What Is Renal Papillary Necrosis?
Renal papillary necrosis (RPN) is a disorder marked by the death of renal papillae, structures in the kidneys that help move urine through the them before it is excreted from the kidneys and into the ureter. Underlying health conditions which can lead to RPN include:
- Drug abuse
- Sickle cell anemia (this is the most common cause of RPN in children)
- Kidney infection
- Ureter infection
- Blood clots in veins that are located in the kidneys
- Complete or partial blockage of urine flow in the kidneys
- Chronic kidney disease
When renal papillae die in sufficient numbers, the kidneys become deficient at concentrating urine for its discharge from the body. In most cases, failure to properly treat RPN results in kidney failure, a life-threatening condition.
What Are The Symptoms Of Renal Papillary Necrosis?
A person who is inflicted with RPN may exhibit one or more symptoms, some of which may be very serious. These possible symptoms include:
- Unusually colored urine (dark brown or rust color)
- Blood in the urine
- Opaque or cloudy urine
- Dead tissue in the urine
- Back pain
- Pain on one side of the body between the upper abdomen and back
- Painful urination
- Frequent urination
- Urine leakage through the urethra and from the body (a condition that is otherwise known as incontinence)
How Is Renal Papillary Necrosis Diagnosed?
Clinical diagnosis of RPN is very difficult to achieve. In many instances, RPN is diagnosed by performing intravenous urography, a radiological (x-ray) technique that uses dye to assess whether any abnormalities exist in the kidneys. In this technique, the presence of RPN in the patient is confirmed if it appears that the dye has accumulated and concentrated at or near the renal papillae.
RPN also can be diagnosed via an imaging method known as computed tomography. In this technique, multiple images of cross-sections of kidneys are taken and processed by a computer program in a way that allows the patient’s kidneys to be displayed to medical personnel in 3D. These 3D images are more useful that are 2D x-ray images for inspecting the degree to which contrast agents (dye) concentrate in or near the renal papillae.
In addition to the imaging methods described above, medical personnel sometimes also perform urinalysis when diagnosing RPN. In this method, urine is inspected by using a battery of physical, chemical, and visual techniques. The observation that tissue or blood is present in the urine serves as further evidence that the patient is suffering from RPN.
Treatment of Renal Papillary Necrosis
Unfortunately, there is no sure-fire and straightforward way of treating RPN. The typical and best therapeutic course is to treat the underlying condition that has led to RPN in each particular patient. (For example, if diabetes is the underlying cause, it is best to focus on treating the diabetes.) Successful treatment of the underlying condition often allows the kidneys to heal over time such that RPN is overcome and no longer problematic.
The main goal of any treatment course that is chosen is to prevent RPN from progressing to the point that kidney failure is experienced. Patients who experience kidney failure must undergo dialysis, in which the patient is attached to a machine that largely serves as an artificial replacement to kidneys by removing waste and fluid from the body, and are at great risk of dying.
This article is meant only to provide some basic information regarding the serious condition known as renal papillary necrosis. It is not meant to replace the good advice of your doctor.
A.E. Brix, Renal Papillary Necrosis, Toxicology Pathology 30:672-674 (2002). https://tpx.sagepub.com/content/30/6/672.long
D.C. Jung et al., Renal Papillary Necrosis: Review and Comparison of Findings at Multi-detector Row CT and Intravenous Urography, Radiographics 26:1827-1836 (2006). https://radiographics.rsna.org/content/26/6/1827.long
Medline Plus, National Institutes of Health, Renal papillary necrosis: https://www.nlm.nih.gov/medlineplus/ency/article/000488.htm