PAN is associated with

Polyaeritis nodosa (PAN) is a systemic vasculitis of small or medium-sized muscular aeries that typically involves the renal and visceral vessels and spares the pulmonary circulation. There is no association with ANCAs, but a third of the patients have chronic hepatitis B infection, which leads to the formation of immune complexes containing hepatitis B antigens that deposit in affected vessels. The cause is unknown in the remaining cases. (Robbins Basic Pathology,9th edition,pg no.352)