Objective To investigate the treatment of atypical hemolytic uremic syndrome (aHUS) in their acute phase and relate the prognostic factors.Methods Twenty-eight patients with aHUS treated in Department of Nephrology,Beijing Children's Hospital Affiliated to Capital Medical University from January 2011 to March 2015 were collected,the outcomes of the treatment were summarized.Results All the patients were given plasma exchange (PE)treatment,21 patients with hemodialysis (HD) treatment;13 patients with H factor (FH) antibody were further treated with corticosteroid therapy,and 1 patient was treated with the combination of mycophenolate mofetil.Evaluation of patients' indices were conducted at month 3.Out of the 28 patients,there were 13 patients with complete remission;of the 14 patients showed improvement,6 patients were complicated with hypertension and 4 patients with renal dysfunction.One patient,with ongoing hemodialysis,did not show restoration of renal function.There was no death in children.Statistical analysis showed that the acute phase serum creatinine levels were (430.0 ± 124.7) μmol/L and (265.6 ± 90.8)μmol/L for the group with remaining kidney injury and the group with complete remission,respectively,the difference was statistically significant(P ＜0.01).The levels of FH for the 2 groups were (206.5 ± 134.9) mg/L and(415.4-±214.1) mg/L,and the difference was statistically significant (P ＜ 0.01) as well.Statistical analysis showed that differences were no statistically significant between the 2 groups of patients on their age,platelets,complement C3,complement C4,hemoglobin and lactate dehydrogenase (all P ＞ 0.05).For the group with positive antibody,its average serum creatinine was (346.4 ± 112.5) μmol/L.For the group with negative antibody,its average serum creatinine was (297.0 ± 89.3) μmol/L.The FH for group with positive antibody and group with negative antibody were (307.4 ±187.3) mg/L and (379.8 ± 203.5) mg/L,respectively.The differences were not statistically significant (all P ＞0.05).Conclusions PE is an effective treatment for aHUS at acute phase,and corticosteroid and immunosuppressive therapy are effective for patients with positive anti-FH antibody.For patients with severe kidney injury at acute phase,the possibility of long-term kidney damage is high.Low concentration of serum FH indicates a poor prognosis.