RBC casts seen in

RBC casts are a feature of glomerular damage .Normally <3 RBC/HPF are going to leak. But in the case of glomerular damage the number of RBC in the urine will exceed the limit mentioned above and these RBC get impinged on Tamm horsefall protein. The resultant RBC casts can be seen under microscopic examination of urine. Refer robbins 9/e p912