[Paroxysmal Nocturnal Hemoglobinuria: A Rare but Treatable Cause of Acute Kidney Injury. Case Report]

Early recognition of acute kidney injury is essential to prevent progression to chronic kidney disease. We present the case of a 19-year-old man with multiple emergency department visits for fatigue, abdominal pain, and intermittent dark urine. Upon admission, he had pancytopenia with elements suggestive of hemolysis and acute kidney injury. Thrombotic thrombocytopenic purpura was suspected, so he was treated with dexamethasone and plasmapheresis. The complementary study ruled out this suspicion, and plasmapheresis was suspended. The renal histology showed an acute kidney injury consistent with paroxysmal nocturnal hemoglobinuria (PNH), and bone marrow biopsy excluded marrow infiltration. The diagnosis of PNH was confirmed by flow cytometry. He was treated with prednisone, anticoagulation, iron, and folic acid supplementation. He progressed with a favorable clinical and laboratory response.