{"title":"A single-center experience of post-transplant atypical hemolytic uremic syndrome.","authors":"Bassam G Abu Jawdeh, Muhammad A Khan","doi":"10.5414/CN111160","DOIUrl":null,"url":null,"abstract":"<p><strong>Purpose: </strong>Atypical hemolytic uremic syndrome (aHUS) is a genetic-based thrombotic microangiopathy (TMA) that is mediated by the activation of the alternative complement pathway. Heterozygous deletion in CFHR3-CFHR1 occurs in 30% of the general population and has not been classically linked to aHUS. Post-transplant aHUS has been associated with a high rate of graft loss. Herein, we report our case series of patients who developed aHUS after solid-organ transplantation.</p><p><strong>Materials and methods: </strong>Five consecutive cases of post-transplant aHUS were identified at our center. Genetic testing was performed in all but one.</p><p><strong>Results: </strong>One patient had a presumed TMA diagnosis before transplant. One heart and 4 kidney (KTx) transplant recipients were diagnosed with aHUS based on the clinical picture of TMA, acute kidney injury, and normal ADAMTS13 activity. Genetic mutation testing revealed heterozygous deletion in CFHR3-CFHR1 in 2 patients and a heterozygous complement factor I (CFI) variant of uncertain clinical significance (VUCS) (Ile416Leu) in a third. Four patients were on tacrolimus, 1 had anti-HLA-A68 donor-specific antibody (DSA), and another had borderline acute cellular rejection at the time of aHUS diagnosis. Four responded to eculizumab, and 1 out of 2 patients came off renal replacement therapy. One KTx recipient died from severe bowel necrosis in the setting of early post-transplant aHUS.</p><p><strong>Conclusion: </strong>Calcineurin inhibitors, rejection, DSA, infections, surgery, and ischemia-reperfusion injury are common triggers that could unmask aHUS in solid-organ transplant recipients. Heterozygous deletion in CFHR3-CFHR1 and CFI VUCS may be important susceptibility factors acting as the first hit for alternative complement pathway dysregulation.</p>","PeriodicalId":10396,"journal":{"name":"Clinical nephrology","volume":"100 2","pages":"75-81"},"PeriodicalIF":1.1000,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Clinical nephrology","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.5414/CN111160","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"UROLOGY & NEPHROLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Purpose: Atypical hemolytic uremic syndrome (aHUS) is a genetic-based thrombotic microangiopathy (TMA) that is mediated by the activation of the alternative complement pathway. Heterozygous deletion in CFHR3-CFHR1 occurs in 30% of the general population and has not been classically linked to aHUS. Post-transplant aHUS has been associated with a high rate of graft loss. Herein, we report our case series of patients who developed aHUS after solid-organ transplantation.
Materials and methods: Five consecutive cases of post-transplant aHUS were identified at our center. Genetic testing was performed in all but one.
Results: One patient had a presumed TMA diagnosis before transplant. One heart and 4 kidney (KTx) transplant recipients were diagnosed with aHUS based on the clinical picture of TMA, acute kidney injury, and normal ADAMTS13 activity. Genetic mutation testing revealed heterozygous deletion in CFHR3-CFHR1 in 2 patients and a heterozygous complement factor I (CFI) variant of uncertain clinical significance (VUCS) (Ile416Leu) in a third. Four patients were on tacrolimus, 1 had anti-HLA-A68 donor-specific antibody (DSA), and another had borderline acute cellular rejection at the time of aHUS diagnosis. Four responded to eculizumab, and 1 out of 2 patients came off renal replacement therapy. One KTx recipient died from severe bowel necrosis in the setting of early post-transplant aHUS.
Conclusion: Calcineurin inhibitors, rejection, DSA, infections, surgery, and ischemia-reperfusion injury are common triggers that could unmask aHUS in solid-organ transplant recipients. Heterozygous deletion in CFHR3-CFHR1 and CFI VUCS may be important susceptibility factors acting as the first hit for alternative complement pathway dysregulation.
期刊介绍:
Clinical Nephrology appears monthly and publishes manuscripts containing original material with emphasis on the following topics: prophylaxis, pathophysiology, immunology, diagnosis, therapy, experimental approaches and dialysis and transplantation.