Microangiopathic hemolytic anemia due to ADAMTS-13 loss in idiopathic systemic capillary leak syndrome

Essentials Idiopathic systemic capillary leak syndrome (SCLS) is characterized by episodes of vascular leakage. We present the case of a patient with SCLS who developed microangiopathic hemolytic anemia (MAHA). We propose that this anemia is the result of ADAMTS-13 loss in the third-space fluid. This suggests that MAHA can occur in patients with significant extravasation of proteins. Summary: Idiopathic systemic capillary leak syndrome (SCLS) is a rare process characterized by acute and recurrent episodes of vascular leakage with severe hypotension, hypoalbuminemia, hemoconcentration and edema. Anemia and thrombocytopenia are not part of this syndrome, but here we present the case of a pediatric patient with a clinical presentation consistent with SCLS who subsequently developed microangiopathic hemolytic anemia at a time when she had significant fluid loss and anasarca. Based on serial ADAMTS-13 levels, we propose that the anemia in this patient developed as a result of ADAMTS-13 loss in the third-space fluid, a novel mechanism for acquired microangiopathic hemolytic anemia.