Do patients eventually go into remission or is there evidence for permanent kidney injury after PSGN?
The recovery of the kidney from PSGN follows a different time sequence when looking at the GFR, hematuria, and proteinuria. Of note, the acute kidney injury begins to improve within 1 to 2 weeks of onset and the serum creatinine returns to its baseline level after 3 to 4 weeks.
This improvement in GFR usually parallels the clearance of infiltrating neutrophils in the glomerulus and the decrease in the proliferation of endothelial cells.
The proteinuria in PSGN is a result of the subepithelial immune complexes and will improve only as these complexes are removed. As a result of their location, these immune complexes are cleared very slowly, and proteinuria may persist for months or years after the initial episode. The hematuria seen in PSGN is a result of the subendothelial immune complexes, and these are more rapidly removed from the basement membrane. Consequently, hematuria will resolve within 3 to 6 months. Complement levels of C3 should return to normal within 6 weeks after the onset of kidney disease. It is recommended that failure to resolve the hematuria or proteinuria or normalize the C3 level should warrant a biopsy to determine if a kidney disease other than PSGN is present.
The risk of developing chronic kidney disease and eventually end-stage kidney disease from PSGN is extremely low in children. In adults, however, this can be seen in a minimum of 10% to 15% of cases, especially in third-world countries, where impaired nutrition may lead to immune dysregulation and progressive kidney injury.
