Type 1 AIP patients tended to be older and have a high relapse rate, but patients with Type 2 AIP do not experience relapse and tend to be younger.
Type 1 AIP is now regarded as a manifestation of IgG4-related disease, and those affected have tended to be older and to have a high relapse rate. Patients with Type 2 AIP do not experience relapse and tend to be younger.