Seronegative autoimmune autonomic neuropathy: a distinct clinical entity.

In these cases of autoimmune autonomic failure, key differences from seropositive AAG emerge. Testing showed prominent sympathetic (rather than cholinergic) failure, specific pupillary findings of AAG were absent, and sensory symptoms were prominent. AAG responds to antibody-targeted immunotherapy, while these patients responded best to steroids. This seronegative autoimmune autonomic neuropathy is a distinct clinical entity requiring a different treatment approach from AAG.