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Acute cellular rejection occurs early or late after liver or intestine transplantation in children. This is the most common type of rejection and it happens when T-lymphocytes from the recipient directly attack and destroy cells in the transplanted liver or intestine. Acute cellular rejection is usually suspected because of the dysfunction of the transplanted organ. Dysfunction is suggested by elevated liver function tests which can be measured in the blood of a liver recipient. For intestine transplant rejection, the only evidence may be high stool output, however, high stool output can also occur with an infection. Elevated liver function tests can also be seen with infection and mechanical blockage. A “for cause” biopsy is needed to confirm rejection. These biopsies can cause bleeding or perforation and, sometimes, may not affirm a rejection. These side effects can be especially harmful in children. Acute cellular rejection can also occur without clinical evidence of organ dysfunction, especially if immunosuppression is suboptimal. Surveillance biopsies are performed at predetermined intervals to detect this type of ‘silent’ rejection and assess immunosuppression.

An FDA-approved blood test, PleximmuneTM measures the risk of acute cellular rejection after liver or intestine transplantation in children and young adults less than 21 years of age.

PleximmuneTM is an FDA-approved blood test that measures the risk of acute cellular rejection after liver or intestine transplantation in children and young adults up to 21 years of age. The test measures whether recipient lymphocytes called T-cytotoxic memory cells show increased anti-donor activity. This activity is measured after stimulating lymphocytes from the recipient with donor or donor-like cells. This then determines whether the anti-donor activity has increased or decreased, it is then compared with activity toward non-donor (reference) cells.

Knowledge about the likelihood of acute cellular rejection can be combined with clinical information to develop a treatment plan by:

  • Assessing whether dysfunction of the transplanted liver or intestine indicates increased risk of acute cellular rejection

 

# CATEGORY DETAILS

1

Assay Category

Lab-developed test, antigen-specific T-cell function.

2

Intended Use

To measure the risk of acute cellular rejection after liver or intestine transplantation in children and young adults < 21 years.

3

Methodology

Stimulation of peripheral blood leukocytes with donor and non-donor cells, Flow Cytometry.

4

Test Report

Available within 30 hours of receiving the blood sample.

5

Test Readout

Immunoreactivity Index (IR), the IR is the ratio of the recipient T-cytotoxic memory cell activity toward donor or donor-like cells and reference cells.

6

Reference Range

The IR is an absolute number with a range less than 1.1 to 1.1 or greater.

7

Test Interpretation

An IR of 1.1 or greater indicates increased risk of acute cellular rejection.

Purpose

Knowledge about the risk of rejection can be combined with available clinical data to plan additional treatment for your patient.

Rationale

  • Liver or intestine transplant rejection is usually suspected because of abnormal liver function blood tests, or high stool output, respectively. Such changes are also seen with infection and mechanical blockage. A “for cause” biopsy is needed to confirm rejection. Up to half of all “for cause” biopsies do not show rejection.
  • Rejection can also occur without abnormalities in liver function tests or stool output, especially if anti-rejection drug doses are not sufficient. To detect this type of ‘silent’ rejection, biopsies are performed several times, at pre-determined intervals.
  • The Pleximmune™ blood test measures the likelihood of rejection. This knowledge can be combined with clinical information to develop a treatment plan. Benefits include:
    • Optimizing the frequency of surveillance biopsies.
    • Distinguishing rejection from infection in biopsies where such distinctions are difficult.
    • Improving the long-term management of anti-rejection medications.

Intended Use

To assess the risk of acute cellular rejection after liver or intestine transplantation in children.

Procedure

  • Pleximmune™ is a functional cell-based blood test, which measures the immune response of recipient lymphocytes to donor lymphocytes in cell culture.
  • The test requires whole blood in sodium heparin tubes to be shipped at ambient temperature for overnight delivery to Plexision’s laboratory. A five mL (3 mL minimum) whole blood sample is needed.
  • Recipient T-cytotoxic memory cells, which express the inflammatory marker, CD40 ligand, or CD154 are measured with flow cytometry.
  • Results are expressed as an immunoreactivity index or IR, which is a measure of the risk of rejection.
  • Results are reported the day after the blood sample is received at the laboratory and within two days of obtaining the blood sample from the patient if the sample is shipped overnight.
  • The Pleximmune™ test has been evaluated in over 200 children with liver or intestine transplantation and adults with renal transplantation.

Performance

The Pleximmune™ test is performed in Plexision's CLIA- approved laboratory and

  • Has been evaluated during routine clinical monitoring, in relation to for-cause biopsies and in relation to surveillance biopsies, which are performed at pre-determined intervals.
  • Identifies liver or intestine transplant recipients experiencing rejection with sensitivity and specificity of 84% and 80%, respectively.

Benefits

Determining whether rejection is likely is important in deciding

  • Whether the right amount of immunosuppression is being given.
  • Whether anti-rejection medications can be decreased or not.
  • Whether additional tests are needed to confirm rejection.

Knowledge about the likelihood of rejection from the PleximmuneTM test can be combined with other clinical data by your healthcare provider to make clinical decisions.

Insurance Coverage

Plexision will bill the patient's insurance plan and work directly with the insurer for payment. Plexision will assist with the cost of Pleximmune™, if there is no insurance coverage. For additional information, call 1.855.753.9474 or email info@plexision.com

Samples & Handling

# CATEGORY DETAILS

1

Sample Type

Whole blood collected in a sodium heparin (green-top) tube.

2

Volume

5 mL in children.

3

Transport Conditions

Ship priority overnight, at room temperature. Sample must get to Plexision within 30 hours of phlebotomy.

4

Specimen Stability

30 hours at room temperature from the time of phlebotomy.

5

Sample Discard Criteria

  • Transport time more than 30 hours from phlebotomy.
  • Lithium heparin (green-top) tube or ACD (yellow-top) tube.
  • Clotted, hemolyzed, frozen, refrigerated, or broken vacutainer seal.

How to Order

# CATEGORY DETAILS

1

Test Brochure View and download the product brochure here

2

Ordering Tests Please complete this form, print, and fax to 412-224-2776

PleximmuneTM is a blood test that helps your healthcare provider determine the risk of rejection after liver or intestine transplantation in children and young adults < 21 years old.

Liver or intestine transplant recipients < 21 years old can benefit from the PleximmuneTM test.

The PleximmuneTM test must be ordered by your healthcare provider. The test requires a blood sample measuring a teaspoon. This sample is to be shipped overnight to Plexision’s laboratory for analysis. Results are sent to your healthcare provider within a day of your sample arriving at the laboratory. Your healthcare provider will help you understand the results.

Results are ready within 30 hours after the laboratory receives the blood sample.

The PleximmuneTM test determines whether the recipient's immune system is reacting excessively toward the transplanted organ. This type of immune response occurs during transplant rejection and can be measured by a type of white blood cell. When present, this increased immune response tells your healthcare provider whether transplant rejection is likely or not.

The results are reported as an Immunoreactivity Index or IR. An IR less than 1.15 implies a decreased risk of rejection. An IR of 1.15 or greater implies an increased risk of rejection.

Determining whether rejection is likely is important in deciding whether the amount of anti-rejection medications is enough, whether these anti-rejection medications can be decreased further, or whether additional tests are needed to confirm whether rejection is already present or not. Knowledge about the likelihood of rejection can be combined with other clinical data by your healthcare provider to make clinical decisions.

The PleximmuneTM test must be ordered by your healthcare provider. The test requisition form is provided here. The completed form can be faxed to 412-224-2776. If there are any questions, please contact (855) PLE.XISION (753.9474) or 412-224-2504.

Plexision will bill your healthcare facility or your insurance plan as indicated on the requisition form. If there is no insurance coverage, Plexision patient assistance plans will assist with the cost of PleximmuneTM.

1. Patent 8759016

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3. Am J Transplant. 2009 Jan;9(1):179-91. PMID:18976293.

4. Surgery. 2009. Aug;146(2):166-73.PMID:19628070.

5. Pediatr Transplant. 2012 Feb;16(1):83-91. PMID: 22122074

6. Curr Opin Organ Transplant. 2011 Oct;16(5):515-21. PMID: 21844808

7. World J Transplant. 2014 March 24; 4(1): 30–39. PMID: 24669365

8. CLIA ID: 39D2042664

PleximmuneTM is FDA-approved

About

Plexision develops cellular biomarkers for personalized diagnosis and drug development in solid organ transplantation and immunological disorders. We also pioneer in R&D projects centered on integrating biomarker targets in all phases of drug development, from preclinical to post-marketing. Plexision’s technology can be adapted to

  • - Assess disease risk for several immunological disorders.
  • - Predict the success of a drug for a specific patient.
  • - Develop dosing recommendations for new immunological drugs.

Our state-of-the-art laboratory is CLIA-certified and located in Pittsburgh, PA.

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