Detection of canine kidney allograft rejection with 51Cr-labeled lymphocytes

Allograft rejection and tubulointerstitial fibrosis in human kidney allografts: interrogation by urinary cell mRNA profiling

Because the kidney allograft has the potential to function as an in-vivo flow cytometer and facilitate the access of immune cells and kidney parenchymal cells in to the urinary space, we hypothesized that mRNA profiling of urinary cells offers a noninvasive means of assessing the kidney allograft status. We overcame the inherent challenges of urinary cell mRNA profiling by developing pre-amplification protocols to compensate for low RNA yield from urinary cells and by developing robust protocols for absolute quantification mRNAs using RT-PCR assays. Armed with these tools, we undertook first single-center studies urinary cell mRNA profiling and then embarked on the multicenter Clinical Trials in Organ Transplantation-04 study of kidney transplant recipients. We report here our discovery and validation of diagnostic and prognostic biomarkers of acute cellular rejection and of interstitial fibrosis and tubular atrophy (IF/TA). Our urinary cell mRNA profiling studies, in addition to demonstrating the feasibility of accurate diagnosis of acute cellular rejection and IF/TA in the kidney allograft, advance mechanistic and potentially targetable biomarkers. Interventional trials, guided by urinary cell mRNA profiles, may lead to personalized immunosuppression in recipients of kidney allografts.

Kidney graft rejection studies with labeled platelets and lymphocytes

The usefulness of In-111-labelled platelets and lymphocyte scintigraphy in acute kidney graft rejection is evaluated. One hundred fifty-five patients (36 treated with cyclosporine A) were studied with labelled platelets and 27 with labelled lymphocytes. Blood cels were labelled with 100-150 microCi of In-111-oxine and reinjected. Subsequently patients were scanned once daily from 2 hours post-reinjection up to a week. The graft/contralateral area activity ratio was calculated in all scans (index I). Four groups of patients were established: Functioning grafts (FG); post-operative acute renal failure (p-ARF); acute rejection (AR) and nephrotoxicity (NTX), the last one only in patients under cyclosporine therapy. Results with labelled platelets showed similar index I mean values in FG, p-ARF and NTX patients I = 1.1 +/- 0.1 and a significant increase (p less than 0.001), in acutely rejecting grafts I = 1.9 +/- 0.4. Evolving controls showed a decrease a decrease of graft activity parallel to rejection resolution while the activity maintains or increases in patients with less or no response to treatment. Overall sensitivity was 97.2%, specificity 90.2% and accuracy 92.8%. Results with labelled lymphocytes were similar to those with platelets. They showed a significant (p 0.001) difference of activity index between rejecting (I = 1.86 +/- 0.3) and non rejecting grafts (I = 1.05 +/- 0.1). Decrease of graft activity was only seen in patients with good response to treatment. It is concluded that In-111-labelled platelets scintigraphy is nowadays the method of choice for acute kidney graft rejection diagnosis, especially in patients under cyclosporine immunosuppression.

Clinical usefulness of 111In-oxine-labeled autologous lymphocytes in kidney-graft rejection

A method of lymphocyte labeling with 111In-oxine was applied for the diagnosis of acute kidney-graft rejection. After the injection of labeled lymphocytes, scintigrams of the graft area, contralateral iliac fossa, and spleen were obtained. Indexes of activity were calculated. No patient without rejection (n = 3) showed lymphocyte graft deposition. Twenty-two patients with acute graft rejection and two patients with on abdominal-wall abscess over the graft area showed lymphocyte graft trapping. When acute graft rejection was present, index i (graft/contralateral iliac fossa) increased, and index c (spleen/graft) decreased. The improvement after the rejection crisis occurred parallel to the decrease in index i. Index c remained unchange regardless of rejection evolution. In summary, 111In-oxine-labeled lymphocytes may be used for the diagnosis of acute kidney-graft rejection and for evolving control.

99m technetium sulfur colloid scanning in diagnosis of renal transplant rejection

To evaluate the possible presence of rejection 37 99mtechnetium sulfur colloid imaging procedures were done on 17 renal transplant patients. There was good correlation between the clinical diagnosis and the results of the technetium sulfur colloid images, with no falsely positive studies in the series. An illustrative case and a review of pertinent literature confirm this technique to be an excellent method for the early detection of renal transplant rejection.