Wegener's granulomatosis pathophysiology


 * Associate Editor-In-Chief:

Pathophysiology
Inflammation with granuloma formation against a nonspecific inflammatory background is the classical tissue abnormality in all organs affected by Wegener's granulomatosis.

It is now widely presumed that the anti-neutrophil cytoplasmic antibodies (ANCAs) are responsible for the inflammation in Wegener's. The typical ANCAs in Wegener's are those that react with proteinase 3, an enzyme prevalent in neutrophil granulocytes. This type of ANCA is also known as cANCA, with the cindicating cytoplasmic (in contrast to pANCA, which is perinuclear).

ANCAs activate neutrophils, increase their adherence to endothelium, and lead to their degranulation. This causes extensive damage to the vessel wall, particularly of arterioles.

The exact cause for the production of ANCAs is unknown, although some drugs have been implicated in secondary forms of Wegener's. As with many autoimmune disorders, the cause is probably genetic predisposition combined with molecular mimicry caused by a virus orbacterium.