Fulminant recurrence of atypical hemolytic uremic syndrome during a calcineurin inhibitor-free immunosuppression regimen

Recurrence of hemolytic uremic syndrome (HUS) after kidney transplantation is frequent, occurring almost exclusively in patients with atypical HUS, which is not caused by Escherichia coli gastroenteritis and in which diarrhea is absent. Calcineurin inhibitors are associated with recurrence of HUS. In two children who underwent living donor kidney transplantation for atypical HUS, we pre-emptively employed sirolimus in a calcineurin inhibitor-free immunosuppression regimen. Both children had excellent early graft function, yet both developed severe recurrent disease and subsequently lost their grafts. Avoidance of calcineurin inhibitors did not prevent recurrence of severe HUS and graft loss. Transplantation for severe atypical HUS remains problematic.     

Tacrolimus‐associated hemolytic uremic syndrome in a pediatric heart transplant recipient

HUS is a well‐known entity primarily associated with bacterial infection and is characterized by a classic triad of anemia, thrombocytopenia, and kidney injury. Its atypical form has been associated with calcineurin inhibitors and has been extensively discussed in renal transplantation. We present a case of tacrolimus‐associated HUS in a pediatric heart transplant recipient, which we believe to be previously unreported in the literature.     

Autoimmune‐type atypical hemolytic uremic syndrome treated with eculizumab as first‐line therapy

We report a case of atypical hemolytic uremic syndrome (aHUS) in a 4‐year‐old boy. Although the patient had the typical triad of aHUS (microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury), urgent dialysis was not indicated because he had neither oliguria nor severe electrolyte abnormality. He was given eculizumab as first‐line therapy, which led to significant clinical improvement, thus avoiding any risk of complications associated with plasma exchange and central venous catheterization. Retrograde functional analysis of the patient's plasma using sheep erythrocytes indicated an increase in hemolysis, suggesting impairment of host cell protection by complement factor H. The use of eculizumab as first‐line therapy in place of plasma exchange might be reasonable for pediatric patients with aHUS.     

Prophylactic eculizumab for kidney transplantation in a child with atypical hemolytic uremic syndrome due to complement factor H mutation

We present a case of successful deceased‐donor kidney transplantation in a three‐yr‐old child with aHUS due to complement factor H mutation, using only prophylactic eculizumab treatment prior to transplant. She developed disease exacerbation in the immediate post‐operative period despite having therapeutic eculizumab concentrations and evidence for complete complement pathway blockade. The patient responded well to additional doses of eculizumab and has maintained excellent graft function and disease control in the first year post‐transplantation. The optimal dosing scheme for eculizumab in the perioperative period remains to be determined. More sensitive biomarkers of early disease activity are needed to improve disease monitoring. Finally, the duration of eculizumab therapy in patients with aHUS remains to be determined.     

Arterial hypertension in children with hemolytic uremic syndrome after kidney transplantation

The development of arterial hypertension after KTX is a well‐known complication. HUS is a systemic disease associated with arterial hypertension during long‐term follow‐up. Our goal was to report on the severity of arterial hypertension after KTX in patients with typical and atypical HUS. We analyzed the course of 197 patients with HUS, of which 22 (n = 10 with typical HUS; n = 12 with atypical HUS) developed ESRF and received KTX as renal replacement therapy. We analyzed data from 1766 casual BP and 85 24‐h ABPM measurements. In addition, we evaluated the used antihypertensive strategy. Comparison between the two patient groups revealed that patients with atypical HUS had significantly higher casual SBP‐SDS and DBP‐SDS values after KTX despite similar intensity of antihypertensive treatment. These data were supported by analysis of ABPM profiles showing comparable results for the interval 1–5 yr after KTX. Patients with atypical HUS had a greater severity of arterial hypertension despite similar treatment strategies and intensity of treatment. Our observation, even though in a small cohort, supports recent genetic studies showing arterial hypertension closely associated with HUS‐causing mutations in patients with atypical HUS.     

Efficacy of recombinant human soluble thrombomodulin for childhood hemolytic uremic syndrome

Recombinant human soluble thrombomodulin (rhTM) is a promising therapeutic natural anticoagulant and is used clinically for the treatment of disseminated intravascular coagulation (DIC). Herein is reported the cases of two HUS children treated with rhTM. The patients were diagnosed as having typical HUS on the basis of thrombocytopenia, hemolytic anemia, acute renal failure, and the detection Escherichia coli 0157. I.v. rhTM was started as an anti‐coagulant drug. At 2 days after the first treatment in both patients, fibrin/fibrinogen degradation products and d ‐dimer levels were significantly decreased, and there was a subsequent slight improvement in thrombocytopenia, and a decrease in serum lactate dehydrogenase level. Urinary protein excretion gradually diminished and a decrease in serum creatinine level was observed. The patients did not require dialysis therapy. The present results suggest that rhTM may be a safe and effective treatment for DIC complicated with HUS in children.     

CFI基因与非典型溶血尿毒综合征

CFI基因位于染色体4q25,编码补体I因子.补体I因子在抑制补体旁路途径的级联反应中发挥重要作用.CFI突变大多是点突变,没有大缺失.CFI基因突变所致非典型溶血尿毒综合征(aHUS)呈常染色体隐性遗传.携带CFI突变患者的发病年龄从出生到成年不等(2个月～32岁),约70%的患者补体C3低于正常水平.携带CFI突变的aHUS患者预后差,69.6%进展至终末期肾脏病,且肾移植后溶血尿毒综合征的复发率高.对CFI基因的研究有助于指导aHUS的治疗和预后判断.     

Cobalamin C defect‐hemolytic uremic syndrome caused by new mutation in MMACHC

Atypical hemolytic uremic syndrome (aHUS) is mostly linked to defects in the regulation of alternative complement pathway, but a rare form is caused by an inherited defect of cobalamin 1 metabolism. Cobalamin C (cblC) deficiency is an autosomal recessive disorder of vitamin B12 metabolism that results from mutations in methylmalonic aciduria and homocysteinuria (MMACHC). The most severe form of cblC deficiency and the associated high mortality rate are mostly observed in neonates or in infants <6 months of age. Early diagnosis of cblC deficiency leads to early treatment and an improved prognosis. We describe the case of a 6‐year‐old girl with cblC disorder, who presented with severe multiorgan involvement at the age of 5 months and who was successfully treated with vitamin B12, betaine, coenzyme Q10 and l ‐carnitene, and who had a new homozygous mutation of MMACHC.     

Clinical guides for atypical hemolytic uremic syndrome in Japan

Atypical hemolytic uremic syndrome (aHUS) is a rare disease characterized by the triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury. In 2013, we developed diagnostic criteria to enable early diagnosis and timely initiation of appropriate treatment for aHUS. Recent clinical and molecular findings have resulted in several proposed classifications and definitions of thrombotic microangiopathy and aHUS. Based on recent advances in this field and the emerging international consensus to exclude secondary TMAs from the definition of aHUS, we have redefined aHUS and proposed diagnostic algorithms, differential diagnosis, and therapeutic strategies for aHUS.     

小儿溶血尿毒综合征10例临床分析

目的探讨小儿溶血尿毒综合征(HUS)的临床特点及诊治经验。方法总结分析7a间收治的10例溶血尿毒综合征患儿的临床表现、辅助检查和治疗过程及疗效。结果10例HUS均具备不同程度溶血性贫血、血小板减少和急性肾功能不全。部分病例有上呼吸道感染病史(40%)或腹泻病史(20%)。该病的诊断必须对病史、临床表现以及实验室检查结果进行综合分析,治疗的关键是早期改善肾功能不全、及时纠正贫血及血小板减少。糖皮质激素疗效不佳,不应作为首选,丙种球蛋白对于部分患儿有效,对于重症和不典型HUS患儿,早期联合应用血浆置换可以迅速控制病情,改善症状。结论早诊断、早治疗,选择正确的治疗方案是该疾病取得良好预后的关键因素。     

非典型溶血尿毒综合征分子遗传学研究进展

非典型溶血尿毒综合征是一种罕见的有遗传倾向的疾病,易患基因主要是补体旁路途径活化的调控基因:补体因子H基因、膜辅助蛋白基因和补体因子Ⅰ基因.但其总突变率约为50%,突变类型包括错义突变、无义突变、缺失突变、插入突变和剪切位点突变.遗传方式有常染色体隐性遗传和常染色体显性遗传,显性遗传的三个突变基因均为不完全外显.     

Clinical characteristics of children with hemolytic uremic syndrome in Hangzhou,China

Background:Hemolytic uremic syndrome (HUS) is a main cause of acute renal failure in children.This study aimed to analyze the clinical characteristics of HUS.Methods:A retrospective analysis was performed in 46 children with sporadic HUS.Results:Of the 46 HUS patients,20 (43.5％) were diarrhea-related HUS,and 26 (56.5％) were atypical HUS.Anemia,edema,oliguria,hemoglobinuria and hypertension were the most common manifestations.Thrombocytopenia,hyponatremia,hypocalcemia,hyperkalemia,metabolic acidosis,increased fibrinogen and hypocomplementemia were found in most patients.The age of onset (younger than 2 years or not,P=0.009),the duration of oliguria or anuria (more than one week or not,P=0.005),accompanied with extrarenal complications or not (P=0.005),dialysis and plasma exchange (P=0.04) were associated with the mortality rate.Conclusion:The age of onset younger than 2 years,oliguria/anuria more than 1 week,and associated with extrarenal complications were predictive factors of poor prognosis.     

汉族非典型溶血尿毒综合征儿童CFI基因突变分析

目的分析汉族非典型溶血尿毒综合征(aHUS)儿童CFI基因突变及其特点。方法研究对象为9例汉族aHUS儿童和50例尿检正常的汉族成年人。分别取其外周血3ml,提取基因组DNA,应用聚合酶链式反应(PCR)扩增CFI基因的全部13个外显子及其周围部分内含子。应用正反向引物对PCR产物进行直接DNA序列测定。结果在9例汉族aHUS儿童中未发现CFI基因致病突变;但检测出6个CFI基因多态性,即IVS5+61G>A、804G>A、IVS7+99delT、IVS8-49C>G、IVS11+33A>G和*112C>T。结论CFI基因突变不是本研究9例汉族aHUS儿童的主要致病原因。     

溶血尿毒综合征患儿MCP基因突变分析

目的对溶血尿毒综合征（HUS）患儿进行膜辅助蛋白（MCP）基因突变分析。方法对9例HUS患儿提取外周血MCP基因组DNA,应用聚合酶链反应（PCR）扩增MCP基因全部14个外显子及其周围的部分内含子,进行DNA序列测定及基因突变检测。50例尿检正常的南方汉族成年人为对照人群。结果9例HUS患儿未发现MCP基因突变,但2例检测到1个MCP变异（IVS9-78G〉A）,1例为纯合子,另1例为杂合子,50例对照人群基因测序发现同样MCP变异,表明其为MCP基因多态性,但在9例HUS患儿中的等位基因频率与50例对照人群等位基因频率比较,差异有统计学意义（P〈0.05）。结论MCP基因多态性（IVS9-78G〉A）可能是本研究9例HUS患儿发病的易感因素。     

儿童典型溶血尿毒综合征36例临床分析

目的探讨儿童典型溶血尿毒综合征(D+HUS)的临床表现、辅助检查结果、预后及治疗。方法分析2001年1月至2019年1月中国人民解放军东部战区总医院儿科收治的36例D+HUS患儿的临床资料,比较治疗前后血常规、肝肾功能、凝血功能、体液免疫和尿液等实验室检查结果。结果经治疗,患儿血白细胞计数[(9.28±6.77)×109/L比(11.20±5.93)×10^9/L]、C-反应蛋白[7.15(3.34,29.33)mg/L比31.83(25.03,39.75)mg/L]、网织红细胞计数[(112.49±76.25)×10^9/L比(206.49±147.99)×10^9/L]、红细胞沉降率[15.02(11.79,22.83)mm/1 h比28.06(24.13,40.52)mm/1 h]、天冬氨酸氨基转移酶[50.04(41.92,60.11)U/L比62.61(54.58,83.52)U/L]、丙氨酸转氨酶[16.72(11.80,24.74)U/L比24.54(20.30,34.36)U/L]、尿酸[(532.84±309.06)μmol/L比(606.64±327.23)μmol/L]、血肌酐[160.07(124.87,221.18)μmol/L比200.56(160.62,283.01)μmol/L]、血尿素氮[20.74(15.77,28.40)mmol/L比33.67(25.91,45.84)mmol/L]、乳酸脱氢酶[488.21(337.59,692.82)U/L比1520.68(734.24,2272.10)U/L]、凝血酶原时间[(12.14±5.89)s比(17.91±6.12)s]、活化部分凝血酶时间[(25.05±6.26)s比(32.38±5.49)s]、纤维蛋白原[(3.79±2.17)g/L比(5.17±3.88)g/L]、D-二聚体[0.92(0.30,1.13)mg/L比1.27(1.01,1.90)mg/L]、24 h尿蛋白定量[(84.05±44.19)mg/(kg·24 h)比(112.18±78.26)mg/(kg·24 h)]、尿沉渣[175.73(79.72,258.66)×10^7/L比160.38(118.68,361.83)×10^7/L]、尿N-乙酰-β-D-葡萄糖苷酶[25.10(18.84,33.02)U/(g·cr)比41.57(29.49,58.61)U/(g·cr)]和尿视黄醇结合蛋白[0.35(0.18,1.33)mg/L比1.05(0.66,1.68)mg/L]水平均明显下降,差异均有统计学有意义(均P<0.05);红细胞计数[(4.51±1.73)×10^9/L比(2.43±1.40)×109/L]、血小板[(126.82±78.35)×10^9/L比(85.21±69.38)×10^9/L]、血红蛋白[(118.46±18.27)g/L比(62.36±16.11)g/L]和补体C3[(0.74±0.39)g/L比(0.58±0.27)g/L]水平均明显升高,差异均有统计学有意义(均P<0.05)。儿童D+HUS表现为多系统损伤,36例患儿中,发热17例(47.22%);腹痛、腹泻31例(86.11%),恶心、呕吐29例(80.56%);头痛、头晕8例(22.22%);蛋白尿、血尿36例(100.00%),肾功能不全34例(94.44%);皮肤巩膜黄染21例(58.33%)。肾脏病理主要表现为系膜增殖,内皮细胞增殖、肿胀和肾小管刷状缘脱落等,骨髓穿刺示骨髓增生活跃。肾脏B超示86.67%存在双肾肾损伤。结论儿童D+HUS表现为多系统损伤,消化系统异常是儿童D+HUS的最主要诱发因素,且病情凶险,早诊断和积极治疗可改善预后。     

溶血尿毒综合征23例诊治分析

目的 探讨溶血尿毒综合征(HUS)的进程、影响预后因素及治疗.方法 分析1993年11月-2007年6月收治的23例HUS患儿的临床资料.结果 随访时间1个月～15年.存活14例,13例血压、BUN、Cr、尿常规均正常,1例尿常规异常、肾功能不全,其中有2例复发.死亡9例均为鼋型,其中6例在短期内(3例于急性期,3例于急性期后)放弃治疗,自动出院,分别于病程的第27～48天死亡;另3例持续尿检异常,进展为终末期肾衰竭,分别于病程的第5、8和13个月死亡.结论 影响预后的主要因素是病情轻重及是否早期、积极治疗.在急性期采用以对症治疗为主的综合措施,对度过急性期的HUS患儿定期随访,继续治疗,并依据其临床分型和肾病理改变参照小儿肾小球疾病的临床分类、诊断及治疗方案治疗,可明显改善预后.     

Atypical hemolytic uremic syndrome

The pathogenesis of atypical uremic syndrome (HUS), which is rarely encountered in childhood, is poorly understood and its mortality and morbidity rates are high. A wide variety of therapeutic approaches has been attempted and the literature contains numerous conflicting reports about the results of these approaches. In a case diagnosed as recurrent atypical HUS, pulse methyl prednisolone, fresh frozen plasma infusions and plasma exchange transfusion were used at different stages of the disease with satisfactory response.