Racial differences in myasthenia gravis in Alabama

Abstract

Demographic, clinical, and laboratory features were compared in 235 white and African-American (AA) patients with myasthenia gravis (MG) at the University of Alabama at Birmingham Neuromuscular Disease Clinic from May 2003 to January 2008. Seventy nine percent of patients were white. Acetylcholine receptor antibody was positive in 71% of white patients and in 59% of AA. In patients with seronegative generalized MG, the rate of positive muscle-specific tyrosine kinase antibody (MuSK-Ab) was significantly higher in AA than it was in whites (50% in AA vs. 17% in whites). Ocular MG was seronegative in 75% of AA patients. In AA, MG occurred earlier and more frequently in females, whereas, in whites, disease onset was later and more common in males. Another significant difference was a higher percentage of abnormality on repetitive nerve stimulation in AA. There was also a tendency for more severe forms of MG in AA. There are racial differences in MG between whites and AA in Alabama. These racial differences highlight the need to study biological factors in the pathogenesis of MG and to assess different approaches in diagnosis and treatment.

Clinical findings in MuSK‐antibody positive myasthenia gravis: A U.S. experience

“…13 A general impression is that MuSK MG patients fare worse than AChR-Ab-positive patients. 26 This impression is based on the remission rate.…”

“…11 An ''improved'' (I) status was defined as any of the following: improvement to normal (MGFA 0 class), complete stable or pharmacologic remissions (R), ''minimal manifestation'' (MM) status, or at least a two-class improvement by MGFA clinical classification. 13 Any improvement that did not meet these criteria was recorded as ''minimally improved'' (MI).…”

“…12 MGFA classification was based on overall assessment of symptoms and signs. 13 Patients were also classified by the MGFA postintervention status at their last follow-up. 11 To evaluate treatment response and long-term (3 years) outcome, we used the MGFA postintervention status.…”

Muscle-Specific Receptor Tyrosine Kinase Antibody Positive Myasthenia Gravis Current Status

“…The most striking racial difference was observed between whites and African-Americans (AA) in the United States. Oh et al41 reported a significantly higher positive rate (50%) of MuSK-Ab in AA compared with that (17%) in whites in Alabama, USA. This difference was also observed in three different institutions in the USA, confirming that this racial difference is genuine 42.…”

Characteristics of myasthenia gravis according to onset-age: Japanese nationwide survey

“…African patients present with a lower positivity for anti-acetylcholine receptor (AChR) antibodies, a higher positivity for anti-MuSK antibodies, and a more severe form of disease, compared with Caucasians [4]. A high frequency of juvenile-onset MG has been described in Asian countries [5][6][7][8]; in China, 39-50% of all MG patients were reportedly children (b15 years) [6,7].…”