Protein Loss In Transplanted Kidneys

After your kidney transplant, your nephrologist will regularly test your blood and urine. The many lab tests he will order include measuring the protein in your urine. Healthy kidneys keep protein in the blood. Protein getting lost into the urine is a sign that something is wrong with your transplant. This is called proteinuria, or high urine protein.

Causes

Abnormally high urine protein levels after transplant can mean several things. It can indicate that your body is rejecting the new kidney. Rejection can happen even years after transplant if you stop taking your immunosuppressant drugs. It can signal disease recurrence, which would mean that the underlying kidney disease was still active. This would be more likely if the reason for the transplant had been an aggressive glomerular disease such as MPGN -- membranoproliferative glomerulonephritis -- or FSGS -- focal segmental glomerulosclerosis. Urine protein levels can be high because the kidney is getting worn out. Transplanted kidneys do not last forever. Lastly, urine protein levels can be high because the immunosuppressants you are taking are nephrotoxic -- toxic to your kidneys.

Treatment

Your nephrologist may schedule a biopsy to determine why you are spilling protein into your urine. By taking a tiny bit of kidney tissue and examining it in the pathology laboratory, the doctor can distinguish between recurrence, rejection, nephrotoxity or other causes. While a kidney biopsy is an invasive procedure, it is very important to determine why urine protein levels are high. Nephrologists can often prevent further damage to the kidney by changing a drug regimen.

Research

A May 2004 article on the Science Daily website reported on an a special urine test that might take the place of post-transplant biopsy. As of 2011, this test is not used yet, although research in this area continues to be active. Instead of measuring the total amount of protein lost in the urine, it looks at very specific proteins that signal rejection is taking place. The researcher identified 13 possible protein markers. Testing for these specific proteins allows doctors to tailor the immunosuppressant regimen so that the patients is taking the lowest doses possible without worrying about onset of rejection.

Prevention

While you can't prevent all of the causes of proteinuria in transplanted kidneys, taking your immunosuppressant drugs as directed will go a long way toward preventing rejection episodes. Your nephrologist should be your partner in your post-transplant care. If side effects are an issue, talk to him first before changing a drug regimen. The September 2008 issue of "Pediatric Transplantation" reports that teenagers and patients in their early 20s are often noncompliant about taking medication. Encouraging your teen to be responsible in his own care is critical to the well-being of his new kidney.