New subsets of the antiphospholipid syndrome in 2006: "PRE-APS" (probable APS) and microangiopathic antiphospholipid syndromes ("MAPS").

The concept of "probable" antiphospholipid syndrome (APS) is almost identical with several conditions which may presage the development of the APS with its major complications of large vessel thromboses resulting in deep vein occlusions in the lower limbs (DVT) particularly and strokes. These conditions comprising livedo reticularis, chorea, thrombocytopenia, fetal loss and valve lesions. These conditions, comprising livedo reticularis, chorea, thrombocytopenia, fetal loss and valve lesions may be followed, often years later by diagnosable APS. The issue whether these patients should be more aggressively treated on presentation in order to prevent the thrombotic complications. A new subset of the APS is proposed viz. microangiopathic antiphospholipid syndrome ("MAPS") comprising those patients presenting with thrombotic microangiopathy and demonstrable antiphospholipid antibodies who may share common although not identical provoking factors (e.g. infections, drugs), clinical manifestations and haematological manifestations (severe thrombocytopenia, hemolytic anaemia) and treatments viz. plasma exchange. Patients without large vessel occlusions may be included in the MAPS subset. These conditions include thrombotic thrombocytopenic purpura (TTP), hemolytic-uremic syndrome (HUS), and the HELLP syndrome. Patients with catastrophic antiphospholipid syndrome (CAPS) who do not demonstrate large vessel occlusions also fall into this group. Disseminated intravascular coagulation (DIC) has also been reported with demonstrable antiphospholipid antibodies and also manifests severe thrombocytopenia and small vessel occlusions. It may cause problems in differential diagnosis.