--is most often associated with Churg-Strauss syndrome, a vascuitic/cutaneous tissue inflammation that is considered part of the broad range of autoimmune syndromes that are grouped under connective tissue disorders. There are also some drug-induced situations that may result in a positive titre, and cardiomyopathic inflammation can result in a positive titre in some cases as well.

See:

http://neuromuscular.wustl.edu/antib...tml#vasculitis

http://neuromuscular.wustl.edu/nothe...body.html#anca