Acute Kidney Injury by Renal Hemosiderosis Secondary to Primary Cold Agglutinin Disease Associated with an Excessive Alcohol Intake.

Renal hemosiderosis occurs in the context of severe intravascular hemolysis, with the most common cause being paroxysmal nocturnal hematuria. Patients with cold agglutinin disease (CAD) have relatively mild hemolysis, and acute kidney injury (AKI) due to renal hemosiderosis has not been reported. We encountered a patient with CAD caused by lymphoplasmacytic lymphoma who developed AKI secondary to renal hemosiderosis after an excessive alcohol intake.

Acute Kidney Injury and Hemolytic Anemia Secondary to Mycoplasma pneumoniae Infection.

Glomerulonephritis as well as kidney injury secondary to fulminant intravascular hemolysis are rare extrapulmonary manifestations of Mycoplasma pneumoniae infection. We describe a 50-year-old female diagnosed with M. pneumoniae infection-associated hemolytic anemia, characterized by negative cold agglutinin tests but with laboratory evidence of complement alternative pathway activation. The patient presented both with anemia and severe kidney failure and she was treated with steroids and red blood cell transfusions along with plasmapheresis. She also received a short course of antibiotics. Renal biopsy showed combined features of resolving postinfectious glomerulonephritis and hemolysis-associated extensive acute tubular injury characterized by renal hemosiderosis and intratubular hemoglobin casts. Electron microscopy revealed features of glomerular microangiopathic injury. The treatment led to complete disease remission and a favorable renal outcome at the first year follow-up.