Atypical, recurrent hemolytic uraemic syndrome (HUS) often leads to end-stage renal disease and can relapse after a renal transplantation. Plasmapheresis and fresh frozen plasma (FFP) therapies are used to treat acute relapses. We report on the prophylactic use of FFP in a child with atypical recurrent HUS with low serum C3. The girl experienced four episodes of atypical HUS over a year from the age of 18 months. During the first relapse a decreased level of C3--0,62 g/l (normal: 0.88-2.01 g/l) was revealed. Initially daily plasma infusions were given (8-14 ml/kg for 5-15 days) during acute episodes. Following the 4th episode prophylactic FFP therapy was started. Three-times weekly plasma transfusions were continued for three months and then doses were tapered off over the next months to once-weekly FFP. During the one year follow-up no relapse has been observed. At the age of 3 1/2 years she is thriving (10th percentile for height and weight). She has severe but well controlled hypertension without end-organ involvement. The child demonstrates signs of stage 2 chronic kidney disease (CKD): serum creatinine--0.65 mg/dl, Schwartz estimated GFR--79.9 ml/min/ 1.73 m2, persistent slight proteinuria and haematuria, increased renal cortical echogenicity on ultrasound. Genetic studies for the known atypical HUS mutations and assessment of complement activation proteins (factors H and I) are under investigation.
Conclusion: Prophylactic FFP infusions can be successful in preventing relapses and further progressive renal damage in individual patients with atypical HUS associated with low C3.