What condition is characterized by UA findings of 1+ protein, RBC casts, and azotemia?

The presence of 1+ protein, red blood cell (RBC) casts, and azotemia in the urine analysis is indicative of acute glomerulonephritis. This condition involves inflammation of the glomeruli, which are the filtering units of the kidneys. The inflammation leads to damage to the glomerular filtration barrier, allowing proteins and red blood cells to leak into the urine, which explains the proteinuria and the presence of RBC casts.

Azotemia, referring to an elevation of blood urea nitrogen (BUN) and creatinine levels, occurs because the kidneys are not filtering waste products effectively due to the glomerular dysfunction. The combination of these urinary findings — specifically the RBC casts which are pathognomonic for glomerular injury — confirms the diagnosis.

In contrast, acute tubular necrosis typically presents with muddy brown casts and is associated with renal tubular damage rather than glomerular inflammation, while cystitis primarily presents with dysuria and may show some degree of hematuria but does not feature RBC casts or significant azotemia. Chronic kidney disease may have proteinuria but is usually characterized more by a gradual decline in kidney function rather than an acute presentation with RBC casts and recent onset of azotemia.