Proteinuria in Children - An Overview

What Is Proteinuria?

Elevated protein in the urine is known as proteinuria or albuminuria. It is a sign of certain kidney-related disorders rather than a disease in and of itself. Excessive protein in the urine usually indicates that the glomeruli, the kidneys' filters, are malfunctioning and letting too much protein leak into the urine. The disorder known as glomerulonephritis or nephritic occurs when the glomeruli are injured. Nephropathy can also result from other illnesses such as diabetes, heart disease, hypertension, and renal disease.

Proteinuria is sometimes referred to as albuminuria because albumin is the protein that is most likely to be found in the urine. Urine may also contain other proteins that seep out. The kind and amount of protein indicate the extent of the injury and the likelihood of renal failure. The illness is known as microalbuminuria and indicates limited damage if the protein levels are slightly raised. Full-blown albuminuria, however, develops when the disease worsens and more protein leaks into the urine.

What Is Proteinuria in Children?

A child that exhibits proteinuria has protein in their urine. Every child's urine contains some protein. However, too much could indicate a kidney issue for the youngster. The kidneys are organs that remove excess fluid, waste, and salt. Urine is how the body excretes these wastes.

Orthostatic proteinuria can occasionally affect older children. In orthostatics, "upright" indicates. This condition is known as orthostatic proteinuria because the youngster only pees with protein while standing up. Kidney damage is nonexistent in children with this disease. However, during the day, when they are active, they lose protein in their urine for an unexplained cause. Their kidneys do not excrete protein into the urine when they are sleeping.

What Are the Types of Proteinuria in Children?

1. Transient Proteinuria: Temporary or functional proteinuria disappears when the triggering element disappears or is removed. Exercise, stress, dehydration, or exposure to the cold can all trigger transient proteinuria, as can medical conditions like fever or seizures. Moreover, it may be idiopathic.

2. Orthostatic Proteinuria: Children's proteinuria most commonly results from orthostatic proteinuria, particularly in male adolescents. Without any clinical importance, it is a benign disorder. In a spot urine sample taken first thing in the morning after the patient has been supine through the entire night, the diagnosis is suggested with normal protein excretion (that is, a negative urine dipstick test result or a UPr/Cr ratio of 0.2 or less), but increased protein excretion (that is, a positive urine dipstick test result, or a UPr/Cr ratio of more than 0.2) at least four to six hours after the patient has been upright. Anatomic constriction of the left renal vein has been proposed as a possible cause of orthostatic proteinuria, though this remains unclear.

3. Persistent Proteinuria: Persistent proteinuria may originate from tubulointerstitial or, more frequently, glomerular sources. The typical markers for glomerular disorders in the urine include albumin and immunoglobulin G. Nephrotic and nephritic characteristics can be present in glomerular disorders; differentiating between these symptoms might aid in narrowing the differential diagnosis. The symptoms of nephrotic syndrome include edema, hypoalbuminemia (less than 2.5 g per dL [25 g per L]), hyperlipidemia, and severe proteinuria (more than 1,000 mg per m2 daily or a UPr/Cr ratio of more than 2). Among the symptoms of nephropathy are hematuria, hypertension, oliguria, and active urinary sediments, such as cellular casts, white blood cells, and red blood cells.

What Are the Causes of Proteinuria in Children?

Substances or infections can occasionally harm the kidneys. This impairs the kidneys' functionality. If the child has an illness, treating the causing infection will cure the proteinuria. Here are listed a few of the causes

• Sick.

• Feverish.

• Physically stressed.

• Physical exercises.

This kind of proteinuria is likewise not the same as normal. Diabetes types 1 and 2 have also been linked to protein in the urine. If the child has been unusually hungry, thirsty, or has accidentally lost weight—or if their breath smells like fruit—inform the doctor. These might indicate type 1 diabetes.

What Are the Symptoms of Proteinuria in Children?

Suppose the child's urine does not contain protein. It might be linked to the following.

• Swelling in their legs.

• Swelling in ankles.

• Swollen eyes.

• Hypertension (elevated blood pressure).

Proteinuria is not painful. Severe proteinuria may result in legs, stomach, or facial edema. The kidney disease, known as nephrotic syndrome, is characterized by swelling brought on by proteinuria. The condition causing proteinuria in children can also cause other symptoms, including rash or joint pain.

How Can Proteinuria in Children Be Diagnosed?

Protein in the child's urine cannot be seen, so a urine test is required to make the diagnosis. A urine sample from the child will be taken for this test to make a diagnosis.

The doctor might want to examine the child's urine for protein after the initial test. This is because temporary proteinuria, or protein loss, frequently occurs independently. If the protein level remains elevated after the second test, the physician can request that one get a 24-hour urine sample from the child. This improves the accuracy with which the doctor measures the protein content of the urine.

The doctor may test the child's blood. They might also request a CT scan or ultrasound. To check for issues, these two procedures take images of the child's kidneys and surrounding tissue. These operations do not cause any pain.

The doctor will examine two urine samples from the child to diagnose orthostatic proteinuria. The first is picked up in the morning once the child wakes up. The second sample is gathered throughout the day. Separate containers are used to store the samples. If the child has orthostatic proteinuria, the morning sample will not contain any protein. However, there will be protein in the urine collected during the day.

How Can Proteinuria in Children Be Treated?

• The family might be comfortable if the child is asymptomatic, has normal blood pressure and glomerular filtration rate, and the proteinuria is transitory or orthostatic. However, routine monitoring is crucial as long as there is noticeable proteinuria.

• A child with recurrent proteinuria should first get a physical examination every six to twelve months, which should include a blood pressure check, urine, and blood tests for creatinine and urea nitrogen levels, even though there are no official criteria for monitoring. Regarding nutrition and exercise, there are no particular restrictions. When the child is stable, yearly follow-ups are possible.

• The underlying cause of persistent proteinuria should be addressed in treatment.

• Prednisone at a dosage of 60 mg per m2 daily (maximum, 80 mg daily) is the conventional treatment for idiopathic nephrotic syndrome. This is followed by four weeks of taking 40 mg per m2 daily (maximum, 60 mg daily) every other day.

• Renoprotection with an angiotensin II receptor blocker or an angiotensin-converting enzyme inhibitor may reduce proteinuria and delay the progression of renal disease in people with renal failure.

• Renal biopsy and referral to a pediatric nephrologist may be necessary for patients with active urinary sediments, hematuria, hypertension, hypocomplementemia, renal insufficiency with decreased glomerular filtration rate, or signs and symptoms suggestive of vasculitis illness.

The doctor could refer the child to a kidney specialist if testing reveals a significant amount of protein in their urine and if they have swelling in their legs and eyelids. They are referred to this physician as a nephrologist. A nephrologist can carry out the kidney biopsy. This straightforward surgical treatment involves the removal of a little renal tissue fragment. The fragment will be examined under a microscope by the physician. This could assist them in determining the source of the protein in the child's urine. The doctor can treat the issue once they have determined the cause.

Conclusion:

An excess of protein in the urine is known as proteinuria. Only extremely modest amounts of protein from the blood can enter the urine when the kidneys are healthy. Proteinuria could be an indication of renal disease. The method to assess kidney health is to measure the protein levels in the urine. Thankfully, a large number of kids simply experience transient proteinuria and do not have renal illness.