Abstract
CT-871: Isolated Renal Thrombotic Microangiopathy After Match-Related Allogeneic Stem Cell Transplant: A Case Report and Diagnostic Considerations
Clinical lymphoma, myeloma and leukemia, Vol.25(Suppl 1), pp.S1033-S1033
09/2025
DOI: 10.1016/S2152-2650(25)02814-9
Abstract
Transplant-associated thrombotic microangiopathy (TA-TMA) is a complication of autologous and allogenic hematopoietic stem cell transplantation (HSCT). TA-TMA is characterized by microangiopathic hemolytic anemia (MAHA) with elevated markers for hemolysis and microvascular thrombosis. Absence of MAHA in TA-TMA is not common, and the initial absence of schistocytes has been reported in some cases. Here we report a case of TA-TMA without MAHA, with a review of diagnostic criteria.
A 25-year-old male underwent matched sibling allogenic HSCT for severe aplastic anemia. His post-HSCT course was complicated by cytomegalovirus viremia, BK virus cystitis, and delayed engraftment. Three months post HSCT, he developed worsening renal function, anemia, and thrombocytopenia. Acute kidney injury (AKI) was initially attributed to BK cystitis and cidofovir. Thrombocytopenia and anemia were attributed to poor graft function and were treated with elthrombopag and darbapoetin alpha. AKI continued to worsen and was later attributed to desferasirox side effects. Renovascular hypertension resulted in a seizure secondary to posterior reversible encephalopathy syndrome. Additional workup ensued: anti-GBM antibody, C3 and C4 complement levels, and soluble c5-b9 were normal. A panel of complement-mediated TMA (CH50, APFA, C3b deposit assay, FH autoAb, FB autoAB, Ba level, Bb level, Factor D level, FH level, and FI level) was unremarkable. University of Iowa Genetic renal panel v.8 (encompassing 13 genes) showed heterozygous DGKE H505N (variant of uncertain significance). With significant proteinuria, renal biopsy was pursued and showed extensive C4 stain, suggestive of renal TMA. Eculizumab was deferred due to improved renal function with blood pressure control. Interestingly, he never developed evidence of hemolysis, or manifestation of other TMA end-organ damage. Fourteen months post HSCT, the patient has now recovered graft function, transfusion independent, and current eGFR trends ~50 mL/min/1.73 m2.
TA-TMA arises from a multihit process involving predisposition to endothelial dysfunction or complement dysregulation, consolidative treatments, post-transplant alloreactivity, and infections. Diagnosis remains challenging due to multi-organ involvement and overlapping features with other transplant-related toxicities. Classic TMA laboratory abnormalities appear variably, with schistocytes being a late finding and potentially absent in severe cases due to increased endothelial permeability. Clinicians must maintain a high index of suspicion for TA-TMA, even without MAHA, to ensure timely supportive intervention.
Details
- Title: Subtitle
- CT-871: Isolated Renal Thrombotic Microangiopathy After Match-Related Allogeneic Stem Cell Transplant: A Case Report and Diagnostic Considerations
- Creators
- Lekha Yadukumar - University of IowaTushar Abhinav - The Wright Center for Graduate Medical EducationMargarida Magalhaes-Silverman - University of IowaHira Shaikh - University of IowaKittika Poonsombudlert - University of Iowa
- Resource Type
- Abstract
- Publication Details
- Clinical lymphoma, myeloma and leukemia, Vol.25(Suppl 1), pp.S1033-S1033
- DOI
- 10.1016/S2152-2650(25)02814-9
- ISSN
- 2152-2650
- Publisher
- Elsevier Inc
- Language
- English
- Date published
- 09/2025
- Academic Unit
- Hematology, Oncology, and Blood & Marrow Transplantation; Internal Medicine
- Record Identifier
- 9984949232402771
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