P<0.05),but no correlation with its isotype IgG(1), IgG(2), and IgG(3), respectively(P>0.05). Expression of IL-21R mRNA in the PBMCs showed no correlation with the level of serum anti-AChR-IgG and its isotype IgG(1), IgG(2), and IgG(3), respectively(P>0.05); however the expression of IL-21R in B lymphocytes showed positive correlation with anti-AChR-IgG and it's isotype IgG(1) and IgG(3) (P<0.05,P<0.01,P<0.05), but no correlation with IgG(2) (P>0.05). CONCLUSION IL-21 might induce the class switch of anti-AChR antibodies to IgG(1) and IgG(3) isotype through IL-21R on B lymphocytes which promotes the pathogenesis of the MG.
Adolescent ; Adult ; Autoantibodies ; classification ; immunology ; Female ; Humans ; Immunoglobulin Class Switching ; immunology ; Immunoglobulin G ; classification ; Interleukins ; blood ; genetics ; Male ; Middle Aged ; Myasthenia Gravis ; blood ; immunology ; RNA, Messenger ; blood ; genetics ; Receptors, Cholinergic ; immunology ; Receptors, Interleukin-21 ; blood ; genetics ; Young Adult

OBJECTIVETo investigate the effect and mechanisms of Compound Astragalus Recipe (CAR) for regulating cellular immune in patients with myasthenia gravis (MG).

METHODSSixty MG patients were equally assigned to two groups randomly, the test group administered with CAR and the control group with prednisone for 3 months. Changes of patients' symptoms and adverse reactions were observed. The peripheral lymphocyte subsets distribution was examined by flow cytometry, and the levels of immunoglobulins and complements in the peripheral blood were measured by immuno-turbidimetry before and after treatment.

RESULTSThe total effective rate in the test group after 12-week treatment reached 80% (24/30), while that of the control group reached 83.3% (25/30), difference between them showed no statistical significance (P > 0.05). CD4+ and CD4+/CD8+ ratio were lowered significantly in both groups, but the decrement of CD4+/CD8+ ratio in the test group was more significant than that in the control group, showing significance between groups (P < 0.05). While CD8+ in the test group after treatment was significantly increased as compared with that before treatment (P < 0.05), but with no significant difference in comparing with that in the control group (P > 0.05). Serum levels of IgM and IgA in MG patients were significantly higher than normal range (P < 0.01). Levels of C3 and C4 were significantly increased in both groups after treatment (P < 0.05). Moderate high level of ALT and AST revealed transiently at the 2nd week in 5 patients of the control group, while no adverse reaction was found in the test group.

CONCLUSIONOne of the mechanisms for CAR in playing its immuno-modulate effect may be its regulation on lymphocyte subsets distribution and humoral immune function.

Adolescent ; Adult ; Aged ; Astragalus membranaceus ; chemistry ; Child ; Complement System Proteins ; metabolism ; Drugs, Chinese Herbal ; therapeutic use ; Female ; Humans ; Immunoglobulins ; blood ; Lymphocyte Subsets ; drug effects ; Male ; Middle Aged ; Myasthenia Gravis ; drug therapy ; immunology ; Phytotherapy ; Young Adult