A 10-year-old girl was admitted with a 38-hour history of widespread subcutaneous petechiae and hematuria and a 6-hour history of jaundice and oliguria. Physical examination revealed widespread subcutaneous petechiae and jaundice of the skin and sclera. Laboratory tests showed anemia, thrombocytopenia, acute kidney injury, and markedly elevated lactate dehydrogenase. Thrombotic microangiopathy was initially diagnosed, with a high suspicion of atypical hemolytic uremic syndrome (aHUS). Eculizumab was initiated within 9 hours of admission (within 48 hours of onset). After the first infusion, hemolysis rapidly ceased, and the platelet count and renal function gradually returned to normal. Whole-exome sequencing identified homozygous deletions of CFHR1 exon 2 and CFHR4 exon 1. aHUS typically has abrupt onset and rapid progression. Clinicians should maintain high suspicion for aHUS when the triad of thrombocytopenia, microangiopathic hemolytic anemia, and acute kidney injury is present. Ultra-early eculizumab (within 48 hours of onset) rapidly blocks complement-mediated thrombotic microangiopathy, reverses organ injury, and improves long-term prognosis. Additionally, complement-related genetic testing is important for etiological clarification and individualized determination of eculizumab treatment duration.
Humans ; Antibodies, Monoclonal, Humanized/administration & dosage* ; Female ; Atypical Hemolytic Uremic Syndrome/drug therapy* ; Child ; Complement C3b Inactivator Proteins

Critical care emphasizes critical thinking, focuses on the triggers that lead to disease progression, and attaches great importance to early diagnosis of diseases and assessment of the compensatory capacity of vital organs. Pregnancy-associated atypical hemolytic uremic syndrome (P-aHUS) is relatively rare in the intensive care unit (ICU). Most cases occur within 10 weeks after delivery. Severe cases can be life-threatening. It characterized by microangiopathic hemolytic anemia, decreased platelet count (PLT), and acute kidney injury (AKI). Early clinical diagnosis is difficult due to its similarity to various disease manifestations. On January 28, 2024, a 26-year-old pregnant woman at 26⁺³ weeks gestation was transferred to the ICU 19 hours post-vaginal delivery due to abdominal pain, reduced urine output, decreased PLT, elevated D-dimer, tachycardia, increased respiratory rate and declined oxygenation. On the day of ICU admission, the critical care physician identified the causes that triggered the acute respiratory and circulatory events based on the "holistic and local" critical care thinking. The condition was stabilized rapidly by improving the capacity overload. In terms of etiological diagnosis, under the guidance of the "point and face" critical care thinking, starting from abnormality indicators including a decrease in hemoglobin (Hb) and PLT and elevated D-dimer and fibrin degradation product (FDP) without other abnormal coagulation indicators, the critical care physician ultimately determined the diagnosis direction of thrombotic microangiopathy (TMA) by delving deeply into the essence of the disease and formulating a laboratory examination plan in a reasonable and orderly manner. In terms of in-depth diagnosis, combining the disease development process, family history, and past history, applying the two-way falsification thinking of "forward and reverse" as well as "questioning and hypothesis", the diagnosis possibilities of preeclampsia, HELLP syndrome [including hemolysis (H), elevated liver function (EL) and low platelet count (LP)], thrombotic thrombocytopenic purpura (TTP), typical hemolytic uremic syndrome (HUS), and autoimmune inflammatory diseases inducing the condition was ruled out. The diagnosis of complement activation-induced P-aHUS was finally established for the patient, according to the positive result of the complement factor H (CFH). Active decision was made in the initial treatment. The plasma exchange was initiated early. "Small goals" were formulated in stages. The "small endpoints" were dynamically controlled in a goal-oriented manner to achieve continuous realization of the overall treatment effect through phased "small goals". On the 5th day of ICU treatment, the trend of microthrombosis in the patient was controlled, organ function damage was improved, and the patient was transferred out of the ICU. It is possible to reach a favorable clinical outcome for critically ill patients by applying a critical care mindset to quickly integrate diagnostic and therapeutic strategies, accurately identifying the triggers and causes that led to the progression of the disease, and using critical care medical techniques for early and effective intervention.
Humans ; Female ; Pregnancy ; Adult ; Atypical Hemolytic Uremic Syndrome/therapy* ; Intensive Care Units ; Pregnancy Complications, Hematologic/therapy* ; Critical Care

Atypical hemolytic uremic syndrome (aHUS) is a thrombotic microangiopathy characterized by microangiopathic hemolytic anemia, thrombocytopenia, and multi-organ damage, with the kidneys being predominantly affected. aHUS results from dysregulation of the complement alternative pathway, triggered by factors including infection, pregnancy, and surgery, among others. Therefore, complement inhibitors play a crucial role in the treatment of aHUS by blocking abnormal activation of the complement system and improving patients' prognosis. This consensus, developed by the Multidisciplinary Consensus Working Group on Atypical Hemolytic Uremic Syndrome Diagnosis and Treatment, is based on the latest literature and guidelines, discusses the pathogenesis, diagnosis and differential diagnosis, and treatment strategies for aHUS, and provides a guide and reference for the standardized diagnosis and management of aHUS in China.
Humans ; Atypical Hemolytic Uremic Syndrome/therapy* ; Consensus ; Diagnosis, Differential ; Prognosis

OBJECTIVE: To explore the clinical characteristics and genetic etiology for a child with atypical Hemolytic uremic syndrome (aHUS) in conjunct with nephrotic level proteinuria. METHODS: A child patient who had visited the Affiliated Hospital of Qingdao University on June 25, 2020 was selected as the study subject. Clinical data of the patient was collected. Whole exome sequencing (WES) was carried out for the child, and candidate variant was verified by Sanger sequencing of the child and his parents. RESULTS: The child, an 8-month-old male, had presented mainly with edema, oliguria, hematuria, nephrotic level proteinuria, anemia, thrombocytopenia, increased creatinine and urea, hypercholesterolemia but normal complement levels. Genetic testing revealed that he has harbored compound heterozygous variants of the DGKE gene, namely c.12_18dupGAGGCGG (p.P7fs*37) and c.1042G>T (p.D348Y), which were respectively inherited from his father and mother. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variants were classified as likely pathogenic and variant of uncertain significance, respectively. By combining his clinical manifestations and results of genetic testing, the child was diagnosed with aHUS with nephrotic level proteinuria. CONCLUSION For infants and young children with aHUS in conjunct with nephrotic level proteinuria, variants of the DGKE gene should be screened. Above finding has expanded the mutational spectrum of the DGKE gene.
Infant ; Female ; Humans ; Child ; Male ; Child, Preschool ; Atypical Hemolytic Uremic Syndrome/diagnosis* ; Mutation ; Genetic Testing ; Thrombocytopenia/genetics* ; Proteinuria/genetics*

Hemolytic uremic syndrome (HUS) is clinically rare, with high mortality and case fatality rates. In recent years, the research on HUS has been intensified and the pathophysiological mechanism has been continuously improved. At present, the main mechanism of pathogenesis is the excessive activation of complement alternative pathways mediated by complement-related gene mutations or the existence of antibodies. The treatment methods and strategies are also constantly updated, mainly including complement-blocking drugs such as Eculizumab, Lavalizumab, and Ravulizumab. In this review, the new developments in the pathogenesis and treatment of HUS is summarized, and provide references for the clinical treatment of HUS.
Complement System Proteins/therapeutic use* ; Hemolytic-Uremic Syndrome/therapy* ; Humans ; Mutation

Antibodies, Monoclonal, Humanized/therapeutic use* ; Atypical Hemolytic Uremic Syndrome/drug therapy* ; Humans

Diagnosis of thrombotic microangiopathy (TMA) is challenging due to its close association with other forms of microangiopathic hemolytic anemia, such as malignant hypertension and disseminated intravascular coagulation, and because other manifestations including cytopenia and acute kidney injury are manifestations of other medical comorbidities. Further challenges for accurate diagnosis include distinguishing between primary and secondary TMA, as well as between hemolytic uremic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP). TTP is typically differentiated from HUS by the presence of more severe thrombocytopenia, along with a higher frequency of altered mental status with relatively preserved renal function. However, the clinical course can vary among patients, requiring polymerase chain reaction testing of patient stools for enterohemorrhagic Escherichia coli and a disintegrin and metalloproteinase with thrombospondin type 1 motif 13 (ADAMTS13) assay. To reduce the mortality rate, prompt initiation of plasmapheresis is important in cases where TPP cannot be excluded. Future advances enabling more rapid testing for ADAMTS13 levels will reduce the need for unnecessary plasmapheresis, so that treatment strategy can be more optimized.
Acute Kidney Injury ; Anemia, Hemolytic ; Comorbidity ; Diagnosis ; Diagnosis, Differential ; Disseminated Intravascular Coagulation ; Enterohemorrhagic Escherichia coli ; Hemolytic-Uremic Syndrome ; Humans ; Hypertension, Malignant ; Mortality ; Plasma Exchange ; Plasmapheresis ; Polymerase Chain Reaction ; Purpura, Thrombotic Thrombocytopenic ; Thrombocytopenia ; Thrombospondins ; Thrombotic Microangiopathies

BACKGROUND: Atypical hemolytic uremic syndrome (aHUS) involves dysregulation of the complement system, but whether this also occurs in thrombotic thrombocytopenic purpura (TTP) remains unclear. Although these conditions are difficult to differentiate clinically, TTP can be distinguished by low (<10%) ADAMTS13 activity. The aim was to identify the differences in complement activation products between TTP and aHUS and investigate ADAMTS13 activity as a prognostic factor in aHUS. METHODS: We analyzed patients with thrombotic microangiopathy diagnosed as TTP (N=48) or aHUS (N=50), selected from a Korean registry (N=551). Complement activation products in the plasma samples collected from the patients prior to treatment and in 40 healthy controls were measured by ELISA. RESULTS: The levels of generalized (C3a), alternate (factor Bb), and terminal (C5a and C5b-9) markers were significantly higher (all P<0.01) in the patients than in the healthy controls. Only the factor Bb levels significantly differed (P=0.008) between the two disease groups. In aHUS patients, high normal ADAMTS13 activity (≥77%) was associated with improved treatment response (OR, 6.769; 95% CI, 1.605–28.542; P=0.005), remission (OR, 6.000; 95% CI, 1.693–21.262; P=0.004), exacerbation (OR, 0.242; 95% CI, 0.064–0.916; P=0.031), and disease-associated mortality rates (OR, 0.155; 95% CI, 0.029–0.813; P=0.017). CONCLUSION: These data suggest that complement biomarkers, except factor Bb, are similarly activated in TTP and aHUS patients, and ADAMTS13 activity can predict the treatment response and outcome in aHUS patients.
Atypical Hemolytic Uremic Syndrome ; Biomarkers ; Complement Activation ; Complement System Proteins ; Enzyme-Linked Immunosorbent Assay ; Humans ; Mortality ; Plasma ; Purpura, Thrombotic Thrombocytopenic ; Thrombotic Microangiopathies

Atypical hemolytic uremic syndrome (aHUS), a rare form of thrombotic microangiopathy, is distinguished from the typical form by the absence of a preceding verotoxin-producing Escherichia coli infection. Notably, aHUS occurs in association with genetic or acquired disorders causing dysregulation of the alternative complement pathway. Patients with aHUS may show the presence of anti-complement factor H (CFH) autoantibodies. This acquired form of aHUS (anti-CFH-aHUS) primarily affects children aged 9–13 years. We report a case of a 13-year-old Lao girl with clinical features of aHUS (most likely anti-CFH-aHUS). The initial presentation of the patient met the classical clinical triad of thrombotic microangiopathy (microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury) without preceding diarrheal illness. Low serum levels of complement 3 and normal levels of complement 4 indicated abnormal activation of the alternative complement pathway. Plasma infusion and high-dose corticosteroid therapy resulted in improvement of the renal function and hematological profile, although the patient subsequently died of infectious complications. This is the first case report that describes aHUS (possibly anti-CFH-aHUS) in Laos.
Adolescent ; Anemia, Hemolytic ; Atypical Hemolytic Uremic Syndrome ; Autoantibodies ; Child ; Complement C3 ; Complement C4 ; Complement Factor H ; Complement Pathway, Alternative ; Female ; Humans ; Immunosuppression ; Kidney ; Laos ; Plasma ; Shiga-Toxigenic Escherichia coli ; Thrombocytopenia ; Thrombotic Microangiopathies

No abstract available.
Escherichia ; Hemolytic-Uremic Syndrome