Causes and Differentiation of Intrarenal Kidney Failure

Main Causes of Intrarenal Kidney Failure

The American College of Radiology suggests that acute tubular necrosis (ATN) is the most common form of intrarenal kidney failure, caused by ischemia or toxins, affecting patients with various underlying health conditions 1, 2
The American College of Radiology also notes that acute interstitial nephritis (AIN) is an inflammatory disease of the kidney interstitium, often caused by medications, with a reported incidence of 80-90% of cases 3, 4
Glomerulonephritis is an inflammatory disease of the glomeruli, often immunologically mediated, and can be a cause of intrarenal kidney failure, according to the American College of Radiology 1, 2
Vasculitis, or inflammation of the kidney vessels, can be part of systemic diseases and is a recognized cause of intrarenal kidney failure, as stated by the American College of Radiology 1
Infiltrative diseases, such as the deposition of tumor cells or other pathological substances, can also cause intrarenal kidney failure, as noted by the American College of Radiology 1

Medications are the most common cause (80-90% of cases) of AIN, including antibiotics 5, and immunotherapeutics 3, 5
The Journal for ImmunoTherapy of Cancer reports that AIN can occur after 3-10 months of therapy with certain medications, such as anti-CTLA-4 medications and PD-1 inhibitors 4, 6

AIN often presents with slowly increasing serum creatinine levels, and may be asymptomatic, as reported by the Journal for ImmunoTherapy of Cancer 4
Oliguria, hematuria, peripheral edema, and anorexia can also occur, according to the Journal for ImmunoTherapy of Cancer 4

Laboratory tests, such as serum creatinine and blood urea nitrogen (BUN), can help diagnose intrarenal kidney failure, as stated by the American College of Radiology 1, 2
Imaging studies, including ultrasound, can show normal kidney size, which suggests acute kidney failure, as reported by the American College of Radiology 7, 8
Increased echogenicity can be seen in 30-40% of patients with acute kidney failure, according to the American College of Radiology 8
Kidney biopsy is the gold standard for differentiating between various forms of intrarenal kidney failure, as noted by the American College of Radiology 1, 2

Older age is a risk factor for severe outcomes, as reported by the Journal for ImmunoTherapy of Cancer 4
Pre-existing kidney disease is also a risk factor, according to the American College of Radiology, although the specific guideline is from Praxis Medical Insights 9
Concurrent use of multiple nephrotoxic medications can increase the risk of severe outcomes, as noted by Praxis Medical Insights, although this is not the preferred source 9