1. Paediatric Nephrology Department, Área de Pediatria Médica, Hospital Dona Estefânia, CHLC, EPE.
2. Nephrology Department, Hospital Curry Cabral, CHLC, EPE.
3. Intensive Care Unit, Área de Pediatria Médica, Hospital Dona Estefânia, CHLC, EPE.
- 17th Congress of the International Pediatric Nephrology Association, 20-24/9/2016, Foz do Iguaçu (Poster)
Introduction: Atypical hemolytic uremic syndrome (aHUS) is now recognized as a disease of complement dysregulation. New treatment approaches targeted to identifiable mutations of complement are being outlined along with genotype-phenotype correlations. Two cases of aHUS with different clinical presentations and treatment options are presented.
Case presentation: Case 1) 5-year-old girl presented acutely with non-immune haemolytic anaemia, thrombocytopenia and acute renal failure with no gastrointestinal or neurological symptoms. Initial evaluation revealed normal ADAMTS-13 activity and absence of secondary causes of aHUS. Daily plasmapheresis (PP) sessions were started on day 3 and maintained until normalization of parameters. Anti-CFH antibodies were found to be positive on the initial blood samples 1 month after presentation. She was started on prednisolone and mycophenolate mofetil and PP sessions stopped. A complete deletion of the CFHR1 gene was found. Case 2) 12-year-old girl presented with a 2 week history of constipation and abdominal pain followed by the appearance of bloody stools. Although initial lab results showed only slight changes, 1 day after admission she was oliguric and showed non-immune haemolytic anaemia (Hb 8.9 g/dL), thrombocytopenia (24x109/l) and elevated urea (163 mg/dL) and creatinine (2.28 mg/dL) levels. Stool cultures were negative for Shiga-toxin producing bacteria. Other secondary causes of aHUS were excluded and daily PP sessions were started on day 7 and maintained until normalization of lab parameters. Eculizumab was started 2 months after initial diagnosis of aHUS and PP stopped. Sequencing revealed no known mutations on associated genes.
Conclusions: Atypical HUS is a rare but potential fatal condition. Time until the beginning of treatment directly influences prognosis in terms of life expectancy and kidney function. Given the high costs of complement blockade treatment, choice of the optimal therapeutic plan is relevant and still subject to geographical asymmetries.
Keywords: Atypical hemolytic uremic syndrome, eculizumab