Atypical Hemolytic Uremic Syndrome During Induction Chemotherapy in
Neuroblastoma, a Rare Phenomenon or Common Congenital Predisposition?
Abstract
Atypical hemolytic uremic syndrome (aHUS) is an infrequently encountered
complement-mediated thrombotic microangiopathy (TMA) usually associated
with germline variants in genes of the complement system. Clinical
findings of microangiopathic hemolytic anemia, thrombocytopenia, and
acute kidney injury (AKI) with severe hypertension arise due to aberrant
complement protein activation in the circulation and significant
endothelial damage. Transplant-associated thrombotic microangiopathy has
been increasingly recognized after high dose carboplatin, etoposide, and
melphalan-chemotherapy followed by autologous hematopoietic stem cell
rescue for treatment of children with neuroblastoma (NB). We report the
case of a 13-month-old boy with metastatic neuroblastoma who developed
aHUS during the first cycle of induction chemotherapy. Germline testing
revealed a Complement factor H (CFH) gene mutation, Cys357Arg,
which is currently classified as a variant of uncertain significance
(VUS), although likely pathogenic based on molecular modeling as well as
this patient’s clinical presentation. The patient has been successfully
managed with complement blockade therapy with no recurrence of disease.
We review presentations of neuroblastoma with hypertension, along with
AKI and thrombocytopenia, to raise awareness about the potential for
aHUS in patients with newly diagnosed NB.