Biomarkers in Transplant Recipients

• Rejection [ Time Frame: 90 day post transplantation (clinical severity) ] [ Designated as safety issue: No ]
  Biopsy-proven acute cellular rejection
  
  

• Thresholds of immunosuppression [ Time Frame: Yearly post transplantation ] [ Designated as safety issue: No ]
  Blood levels and doses of the various immunosuppressants at one year. For example, Tacrolimus is measured as nanograms/ml in whole blood, Mycophenolate mofetil is measured in doses of mg/day, or as blood levels in micrograms/ml, steroids doses are measured in mg/day, Sirolimus is measured in doses of mg/day, or as blood levels in nanograms/ml in whole blood.
  
  

All transplant recipients receive periodic monitoring of drug levels and laboratory tests to assess adequacy of immunosuppression and allograft function. These are performed when the recipient is admitted to the hospital after transplantation or for a complication such as acute rejection or toxicity, or when the recipient is an outpatient.

1. Blood samples: Participants will be asked to provide research blood specimens annually for an indefinite period of time. This will allow longitudinal assessment of the stability of biomarker expression as a reflection of clinical drug concentrations in repeated measurements.
2. Saliva collection: Up to 5 ml of the subject's saliva will be collected no more than four times, if the previous sample does not provide adequate information. Samples will be collected in self-collection container at the time of consent or as early as possible after consents are obtained, and will be stored at room temperature in the Pediatric Transplantation Laboratory, 3344 Forbes Ave. In recipients where both are available, the genotyping results as DNA from saliva will be compared between paired blood samples. Henceforth, saliva collection will only be offered to participants who cannot donate blood specimens for genotyping. Salivary sampling is considered an acceptable alternative standard for whole blood genotyping. A saliva sample will be collected only if the patient or the patient's parent or guardian prefers this option over blood sampling.
3. Collection of urine, feces, and bile: five mls of any body fluid will be collected in sterile urine cups for application of proteomics technologies. Collections may be repeated up to four times, if the first specimen provides suboptimal information.
4. Collection of remaining allograft standard of care biopsy specimens, and tissue from explants: Any piece of allograft biopsy deemed residual by the pathologist will be subjected to gene array testing. This will occur when participant is scheduled for their standard of care biopsy, or while in surgery. Genetic material extracted from the smallest tissue can be amplified using several approaches.
5. Measurements: Biomarker expression will be evaluated after mitogen and antigen stimulation of peripheral blood mononuclear cells. (1-3). Briefly, peripheral blood mononuclear cells (PBMC) are extracted from whole blood by Ficoll gradient separation, Thereafter, either mitogens such as phytohemaglutinin, pokeweed mitogen, or phorbol-myristic acid-ionomycin, or viral and MHC-peptide antigens, or intact alloantigenic cells will be used to stimulate recipient PBMC. Cellular responses that can be measured include but are not limited to expressed pro-inflammatory or anti-inflammatory markers, cytokines, proliferation, cytotoxicity, and apoptosis.