Antiphospholipid syndrome is an autoimmune disease that is characterized by the presence of several antiphospholipid autoantibody types. The clinical presentation involves thromboembolic events affecting vessels of all sizes, ultimately predisposing the patient to malignant hypertension and life-threatening vascular insults in the kidneys, the brain, the lungs, and several other organs. In severe cases, multiorgan failure is seen, with mortality rates of 50%. Thus, an early diagnosis is mandatory. The criteria consist of pregnancy-related events, laboratory confirmation of autoantibodies, and signs of blood vessel abnormalities.
Antiphospholipid syndrome is a still incompletely understood autoimmune disorder that possesses a highly variable clinical presentation, as virtually any organ or part of the body may be affected by the vascular pathological changes that occur . The symptoms stem from two events - formation of venous (or sometimes arterial) thrombosis and thrombotic microangiopathy (TMA)   . Venous thrombosis of the lower extremities is regarded as a frequent finding in patients with antiphospholipid syndrome, whereas pulmonary embolism (developing either from distal thrombi or cardiac valve vegetations) can appear in up to 50% of cases . In addition to the lower extremities, thrombotic changes often affect the subclavian, retinal, and renal arteries . In fact, the kidneys are the primary site where both thrombotic and TMA-related effects of antiphospholipid syndrome are exerted  . Occlusion of both larger and smaller renal vessels leads to profound hypertension, proteinuria, and renal insufficiency that presents with anuria . Apart from the kidneys, other organs that are prone to damage are the brain, the heart, the lungs, and the skin  . The term "catastrophic antiphospholipid syndrome" is used to describe patients who suffer from life-threatening forms of this disease  . Hypertension, hemolytic anemia, disseminated intravascular coagulation (DIC), microthrombotic events involving the heart and the brain, as well as adult respiratory distress syndrome (ARDS), are hallmarks of catastrophic antiphospholipid syndrome, which carries a mortality rate of 50%   .
The recognition of antiphospholipid syndrome rests on a thorough clinical and laboratory assessment and the diagnostic criteria are comprised of the following:
Although nephropathy, thrombocytopenia, and valvular heart disease are notable findings in these patients, at least one clinical and one laboratory criteria are needed in order to make the diagnosis of the antiphospholipid syndrome   .