Reflux nephropathy is kidney damage (nephropathy) due to urine flowing backward (reflux) from the bladder toward the kidneys; the latter is called

vesicoureteral reflux Vesicoureteral reflux (VUR), also known as vesicoureteric reflux, is a condition in which urine flows retrograde, or backward, from the urinary bladder, bladder into one or both ureters and then to the renal calyx or kidneys. Urine normally trave ...

(VUR). Longstanding VUR can result in small and scarred kidneys during the first five years of life in affected children. The end results of reflux nephropathy can include

high blood pressure Hypertension, also known as high blood pressure, is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure usually does not cause symptoms itself. It is, however, a major ri ...

, excessive protein loss in the urine, and eventually

kidney failure Kidney failure, also known as renal failure or end-stage renal disease (ESRD), is a medical condition in which the kidneys can no longer adequately filter waste products from the blood, functioning at less than 15% of normal levels. Kidney fa ...

. When reflux nephropathy is suspected as a cause of kidney disease, other conditions to consider include chronic

pyelonephritis Pyelonephritis is inflammation of the kidney, typically due to a bacterial infection. Symptoms most often include fever and flank tenderness. Other symptoms may include nausea, burning with urination, and frequent urination. Complications ...

obstructive uropathy Obstructive uropathy is a structural or functional hindrance of normal urine flow, sometimes leading to renal dysfunction (obstructive nephropathy). It is a very broad term, and does not imply a location or cause. Presentation Symptoms, less lik ...

, and analgesic overuse. The term "reflux nephropathy" was introduced in 1973.

Signs and symptoms

The symptoms of reflux nephropathy are comparable to

nephrotic syndrome Nephrotic syndrome is a collection of symptoms due to kidney damage. This includes proteinuria, protein in the urine, hypoalbuminemia, low blood albumin levels, hyperlipidemia, high blood lipids, and significant edema, swelling. Other symptoms ...

and infection of the

urinary tract The human urinary system, also known as the urinary tract or renal system, consists of the kidneys, ureters, bladder, and the urethra. The purpose of the urinary system is to eliminate waste from the body, regulate blood volume and blood pressu ...

, though some individuals may not exhibit any evidence (symptom) of reflux nephropathy.

Cause

The abnormal retrograde flow of urine from the bladder into one or both the ureters leads to vesicoureteral reflux (VUR), which is a direct consequence of incompetent and mislocated ureterovesical valves. Reflux nephropathy is a direct consequence of VUR or other urologic congenital anomalies stemming from chronic high-pressure sterile urine reflux and often leads to recurrent urinary tract infections (UTIs) in the early childhood.Aeddula NR, Baradhi KM. Reflux Nephropathy. pdated 2018 Sep 23 In: StatPearls nternet Treasure Island (FL): StatPearls Publishing; 2018 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK526055/

Pathophysiology

The underlying calyces lose their normal concave shape and show clubbing.

Diagnosis

It is diagnosed by micturating

cystography In radiology and urology, a cystography (also known as cystogram) is a procedure used to visualise the urinary bladder. Using a urinary catheter, radiocontrast is instilled in the bladder, and X-ray imaging is performed. Cystography can be used t ...

; scarring can be demonstrated by

ultrasound Ultrasound is sound with frequency, frequencies greater than 20 Hertz, kilohertz. This frequency is the approximate upper audible hearing range, limit of human hearing in healthy young adults. The physical principles of acoustic waves apply ...

or DMSA.

Prognosis

Children with reflux nephropathy have higher risk of developing kidney scarring and hypertension in later life.

Treatment

The aim of treatment is to reduce renal scarring. Those children with grade II or worse should receive low dose

prophylactic Preventive healthcare, or prophylaxis, is the application of healthcare measures to prevent diseases.Hugh R. Leavell and E. Gurney Clark as "the science and art of preventing disease, prolonging life, and promoting physical and mental health a ...

antibiotic An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting pathogenic bacteria, bacterial infections, and antibiotic medications are widely used in the therapy ...

s (

Nitrofurantoin Nitrofurantoin, sold under the brand name Macrobid among others, is an antibacterial medication of the nitrofuran class used to treat urinary tract infections (UTIs), although it is not as effective for kidney infections. It is taken by mouth ...

trimethoprim Trimethoprim (TMP) is an antibiotic used mainly in the treatment of bladder infections. Other uses include for middle ear infections and travelers' diarrhea. With sulfamethoxazole or dapsone it may be used for ''Pneumocystis'' pneumonia ...

cotrimoxazole Trimethoprim/sulfamethoxazole, sold under the trade names Bactrim, Cotrim (a short form of the British Approved Name, Co-trimoxazole) and Septra, among others, is a fixed-dose combination antibiotic medication used to treat a variety of bacte ...

cefalexin Cefalexin, also spelled cephalexin, is an antibiotic that can treat a number of bacterial infections. It kills gram-positive and some gram-negative bacteria by disrupting the growth of the bacterial cell wall. Cefalexin is a β-lactam antibi ...

in those with CRF). Hypertension should be managed with

ACE inhibitor Angiotensin-converting-enzyme inhibitors (ACE inhibitors) are a class of medication used primarily for the treatment of high blood pressure and heart failure. This class of medicine works by causing relaxation of blood vessels as well as a decr ...

or ARBs. Other treatment modalities include surgery (endoscopic injection of collagen behind the intra-vesical ureter, ureteric re-implantation or lengthening of the submucosal ureteric tunnel) which has its protagonists.

Epidemiology

There is a genetic predisposition, first-degree relatives have a great increase in the chance of VUR. The gene frequency is estimated to be 1:600. The American Academy of Pediatrics recommends that children from 2 to 24 months presenting with a UTI should be investigated for VUR.

References

External links

{{Authority control Nephrology