Interesting case for the weekend: young woman with known lupus, baseline normal kidney function; admitted initially with headaches and "feeling more lupusy than usual", found to have a creatinine of 2.5 on admission with some dysmorphic RBCs on u/a and low complements. Presumed to have lupus nephritis and a biopsy was deferred for several days due to significant thrombocytopenia. When her Cr kept on increasing to the 5's & platelets had improved, a biopsy was eventually performed, and did NOT show lupus nephritis: instead, it showed rip-roaring thrombotic microangiopathy! The patient's lupus anticoagulant is positive, and we are now operating on the assumption that she has renal failure based on antiphospholipid antibody syndrome-induced TMA. How do we treat it?
Catastrophic Antiphospholipid Syndrome (CAPS) describes a rare subset (about 1%) of patients with APLAS who develop significant end-organ damage as a result of widespread thrombotic occlusion. It can cause kidney damage by virtue of thrombic microangiopathy. In addition to treatment with anticoagulants (e.g., coumadin) , steroids, and possibly IVIG, there is also a purported role for therapeutic plasma exchange. There is however a controversy as to what type of replacement fluid should be given: some believe that FFP should be used, as it contains "natural anticoagulants" which may help in treating the underlying condition, while other believe that albumin should be used, using the rationale that the clotting factors, cytokines, and complement activation products present in FFP could worsen the "thrombotic storm" driving the thrombotic microangiopathy. Although the numbers are small, current data seems to indicate that plasma exchange does help in the treatment of this condition with relatively high morbidity & mortality.