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

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

Antibodies, Monoclonal, Humanized ; therapeutic use ; Atypical Hemolytic Uremic Syndrome ; drug therapy ; surgery ; China ; Humans ; Kidney Transplantation ; Male

OBJECTIVETo investigate the clinical characteristics, renal pathology, treatment and prognosis of children with atypical hemolytic uremic syndrome associated with H factor antibody.

METHODFour children less than 18 yr of age admitted from Nov. 2010 to May 2011 in Peking University First Hospital were included. They all met the criteria for atypical hemolytic uremic syndrome and with positive serum anti factor H antibody. They aged from 5 to 11 yr. Data on clinical manifestations, renal pathology, treatment and prognosis were analyzed.

RESULTAll of the 4 cases had gastrointestinal symptoms such as vomiting, abdominal pain, or abdominal distension. None of them had diarrhea. Two children had hypertension. One child had episodes of convulsion. One child had history of atypical hemolytic uremic syndrome. All of them had low serum complement C3. Three of them had low serum factor H (38.0, 88.4, 209.4 mg/L). All of them had serum antibody to factor H (1: 7 068, 1: 1 110, 1: 174, and 1: 869). Three of them received renal biopsy, all of them showed thrombotic microangiopathy. All of them were treated with steroid combined with mycophenolate mofetil. Two children received plasma exchange. They were followed up for 8 to 29 months. The renal function became normal and proteinuria relieved in all of them. The serum factor H concentration increased to 405.8, 155.8 and 438.4 mg/L, respectively. The titer of anti factor H antibody decreased to 1: 119, 1: 170, 1: 123, and 1: 674, respectively.

CONCLUSIONGastrointestinal symptom is common in children with atypical hemolytic uremic syndrome associated with H factor antibody. Hypocomplementemia was observed in all of them. Steroid combined with mycophenolate mofetil seemed to be effective for them. The monitoring of serum factor H and antibody to factor H may help diagnosis and treatment.

Atypical Hemolytic Uremic Syndrome ; Autoantibodies ; blood ; immunology ; Child ; Child, Preschool ; Complement Factor H ; immunology ; Creatinine ; blood ; Female ; Hemolytic-Uremic Syndrome ; drug therapy ; immunology ; pathology ; Humans ; Kidney ; pathology ; physiopathology ; Kidney Function Tests ; Male ; Mycophenolic Acid ; administration & dosage ; analogs & derivatives ; therapeutic use ; Plasma Exchange ; Prednisolone ; administration & dosage ; therapeutic use ; Prognosis ; Retrospective Studies