Dialysis and Transplant Unit, Center for HUS Prevention Control and Management at the Pediatric Nephrology, Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, Via della Commenda 9, 20122, Milan, Italy.
Giuliana and Bernardo Caprotti, Chairs of Pediatrics, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy.
J Nephrol. 2022 Jan;35(1):279-284. doi: 10.1007/s40620-021-00965-8. Epub 2021 Jan 18.
Atypical haemolytic uremic syndrome (aHUS) is at high risk of relapse at any time, therefore patients require lifelong monitoring. The most appropriate way to monitor patients is not yet clear. Patients could be monitored for relapse by urine dipstick testing for haemoglobinuria based on the hypothesis that thrombotic microangiopathy involving the glomerulus and associated with renal damage (like aHUS) cannot occur without haematuria.
The aim of this retrospective study is to analyse our experience with this approach in aHUS patients who have never previously been treated, who are currently on treatment or who have discontinued C5 inhibition. The records of all aHUS patients (children and adults) managed by or referred to our Centre from January 2009 to March 2020 were included and the analysis for the presence of haemoglobinuria was restricted to the period following primary remission. A positive test was defined as haemoglobin ≥ 1 + . Patients reporting positive urine dipstick tests underwent laboratory investigations to rule in or out the diagnosis of aHUS relapse.
Eighty-four patients were included with 1517 determinations of haemoglobinuria during a cumulative observation period of 8904 patient-months. Haemoglobinuria for the early diagnosis of ongoing aHUS relapse shows a sensitivity of 100% and a specificity of 87.4% with a positive predictive value (PPV) of 10.5% and a negative predictive value (NPV) of 100%. The accuracy of the test was 87.6%.
Haemoglobinuria is a very sensitive and acceptably specific marker of aHUS relapse. This finding and its validation may have a positive impact on patients' quality of life and on the outcome of this life threatening disease via early diagnosis of relapse.
非典型溶血尿毒综合征（aHUS）随时都有复发的高风险，因此患者需要终身监测。目前尚不清楚最适合监测患者的方法。根据血栓性微血管病（TMA）累及肾小球并伴有肾损伤（如 aHUS）时必然出现血尿的假说，患者可以通过尿潜血检测来监测复发。
本回顾性研究旨在分析我们从未接受过治疗、正在接受治疗或已停止 C5 抑制的 aHUS 患者应用该方法的经验。纳入 2009 年 1 月至 2020 年 3 月期间由本中心管理或转来的所有 aHUS 患者（儿童和成人）的记录，并将血尿分析仅限于初次缓解后的时期。阳性检测定义为血红蛋白≥1+。报告尿潜血检测阳性的患者接受实验室检查以排除或确诊 aHUS 复发。
共纳入 84 例患者，在 8904 患者月的累计观察期内进行了 1517 次血红蛋白尿检测。血红蛋白尿早期诊断持续的 aHUS 复发的敏感性为 100%，特异性为 87.4%，阳性预测值（PPV）为 10.5%，阴性预测值（NPV）为 100%。该检测的准确性为 87.6%。
血红蛋白尿是 aHUS 复发的一种非常敏感且具有可接受特异性的标志物。这一发现及其验证可能通过早期诊断复发对患者的生活质量和这种危及生命疾病的结果产生积极影响。
