Epidemiological study of myasthenia gravis in Japan

AbstractMyasthenia gravis (MG) is an autoimmune-mediated neurological disorder. The relationship between MG and thymic abnormalities is well recognized, and thymectomy is one of the therapies for anti-acetylcholine receptor (AChR) antibody-positive MG. The major pathogenic factor is anti-AChR antibody followed by anti-muscle specific kinase (MuSK) antibody, and commercial kits are available to detect these antibodies. Several decades ago, the prognosis of MG was not favorable; therefore, the Ministry of Health and Welfare (predecessor of the Ministry of Health, Labour and Welfare) organized a Taskforce for intractable diseases, which included MG, in 1972. The Taskforce performed consecutive epidemiological studies for MG in 1973, 1987, 2006, and 2018. The four studies revealed: 1) increasing prevalence, 2) increasing late- and elderly-onset, 3) decreasing female dominancy, 4) decreasing infantile-onset (onset age of 0- 4  years), and 5) decreasing frequencies of crisis. The latest epidemiological study in Japan and studies from other countries suggest an increasing number of patients with anti-AChR antibody-positive MG without thymoma in the elderly. It is important to find out the causes of this phenomenon, which will improve the prevention of MG.
Source: Clinical and Experimental Neuroimmunology - Category: Neurology Authors: Tags: INVITED REVIEW Source Type: research