What are the typical urine findings in interstitial nephritis?

In interstitial nephritis, the typical urine findings include the presence of white blood cells (WBCs) and WBC casts. This condition is characterized by inflammation of the renal interstitium, often triggered by drugs, infections, or other inflammatory processes. The inflammation leads to an increase in WBCs as the immune system responds to the underlying cause.

The presence of WBC casts indicates that these white blood cells are originating from the renal tubules, confirming that the process is involved with the nephron itself rather than simply being a result of urinary tract infection or other extrarenal sources. Additionally, WBC casts are a distinctive feature that helps distinguish interstitial nephritis from other types of kidney diseases.

Other findings such as dysmorphic RBCs typically suggest glomerular disease, while the presence of proteins and glucose can be indicative of different renal pathologies, including diabetic nephropathy but are not hallmarks of interstitial nephritis. Finally, crystals would suggest metabolic disturbances or obstruction, which are unrelated to interstitial nephritis. Therefore, the presence of WBCs and WBC casts is the hallmark finding in this condition.