Assessment of Cytotoxic Lymphocyte Gene Expression in the Peripheral Blood of Human Islet Allograft Recipients

Abstract

Studies in nonhuman primates have demonstrated that elevation of the cytotoxic lymphocyte (CL) genes granzyme B, perforin, and Fas ligand in peripheral blood precedes islet allograft rejection. The purpose of this study was to determine whether this approach has utility for prediction of human islet allograft loss. We studied 13 patients who had long-term type 1 diabetes and were treated with steroid-free immunosuppression and given sequential islet cell infusions. All recipients became insulin independent, and eight of them experienced deterioration in glycemic control, followed by reinitiation of insulin therapy. Frequent peripheral blood samples were collected to monitor CL gene mRNA levels with real-time PCR. For the eight back-to-insulin patients, there was a clear elevation of CL gene mRNA levels 25-203 days before the onset of frequent hyperglycemia. Granzyme B was the most reliable indicator of ongoing graft loss. Additional correlations with infection were noted; however, evidence of sensitization in antidonor mixed lymphocyte reaction was observed in seven of eight patients who experienced partial graft loss, whereas this was not seen when upregulated CL gene expression was associated with infection. The results suggest that, when taken into consideration with other clinical parameters, elevated CL gene levels may enable prediction of islet allograft loss.

Bone Marrow-Derived Stem Cell Transplantation for the Treatment of Insulin-Dependent Diabetes

“…At that time, there were no sufficiently sensitive immune monitoring methods, nor objective criteria, to guide the decision to stop, or to continue, immunosuppression in the study subjects. More recent studies are trying to identify specific markers and/or molecular signatures of a tolerogenic status in organ transplant recipients [44][45][46][47][48]. Such knowledge may assist the design of stringent rules for future trials.…”

Detecting Rejection after Mouse Islet Transplantation Utilizing Islet Protein-Stimulated ELISPOT

“…Here again, ex vivo blood-based monitoring strategies have been esassessed, including the use of positron emission tomography (PET) (14,38), magnetic resonance imaging (MRI) tablished, and patients with type 1 diabetes have higher levels of lymphocyte reactivity against islet-specific (26,37), liver biopsy (34), and immunological markers (PCR for granzyme B and/or insulin mRNA, soluble peptides and proteins than control individuals (25,31). This study was designed to assess the feasibility and CD30, flow cytometry) (5,16,19,32). At the present time, none of these modalities has gained broad clinical usefulness of islet donor antigen-stimulated enzymelinked immunosorbent spot assay (ELISPOT) monitoring acceptance, and the more complex, time-consuming, and expensive procedures like PET, MRI, and biopsy will after islet transplantation using mouse models.…”

Prospective prediction of spontaneous but not recurrent autoimmune diabetes in the non-obese diabetic mouse

“…Interestingly, Han and colleagues were able to predict graft rejection following transplant of islet allografts based on an increase in granzyme B mRNA levels in peripheral blood (a marker of cytotoxic CD8 + T lymphocyte and natural killer cell activity), along with other clinical correlates. This suggests that other blood-based predictive tests may be feasible in humans [24].…”