Myasthenia Gravis With Acetylcholine Receptor Antibodies in the Very Old: Treatment Challenges and Diagnostic Pitfalls.

[BACKGROUND] In myasthenia gravis (MG) with acetylcholine receptor (AChR) antibodies, epidemiology, disease mechanisms, diagnosis, and treatment depend on age. MG with debut after 65 years has an increasing incidence and prevalence but is underrepresented in clinical studies.

[METHODS] This is a systematic review of very late onset MG and MG in patients above 65 years with focus on epidemiology, pathogenesis, diagnosis, clinical characteristics, and treatment.

[RESULTS] Both innate and adaptive immune responses are influenced by age. The increase in MG incidence in the very old is probably caused by unknown environmental factors. Both patients' and doctors' diagnostic delays are substantial for very late onset MG. Comorbidities are frequent and can lead to misdiagnosis. MG needs to be considered as a potential diagnosis in all elderly patients with newly localized or generalized muscle weakness. AChR antibodies have near 100% diagnostic specificity and 80% sensitivity in this age group. Very late onset MG is often mild and with an excellent response to pyridostigmine and first-line immunosuppressive therapy. One in five has a debut with life-threatening respiratory insufficiency. Rituximab, complement inhibitors, and FcRn blockers can be used on the same indications as for younger MG patients. MG in the very old is a fluctuating disease with the need of frequent adjustments of drug therapy.

[CONCLUSIONS] Very late onset MG and MG in the very old should be treated actively with symptomatic and immunosuppressive drugs, physical activity programs, and general support. The treatment aim should be pharmacological remission or minimal manifestations only.