Tool For Diagnosis Of Rejection Research Articles

Effects of Sample Timing and Treatment on Gene Expression in Early Acute Renal Allograft Rejection

We have shown that genomic biomarkers in peripheral blood provide evidence of early graft rejection and may offer an important option for posttransplant monitoring, and we are working to improve this signature to maximize assay performance. This clinical refinement study (n=79) used gene expression profiling in a case-control design to compare whole blood samples between normal subjects (n=20) and patients with (n=20) or without (n=39) biopsy-confirmed acute rejection (BCAR). Gene expression in peripheral blood from subjects with BCAR before treatment differed significantly from that of normal subjects and transplant recipients without BCAR. Hierarchical clustering and principal component analysis showed that samples obtained 1 to 5 days after the start of treatment of BCAR were segregated across both groups before treatment or without BCAR and that this was closely related to the time lag between treatment and sampling. Genes differentially expressed during BCAR included FKSG49, LMAN2, NFYC, LIMK2, JUNB, NASP, MALAT1, ITGAX, HLA-J, FKBP1A, and RBMS1, and gene ontology analysis highlighted changes in networks related to cytoskeletal reorganization, apoptosis, and immune signaling, whereas after treatment change highlighted pathways of cellular metabolism, cell-cycle regulation, DNA damage, and apoptosis. Gene expression in the peripheral blood is associated with BCAR, and the pattern of expression changes rapidly after treatment. This may offer a potential tool for diagnosis of rejection and immunologic monitoring of response to treatment, which is now being evaluated in a large multicenter international study.

Magnification Endoscopy as a Reliable Tool for the Early Diagnosis of Rejection in Living Related Small Bowel Transplants: A Case Report

The purpose was to determine whether magnification endoscopy (ME) accurately diagnosed rejection in living related small bowel transplants (LRSBTx) during initial morphological adaptation of segmental intestinal grafts. The small bowel recipient was a 44-year-old woman with short gut syndrome following multiple bowel surgeries for familial adenomatous polyposis. ME was enhanced by chromoendoscopy staining. Bowel mucosa was washed with acetic acid and stained with methylene blue for optimal visualization of mucosal villi and to improve the diagnostic yield of biopsies. The recipient underwent surveillance ME with biopsy 16 times through the ileostomy in the first 9 months following transplantation. The recipient developed diarrhea in the postoperative course, which led to the suspicion of rejection. ME findings of patchy villus blunting were consistent with biopsy samples that showed mild acute cellular rejection. Episodes of rejection were treated with high-dose immunosuppressants and steroids. Reversal of rejection was monitored by follow-up ME, which showed increased length of villi and normalization of morphology. Biopsy confirmed these findings. The first endoscopy, at 5 days posttransplant, showed no evidence of intestinal ischemia. LRSBTx involves early morphological adaptation of the recipient small bowel mucosa, characterized by an increased length of villi. ME is a reliable technique to follow adaptation and detect early rejection. The superior imaging of small bowel mucosa created by ME chromoendoscopy enables early diagnosis and delivery of more prompt antirejection therapy to prevent progression of rejection. ME also confirmed that segmental LRSBTx caused minimal ischemic injury to the recipient.

The expression patterns of CD44 and CD45RB on peripheral blood T lymphocytes in the rejection of allogeneic murine skin transplantation

Until now, the rejection was diagnosed through a biopsy, but this method of diagnosis reflected the advanced tissue damage of the transplanted organ and contained the innate problem of being invasive. In relation, our research attempted to evaluate the viability of analyzing the surface antigens of the peripheral blood activated T lymphocytes after murine skin transplantation as a non-invasive and early diagnostic tool for diagnosis of rejection. After mouse skin was transplanted, the expression patterns of activated T lymphocyte markers, CD44 and CD45RB were analyzed along with T lymphocyte markers, CD3, CD4 and CD8 using flow cytometry. The skins from the tails of allogeneic BALB/c(H2d) mice and syngeneic C57BL/6J mice were transplanted to C57BL/6J(H2b) mice as test and control groups, respectively. Peripheral blood, which was sampled from the tail every other day from day 3 to day 15 was stained with anti-CD44 (or CD45RB), anti-CD4 (or CD8) and anti-CD3 monoclonal antibodies simultaneously, and analyzed by 3-color FACS. Rejection occurred only in the test group from day 8 to day 13 (median: day 10). Although the proportions of CD3 + lymphocytes, CD4 + lymphocytes and CD8 + lymphocytes showed no difference, the total number of peripheral blood lymphocytes and the number of CD3 + lymphocytes and CD8 + lymphocytes decreased more sharply in the control after day 7. The proportion and the number of CD44 +CD3 +-lymphocytes, CD44 +CD4 +-lymphocytes and CD44 +CD4 +CD3 +-lymphocytes began to increase after day 7, to peak on day 11, and then to decrease, showing a significant difference. The proportion and number of CD44 +CD8 +-lymphocytes and CD44 +CD8 +CD3 +-lymphocytes showed similar trends. No significant difference was observed in any subsets of the CD45RB antigen. The analysis of the expression patterns of surface antigen CD44 on peripheral blood T lymphocytes using flow cytometry is sensitive, safe, easily repeatable and controllable, and, therefore, can be considered a promising tool for the diagnosis of rejection. However, the clear change in CD44 occurred between day 9 and day 13, when rejection was observed grossly. Therefore, it is regarded more useful as a screening test or follow-up indicator rather than as an early diagnostic tool.