PROTEINURIA (Protein in the Urine)
An average adult excretes up to 150 mgs of Protein in the urine during a 24 hour period. (Children and adolescents might excrete slightly more). When the protein in a twenty four hour urine collection is more than 150 mgs, then it is recognized as Proteinuria. It is one of the common findings in patients with kidney disease. Proteinuria can also occur in the absence of kidney disease. Absence of Proteinuria does not exclude kidney disease. Most of the time proteinuria has no symptoms and is usually discovered on routine urine tests. But when proteinuria is severe some symptoms could occur. When the proteinuria is severe (usually exceeding 2500 mgs per 24 hr) and when symptoms occur, it is then called Nephrotic Syndrome.
Finding of Proteinuria might require evaluation by your physician to determine:
1. Is protein in the urine of normal or abnormal kind?
2. What is the cause
of such proteinuria?
3. What can be expected if it is not treated? (Natural Course)
4. What are the treatments available?
5. What are the complications of such treatment?
Some of the causes of Proteinuria:
1.
Primary kidney diseases (collectively called Nephritis or Glomerulo-Nephritis)
2.
Secondary kidney diseases due to:
a. Diabetes Mellitus
b. High Blood Pressure
c. Lupus
d. Hardening of Blood Vessels (Atherosclerosis) causing
Nephrosclerosis
e. Ischemic Nephropathy (where the kidneys suffer chronic lack of blood
supply)
f. Medications
g. Hepatitis
h.
Aids
i. Cancers
j. Multiple Myeloma
k.
Pregnancy/Eclampsia/Toxemia
l.
Vasculitis (inflammation of Blood Vessels)
m.
Congestive Heart Failure
n. Fever due to any cause
1. May not have any symptoms or may have
one or more of the following
2.
Tiredness
3.
Frothy urine
4.
Puffiness of face especially on waking up
5.
Swelling of legs (edema)
6.
Excessive flatulence and distention of the belly
7.
Shortness of breath especially on lying down
8.
Other symptoms depending on the cause of proteinuria
PLEASE READ 'HOW DO KIDNEYS WORK' FOR A BETTER
UNDERSTANDING OF WHY PROTEINURIA IS
DETRIMENTAL
Normally the kidneys do not excrete Protein more than 150mgs per day.
When the Glomeruli abnormally leak the protein then tubules are faced with
abundant protein (several thousand mgs per day!) Some of the protein
enter the cells lining the tubule. These proteins are alien to the inside of the
cells of the tubule. They cause numerous deleterious changes and
reactions (intracellular storm) and lead to unregulated growth,
as well as death of those cells. This leads to further scarring in the kidney.
Ultimately this process, usually over a period of several years,
transforms the kidneys into a mass of shriveled scar tissue.
As the normal kidney tissue is being replaced by the scar tissue,
the kidney gradually looses its ability to do its work.
When the kidneys thus fail slowly it is called
CHRONIC RENAL FAILURE. (Renal = Kidney)
As the protein is being lost in the urine, elsewhere in the body more protein
(several folds more than the amount being lost in the urine) is destroyed.
This leads to low levels of protein in the blood. Proteins in the blood are
responsible to hold fluids within the blood vessels and to counteract the natural
physical tendency of the fluid to be forced out of the blood vessels.
Therefore, with the protein level low, fluid from the blood vessel 'oozes' into the
tissues (legs, face, lungs, abdomen) causing swelling. Along with the fluid some
of protein and Salt (Sodium) also leaks into the tissues. Such swelling
also causes malfunction of vital organs that are 'water-logged' now.
As the water and the salt accumulate in the tissues, the volume of the blood
usually shrinks. The remaining normal parts of the kidneys interpretate the shrunken
blood volume as dehydration and do what they are programmed to do - to retain
more water and salt! A vicious cycle sets in - and the swelling keeps
increasing with the patient rapidly gaining several pounds of body weight
due to such retention of salt and water.
As the fluid is being lost from the blood vessels into the tissue, the blood is likely to
become thick. Specific proteins that prevent blood clots from forming within
the blood vessels are also lost as part of proteinuria. These, and various other causes, let
clots form in the blood vessels. These clots could block circulation to various organs
(including Kidneys) and can cause Stroke, Heart-Attack, or Clot in the Lung
(Pulmonary embolus)
Your Kidney Specialist (NEPHROLOGIST) is likely to follow these steps:
1. Find the cause of the proteinuria.
This will involve:
a. Complete history and physical examination (and review of all the available medical information) to evaluate for any existing systemic disorders (like Diabetes, Hypertension, Lupus, Cancer, Multiple Myeloma, infection etc).
b. If no disorder exists and the proteinuria is the only abnormality (Primary Proteinuria) then he will examine for any occult and yet to be diagnosed disorder that might be the cause of protein in the urine. This might involve several blood tests, urine tests, Ultrasound of the kidneys and bladder, CT-scan (CAT-Scan) etc.
c. If any disorder is diagnosed, then your physician will evaluate whether such disorder adequately accounts for the protein in the urine. (Presence of a disorder does not offer the kidneys protection from other disorders).
d. If no systemic disorder is evident or does not account for the protein in the urine,
then he will advice you of a needle 'BIOPSY' of the Kidney and its risks and benefits.
(The word 'BIOPSY' almost always brings up the fear of
Cancer. Biopsy simply means taking a small piece of any
tissue and examining under the microscope for various disorders. It does
not always have to be to look for cancer! During the evaluation of
proteinuria kidney biopsy is almost never performed to exclude cancer in
the kidney!)
e. If the proteinuria is mild and is unassociated with other risk factors (like blood in the urine, abnormal blood tests, etc.), he might want to observe without a kidney biopsy. If kidney biopsy is done too early in the course of proteinuria, when the protein excreted in the urine less than 2000 mgs per 24 hours, the biopsy may not show changes conclusively.
2. Simultaneously, he will evaluate as to the extent of proteinuria and for the dangers of proteinuria like salt and water retention, congestive heart failure, swollen lungs (Pulmonary edema) and will evaluate regarding the need (or lack of such need) to:
a. Prescribe Diuretics ('Water Pills')
b. Advice you regarding restricting salt in your diet ( and in extreme cases, regarding restricting the amount of fluid you drink per day)
c. Prescribe blood thinners to prevent clot formation inside the blood vessels
d. Advice you regarding various medications (prescription as well as over the counter) that you should not be taking, as some of these can further affect your kidneys.
e. Sometimes when the proteinuria is minimal, all that may be needed is observation. Kidney biopsy may not add any further useful information, since the findings on biopsy are likely to be minimal and nondiagnostic.
3. Once a specific cause of protein in the urine is established (with or without kidney biopsy) he will then advice you regarding (and prescribe) the necessary and appropriate medication(s) and advice you of other measures that might be necessary to control the protein in the urine or to prevent the dangers of proteinuria.
4. The kidney specialist then (in conjunction with your internist or family practitioner)
will follow your care for:
-Progress (or lack of it) of
the kidney disease
-Side effects of all
medications prescribed [There is nothing (and certainly no medications)
under the Sun -
including the Sun - without side effects.] This includes medications
prescribed by
other physicians as well.
-Adverse impact, if any, of all the
measures you have been asked to follow.
SOME OF THE MEDICATIONS USED TO CONTROL THE PROTEINURIA:
Prednisone
Cyclosporin
Chlorambucil
ACE-inhibitors AT1-receptor
blockers Cytoxan
Imuran
Fish Oil
(?Lescol)
When untreated,
a. proteinuria, on occasion, could
disappear on its own
b. could remain stable for several
months and years
c. could get worse and cause
Kidney Failure esp.,
i. If it
is associated with high blood pressure (Hypertension)
ii. If the
proteinuria is severe (greater than 3000 mgs per day),
the higher the proteinuria the greater are the risks of Kidney
failure and other complications mentioned above
iii. If a
systemic disease that could have adverse effects
on the kidney also exists
iv. If
medications that are not 'kidney-friendly' are used indiscriminately
v. If
Blood Cholesterol levels are not controlled