Tehran University of Medical Sciences Current Journal of Neurology 2717-011X 13 1 2014 03 15 40 44 Zeinab Peimani Student Research Comittee, Shiraz University of Medical Sciences, Shiraz, Iran. Mohammad Amin Banihashemi Research Center for Traditional Medicine and History of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran. Niloofar Namazi Student Research Comittee, Shiraz University of Medical Sciences, Shiraz, Iran. Anahid Safari Department of Pharmacology, School of Medicine, Islamic Azad University, Kazeroon Branch, Kazeroon, Iran. Ahmad Monabati Department of Pathology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran. Mehra Mojallal Department of Pathology, Dena Hospital, Shiraz, Iran. Afshin Borhani-Haghighi Health Policy Research Center, Shiraz University of Medical Sciences, Shiraz, Iran ; Department of Neurology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran. 2015 10 14 Background:  Myasthenia  gravis (MG) is an  autoimmune disorder   characterized   by  weakness   and   fatigability  of skeletal muscles. The aim of this study was to determine if pathological characteristics in non-thymomatous patients of MG would correlate with prognosis in a three year follow up. Methods:  Patients  who  had  had  their  thymectomy   at least  three  years prior to  the  study  were  selected  from three  hospitals  and were followed for 3 years. Prognosis was assessed  via a devised  prognostic  scoring system. A pathological  exam of the specimen  from the thymus was done  using the following immunohistochemical markers: Bcl2, CD 3, CD 4, CD 5, CD 7, CD 10, CD 20cy, CD 23, CD 43, and Ki67. Results: Fifteen patients  fulfilled the inclusion criteria and had a complete  follow-up. This included  3 males and 12 females with a mean age of 36.6 years at the start of the  study. The dominant  cell population was T lymphocytes. All T cells expressed  CD 3, CD 43, CD 5, and  Bcl-2. In  2 patient , CD 10 marker was positive in T cells. B cells were negative for activation marker CD 23, except for germinal center   dendritic   cells.  Due  to  the  limited  number   of patients  in the study, the power of the study would not allow for an analysis to assess correlation between histopathological data and prognosis. Conclusion: This pilot study was an attempt to discover any prognostic indices from the histopathological examination  of the resected  thymic tissue in the patients with myasthenia gravis. https://ijnl.tums.ac.ir/index.php/ijnl/article/view/626 https://ijnl.tums.ac.ir/index.php/ijnl/article/download/626/176