Successful treatment of neonatal atypical hemolytic uremic syndrome with C5 monoclonal antibody.

Hemolytic uremic syndrome (HUS) is rare in neonates. We report the case of atypical HUS (aHUS) revealed by neonatal seizures. This 18-day-old baby presented with repeated clonus of the left arm and eye deviation. Four days earlier, she had suffered from gastroenteritis (non-bloody diarrhea and vomiting without fever). Her work-up revealed hemolytic anemia (120 g/L), thrombocytopenia (78 g/L), and impaired renal function (serum creatinine=102 µmol/L) compatible with the diagnosis of HUS. Levels of C3 and C4 in the serum were normal. Shiga-toxin in the stools as well as the IgM and IgG against Escherichia coli O157 were negative. ADAMTS 13 deficiency, inborn error of the cobalamin pathway, deficiency in the H and I protein, and factor H antibodies were excluded and we concluded in aHUS. Genetic screening of the alternative complement pathway was normal. Cerebral magnetic resonance imaging performed after 24 h and 1 week showed restricted diffusion areas with periventricular white matter ischemic-hemorrhagic lesions. Extensive infectious work-up was negative. Upon admission the baby received antiepileptic drugs and 2 days later C5 monoclonal antibody (eculizumab) and two transfusions of packed erythrocytes because the hemoglobin value had dropped to 55 g/L. The platelet value was minimal at 30 g/L. Renal function normalized in 48 h without dialysis and neurological examination was normal in 1 week. She was discharged from the hospital at day 10 with eculizumab perfusions (300 mg) planned every 3 weeks. After 24 months, she was relapse-free and seizure-free, with a normal neurological examination.

[Premature kidneys and oligonephronia: long term repercussion]. / Immaturité rénale et oligonéphronie du prématuré: conséquences à long terme.

The premature has a reduced number of nephrons. This condition, added to an immature renal function at birth, increases the vulnerability to hemodynamic changes, drug toxicity, and nephrocalcinosis. The oligonephronia worsens the risk to present in adulthood, hypertension and renal insufficiency. Nephrocalcinosis appears in the postnatal period, secondary to renal calcifications. This condition increases the risk of further renal endowment. The nephrocalcinosis is closely related to rickets in the premature. Indeed, an excess of vitamin D and calcium, increases the risk of nephrocalcinosis. The early recognition of markers, such as microalbuminuria, hypertension and hypercalciuria, allow targeting prevention measures.