Protein Creatinine Ratio (Urine) Test

The Urine Protein Creatinine Ratio (UPCR) test, also called the PCR test, spot PCR test, or spot urine P/C ratio, is a simple urine test that measures protein levels in urine and detects proteinuria. Proteinuria means that several proteins, like albumin, globulin, Bence-Jones protein, mucoprotein, and other plasma proteins, are present in the urine. Normally, these proteins remain in the blood and should not be found in large amounts in urine.

This test is performed with just a single urine sample. It compares the protein level to that of creatinine (a waste product present in urine) in the same sample. By measuring both protein and creatinine, the test estimates the amount of protein lost in the urine. It is a quick and simple test that does not require a 24-hour urine collection.

Doctors use this test because protein in the urine may indicate that the kidneys are not working properly. Kidneys normally act as filters, keeping important substances, such as protein, in the blood. When these filters are damaged, protein leaks into the urine. This can be an early sign of kidney disease and indicate worsening kidney function over time.It helps estimate whether the kidneys are leaking protein in conditions such as kidney disease, high blood pressure, diabetes, pregnancy-related issues, and immune system diseases.

The UPCR test primarily evaluates kidney and urinary system function. It helps doctors identify kidney problems, understand their severity, and monitor diseases that cause protein loss in urine.

A UPCR test is recommended if kidney disease is suspected or if protein is detected in urine, especially in cases of nephrotic syndrome or chronic kidney disease, which can cause symptoms such as: 

• Swelling around the eyes, face, hands, legs, or feet
• Foamy urine or sometimes blood in urine (seen especially in nephrotic syndrome) 
• Feeling very tired or weak without a clear reason 
• Loss of appetite or unplanned weight loss 
• Passing urine more or less than normal 
• Dry skin, itching, or feeling of numbness 
• Nausea, vomiting, or stomach discomfort 
• Muscle cramps or general weakness 
• Shortness of breath in some cases 
• Difficulty concentrating or feeling mentally slow
• Swelling with weight gain due to fluid buildup (seen in nephrotic syndrome) 

A UPCR test is usually recommended for people at higher risk of kidney problems or protein in their urine, even before obvious symptoms appear. They include: 

• People with diabetes or high blood pressure 
• People with heart or blood vessel diseases
• People with autoimmune diseases, where the body’s defence system may affect the kidneys 
• People with reduced kidney function or chronic kidney disease 
• Older adults above 60 years of age
• People with swelling in the body, like feet, legs, or around the eyes 
• Pregnant women with high blood pressure or risk of preeclampsia (a pregnancy complication that causes high blood pressure)
• Those whose family members have kidney disease
• Children or adults being checked for protein in urine 
• People with conditions like multiple myeloma (a type of blood cancer)

The UPCR test is not a routine test for everyone. It is mainly done to check for protein in the urine, detect kidney problems, and monitor how kidney disease is progressing or responding to treatment, as shown in the table below:

A UPCR test is used to assess the level of protein loss and provide important information about kidney-related conditions, such as:

• Proteinuria (protein in urine): In adults, this test detects and measures the amount of protein in the urine. In diseases such as nephrotic syndrome, the amount of protein loss shows how active the disease is. In children, the test helps find and track protein in the urine when kidney problems are suspected. 
• Chronic kidney disease (CKD): UPCR is used in the diagnosis, management, and staging of CKD by assessing protein loss in urine.
• Non-diabetic kidney-related protein loss in children: In children, proteinuria may occur due to urinary tract or tubular disorders, and UPCR is used to assess protein loss in such cases. 
• Nephrotic syndrome: UPCR detects heavy protein loss in urine, which is a key feature of nephrotic syndrome and reflects disease severity.
• Preeclampsia: After 20 weeks of pregnancy, UPCR is used to measure protein levels in the urine when preeclampsia is suspected.
• Proteinuric kidney diseases and related conditions that change the protein amount in urine: UPCR is used to assess and monitor protein loss in conditions such as diabetes-related kidney disease, hypertension-related kidney disease, lupus nephritis, and multiple myeloma.

What to Expect Before the PCR (Urine) Test

Collect first morning urine - overnight urine has the highest bacterial concentration. Do NOT start antibiotics before collecting the sample. Clean the genital area before collection using a sterile wipe or clean water to reduce contamination. If the sample cannot reach the lab within 2 hours, refrigerate it at 2 to 8°C - bacteria multiply rapidly at room temperature and can give a falsely high colony count.

What to Expect During the Sample Collection

Open the sterile container without touching the inside or lid. Clean the genital area with two or three gauze pads saturated with soapy water, using a forward-to-back motion, then rinse with sterile saline and water. Begin urinating into the toilet. After the first few drops, collect the middle stream directly into the container without stopping. This midstream clean-catch technique flushes out urethral bacteria before collection begins. Close and label the container with your name, date, and time. Hand it to the PharmEasy phlebotomist or deliver it to the lab within 2 hours.

What to Expect After the PCR (Urine) Test

No recovery time is needed - urine collection is completely painless and non-invasive. Continue drinking fluids normally. Do not start antibiotics until your doctor has reviewed the culture and sensitivity report. Results are available within 24 to 72 hours.

This test measures one important urine parameter: 

• Protein Creatinine Ratio (UPCR): A calculated value obtained from a spot urine sample that compares urine protein with urine creatinine. 

The table below shows the normal range for UPCR: 

A UPCR value below 0.20 is generally considered normal and suggests that there is no significant protein loss in urine. Higher values indicate increased protein leakage from the kidneys, as shown in the table below: 

The UPCR test is a simple urine test with no known risks or side effects. However, it has some limitations that can affect the results, such as: 

• Urine concentration can affect results, as very dilute or very concentrated urine may compromise accuracy.
• Fever, stress, or intense exercise can temporarily increase the amount of protein in urine.
• Urinary tract infection or menstruation may affect the test result. 
• Muscle mass, diet, medicines, and overall health can influence creatinine levels and affect results.
• A single urine sample may not fully reflect daily protein loss in urine. 
• Results may vary slightly between different laboratories due to different testing methods.

Along with the UPCR test, doctors may recommend additional tests to find out why protein is leaking into the urine and to assess overall kidney health and related causes. These may include: 

• Estimated glomerular filtration rate (eGFR; kidney function blood test)
• Urine test under a microscope
• Urine albumin test (checks protein in urine)
• Kidney ultrasound (scan of the kidneys)
• Hepatitis tests (checks for liver infections that can affect the kidneys)
• Antinuclear antibody (ANA) test (checks for autoimmune diseases)
• Human immunodeficiency virus infection (HIV test; checks infection that can affect immunity and kidneys)
• Complement test (checks immune system activity)