Remission and recurrence free 1 year follow up in a patient with onset of factor H antibody associated atypical HUS under induction therapy with Plasmapheresis and introduction of maintenance therapy with i.v. IgG and MMF

Abstract

Introduction: Factor H antibodies (FH Ab) develop in 6- 10 % of aHUS patients. The role of FH Ab in disease onset, progression and treatment is of critical interest for physicians and patients dealing with this unsolved problem. At present, evidence based therapy recommendations for this group of patients are missing. Many patients develop end stage renal disease and recurrence rates within the first year are up to 70 %. Material and methods: A 15 year old girl was addmited to the hospital because of weakness, vommiting anddecreasing amount of urine. 6 days ago she had otitis. On examination slight oedema and normal blood pressure. Laboratory analysis showed anemia (Hb - 71 g/l), thrombocytopaenia (55x10 9/l), elevated serum creatinin concentration (1219 μmol/l), high LDH (2612 U/l), low haptoglobin (86 mg/l) and low C3 (0,38 g/l) levels. Hemodialysis (n0 8) and plasmapheresis (regime as recommended in Guidlines of The European Paediatric Study Group for HUS) were started within 24 hours after addmition to the hospital. After 18 plasmapheresis sessions total remission (normalization of hematologic parameters and renal function) was obtained. 17 day later plasmapheresis sessions had to be started again because of hematologic relapse: Hb – 57 g/l, thrombocytes – 87x10 9/l, haptoglobin – 29 mg/l, C3 – 0,48 g/l, LDH – 418 U/l, serum creatinin concentration – 95 μmol/l (total number of plasmapheresis – 36). At that time FH Ab associated aHUS was diagnosed and after remission maintanance therapy (3 months after the onset) with i.v. IgG 2 g/kg body weight (days 0, 21, 41) and Mycophenolate mofetil (started on day 2; 600 mg/m² twice a day) was introduced.Results: 12 months after onset of the disease the patient is on hematological and renal remission. The FH Ab Titers are in the low range (Titer cut off <100 AU/ml; low range <500 AU/ml). Despite normal C3 levels the measurement of the terminal [...]