Martin Sandra M, Balestracci Alejandro, Puyol Iris, Toledo Ismael, Cao Gabriel, Arizeta Gema
Nephrology Unit, Hospital General de Niños Pedro de Elizalde, Montes de Oca 40, Ciudad Autónoma de Buenos Aires, Barcelona, España, Argentina.
Division of Pathology, Hospital General de Niños Pedro de Elizalde, Montes de Oca 40, Ciudad Autónoma de Buenos Aires, Argentina.
Indian J Nephrol. 2021 Sep-Oct;31(5):478-481. doi: 10.4103/ijn.IJN_271_20. Epub 2021 Apr 2.
Atypical hemolytic uremic syndrome (aHUS) is an ultra-rare disease characterized by microangiopathic hemolytic anemia, thrombocytopenia and renal damage. Its presentation as nephrotic syndrome (NS) during first year of life is uncommon; we describe a child with clinical and laboratory findings of NS whose renal biopsy revealed thrombotic microangiopathy (TMA). A previously healthy 4-month-old male was admitted with severe dehydration, diarrhea and anuria. Laboratory results showed electrolyte disturbances, increased serum creatinine, anemia without schistocytes, thrombocytosis, normal lactic dehydrogenase (LDH) levels, hypoalbuminemia hypercholesterolemia and decreased C3 levels. After rehydration hematuria and massive proteinuria were also documented and an initial diagnosis of NS of the first year was established. Studies seeking for infectious agents were negative. During hospitalization he continued to be oligo-anuric needing dialysis and a renal biopsy was performed, which showed TMA findings. We here considered the diagnosis of aHUS and started plasma infusions as a bridge until starting eculizumab. After two infusions urine output improved leading to discontinuation dialysis. The diagnoses of STEC infection and thrombocytopenic thrombotic purpura were ruled out. Factor B, H, I and properdin levels were normal. Antibodies against CFH negative were negative. Screening for genes causative of aHUS detected a heterozygous variant in CFHR3 of uncertain significance. On day 20, treatment was switched to eculizumab, which induced a progressive remission of the NS. This case outlines the need for a heightened diagnosis suspicion of this already rare disease since early initiation of eculizumab therapy improves its prognosis.
非典型溶血尿毒综合征（aHUS）是一种极为罕见的疾病，其特征为微血管病性溶血性贫血、血小板减少和肾损伤。在生命的第一年表现为肾病综合征（NS）并不常见；我们描述了一名患有NS临床和实验室检查结果的儿童，其肾活检显示为血栓性微血管病（TMA）。一名此前健康的4个月大男性因严重脱水、腹泻和无尿入院。实验室结果显示电解质紊乱、血清肌酐升高、无裂体细胞的贫血、血小板增多、乳酸脱氢酶（LDH）水平正常、低白蛋白血症、高胆固醇血症和C3水平降低。补液后也记录到血尿和大量蛋白尿，并初步诊断为第一年的NS。寻找感染源的检查结果为阴性。住院期间，他持续少尿无尿，需要透析，并进行了肾活检，显示为TMA表现。我们在此考虑诊断为aHUS，并开始进行血浆输注作为过渡，直到开始使用依库珠单抗。两次输注后尿量改善，导致停止透析。排除了产志贺毒素大肠杆菌（STEC）感染和血小板减少性血栓性紫癜的诊断。补体因子B、H、I和备解素水平正常。抗CFH抗体阴性。对aHUS致病基因的筛查在CFHR3中检测到一个意义不确定的杂合变异。在第20天，治疗改为依库珠单抗，这使NS逐渐缓解。该病例概述了对于这种本就罕见的疾病需要提高诊断怀疑度，因为早期启动依库珠单抗治疗可改善其预后。
