Organ Rejection

The human immune system is very complicated. It enables you to defend your body against invasion by foreign protein substances, whether in disease-causing microbes or transplanted organs from another human being who is not genetically identical.

In a healthy immune system, white blood cells circulate through the body looking for foreign invaders like bacteria or viruses. If a foreign invader enters your body, perhaps through a skin cut, your immune system automatically sees it as a threat and attacks it.

How organ rejection works

Unfortunately, your new heart is also foreign and your immune system treats it the same as it would a bacteria or virus. Rejection is your body's attempt to protect you by attacking a foreign protein that has entered your body.

Currently, the only way to diagnose rejection is a heart biopsy. Routine biopsies begin approximately two weeks after your transplant and then as ordered by your transplant cardiologist. The biopsies will become less frequent as time goes on as long as you are not experiencing frequent episodes of rejection.

Episodes of rejection of your transplanted organ(s) occur at random times following surgery, and are most frequent within the first few weeks or months after surgery. There is nothing other than taking the prescribed medications that you can do to prevent them. Treatment for rejection is determined by severity and the time interval since transplantation.

Immunosuppressants

Preventing rejection requires taking medications called immunosuppressants. Immunosuppressant medications help prevent rejection and help your body accept the new heart by weakening or suppressing the immune system. Unfortunately, there are no currently available methods to suppress your body's response to a foreign organ without also impairing its response to infections.

You will be placed on an individualized regimen suited to your needs. You may be using different immunosuppressive combinations and dosages at various times. The ideal goal of an individual medication regimen is to suppress organ rejection while minimizing drug toxicity and the susceptibility to infection.

Gene express profiling

A non-invasive test being used on selected patients is gene expression profiling. This test is a 20-gene, real-time, quantitative polymerase chain reaction (PCR) test that measures the expression of genes associated with cardiac allograft rejection in  blood  cells.  The test is useful to identify low-risk patients who can be safely managed without routine biopsy. 

Grading rejection

The pathologist, the medical Doctor who reviews the tissue slide for the diagnosis of rejection rates the presence and severity of rejection based in the International Society and Heart Lung Transplant (ISHLT) scale.

• Acute Cellular Rejection (ACR)
  0 = No evidence of rejection (NER)
  1R= mild rejection
  2R= moderate rejection
  3R= Severe rejection.
• Antibody-mediated rejection (AMR): Is a type of late or chronic rejection.  It represents a continuum of humoral responses to the cardiac allograft. AMR is diagnosed by both the biopsy and by the detection of antibodies specific to the donor in the blood.

Treating rejection

Having an episode of rejection can be discouraging, but remember that they are common. Most rejection episodes can be reversed if detected and treated early. Treatment for rejection is determined by severity.

The treatment may include giving you high doses of intravenous steroids called Solumedrol, changing the dosages of your anti-rejection medications, or adding new medications. Severe or persistent rejections may require treatment with powerful medications and/or plasmapheresis, a procedure in which antibodies are removed from your blood.

Early treatment is critical to successfully reversing rejection. Do not try to treat your symptoms yourself.