The kidneys filter impurities from the blood. When physicians want to speak of how effectively this filtration happens, they refer to the patient's kidney function or renal function.
Diseases that affect renal function in children are relatively rare. Renal failure in kids is even rarer. According to the National Institute of Diabetes and Digestive and Kidney Diseases, or NIDDK, the annual rate of renal failure in children was one to two new cases in every 100,000 children in 2005.
Pediatric Renal Disorders
The NIDDK explains that a sizable handful of pediatric renal diseases can lower renal function in children. Some of these diseases, such as polycystic kidney disease and hydronephrosis, are present at birth. Other diseases, such as minimal change, commonly develop when the child is a toddler. Still others such as membranoproliferative glomerular nephritis, or MPGN, emerge during adolescence. All of these diseases can affect renal function over time.
Effects
The NIDDK reminds us that kidneys play an important role in a child's growth because the kidneys regulate levels of phosphorus, calcium and vitamin D that are essential for bone growth. This factor alone could cause stunted growth. Many kids also take prednisone regularly--and this also prevents growth.
If a child's growth lags too far behind other children his age, the nephrologist may consider prescribing growth hormone.
Considerations
According to the NIDDK, minimal change--also called MCNS or minimal change nephrotic syndrome--is one of the most common pediatric kidney diseases. Minimal change produces a cluster of symptoms including high urine protein, lower serum protein and edema. Taken together, these symptoms are called nephrotic syndrome.
Minimal change tends to go away as the child grows older without permanently affecting renal function.
Expert Insight
Writing for NephKids, nephrologist Sue Conley opines that minimal change is on a continuum with another disease called focal segmental glomerular sclerosis, or FSGS. Although the symptoms of the two are initially identical, FSGS gets progressively worse instead of going away. Ultimately, the renal function of FSGS patients gets to the point where transplant or dialysis is necessary.
Treatment
The goal of treating pediatric kidney disease involves retaining as much kidney function as possible while providing symptomatic relief for hypertension, anemia and other aspects of kidney disease. Getting control of the high urine protein that accompanies kidney disease prevents further loss of kidney function.
"Clinical Pediatric Nephrology" by Kanwal K. Kher, et al. indicates that angiotensin converting enzyme inhibitors--commonly known as ACE inhibitors--are the first choice to lower urine protein. Other medications, including prednisone, may be appropriate if this does not work.
References
- National Institute of Diabetes and Digestive and Kidney Diseases: Growth Failure in Children With Kidney Disease
- National Institute of Diabetes and Digestive and Kidney Diseases: Childhood Nephrotic Syndrome
- NephKids: MCNS & FSGS
- "Clinical Pediatric Nephrology"; Kanwal K. Kher, et al.; 2007
