Vasculopathy of the Antiphospholipid Syndromes Revisited: Thrombosis is the Culprit and Vasculitis the Consort

Abstract

Whether the vasculopathy in APS is thrombosis or vasculitis is more than a mere academic interest; the distinction is important not only for unravelling the pathogenesis of vascular injuries in APS but also for selecting the appropriate choice of drug treatment. A diagnosis of vasculitis would call for treatment with corticosteroids and cytotoxic agents which are not without serious side effects and drug toxicity. The same powerful but potentially dangerous drugs are clearly quite ineffectual in treating or preventing thrombosis associated with APS which has been known to respond in the lowly and inexpensive aspirin. The vasculopathy of APS remains almost exclusively thrombotic in nature according to our current state of knowledge, even if one were to accept capillaritis as a bona fide member in the family of vasculitides, the ‘microangiitis’. Vasculitis secondary to an independent underlying disease, such as SLE, may coexist with APS in a patient. In the management of APS patients, the distinction between a true vasculitis coincidental with and one that is causally related to APS affects clinical decision making, and not just a matter of semantics or an academic curiosity. In vasculopathy of APS, thrombosis is the culprit and vasculitis, when present, is the consort. This is still true until newer and more convincing evidence emerges and proves to be contrary.