Capillary leak syndrome as a complication of antibody-mediated rejection treatment: a case report

We report a case of capillary leak that developed during treatment of antibody-mediated rejection in a kidney transplant recipient. A 53-year-old female transplant recipient experienced an increase in serum creatinine from 1.1 to 1.8 mg/dL. Antibody-mediated rejection was diagnosed by graft biopsy. She was treated with five plasmapheresis sessions (on alternate days with albumin replacement), five doses of immunoglobulin (5 g/dose at 100 mg/kg), a single dose of rituximab (500 mg), and four doses of bortezomib on days 1, 4, 7, and 10 (1.72 mg/dose at 1.3 mg/m² body surface area). During treatment, edema, slight diarrhea, pancytopenia, hypoalbuminemia, peripheral neuropathy, and postural hypotension were noted. Despite control of liquids, she presented with edema progressing to an increase of more than 10 kg body weight. Prerenal acute graft dysfunction associated with hypotension was diagnosed on day 12, heart failure or other infectious complications being discounted. On day 13, daily hemodialysis was prescribed, and a stable volume status was reached after five hemodialysis sessions. On day 20, the patient recovered diuresis and the edema and diarrhea abated, but she remained on chronic hemodialysis. After excluding other causes of distributive shock, the diagnosis of capillary leak syndrome was based on the presence of hypotension, generalized edema, and hypoalbuminemia in the absence of significant proteinuria. The concomitant presence of diarrhea, peripheral neuropathy, and pancytopenia, suggest a possible causal role for bortezomib. Awareness by clinicians of capillary leak syndrome associated with bortezomib-based treatment of AMR is paramount, despite its rarity.