Enhanced Donor Antigen Presentation by B Cells Predicts Acute Cellular Rejection and Late Outcomes After Transplantation.

Background: Enhanced B-cell presentation of donor alloantigen relative to presentation of HLA-mismatched reference alloantigen is associated with acute cellular rejection (ACR), when expressed as a ratio called the antigen presenting index (API) in an exploratory cohort of liver and intestine transplant (LT and IT) recipients.

Methods: To test clinical performance, we measured the API using the previously described 6-h assay in 84 LT and 54 IT recipients with median age 3.3 y (0.

Nutrition support considerations in pediatric small bowel transplantation.

Enteral autonomy is the primary goal of intestinal failure therapy. Intestinal transplantation (ITx) is an option when enteral autonomy cannot be achieved and management complications become life-threatening. The purpose of this review is to summarize existing medical literature related to nutrition requirements, nutrition status, and nutrition support after pediatric ITx.

Operational tolerance after intestine re-transplantation in childhood and immunological correlates. Case report and review.

Background: Operational tolerance after retransplantation of the intestine has never been reported.

Purpose: To two recently described intestine transplant recipients with operational tolerance, we now add a third.

Methods: Review of case record and immunological testing to confirm donor-specific hyporesponsiveness in multiple immune cell compartments.

CD154-expressing CMV-specific T cells associate with freedom from DNAemia and may be protective in seronegative recipients after liver or intestine transplantation.

Cell-mediated immunity to CMV, if known, could improve antiviral drug therapy in at-risk children and young adults with LT and IT. Host immunity has been measured with CMV-specific T cells, which express IFNγ, but not those which express CD154, a possible substitute for IFNγ. CMV-specific CD154+ T cells and their subsets were measured with flow cytometry after stimulating PBL from recipient blood samples with an overlapping peptide mix of CMV-pp65 antigen for up to 6 hours.

Predicting Cellular Rejection With a Cell-Based Assay: Preclinical Evaluation in Children.

Background: Allospecific CD154+T-cytotoxic memory cells (CD154+TcM) predict acute cellular rejection after liver transplantation (LTx) or intestine transplantation (ITx) in small cohorts of children and can enhance immunosuppression management, but await validation and clinical implementation.

Methods: To establish safety and probable benefit, CD154+TcM were measured in cryopreserved samples from 214 children younger than 21 years (National Clinical Trial 1163578). Training set samples (n = 158) were tested with research-grade reagents and 122 independent validation set samples were tested with current good manufacturing practices-manufactured reagents after assay standardization and reproducibility testing.

Proliferative alloresponse of T-cytotoxic cells identifies rejection-prone children with steroid-free liver transplantation.

Donor-induced and third-party-induced proliferation of T-helper and T-cytotoxic (Tc) cells and their naïve and memory subsets was evaluated simultaneously in single blood samples from 77 children who received steroid-free liver transplantation (LTx) after induction with rabbit anti-human thymocyte globulin. Proliferation was measured by dilution of the intravital dye carboxyfluorescein succinimidyl ester (CFSE) in a 3- to 4-day mixed lymphocyte response coculture. The ratio of donor/third-party-induced proliferated (CFSE(low)) T-cells was reported as the immunoreactivity index (IR) for each subset.

Allospecific CD154+ T cells identify rejection-prone recipients after pediatric small-bowel transplantation.

Background: Up to 70% of children with small bowel transplantation (SBTx) experience acute cellular rejection (ACR). Allospecific CD154+ T cells predict liver ACR in children in a novel, 16-hour mixed leukocyte response (MLR) assay, but remain untested in SBTx.

Methods: The expression of CD154 was measured in 4 subsets-naive (N) and memory (M) CD154+ T-helper (Th) and T-cytotoxic (Tc) cells (ie, CD154+ ThN, CD154+ ThM, CD154+ TcN, and CD154+ TcM, respectively)-in the MLR of single blood samples obtained from 32 children with SBTx within 60 days of SBTx biopsy.