Atypical Hemolytic Uremic Syndrome in a Patient with Acute Promyelocytic Leukemia: A Case Report

Introduction: Acute Promyelocytic Leukemia (APL) is highly associated with hemostasis alterations. The atypical hemolytic uremic syndrome (aHUS) is a rare type of Thrombotic Microangiopathy (TMA) due to an overactivation of the alternative complement pathway. Case Presentation: A 48-years-old woman was diagnosed with APL and achieved molecular remission after induction therapy. During the second consolidation cycle she presented with TMA. She began treatment with plasma exchange plus corticotherapy but due to aggravation of symptoms Eculizumab was initiated. Thrombotic thrombocytopenic purpura, infections and drug toxicity causes were ruled out. There was no evidence of relapse of the APL. Genetic studies of the hereditary anomalies of the alternative complement pathway were negative and the decision of stopping Eculizumab was made. During maintenance therapy for the APL she presented a severe relapse of the aHUS, requiring dialysis. She re-started treatment with Eculizumab with a progressive hematologic recovery and improvement of renal function. She completed APL treatment without relapse of the leukemia for the moment and continues to be treated with Eculizumab. Conclusion: This is the first published case of coexisting aHUS and APL successfully treated with Eculizumab.

Update on hemolytic uremic syndrome:Diagnostic and therapeutic recommendations

Hemolytic uremic syndrome （HUS） is a rare disease. In this work the authors review the recent findings on HUS, considering the different etiologic and patho-genetic classifications. New findings in genetics and, in particular, mutations of genes that encode the complement-regulatory proteins have improved our understanding of atypical HUS. Similarly, the comple-ment proteins are clearly involved in all types of thrombotic microangiopathy： typical HUS, atypical HUS and thrombotic thrombocytopenic purpura （TTP）. Fur-thermore, several secondary HUS appear to be related to abnormalities in complement genes in predisposed patients. The authors highlight the therapeutic as-pects of this rare disease, examining both “traditional therapy” （including plasma therapy, kidney and kidney-liver transplantation） and “new therapies”. The latter include anti-Shiga-toxin antibodies and anti-C5 mono-clonal antibody “eculizumab”. Eculizumab has been recently launched for the treatment of the atypical HUS, but it appears to be effective in the treatment of typical HUS and in TTP. Future therapies are in phases Ⅰ and Ⅱ. They include anti-C5 antibodies, which are more purifed, less immunogenic and absorbed orally and, anti-C3 antibodies, which are more powerful, but potentially less safe. Additionally, infusions of recombinant complement-regulatory proteins are a potential future therapy.

Successful Renal Transplantation in a Patient with Atypical Hemolytic Uremic Syndrome Treated with Eculizumab in China

Hemolytic uremic syndrome （HUS） is a rare disease characterized by thrombocytopenia and acute renal failure. Atypical HUS （aHUS） accounts for approximately 10% of all HUS cases. The pathogenesis of aHUS is mainly associated with gene mutations in complement factor H, complement factor I, and membrane cofactor protein （MCP）. The prognosis of aHUS is generally poor.

Combined liver-kidney transplantation for rare diseases

Combined liver and kidney transplantation(CLKT)is indicated in patients with failure of both organs,or for the treatment of end-stage chronic kidney disease(ESKD)caused by a genetic defect in the liver.The aim of the present review is to provide the most up-to-date overview of the rare conditions as indications for CLKT.They are major indications for CLKT in children.However,in some of them(e.g.,atypical hemolytic uremic syndrome or primary hyperoxaluria),CLKT may be required in adults as well.Primary hyperoxaluria is divided into three types,of which type 1 and 2 lead to ESKD.CLKT has been proven effective in renal function replacement,at the same time preventing recurrence of the disease.Nephronophthisis is associated with liver fibrosis in 5%of cases and these patients are candidates for CLKT.In alpha 1-antitrypsin deficiency,hereditary C3 deficiency,lecithin cholesterol acyltransferase deficiency and glycogen storage diseases,glomerular or tubulointerstitial disease can lead to chronic kidney disease.Liver transplantation as a part of CLKT corrects underlying genetic and consequent metabolic abnormality.In atypical hemolytic uremic syndrome caused by mutations in the genes for factor H,successful CLKT has been reported in a small number of patients.However,for this indication,CLKT has been largely replaced by eculizumab,an anti-C5 antibody.CLKT has been well established to provide immune protection of the transplanted kidney against donor-specific antibodies against class I HLA,facilitating transplantation in a highly sensitized recipient.