CONSULT ROUNDS: Hematuria and renal failure?

45 year old with IgA Nephropathy has gross macroscopic glomerular hematuria. Following that, an episode of AKI ensues.  Is this pigment nephropathy? How does AKI result from gross hematuria?

1. 25% of patients with gross hematuria associated AKI had adverse long term outcomes
2. Of all the glomerular diseases, IgA is the most common cause of gross hematuria associated AKI
3. Older age seems to be a risk factor for longer recovery time from AKI from the hematuria
4. Severe ATN was the cause on biopsy for cause of late recovery
5. No cases of Alport's Syndrome and AKI with hematuria in the literature and one case of thin basement  membrane disease with Aki with hematuria.
6. Oral anticoagulation related injury has been now described and cases of warfarin associated renal disease have been identified
7. Hemoglobinuria from entities such as paroxysmal nocturnal hemoglobinuria have been associated with AKI due to hemolysis, intra-tubular cast obstruction.
8. Overall, why does hematuria cause AKI and renal damage. Initially, it was thought to be from intra-tubular obstruction from RBCs or hemoglobin casts.
9. Recent data suggest that there is direct tubular toxicity of hemoglobin, heme, iron molecules released from RBCs.  There is decrease in nitric oxide leading to intra renal vasoconstriction and ischemia.

A recent CJASN article summarizes these studies.