A 40-year-old man with recently diagnosed PNH was referred for renal evaluation. In the previous 9 months he had presented with repeated episodes of dark urine and low back pain. He presented with severe haemolytic anaemia, haemoglobin 7.7 mg/dl, undetectable haptoglobin, elevated LDH 3,800 U/l, requiring red blood cell transfusion. Ferritin and transferan saturation normal. Renal function normal, creatinine 0.8 mg/dl, proteinuria 427 mg/24 h, with albuminuria 120 mg/24 h. Haemoglobinuria with normal sediment, negative glycosuria and normal fractional excretion of phosphate.
In the following 10 months he presented repeated haemolytic crises, with macroscopic haemoglobinuria. He reported difficulty concentrating and recurrent headache. An MRI showed marked signal hypointensity in the renal cortex on all sequences, and a brain MRI revealed multiple subcortical lacunar lesions. Due to brain involvement attributable to PNH, treatment with eculizumab was initiated.

The patient progressed, with no new haemoglobinuria crises, resolution of anaemia and normalisation of LDH (decreased haptoglobin persisted).
Seventeen months after the start of treatment, a new MRI showed normalisation of the signal in the renal cortex. Renal function remained normal, with proteinuria 130mg/day and negative haemoglobinuria.