The exact pathogenesis of PAN is not fully understood.It is a disease of unknown cause that affects arteries, the blood vessels that carry oxygenated blood to organs and tissues.PAN affects the medium sized arterial vessels.PAN does not affect large arterial vessels, capillaries, small arterioles and venous system. It occurs when certain immune cells attack the affected arteries.Inflammation starts in the vessel intima and results in fibrinoid necrosis by destroying the internal and external elastic lamina.Aneurysms and thrombi may develop at the site of lesions.One hypothesis is that this condition is caused by antibodies against HBV, via a  type IIII hypersensitivity reaction.Due to inflammation of the medium to small sized vessels in PAN and the presence of impaired endothelial function, there could be direct endothelial cell activation and damage resulting from proinflammatory cytokines or antibodies (anti-endothelial cells antibodies).Mutation in CECR1 can lead to vascular and inflammatory disorders which also include PAN.
Polyarteritis nodosa pathophysiology
Buerger's disease pathophysiology
Microscopic polyangiitis pathophysiology
Takayasu's arteritis pathophysiology
Polyarteritis nodosa epidemiology and demographics
Uveitis pathophysiology
Microscopic polyangiitis risk factors
Polyarteritis nodosa risk factors