Studying the relationship between clinical features and mental health among late-onset myasthenia gravis patients.

BACKGROUND: Mental disorders are common comorbidities among individuals with neurological diseases, and the prevalence of depressive and anxiety-related symptoms in newly referred patients at neurology outpatient clinics is high. There have been few studies on the mental health of patients with late-onset myasthenia gravis (MG). AIM: To examine the relationship between clinical features and the mental health symptoms within late-onset MG patients. METHODS: A total of 105 patients diagnosed with MG were recruited consecutively from a neuromuscular outpatient clinic between December 2020 and February 2021. Patients were classified into two groups: early-onset MG (age at onset < 50 years, n = 63) and late-onset MG (age at onset ≥ 50 years, n = 42). Social demographic data and information about marital status, education level, clinical symptoms, serum antibody levels, and therapies used were collected for all participants. Participants were also evaluated using the Myasthenia Gravis Composite scale, the Myasthenia Gravis Activities of Daily Living scale, the Myasthenia Gravis Quality of Life 15 (MG-QOL-15) questionnaire, the 17-item version of the Hamilton Depression Rating Scale (HAM-D) and the Hamilton Anxiety Rating Scale (HAM-A). The relationship between clinical features and mental health in late-onset MG patients was examined using multivariate logistic regression analyses. RESULTS: Late-onset MG patients were more prone to dyspnea, had higher levels of serum anti-acetylcholine receptor antibodies, and higher total scores on the MG-QOL-15, HAM-D, and HAM-A questionnaires, than early-onset MG patients had (P < 0.05). Among those with late-onset MG, female patients had higher total HAM-D and HAM-A scores than male patients had (P < 0.05). High scores on the QOL-15 questionnaire were associated with higher incidences of anxiety and depression, and the association was found to be independent after adjusting for confounding risk factors. In the late-onset subgroup, the areas under the receiver operating characteristic curves for the MG-QOL-15 score-based diagnostic accuracy for anxiety and depression state were 0.816 (P = 0.001) and 0.983 (P < 0.001), respectively. CONCLUSION: Higher MG-QOL-15 scores were a risk factor for anxiety and depression in late-onset MG, and women with late-onset MG were more likely to have anxiety and depression than men were.

Exposure to nitrite alters thyroid hormone levels and morphology in Takifugu rubripes.

Nitrite (NO2-) can act as a toxic nitrogenous compound with the potential to disrupt endocrine systems in fish. The aim of the present study was to investigate the effects of nitrite on the thyroid endocrine system of Takifugu rubripes. Fish were exposed to 0, 0.5, 1, 3, and 6 mM nitrite concentrations. Blood was collected to assay the concentrations of thyroid-stimulating hormone (TSH), thyroxine (T4), triiodothyronine (T3), free thyroxine (FT4), free triiodothyronine (FT3), and 3,3,5'-triiodothyronine (rT3), as well as the activity of iodothyronine deiodinases (Dio1, Dio2, and Dio3,) after 0, 12, 24, 48, and 96 h of exposure to nitrite. The first branchial arch to the third branchial arch of T. rubripes were sampled and fixed, and thyroid morphology was observed. The results showed that exposure to nitrite significantly increased the concentrations of TSH, T3, FT3, and reduced the concentrations of T4, FT4, and rT3. The activity of Dio1 and Dio2 increased significantly, whereas Dio3 activity decreased significantly. Additionally, thyroid follicles degenerated and became blurred and most colloid material disappeared 96 h after exposure to high nitrite concentrations. Based on these results, high nitrite concentration exposure can disturb thyroid hormone homeostasis, alter thyroid follicle morphology, and result in thyroid endocrine toxicity.

The HLA-B*4601-DRB1*0901 haplotype is positively correlated with juvenile ocular myasthenia gravis in a southern Chinese Han population.

Myasthenia gravis (MG) is a sporadic disorder that has been increasingly linked to inherited genetic factors. Previous studies have demonstrated that human leukocyte antigen (HLA) plays an important role in the pathogenesis of MG. We determined the genotypes of the HLA-A, B, and DRB1 alleles in 257 southern Chinese Han MG patients using polymerase chain reaction sequence-based typing (PCR-SBT). The allele frequencies in the MG patients were compared to 292 healthy controls using the case-control method. HLA-A*0207, HLA-B*4601, HLA-DRB1*0403, HLA-DRB1*0901, and HLA-DRB1*1602 were more frequent in juvenile ocular MG patients than controls. HLA-DRB1*0701 was significantly reduced in the juvenile ocular MG group compared with controls. HLA-A*0207-B*4601, HLA-B*4601-DRB1*0403, HLA-B*4601-DRB1*0901, and HLA-B*4601-DRB1*1602 were found to be in strong linkage disequilibrium in juvenile ocular MG patients. Within the MG patients, there was a strong positive association between HLA-B*4601-DRB1*0901 and juvenile ocular MG patients, and the value of odds ratios (OR) decreased as the disease became more severe and the age of onset increased. We believe this could be the main heredity phenotype in juvenile ocular MG patients from southern China and may be a clinical marker to predict the severity of the disease.

West nile virus infection in Xinjiang, China.

An outbreak of fever and meningitis/encephalitis occurred in Xinjiang, China, from August 5 to September 3, 2004. In preliminary diagnostic testing, several cerebrospinal fluid (CSF) and serum samples showed positive immunoglobulin M (IgM) antibody to Japanese encephalitis virus. Here, the CSF and serum samples of 6 cases collected at that time were tested by immunofluorescence assay (IFA), enzyme-linked immunosorbent assay (ELISA), and plaque reduction neutralization assay (PRNT) for the existence of IgM antibody or neutralization antibody against West Nile virus (WNV) or other arboviruses. The results demonstrate the evidence of West Nile infection in Xinjiang, China.

The high frequency and clinical feature of seronegative myasthenia gravis in Southern China.

Anti-acetylcholine receptor antibodies (anti-AChR-Ab) are responsible for the failure of neuromuscular junction in myasthenia gravis (MG). Some anti-AChR-Ab-seronegative MG patients have anti-muscle-specific tyrosine kinase antibodies (anti-MuSk-Ab). Here, the anti-AChR-Ab was tested in 250 MG outpatients from Southern China. While anti-MuSk-Ab was tested in 66 patients who had no anti-AChR-Ab in blood serum, but none of them was positive. The antibodies were measured by a radioimmunoprecipitation assay. The frequency of anti-AChR-Ab was 51.2 %. The percentage of anti-AChR-Ab in ocular type was lower than generalized type (44.9 vs. 66.2 %, P = 0.002). Seronegative MG was characterized by a lower percentage of thymoma than seropositive patients (P = 0.013). It seemed to be less severe in seronegative MG than seropositive MG in these 250 patients. In ocular type, seronegative MG mainly manifesting blepharoptosis but seldom diplopia or eyeball fixation related to ocular movement disability (P = 0.016). While in generalized type, seronegative MG was characterized by a lower percentage of bulbar muscle involvements than seropositive patients (P = 0.005). Logistic regression analysis revealed that bulbar weakness was affected by the existence of anti-AChR antibodies (OR = 3.524, P = 0.015). Besides, seronegative MG tended to be characterized by a lower percentage of neck extensor involvement, but this did not reach significance. The percentage of anti-AChR antibodies was much lower than other countries. Seronegative MG has characteristic clinical features that are different from features of the remaining seropositive MG. This emphasises the predictive value of anti-AChR antibodies analysis in MG patients.

[Randomized controlled clinical trial of middle-dose cyclophosphamide plus methylprednisolone for myasthenia gravis patients in crisis].

OBJECTIVE: To evaluate the efficacy and safety of middle-dose cyclophosphamide plus methylprednisolone for myasthenia gravis (MG) patients in crisis. METHODS: For this prospective, open, parallel, randomized controlled trial, we recruited a total of 156 MG patients in crisis from January 1999 to October 2011 at Department of Neurology, First Affiliated Hospital, Sun Yat-sen University. They were divided into two groups of cyclophosphamide and control (n = 78 each). In the cyclophosphamide group, each received methylprednisolone 500 mg/d for 3 days, then tapered to 250 mg/d and tapered half every 3 days until 62.5 mg/d. Afterward an oral dose of prednisone was prescribed at 30 mg/d until the end of the trial. At the same time, an intravenous injection of cyclophosphamide was offered at 0.4 g/d for 3 days and then 0.4 g/d every 3 days. In the control group, each received methylprednisolone alone. And the efficacies were assessed by absolute and relative MG scores. RESULTS: (1) There were 54 (69.2%) patients off-ventilation in 3 days in the cyclophosphamide group versus 36 (46.2%) patients in 8 - 14 days in the control group. Notable statistical significance existed between two groups (P = 0.000). (2) More than half of the patients in cyclophosphamide group with extremity weakness (n = 44, 56%) and dysphagia (n = 47, 60.3%) significantly improved in 10 - 14 days versus 28 days in the control group. Notable statistical significance existed between two groups (P = 0.000). (3) In the cyclophosphamide group, dyspnea disappeared in 54 (69.2%) patients when the dose reached 1.2 g. The recovery of dysphagia (n = 47, 60.3%) and extremity weakness (n = 44, 56.4%) occurred in more than half of the patients when the dose reached 2.8 g. Notable statistical significance existed among three groups (P = 0.000). (4) During the treatment period, there were 17 cases (21.8%) with pulmonary infection in the cyclophosphamide group versus 53 cases (67.9%) in the control group. Notable statistical significance existed between two groups (P = 0.000). (5) Brief and minor side effects appeared in the patients of the cyclophosphamide group. CONCLUSION: (1) The combined treatment of middle-dose cyclophosphamide and methylprednisolone for MG patients in crisis is both effective and safe. (2) When combined with methylprednisolone, 90% of patients with MG crisis are successfully off-ventilation when the dose of cyclophosphamide reaches 1.6 g.

[Efficacy and safety of low-dose cyclophosphamide plus corticosteroids for type I/II myasthenia gravis].

OBJECTIVE: To evaluate the efficacy and safety of low-dose cyclophosphamide plus corticosteroids for type I/II myasthenia gravis (MG). METHODS: This trial was prospective, non-random and open-labeled. We selected 160 patients with steroid-insensitive MG from January 1999 to October 2011. Each patient received an oral dose of prednisone 0.5 mg×kg(-1)×d(-1), cyclophosphamide 8 mg×kg(-1)×time(-1) once weekly intravenously and oral pyridostigmine 36 mg×kg(-1)×d(-1). The efficacies were assessed by absolute and relative MG scores. The clinical treatment cycle was 30 weeks. RESULTS: (1) Among them, 74/106 type I MG patients (69.9%) reached clinical relative scores ≥ 95% in 30 weeks. The total dose of cyclophosphamide was 12 g. And 35/54 type II MG patients (64.8%) reached clinical relative scores ≥ 95% in 30 weeks. No statistically significant difference existed between two groups (P = 0.521). (2) All patients had various degrees of improvement in 30 weeks. The difference was statistically significant by Mann-Whitney U test (P ≤ 0.05). (3) There were minor side effects in these all patients. (4) When the total dose of cyclophosphamide reached 4 g, the cure rate in type I patients was higher than that of in type II patients (P = 0.000). When the total dose of cyclophosphamide reached 12 g, the cure rate in type II patients was higher than that of in type I patients (P = 0.001). (5) The cure dose of cyclophosphamide was 4-8 g in 58.4% of type I patients versus 8 - 12 g in 61.1% of type II patients. CONCLUSION: The combined treatment of low-dose cyclophosphamide and corticosteroids in glucocorticoid-insensitive type MG (type I/II) is both effective and safe. And the sensitivity to cyclophosphamide varies for different clinical types. It is higher in type I than type II patients.

[Response to thymectomy and analysis of influencing factors in the treatment of children with myasthenia gravis].

OBJECTIVE: To evaluate the efficacy of thymectomy and relevant influencing factors in the treatment of children with myasthenia gravis through a long-term follow-up. METHODS: The clinical records of 59 patients undergoing expanded thymectomy for the treatment of myasthenia gravis (MG) between January 2003 and August 2009 were reviewed retrospectively. Their postoperative outcomes were categorized into complete stable remission (CSR), pharmacological remission (PR), improvement, no change and deterioration (including mortality). RESULTS: During a median follow-up period of 35 months, none of them died or deteriorated clinically among 53 patients with a postoperative follow-up. The overall remission rate was 69.8% and the effective rate 90.6%. No symptomatic relapse occurred among 16 patients in CSR. None of the ocular patients progressed to generalized MG while 16 thymectomized generalized MG developed from ocular MG. Both univariate and logistic regression analyses revealed that the preoperative duration of illness influenced the surgical curative effect (P < 0.05). Survival analysis indicated that the rates of overall remission were 56% or 88% at 24 months and 42% or 75% at 48 months among ocular MG and generalized MG respectively. According to Log-rank analysis, no difference in remission existed between two types of MG. CONCLUSION: Thymectomy is an effective and safe treatment in selected MG children, especially in those with a shorter illness duration.

[Clinical study and case follow-up of 61 cases of familial myasthenia gravis in 28 families].

OBJECTIVE: To explore the clinical features and prognosis of familial myasthenia gravis (FMG). METHODS: The clinical data were collected and analyzed for 61 FMG patients from 28 families from February 1998 to March 2009 at the department of neurology, First Affiliated Hospital, Sun Yat-sen University. And they were compared with 257 cases of sporadic myasthenia gravis (MG) by case-control method. Age at onset, gender, Osserman clinical classification, diagnosis, treatment, thymus imaging examination, prognosis and other family members were measured retrospectively. RESULTS: (1) The proportion of FMG in Southern China was 2.03% and it was lower than the other countries. (2) Onset age was younger in FMG than in sporadic MG. Juvenile MG was more common in FMG than in sporadic MG (70.5% vs 52.1%, P = 0.009). (3) Ocular MG was more common in FMG than in sporadic MG (83.6% vs 62.7%, P = 0.002). (4) There was a higher proportion in FMG with thymic hyperplasia than in sporadic MG (98.3% vs 83.7%, P = 0.014). (5) Better prognosis was found in FMG than in sporadic MG. FMG patients had a higher proportion of completely stable remission than sporadic MG (24.5% vs 11.7%, P = 0.009). (6) The so-called "consistency of the same disease" could only be found in families with pure ocular diseases. If the patients with general type MG were present in the family, their pathogenetic conditions and prognosis might vary greatly. CONCLUSION: There characteristics of FMG in south China are different from those of other countries. Their exact inheritance patterns await further explorations.

A retrospective review of 15 patients with familial myasthenia gravis over a period of 25 years.

We observed, during a 25-year period, 15 patients from 6 families with autoimmune myasthenia gravis (all Chinese Han from Guangdong Province) referred to our department. Their mean onset age was 13.4 years (range 2-25 years) with 10 patients with juvenile onset. The female:male ratio was 3:2. Acetylcholine receptors antibody titers were increased in 11 patients (range 1.62-19.8 nmol/L). Thymectomy was performed in six patients, who received corticosteroids /immune inhibitor plus pyridostigmine treatments after surgery. The other patients were placed on therapy with azathioprine, cyclophosphamide, corticosteroids and acetylcholinesterase inhibitors. All patients responded well to immunosuppressants, and psychiatric symptoms were observed only in one patient who received a high dose of corticosteroids. Patients with generalized type in the same family had different presentations with variable prognosis. HLA-A 0207 was found in 9 patients (9/15), HLA-B 4601 in 11 patients (11/15), and HLA-DRB1 0901 in 12 patients (12/15). When compared to familial autoimmune myasthenia gravis in other countries, we observed peculiar characteristics of Chinese populations, such as the within-family consistency was only found in families with ocular MG type (50% of all MG families), while the pathogenetic conditions and the prognoses of the generalized MG patients may differ greatly within the same family. These findings may shed new light on the genetic predisposition and the origin of immune abnormalities of MG patients.

[Correlation study between Chinese myasthenia gravis patients from Guangdong province and the polymorphism of HLA immunogene].

OBJECTIVE: To explore the correlation between Chinese myasthenia gravis (MG) patients from Guangdong province and the polymorphism of HLA immunogene. METHODS: The genotypes of HLA-A, B and DRB1 alleles in 104 MG patients and 121 healthy blood donors were detected by PCR-SBT (polymerase chain reaction-sequencing-based typing). RESULTS: (1) There were 15 alleles at A locus, 32 at B locus and 23 at DRB1 locus in MG group. (2) The frequency of HLA-A*02:07(P = 0.000, RR = 3.715), -B*46:01(P = 0.000, RR = 5.698), -DRB1*04:03(P = 0.033, RR = 6.312), -DRB1*09:01(P = 0.000, RR = 5.884) in MG patients was higher than that in healthy controls. (3) There were positive associations of HLA-DRB1*09:01(P = 0.000, RR = 1.349) with juvenile-onset ocular MG. CONCLUSION: There is susceptibility association of HLA-A*02:07, -B*46:01, -DRB1*04:03, -DRB1*09:01 with Chinese MG patients from Guangdong province. There is a close genetic and immunological correlation between HLA alleles and the pathogenesis of MG. It has directional significance in the race and region incidence study, clinical classification, differential diagnosis, treatment and prognosis of MG.

[Therapeutic efficacy and safety of tacrolimus for intractable myasthenia gravis: a report of 36 patients].

OBJECTIVE: To examine the efficacies and adverse events of low-dose tacrolimus in intractable myasthenia gravis (MG) patients during a long-term follow-up. METHODS: Tacrolimus was administered at 0.1 mg×kg(-1)×d(-1) to 36 generalized or ocular MG patients at our department from November 2008 to December 2010. The efficacies of tacrolimus were assessed by the myasthenia gravis activities of daily living (MG-ADL) profile and the classification of Myasthenia Gravis Foundation of America (MGFA). And the adverse events of tacrolimus were monitored in each patient. RESULTS: (1) All patients were followed up for 7 - 23 months. Adverse events occurred in 6 patients (16.67%). (2) The myasthenic symptoms improved up to the levels of MG-ADL and MGFA in 24 patients (66.67%). There was notable statistical significance in the comparison of clinical status at pre- and post-treatment (P = 0.000). (3) The efficacies in patients with generalized MG were better than those with ocular MG (P = 0.032). (4) The average blood trough levels of tacrolimus were lower than the recommended maintenance range from other countries in 24 effective patients. CONCLUSION: The administration of tacrolimus induces symptomatic improvements in MG patients especially in generalized type. And the adverse events should be closely monitored.

[Roles of Bacillus Calmette-Guérin with immunological memory in the pathogenesis of myasthenia gravis].

OBJECTIVE: To explore the roles of immunological memory in the pathogenesis of myasthenia gravis (MG) by Bacillus Calmette-Guérin (BCG). METHODS: For this randomized comparative clinical trial, 58 newly diagnosed MG patients and 32 age-and-gender-matched healthy controls were analyzed by purified protein derivative (PPD) test. The results were observed after 72 hours. peripheral blood mononuclear cell (PBMC) was collected from the MG patients before and after extended thymectomy and cultured with BCG. After a 72-hour incubation, the level of interferon gamma (IFN-γ) was detected by enzyme-linked immunosorbent assay (ELISA). RESULTS: In PPD test, the MG patients did not show a markedly higher positive percentage [48.3% (28/58) vs 65.6% (21/32), P = 0.114]. The pre-thymectomy PBMC had a higher level of IFN-γ than the control group: (650 ± 312) pg/ml vs (346 ± 153) pg/ml. After extended thymectomy, the level of IFN-γ returned to normal: (219 ± 113) pg/ml. The P value is 0.003, 0.001. CONCLUSION: The impairment of immunological memory, may be an important pathogenic cause of relapse in the MG patients.

[Analysis of prognostic factors and efficacy of plasmapheresis in the treatment of myasthenia crisis].

OBJECTIVE: To examine the prognostic factors and efficacy of myasthenia gravis (MG) in crisis on plasmapheresis and detect the reasons for ineffective plasmapheresis. METHODS: The investigators analyzed a total of 69 MG patients in crisis on plasmapheresis by case control study. Gender, age at onset of myasthenic symptoms, duration between the onset of crisis and plasmapheresis, pre-therapeutic use of glucocorticoids, pulmonary infections, other complications, nutritional status, history of thymectomy in 48 hours before crisis, thymic pathology, combined intravenous immunoglobulin (IVIG) and total sessions of plasmapheresis were measured retrospectively. RESULTS: Univariate analysis showed that pulmonary infections (P = 0.000, OR = 29.250), history of thymectomy in 48 hours before crisis (P = 0.046, OR = 0.267), combined intravenous immunoglobulin (P = 0.003, OR = 0.136) and total sessions of plasmapheresis (P = 0.022, OR = 0.498) were all influencing factors of plasmapheresis. However the analysis of multivariate logistic regression revealed that pulmonary infections (P = 0.000, OR = 23.600) was an independent risk factor and combined intravenous immunoglobulin (P = 0.047, OR = 0.192) was an independent protection factor of plasmapheresis. CONCLUSION: Plasmapheresis is ineffective in MG crisis with pulmonary infections. Control of pulmonary infections and combined intravenous immunoglobulin can improve the response to plasmapheresis in patients with MG crisis.

[Study of incidence and correlation factors of depression, anxiety and insomnia in patients with myasthenia gravis].

OBJECTIVE: To investigate the incidence rate and correlation factors of depression, anxiety and insomnia in patients with myasthenia gravis (MG). METHODS: A total of 161 MG patients were assessed and graded with HAMD, HAMA, PSQI, QMG, ADL and a self-made scale chart. And the correlation factors were analyzed by Logistic stepwise regression. RESULTS: The prevalence of depression, anxiety and insomnia was 58.3%, 45.3% and 39.1% respectively. The correlation factors with significant influences on MG were as follows: depression with age, physical weakness, score of QMG, life scale grading; anxiety with experience-sharing; insomnia age, dyspnea, thymoma, physical status at 1 month post-operation, prednisone dose and score of QMG. CONCLUSION: Nearly one half of the MG patients suffer from affective disorders to different degrees. And an analysis of its correlation factors provides references to prevent and treat the affective disorders concurrently with MG.

[Video-assisted thoracoscopic extended thymectomy and transsternal extended thymectomy for treatment of myasthenia gravis: a case-control study].

OBJECTIVE: To compare the therapeutic effects of video-assisted thoracoscopic extended thymectomy (VATET) and transsternal extended thymectomy (TET) for myasthenia gravis (MG). METHOD: This study included 21 patients undergoing VATET through the "three holes" approach on the right chest and 32 undergoing TET with sternum dissection. The thymus was excised and the anterior mediastinum adipose tissue removed in both groups. RESULTS: VATET was associated with reduced intraoperative blood loss and longer operative time without the use of postoperative analgesics; very few patients were admitted into the intensive care unit (ICU), showing significant differences from the TET group (P<0.05). No significant difference was found between the two groups in tracheal tube removal time, length of stay in ICU, closed thoracic drainage removal time, and postoperative hospital stay, total hospital stay, postoperative complications, total hospitalization costs, or the rate of remission and improvement (P>0.05). CONCLUSIONS: Compared with TET, VATET requires only a small incision without leaving metal foreign body in the body, and the patients experience less postoperative pain and rapid recovery, with similar mid- and long-term clinical outcomes.

[Expression of regulatory T cells in thymus of myasthenia gravis patients].

OBJECTIVE: To investigate the in situ expression of regulatory T cells (Tregs) in thymus and its significance for myasthenia gravis (MG). METHODS: Thirty nine MG patients who had not accepted immunosuppressive therapy before thymectomy were recruited as study group and 19 patients undergoing cardiosurgery as control. There was no significant statistical difference in age and gender between the two groups (P > 0.05). The location and proportion of Tregs in thymus were analyzed using indirect immunofluorescence double labeling immunohistochemistry and image analysis software. RESULTS: (1) Tregs were all located in medulla zone of thymus in control and MG groups. (2) Cells of germinal center had a high expression of CD25 and a low expression of CD4. It indicates that a majority of germinal center cells were B cells. (3) There were fewer Tregs around germinal center. (4) There was no statistical significant difference in absolute number of Tregs between the two groups (P > 0.05). But the proportion of Tregs was higher in control group (P < 0.05). CONCLUSION: The proportion of thymus Tregs decreases in MG so as to weaken the function of immuno-regulation and suppression. This is probably a precipitating factor of MG.

[Mediation of cellular immune response by TP5 in pathogenesis of myasthenia gravis].

OBJECTIVE: To evaluate the effects of TP5 upon the production of IFN-gamma and different T cell subsets by human peripheral blood mononuclear cells (PBMCs) from patients with myasthenia gravis (MG) and to provide experimental rationales for TP5 in clinical therapy of MG. METHODS: PBMCs were isolated from peripheral blood of MG individuals and cultured with anti-CD3. The level of IFN-gamma in culture supernatants was examined by ELISA. The subsets and frequency of IFN-gamma-producing cells were examined at a single-cell level by flow cytometry. RESULTS: After PBMCs stimulation with anti-CD3 and TP5 (300 microg/ml), the level of IFN-gamma expression was significantly inhibited (P(child) = 0.0001, P(adult) = 0.01); and the level of IFN-gamma expression from normal adult and child controls was also significantly inhibited (P(child) = 0.009, P(adult) = 0.0001). In addition, the inhibition of TP5 on the production of IFN-gamma by PBMCs from MG children was lower compared with normal child control. But as compared with normal adult control, the inhibition of TP5 showed no significant difference in MG adults (P(adult) = 0.481). TP5 inhibited the expression of IFN-gamma by CD8+ T cell and CD4+ T cell. CONCLUSION: TP5 can inhibit the response of cellular immune by decreasing the production of IFN-gamma in MG consequence display that the level of IFN-gamma significant decreased with the addition of TP5 and anti-CD3. But after considering the age, the level of IFN-gamma in MG children was no as much inhibited as normal child. TP5 inhibits the expression of IFN-gamma by CD8+ T and CD4+ T cells.