Diagnosis & Treatment of Pediatric Nephrotic Syndrome
The initial diagnostic work-up includes taking a detailed medical and family history along with a general physical exam followed by common laboratory test. Additional test may be used to further classify the specific type of NS.
History & Physical
Taking a detailed medical history will allow the physician to learn about potential familial patterns or medication use that may be relevant to the presenting symptoms. During the physical your physician will use a common physical exam technique known as percussion. This is when your physician taps on certain areas on the body, paying close attention to the sound made. Normally, certain areas of the body produce a resonant sound, however dull or thud-like sounds can be heard if the air is full of fluid. Edema, or fluid buildup in tissue, is one of the major clinical features associated with NS. Another classic sign of edema is the formation of a pit on the skin when pressure is applied. This is due to the shifting water just underneath. It is important to note that several diseases can also result in edema. In order to confirm a diagnosis of NS a physician will proceed to order urine and blood tests.
A urine test is one of the most common methods of medical diagnosis. Your kidneys play an important role in removing various waste products and excreting them through your urine. When your kidney is not functioning properly several other molecules may end up being excreted. These molecules are important and can help your physician hone in on the diagnosis. In the case of pediatric NS, the two most important values are the presence of albumin in your urine and the urine albumin-to-creatinine ratio. The presence of albumin is found by dipping a chemically treated strip of paper into the urine sample. The strip then changes color if albumin is present. Another important value to look at is the Urine albumin-to-creatine ratio. A high ratio indicates that the kidneys are leaking large amounts of protein into the urine. This is known as proteinuria and is a key clinical feature of NS.
Blood tests also serve as a critical test in the confirmation of pediatric NS. Two important diagnostic factors to consider are the circulating levels of cholesterol, triglycerides, and albumin. High levels of cholesterol and triglycerides as well as low levels of circulating albumin serve to further confirm the diagnosis of NS. A diagnosis of Pediatric Nephrotic Syndrome is confirmed by urinary protein excretion greater than 50 mg/kg per day and low levels of albumin detected in blood. For a detailed description of the cause behind these values, please click here to learn more.
Other tests that may be performed include an ultrasound of the kidney as well as a kidney biopsy. The ultrasound is a medical device that uses sound waves to visualize the underlying structures. The sound waves are harmless to the child and this examine is typically performed in an outpatient setting. In a kidney biopsy a health care provider takes a small portion of kidney tissue and then examines it using high power microscopes. This procedure can usually be done with a local anesthetic; however, some cases may require the use of general anesthesia. There are several different subclassifications of pediatric NS that can be differentiated this way. Genetic studies should also be done before starting any treatment regiments.
Treatment regimen is dependent on which type of NS – Primary, Secondary or Congenital – a child is diagnosed with. Briefly,
- Primary NS – is NS in the absence of systemic disease
- Secondary NS – NS associated with a systemic disease
- Congenital NS – NS as a result of a genetic defect
Please click here for a more detailed description of the different types of NS.
Primary Nephrotic Syndrome (PNS)
PNS treatment revolves around symptom relief focusing primarily on immune system suppression, removal of extra fluid, and lowering patient’s blood pressure. The main drug of choice to subdue the overactive immune response is prednisone – a corticosteroid. Corticosteroids work by binding to genetic elements and preventing the production of inflammatory immune proteins. Studies have shown that 90% of patient achieve symptom control after 6 weeks of daily corticosteroid use. Unfortunately, many children suffer from recurrent relapses and medication use is altered accordingly. In the case that a child stops responding to glucocorticoids other immune suppressing medication can be prescribed. To address the fluid overload a physician may prescribe a diuretic, which act on different segments of the kidney’s filtration system to prevent the re-uptake of sodium. The sodium in the kidney tubules attracts water in our circulatory system. Once in the kidney tubules the water is expelled in the urine. In addition, other common blood pressure medication may be used in combination with the diuretics.
Secondary Nephrotic Syndrome (SNS)
In SNS treatment focuses on resolving the underlying primary illness this in turn will relieve the stressor causing the kidney damage. SNS can develop as a result of bacterial or viral infections as well as exposure to certain chemicals and medications. Other disease processes can also lead to the development of NS. A physician may prescribe antibiotics, adjust or change medications in order to treat SNS. In addition to these changes, a physician will also address symptom relief with similar medications used to treat PNS.
Congenital Nephrotic Syndrome (CNS)
Treatment of CNS again follows the same initial steps to control symptoms relief. The aggressive nature of this type of NS requires more aggressive treatment such as dialysis, kidney removal, or transplant may be performed. Unfortunately, many cases are fatal within the first year.
Niaudet, Patrick. (2019). Etiology, clinical manifestations, and diagnosis of nephrotic syndrome in children. T. Mattoo & M. Kim (Eds.) UptoDate. Available from https://www-uptodate-com.ezproxy.med.ucf.edu/contents/etiology-clinical-manifestations-and-diagnosis-of-nephrotic-syndrome-in-children?search=nephrotic%20syndrome%20children§ionRank=2&usage_type=default&anchor=H8&source=machineLearning&selectedTitle=1~150&display_rank=1#H8
Niaudet, Patrick. (2019). Symptomatic management of nephrotic syndrome in children. T. Mattoo & M. Kim (Eds.) UptoDate. Available from https://www-uptodate-com.ezproxy.med.ucf.edu/contents/symptomatic-management-of-nephrotic-syndrome-in-children?search=nephrotic%20syndrome%20diagnosis&source=search_result&selectedTitle=5~150&usage_type=default&display_rank=5