P BALI1, L HIDAYATI1, C NELSON1, C DOW1,2,3
1Western Health, Footscray, Australia, 2Dorevitch pathology at Western Health, 3Department of Medicine, University of Melbourne
Background: Thrombopoietin- receptor agonists increase platelet count by stimulating megakaryocytes. Eltrombopag is reserved for patients with idiopathic thrombocytopenic purpura (ITP) who fail to respond to steroids and immunoglobulin. There are two reported cases of acute renal failure associated with eltrombopag in patients with antiphospholipid antibodies, however no cases of renal limited thrombotic microangiopathy (TMA) have been described.
Case report: 64-year-old female presented with a five-week history of nausea, vomiting and reduced oral intake. Her past medical history included steroid intolerant ITP and recent unprovoked pulmonary embolus on apixaban. She was commenced on Eltrombopag ten weeks prior to her admission and her creatinine was 76 μmol/L at the time. She was admitted with oliguric acute kidney injury, haemoproteinuria and creatinine of 477 μmol/L (eGFR of 8mls/min/1.73m2). Autoimmune serology and imaging did not identify a cause of renal impairment. Despite intravenous fluids her creatinine peaked at 789 μmol/L and she was commenced on haemodialysis. She was started on oral prednisolone for presumed acute interstitial nephritis and eltrombopag and apixaban were ceased. Renal biopsy showed subacute TMA predominantly affecting glomerular arterioles and small cortical arteries with focal thrombosis of glomerular capillaries and more widespread evidence of glomerular capillary endothelial damage. There was no peripheral evidence of TMA and her ADAMTS13 was normal (62.5). She was commenced on plasma exchange daily for five days and then alternate daily for two weeks. Her creatinine improved to 190 μmol/L and she was no longer dialysis dependent.
Conclusion: Eltrombopag associated renal limited TMA is very rare. The treatment options are limited and plasma exchange could be considered in the setting of delayed renal recovery.
Parul is a final year advanced trainee in nephrology based at the Royal Melbourne Hospital and has completed her first two years of advanced training at Western Health.