Abstract: TH-PO0048
Acute Presentation of Pulmonary-Renal Syndrome-Like Symptoms in a Patient with Malignant Hypertension, Probably Attributable to Atypical Hemolytic Uremic Syndrome
Session Information
- AKI: Pathogenesis and Disease Mechanisms
November 06, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Acute Kidney Injury
- 102 AKI: Clinical, Outcomes, and Trials
Authors
- Okawa, Hiroyuki, Kitasato Daigaku Igakubu, Sagamihara, Kanagawa Prefecture, Japan
- Wada, Yukihiro, Kitasato Daigaku Igakubu, Sagamihara, Kanagawa Prefecture, Japan
- Abe, Tetsuya, Kitasato Daigaku Igakubu, Sagamihara, Kanagawa Prefecture, Japan
- Takeuchi, Kazuhiro, Kitasato Daigaku Igakubu, Sagamihara, Kanagawa Prefecture, Japan
- Kato, Noritoshi, Nagoya Daigaku Daigakuin Igakukei Kenkyuka Igakubu, Nagoya, Aichi Prefecture, Japan
- Takeuchi, Yasuo, Kitasato Daigaku Igakubu, Sagamihara, Kanagawa Prefecture, Japan
Introduction
Atypical hemolytic uremic syndrome (aHUS) is a rare cause of thrombotic microangiopathy (TMA). Recently, malignant hypertension (MHT) has been reported as a relative common complication of aHUS. We describe a case with aHUS exhibiting pulmonary-renal syndrome (PRS)-like symptoms and hypertensive crisis.
Case Description
A 22-year-old man was admitted because of severe hypertension (HT), pulmonary hemorrhage, and severe renal disorder. Laboratory tests showed anemia, thrombocytopenia, elevated LDH, and low haptoglobin. Coagulation abnormalities, retinal hemorrhages, and renal artery stenosis were not observed. While considering PRS or MHT-induced TMA, we initiated CHDF, antihypertensive therapy, steroid therapy, and plasma exchange (PE). Thereafter, PE was discontinued and steroid was tapering because of the absence of autoantibodies including ANCA and anti-GBM Ab in addition to improvement of hematologic parameters. However, severe renal dysfunction persisted despite control of blood pressure, and he relapsed with pulmonary hemorrhage, anemia, thrombocytopenia, and low complement C3 on hospital day 14. In addition, 50% ADAMTS13 activity without inhibitor were detected. We concern for aHUS, thereby PE were restarted on day 19, followed by initiation of ravulizumab on day 26. Renal biopsy revealed glomerular ischemic change without any depositions. The lumens of interlobar arteries were remarkably narrowed. Anti-CFH Ab was negative, and results for genetic tests are currently pending. Consequently, the patient was discharged with improved hematologic parameters, cessation of dialysis, and normalized C3 (Figure).
Discussion
Clinicopathological findings in this case were consistent with TMA. Given the onset at a young age, decreased C3, and favorable response to PE and monoclonal Ab for C5, aHUS was considered as the underlying cause for MHT. This rare case underlines the difficulty of diagnosing aHUS in patients with severe HT.