Kidney disease in antiphospholipid antibody syndrome: Risk factors, pathophysiology and management

Antiphospholipid antibody syndrome (APLS) is a rare autoimmune disease characterized by recurrent arterial and venous thromboembolic events, pregnancy related complications as well as the persistent detection of antiphospholipid antibodies at a 12 week interval. Renal complications tend to occur in 3% of APLS patients, with renal artery stenosis being the most common kidney related complication. Renal pathology may be subdivided into macro as well as microvascular thrombotic complications with stenosis, thrombosis and infarction representing the principle macrovascular events and APLS nephropathy representing the predominant microvascular complication. APLS related kidney disease may present with an array of heterogenous manifestations ranging from hematuria and non-nephrotic range proteinuria to hypertension or as part of a severe, life threatening and fulminant multiorgan failure disorder known as catastrophic antiphospholipid antibody syndrome (CAPS). Management of APLS related renal complications depends on the site of vascular injury, the thromboembolic risk profile based on the subtype, isotype and titer of the autoantibodies as well as the severity of the injury. Primary prophylaxis in these patients primarily revolves around the use of low dose aspirin, with prophylactic anticoagulation during events that increase thromboembolic like surgery and hospitalization. Anticoagulation is the cornerstone of treatment of APLS related kidney disease with INR targets varying depending on the associated venous or arterial thrombosis. Immunosuppression with the likes of rituximab, mTOR inhibitors, eculizumab and belimumab have been used with some success, but lack randomized control trial validation for their use. Pulsed corticosteroids with Plasmapheresis and intravenous immunoglobulins is the recommended treatment for CAPS.

Concurrent arterial and venous thrombosis in a patient with catastrophic antiphospholipid syndrome

BACKGROUND

Antiphospholipid syndrome (APS) is marked by arterial, venous, or small vessel thrombosis. There have been few reported cases on APS presenting as thrombosis simultaneously involving large arteries and venous side of the blood circulation. CAPS can easily be confused with DIC, HIT, and other TMA. Anticoagulants remain the mainstay of treatment for CAPS, whereas in DIC and TMA, anticoagulants have no role.

CASE PRESENTATION

A 43-year-old male presented to our facility with a chief complaint of right foot pain, calf cramps, and shortness of breath. The patient's right dorsal pedal artery was not palpable. CT angiogram showed bilateral pulmonary emboli (fig.1), emboli within the right saphenofemoral artery (SFA), and popliteal artery (PA). Digital subtraction angiogram showed occlusive thrombi in SFA and in the PA. Thrombolysis was performed by an intra-arterial catheter-directed tissue plasminogen activator. Agitated saline bubble study showed no evidence of atrial shunting. The patient was noted to have thrombocytopenia, hypofibrinogenemia, high serum D-Dimer and normal activated partial thromboplastin time (APTT). The patient tested positive for anticardiolipin (aCL) antibodies and lupus anticoagulant (LA). After 12 weeks, aCL antibodies and LA testing were suggestive of APS.

CONCLUSION

Simultaneous thrombosis in large arteries and veins is a very unusual presentation for the APS. The patients should be started on anticoagulants immediately as the mortality rate associated with CAPS is high and the key to management is initiating anticoagulants expeditiously.