Rapid progression to
end-stage renal disease has been reported in a minority of patients with
immunoglobulin A (
IgA) nephropathy. In particular, crescentic
IgA nephropathy has a poor prognosis in patients with a higher initial serum
creatinine level. The
complement system plays an important role in the pathogenesis of crescentic
IgA nephropathy.
Atypical hemolytic uremic syndrome (aHUS), which is characterized by
thrombotic microangiopathy, is distinct from
Shigatoxin-induced HUS and
thrombotic thrombocytopenic purpura. aHUS is associated with dysregulation of the alternative
complement system.
Eculizumab, an anti-C5 antibody, is effective in limiting complement activation in patients with
paroxysmal nocturnal hemoglobinuria, aHUS, or refractory
IgA nephropathy in some case reports. We herein report the case of a 42-year-old man with
acute kidney injury (AKI) clinically and histologically diagnosed with the coexistence of aHUS and crescentic
IgA nephropathy. The patient was treated with
steroids,
plasmapheresis, and
hemodialysis; however,
eculizumab treatment was initiated on hospital day 21 due to resistance to and dependence on the conventional aggressive
therapy. Clinical remission of aHUS was achieved on day 70, but the renal function failed to recover from dialysis dependence. To the best of our knowledge, this is the first report showing the
clinical course of a refractory patient with the coexistence of aHUS and crescentic
IgA nephropathy treated with
eculizumab. This case highlights the clinical importance of early diagnosis and appropriate initiation of
eculizumab for the treatment of this type of AKI.