What lab tests are used to determine if the body is rejecting a transplanted organ?

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Last updated: July 4, 2025View editorial policy

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From the Guidelines

Laboratory tests used to detect organ transplant rejection include blood tests that measure levels of specific markers like creatinine for kidney transplants, liver enzymes for liver transplants, and troponin for heart transplants, as well as donor-specific antibodies (DSAs) and biopsy of the transplanted organ for definitive diagnosis. These tests are crucial for monitoring the health of the transplanted organ and detecting any signs of rejection early on. Some key tests include:

  • Blood tests to measure specific markers such as creatinine, liver enzymes, and troponin
  • Monitoring immunosuppressant drug levels to ensure they are within therapeutic range
  • Checking for donor-specific antibodies (DSAs) that indicate the immune system is attacking the transplanted organ
  • Complete blood counts to identify signs of infection or inflammation
  • C-reactive protein and erythrocyte sedimentation rate tests to detect general inflammation
  • Biopsy of the transplanted organ for definitive diagnosis, which remains the gold standard for detecting rejection 1. According to the most recent and highest quality study, a biopsy of the transplanted organ is recommended for definitive diagnosis of rejection, especially in cases of allograft dysfunction 1. Additionally, donor-specific antibody testing is recommended for posttransplant assessment of anti-HLA donor-specific antibodies 1. It's also important to note that the frequency of these tests typically decreases over time if the organ functions well, but early detection of rejection is crucial for prompt treatment and prevention of permanent damage to the transplanted organ. Overall, a combination of these tests and monitoring strategies is essential for ensuring the long-term health and function of the transplanted organ.

From the Research

Lab Tests for Organ Rejection

To determine if the body is rejecting a transplanted organ, several lab tests can be used, including:

  • Biopsy samples to detect immune cell infiltration into the graft and other pathological changes 2
  • Magnetic Resonance Imaging (MRI) techniques to monitor the accumulation of immune cells at the transplanted organ 2
  • Liver biopsies to examine the rate of acute rejection in liver transplant recipients 3
  • Therapeutic monitoring of whole blood FK506 drug concentrations to determine the relationship between concentrations of FK506 in the blood and the development of toxicity or the risk for organ rejection 4
  • Multicolor flow cytometry and cytokine analysis to provide enhanced information on kidney transplant biopsies 5

Types of Lab Tests

The types of lab tests used to determine organ rejection include:

  • Invasive tests, such as biopsy samples, which carry associated risks and are prone to sampling errors 2
  • Non-invasive tests, such as MRI techniques, which can monitor the accumulation of immune cells at the transplanted organ 2
  • Blood tests, such as therapeutic monitoring of whole blood FK506 drug concentrations, which can help minimize the risks of toxicity and rejection 4

Immunosuppressive Regimens

Immunosuppressive regimens, such as intravenous mycophenolate mofetil with tacrolimus and steroids, can be used to reduce the risk of organ rejection 3, 6

  • These regimens can help minimize the risks of toxicity and rejection, and can be tailored to individual patients based on their specific needs 3, 6

References

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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