Clinical trial NCT01102192: The Role of the Thymus in Myasthenia Gravis
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Myasthenia Gravis
Thymoma
Keywords: Myasthenia gravis
Thymoma
T-cells
Thymectomy
Lead sponsor: Charite University, Berlin, Germany
Sponsor class: OTHER
Collaborators: name: NeuroCure Clinical Research Center, Charite, Berlin
First posted: 2010-04-13
Enrollment: 20
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: CASE_CONTROL
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Patients with and without Mystenia gravis (with and without thymona) and patients with an indication for a heart or thyroid surgery

Brief summary: Although the association between thymic hyperplasia / thymoma and autoimmune myasthenia gravis has been known for some time, the question of causality remains uncertain. Recent research findings indicate, however, that especially in myasthenia patients with thymomas a non-physiological export of naive CD4 + T-cells can take place by the tumour and this could possibly play an important role in the pathogenesis of myasthenia gravis. The investigators want to analyse the functionality and specificity of t-cells generated in thymomas as well as the effect of thymectomy on the immune system.

Detailed description: On one hand we want to perform a detailed analysis of the T-cells generated in thymomas in terms of their functional capacity and their specificity. We will analyse blood and thymoma tissue of patients with myasthenia gravis with thymona, patients with myasthenia gravis without thymona, and patients with thymona without myasthenia gravis.

Hypothesis: The T-cells which are generated in the thymoma in thymoma-associated myasthenia gravis can be differentiated from T-cells which are generated in normal thymoma tissue with regard to functionality and T-cell receptor specificity. This non-physiological T-cell maturation might be the cause for the formation of auto-antibodies.

On the other hand we want to examine the effects of thymectomy on the immune system in the context of myasthenia gravis. We will analyse blood and thymoma tissue of patients with myasthenia gravis with thymona, patients with myasthenia gravis without thymona, patients with thymona without myasthenia gravis and patients with cardiac, or thyroid surgery.

Hypothesis:

1. Thymectomy in patients with myasthenia gravis leads to a reduced number of auto-reactive, e.g. Acetylcholine receptor (ACh-R)-specific T cells. In contrast, T-cells with other specifities, for example against CMV or tetanus, are not affected.
2. The non-physiological export of thymocytes from thymomas leads to a significant shift in leukocyte populations in peripheral blood.

Eligibility criteria: Inclusion Criteria:

* Patients with compelling indications for thymectomy due to thymoma (with or without myasthenia gravis), Or
* Patients with elective indication for thymectomy due to thymoma without myasthenia gravis
* Patients with indication for a heart or thyroid surgery, in which for op-technical reasons, a (partial) resection of the thymus is performed.
* Signed informed consent form
* Age \> 17 Years

Exclusion Criteria:

* Other immunological diseases such as rheumatoid arthritis, multiple sclerosis

Primary outcomes:
Secondary outcomes:
Other outcomes:
Locations:
city: Berlin
country: Germany
facility: Charite University (Dept of Neurology & NeuroCure Clinical Research Center NCRC)
Study officials:
affiliation: Charite University, Berlin, Germany
name: Andreas Meisel, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Kohler S, Keil T, Alexander T, Thiel A, Swierzy M, Ismail M, Ruckert JC, Meisel A. Altered naive CD4+ T cell homeostasis in myasthenia gravis and thymoma patients. J Neuroimmunol. 2019 Feb 15;327:10-14. doi: 10.1016/j.jneuroim.2019.01.005. Epub 2019 Jan 11.
citation: Kohler S, Keil TOP, Hoffmann S, Swierzy M, Ismail M, Ruckert JC, Alexander T, Meisel A. CD4+ FoxP3+ T regulatory cell subsets in myasthenia gravis patients. Clin Immunol. 2017 Jun;179:40-46. doi: 10.1016/j.clim.2017.03.003. Epub 2017 Mar 9.
citation: Kohler S, Keil TO, Swierzy M, Hoffmann S, Schaffert H, Ismail M, Ruckert JC, Alexander T, Hiepe F, Gross C, Thiel A, Meisel A. Disturbed B cell subpopulations and increased plasma cells in myasthenia gravis patients. J Neuroimmunol. 2013 Nov 15;264(1-2):114-9. doi: 10.1016/j.jneuroim.2013.09.006. Epub 2013 Sep 18.