Abstract: PUB157
The Masquerading Diagnosis of Secondary Thrombotic Microangiopathy
Session Information
Category: Trainee Case Report
- 1202 Glomerular Diseases: Immunology and Inflammation
Authors
- Sabescumar, Janany Jansy, University of Rochester Medical Center, Rochester, New York, United States
- Komisarof, Justin, University of Rochester Medical Center, Rochester, New York, United States
- Levy, David, University of Rochester Medical Center, Rochester, New York, United States
- Goldman, Bruce, University of Rochester Medical Center, Rochester, New York, United States
Introduction
Thrombotic microangiopathy (TMA) is an umbrella term defined by hemolytic anemia, thrombocytopenia and end organ damage secondary to microvascular thrombi. TMA is subclassified as either inherited or acquired (i.e lupus). We report a case of secondary TMA initially masquerading as atypical HUS.
Case Description
A 27 year old female with no significant medical history presented with shortness of breath for one month. She was noted to have acute kidney injury and new onset congestive heart failure. An echocardiogram revealed a dilated left ventricular and a severely reduced ejection fraction (10%). Her admission labs were notable for platelet count of 57, creatinine of 7.4 and schistocytes on peripheral smear. Given the concern for thrombotic thrombocytopenic purpura (TTP), an ADAMST13 level was drawn and plasmapheresis was initiated. Despite therapy, her kidney function worsened. As there were no overt causes of TMA, such as anti-phospholipid syndrome, infections, malignancy, or drugs, we strongly suspected aHUS and administered one dose of eculizumab. On hospital day 4, a kidney biopsy was performed which revealed an immune complex deposition driven glomerulonephritis with significant TMA as well as membranoproliferative changes consistent with class IV/V lupus nephritis. Eculizumab was discontinued and she was started on cyclophosphamide and pulse dose steroids. Her kidney function continued to decline and she eventually required hemodialysis. Serial echocardiograms revealed improvement in cardiac function and she was discharged from the hospital on dialysis.
Discussion
TMA can occur with autoimmune diseases. Although the mechanism remains unclear, there is evidence of complement activation leading to injury. For these cases, there is no evidence that treating TMA itself changes outcomes. It is important to distinguish between the causes of TMA as treatment differs between primary and secondary. There are current ongoing trials of the use of eculizumab in lupus nephritis, however current guidelines recommend induction treatment using cyclophosphamide and steroids. The cause of her heart failure remained unclear, thought was secondary to microvascular coronary damage from SLE.