Humoral and cellular immunity to intrinsic factor in myasthenia gravis.

Myasthenia gravis (MG) is an autoimmune disease often associated with other autoimmune disorders. A case history of MG with a coexisting atypical megaloblastic anaemia with vitamin B12 deficiency and anti Intrinsic Factor (IF) antibodies, led to a study of humoral and cellular immunity to IF in 81 MG patients. Within this series, 3 other patients had a disturbed humoral and cellular immunity to IF. These 3 patients presented no other features of pernicious anaemia. The possible origins and significance of the anti IF antibodies in MG patients are discussed.