Amyotrophic lateral sclerosis with anti-acetylcholine receptor antibody.

We report a case of amyotrophic lateral sclerosis (ALS) with anti-acetylcholine receptor (AChR) antibody in a 73-year-old female patient. She showed the typical course of ALS. She had no clinical findings of myasthenia gravis and had never undergone neurotoxin therapy using snake venom. Anti-AChR antibody was positive with a titer of 0.50 nmol/l on admission. We traced the titers during the progression of ALS; the titer was positive when muscle weakness worsened, and it became negative when the general condition became stable. We suppose that the occurrence of anti-AChR antibody may be partially relevant with abnormalities at the neuromuscular junction during the progression of ALS.