Early Diagnosis Of Rejection Research Articles

Breaking the Barriers to Innovation in Kidney Care: The Time is Now.

Breaking the Barriers to Innovation in Kidney Care: The Time is Now.

PD30-09 TRANSURETHRAL RESECTION OR INCISION OF THE PROSTATE AFTER RENAL TRANSPLANTATION: IS THERE A SAFE TIME FOR THE PROCEDURE?

improvements in graft survival following kidney transplantation. However, there are no non-invasive diagnostic parameters available that enable early and reliable detection of acute rejection. The objective of our study was to establish a urinary protein profile suitable to determine rejectionspecific changes following kidney transplantation and to predict early acute rejection at a postoperative stage. Furthermore, we focused on identification of candidate proteins for the use as biomarkers in clinical practice for diagnosis of acute rejection. METHODS: Urine samples of 116 kidney recipients were included. Rejection was proven by biopsy (n1⁄458) and stable transplant function was monitored for at least 2 years (n1⁄458). Postoperative urine samples were collected between 3rd and 10th day following transplantation. Urinary protein profiles were analyzed by SELDI-TOF-MS. Multiplex-Fluorescence-2DE and Peptide Mass Fingerprinting were used for identification of candidate proteins. Urinary concentration of candidate proteins was validated by ELISA. RESULTS: A protein signature including 4 masses differentiated acute rejection from stable transplant patients at the postoperative stage with 73% sensitivity and 88% specificity. Alpha-1-microglobulin (A1MG) and Haptoglobin (Hp) were identified as putative biomarkers for acute rejection. Protein levels were significantly higher in postoperative urine samples from patients with upcoming rejection than in stable transplant patients (A1MG: 29.13 mg/ml vs. 22.06 mg/ml, p1⁄40.001; Hp: 628.34 ng/ml vs. 248.57 ng/ml, p1⁄40.003). The combination of both proteins enabled the diagnosis of early rejection with 85% sensitivity and 80% specificity. CONCLUSIONS: Protein profiling using mass spectrometry is suitable for non-invasive detection of rejection-specific changes following kidney transplantation. A specific protein profile enables prediction of early acute allograft rejection in the immediate postoperative period. A1MG and Hp appear to be reliable rejection biomarkers. Further analyses have to show if early diagnosis is possible for patients with allograft rejection that occurs several month after transplantation by analyzing changes in urine protein pattern in regular intervals.

Correlation of noninvasive markers of cardiac allograft rejection with endomyocardial biopsy: A case report

Although endomyocardial biopsy remains the gold standard to diagnose cardiac allograft rejection, the search continues for clinical parameters that may aid in the early diagnosis of rejection. We report the case of a 29-year-old man who underwent orthotopic heart transplantation and subsequently had multifocal moderate allograft rejection. During the patient’s hospital course, he exhibited a number of clinical parameters that served as important clues for the worsening rejection. After aggressive immunosuppression, the improvement of these markers hinted toward his eventual recovery.

Intestinal Transplantation Outcomes

Intestinal transplantation has evolved from being considered an experimental procedure into a clinically accepted therapy for patients with intestinal failure and parenteral nutrition life-threatening complications. Early referral, advances in immunosuppression therapy, standardization of surgical techniques, prophylactic therapy of infections, early diagnosis of rejection, and better posttransplant patient management are some of the changes that have allowed more patients to receive transplants, thus recovering intestinal sufficiency, and at the same time allowing the procedure to spread worldwide. Over the last 2 decades, transplant centers have focused on improving short-term patient survival, which has consequently increased by >20%. It is now clear that even though isolated intestinal-transplant recipients have lower mortality risk on the waiting list, they are at higher risk for long-term graft loss. Mortality is higher on the waiting list and early posttransplant in recipients whose intestinal transplants are associated with liver grafts; however, they have better long-term patient and graft survival. Nevertheless, 3-year actuarial patient survival has not changed over the same period of time, and therefore this is our challenge for the next decade.

Heart transplantation

This paper briefly and subjectively reviews a number of the modest or tentative, but noteworthy, advances in heart transplantation that have been made during the past 18 months or so. The advances reviewed concern the selection of recipients, the management of the heart transplantation waiting list, the management of donors, post-heart transplant monitoring of immunological status, the early diagnosis of rejection, the role of mammalian target of rapamycine inhibitors and induction agents, and the definition and grading of cardiac allograft vasculopathy. The findings reviewed indicate progress in the clarification of issues that were in most cases already being investigated. Further studies will in general be needed before corresponding measures are adopted in clinical practice.

Uric acid: a prognostic marker not only before but also after heart transplantation☆

Early diagnosis of rejection after heart transplantation is mandatory, since even mild rejection can rapidly progress to more severe rejection. However, the identification of patients at high risk of acute cellular rejection and their non-invasive diagnosis remains a challenge. To identify patients with a high risk of acute cellular rejection during the first post-transplantation year. A retrospective study of 114 consecutive patients submitted to first heart transplantation (between November 2003 and January 2008). The International Society for Heart and Lung Transplantation (ISHLT) grading system was used for the classification of endomyocardial biopsies. Patients were divided into two groups: group A (non-rejecting)--90 patients who had no significant rejection episodes (ISHLT grade <2R); and group B (rejecting)--included 24 patients with moderate or severe rejection episodes (grade > or =2R) during a 1-year post-transplantation follow-up. The Kaplan-Meier method was used for cumulative survival analysis with the Breslow test for assessing statistical differences between curves. The group B patients tended to have more ischaemic aetiology (42% vs 26%, p=0.13) and lower baseline triglycerides (99.1+/-34.2 vs 117.9+/-63.6 mg dl(-1), p=0.17), tended to receive less cardiac allografts from donors of the same ABO blood type (83% vs 92%, p=0.25) and to have longer cardiopulmonary bypass times (108+/-64 min vs 94+/-26 min, p=0.12). Significantly, they had more hyperuricaemia (71% vs 43%, p=0.02) and longer mechanical ventilation times (19.2+/-17.9h vs 14.3+/-5.3h, p=0.031). During follow-up, the group B patients tended to have more severe infections (46% vs 31%, p=0.16), to be more frequently Quilty-positive (50% vs 30%, p=0.073) and to have a higher 1-year mortality (8% vs 2%, p=0.18). Uric acid levels higher than 7.2 mg dl(-1) were identified as the optimal cut-off value to predict acute rejection after heart transplantation (with a sensitivity of 71%, a specificity of 62% and an area under the curve of 0.64). Our work suggests that hyperuricaemia may be a marker of acute cellular rejection that could be another tool helping to identify acute rejection during the follow-up of cardiac-transplanted patients.

Die Transplantatniere: Farbkodierte Duplex-Sonographie und kontrastmittelverstärkte Sonographie in der Beurteilung nephrologischer und chirurgischer Komplikationen

Contrast ultrasound is a promising and straightforward method that is superior to established sonographic techniques such as conventional B-mode scanning which is used for volume measurement and hematoma demonstration. Color Doppler is important for the evaluation of rejection, the detection of perfusion defects, and complete vascularization in the diagnostic evaluation of kidney grafts. Moreover, contrast US has the potential for tumor characterization in transplanted kidneys. A single examination by contrast ultrasound can answer a variety of questions with respect to the early postoperative phase and chronic damage. New applications of contrast US will arise from the further technical development of ultrasound equipment. The rapid technical advances seen in recent years have been followed by the introduction of new software tools for the analysis of raw datasets or the improved visualization of microbubbles at very low energy. Initial studies show that efficient and early diagnosis of rejection is possible. Surgical complications like perfusion defects or hematoma can also be identified.

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.

Small bowel transplantation: current status and new developments in allograft monitoring

Purpose of review This review aims to summarize the current practices for intestinal allograft monitoring, including the newest developments in the past year. The gold standard has been histologic examination of endoscopy-directed allograft biopsy. Recent findings Plasma citrulline levels, immunohistochemical staining of biopsy specimens, and stool calprotectin levels have all been examined as alternative methods of allograft monitoring. The aims of each diagnostic test are variable and include improvement in the accuracy of biopsy interpretation, early diagnosis of rejection, or a noninvasive method of monitoring the intestinal allograft that might avoid or decrease the risks associated with endoscopic biopsy. Summary Although the results are extremely limited for each of the tests currently being studied in humans, there is good reason to believe that significant progress over the next few years will satisfy all these aims. The development of accurate alternative methods of allograft monitoring will undoubtedly improve the results of intestinal transplantation by allowing lowering of immunosuppression levels in patients not at risk for rejection and limiting exposure to toxicities associated with these medications.

Increased expression of endoarterial vascular cell adhesion molecule-1 mRNA in an experimental model of lung transplant rejection: diagnosis by pulmonary arterial biopsy.

Early detection of rejection after lung transplantation may prevent allograft failure. This study determines if mRNA from the cell adhesion molecules intercellular adhesion molecule-1, vascular cell adhesion molecule (VCAM)-1, and E-selectin in pulmonary endovascular tissue samples could be markers of early rejection. Single left lung transplants were performed in five dogs. Each dog was treated for 2 weeks with immunosuppression, after which rejection was allowed to occur. Percutaneous biopsies from 2- to 3-mm distal branch pulmonary arteries were obtained in each dog from the normal and the transplanted lungs at the end of immunosuppression therapy and periodically (2-4 times) for 1 to 3 weeks until euthanasia. Levels of cell adhesion molecule mRNA in the biopsy samples were quantitated by reverse-transcriptase polymerase chain reaction and normalized to beta-actin mRNA levels. Between three and five pulmonary endoarterial biopsy samples were obtained from each lung at each catheterization procedure. There was a significant increase in VCAM-1 mRNA levels in the biopsies of the transplanted lungs (which were undergoing rejection) compared with the native right lungs in all dogs. Progressive increases in VCAM-1 mRNA were observed with longer rejection times. VCAM-1 mRNA changes were detected earlier than histologic changes of rejection. In pulmonary endoarterial biopsy samples obtained in a canine lung transplant model, there was a progressive increase in VCAM-1 mRNA levels with increasing rejection. Changes in VCAM-1 mRNA were observed earlier than histologic changes of rejection. VCAM-1 quantitation by endoarterial biopsy may be useful in surveillance and early diagnosis of rejection in patients who undergo lung transplantation.

STNF-RII: is it useful for the early diagnosis of rejection and for prognosis after renal transplantation?

Changes in soluble tumour necrosis factor receptor II (sTNF-RII) correlate with transplant rejection, and it increases in the course of sepsis. These changes might help to identify rejection early, and thus lead to more effective treatment. Serum and urine sTNF-RII levels were measured in 70 patients during the first 3 weeks after kidney transplantation and correlated with clinical and laboratory findings. Retrospectively, three groups were identified: I. stable transplant function ( n=23), II. at least one rejection episode ( n=38) and III. other complications (infection or reperfusion injury) ( n=9). The pre-operative maximum for serum sTNF-RII was 22.4 +/- 10.7 ng/ml. In group I it decreased to 9.5 +/- 6.7 ng/ml on day 6 after transplantation ( P<0.01), while in group II sTNF-RII serum levels were significantly higher on day 6 (24.9 +/- 15.0 ng/ml, P<0.01). High levels of sTNF-RII in serum (>40 ng/ml for at least 2 days) predicted a higher risk of an unfavourable outcome. High serum levels of sTNF-RII are not specific but seem to be a prognostic indicator of a complicated course; sTNF-RII in urine has no diagnostic value.

Interleukin-1 receptor antagonist in ascites indicates acute graft rejection after pediatric liver transplantation.

Acute graft rejection is one of the most frequent complications after pediatric liver transplantation (LTx). In clinical practice, it is sometimes difficult to differentiate acute cellular graft rejection from other complications because clinical and chemical findings are often nonspecific. We therefore investigated the value of cytokine quantification in drained ascites, in addition to quantification of cytokine concentrations of serum, in 30 children in the first 2 weeks after orthotopic liver transplantation (OLT). Six of 30 patients showed acute graft rejection, with rising levels of alanine aminotransferase (ALT) and alpha-glutathione-S-transferase (alpha-GST) in serum up to 24 h prior to biopsy-proven rejection. There were no significant elevations of interleukin-2 receptor (IL-2r) and interleukin-6 (IL-6) in serum and ascites. In contrast to these findings, the concentration in ascites of the interleukin-1 receptor antagonist (IL-1ra) increased 48 h before rejection was proven by liver biopsy (p < 0.01, in comparison with the non-rejecting group, n = 24). The IL-1ra concentration in ascites was up to 11-fold higher than in serum during rejection (15.43 vs. 1.38 ng/mL). Two children with early infectious complication showed no significant increase in ascitic IL-1ra concentration. We conclude from these data that quantification of IL-1ra in ascites indicates the start of graft rejection after LTx. As long as abdominal drainage is performed, this non-invasive procedure may be of additional value in differential diagnoses and early diagnosis of rejection.

Videomicroscopic imaging of graft mucosa for monitoring immunosuppressive therapy after small intestinal transplantation in rats.

Early diagnosis of rejection and effective immunosuppressive treatment are essential after small intestinal transplantation. To date little is known about microscopic alterations of the intestinal mucosa of the graft during rejection. We attempted to determine whether videomicroscopic imaging of the graft mucosa is a suitable method for monitoring immunosuppressive therapy. Real-time videomicroscopic imaging of an ileostoma was performed daily after allogeneic heterotopic small bowel transplantation in the rat (BN to LEW) with and without FK506 immunosuppression. Subsequently, the videomicroscopic findings were compared with the histologically determined grade of rejection. A semiquantitative staging system was established for the intravital mucosal changes during graft rejection. The earliest changes related to rejection appeared on POD 6 in the untreated allogeneic group. The mucosa developed patchy paleness and the mucosal architecture was interrupted in places. The crypts were slightly widened and their color turned dark red (stage I). These alterations spread progressively over the mucosa on POD 7 (stage II). On POD 9 the mucosa appeared pale, the villi were shortened, and the crypts appeared wide and rounded (stage III). In the animals treated with FK506 similar changes were observed, but with a delayed onset. When FK506 was administered as antirejection therapy at the onset of rejection, a temporary improvement of mucosal alterations was observed (stage II --> stage I). The video-microscopic stages correlated with the histological grade of rejection. The introduction of videomicroscopy has made computer-based high resolution imaging of mucosal microarchitecture possible. With videomi-croscopy beginning rejection can be detected, although it can still be reversed with antirejection therapy. This is a new noninvasive technique that might be of high clinical relevance.

Flow cytometric analysis of urine lymphocytes isolated from patients with renal transplants—purification of urine lymphocytes

Early diagnosis of rejection is a pivotal problem in renal transplantation. Recent advances in urinary cell analysis using flow cytometry are still burdened with difficulties concerning urine lymphocyte (UL) isolation. The analysis of lymphocytes washed out with the urine from the kidney transplant offers a tool to monitor noninvasively the intragraft immune response. However, the demand for optimal isolation of UL with high viability and good separation of other cell types has not, as yet, been met. The present study was undertaken to evaluate the optimal conditions for harvesting UL in order to perform adequate UL analysis by flow cytometry. We found that UL viability is mainly dependent on the time of urine harvesting. Low UL viability was caused by high urine osmolality due to high concentrations of urea and glucose. In contrast, high protein concentrations protected UL viability. Hence, the following algorithm of adequate UL isolation for flow cytometric analysis was established: (1) Collection of morning urine directly onto foetal calf serum (FCS: 30% v/v); (2) UL isolation within 2 h; (3) Erythrocyte lysis with subsequent two-step density gradient isolation of UL from residual erythrocytes, granulocytes (Ficoll-Isopaque, 1.077 g/cm 3) and from uroepithelial cells (30% methylglucamine 3,5-diacetomido-2,4,6-triiodobenzoicum, 1.085 g/cm 3); (4) Flow cytometric analysis of UL using the `live gate' setting in the area of blood lymphocyte cluster. Adequate UL isolation and special settings of the flow cytometer may provide a useful tool for early diagnosis and the noninvasive monitoring of renal transplant rejection.

Sequential monitoring of urine-soluble interleukin 2 receptor and interleukin 6 predicts acute rejection of human renal allografts before clinical or laboratory signs of renal dysfunction.

The significance of noninvasive techniques to the early diagnosis of acute rejection in kidney transplants remains elusive. In this study, we examined whether an early posttransplant increase in serum- and urine-soluble interleukin (IL) 2 receptor (sIL-2R) and IL-6 levels predicted acute rejection. Sequential determinations of serum and urine sIL-2R and IL-6 were performed in the first 30 postoperative days in 40 renal transplant patients. Changes during the posttransplant period observed in 26 patients who had one or more episodes of acute rejection (group A) were compared with those recorded in 14 patients who did not experience acute rejection of their graft (group B). Serum sIL-2R was higher than normal in patients of groups A and B without statistical differences between the two groups. In the first 3 days after transplantation, urinary sIL-2R was higher than normal in group A but not in group B. Urinary sIL-2R at days 2 and 3 was significantly higher (P<0.05) in group A than in group B. In the first 5 days after transplantation, urinary IL-6 was persistently higher than normal in group A, whereas it progressively decreased to normal value on day 4 in group B. Sudden increases (doubling within 24 hr) in urine IL-6 preceded clinical diagnosis of acute rejection by a mean period of 2 days, with an 87% sensitivity and a 64% specificity, and also predicted recurrent rejection episodes. Sequential monitoring of urinary sIL-2R and IL-6 levels does allow very early diagnosis of rejection without invasive procedures. Specifically, high urinary sIL-2R in the first 5 posttransplant days identifies the subgroup of patients at risk. In the subsequent days, a sudden increase in urinary IL-6 occurs in those of the above patients who will indeed reject their graft.

Rejection and Expression of Thioredoxin in Transplanted Canine Lung

Thioredoxin (TRX) production has been shown to be induced by a variety of stresses. In this study, we examined TRX expression in lung tissues after canine lung transplantation to determine whether it could be induced by allogenic stimulations and could be used to diagnose early rejection. Thirty-five adult mongrel dogs were used in all. In group A, 24 dogs underwent allotransplantation of the left lung with no immunosuppressant and were sacrificed at various times; 5 were sacrificed on postoperative day (POD) 1; 5 on POD 2; 7 on POD 3; and 7 on POD 5. In group B, 5 donor right lungs were used for negative control. In group C, 3 dogs underwent autotransplantation. In group D, 8 dogs underwent allotransplantation of the left lung with optimal immunosuppression and were sacrificed at POD 28. Lung tissues were stained with anti-TRX antibody, and the TRX high-producer (TRXh) cells in a randomly chosen field were counted as the index of TRX expression. In group A, the number of TRXh cells were as follows: 1.68 +/- 1.14 in grade 0; 4.87 +/- 1.07 in grade 1; 10.42 +/- 4.24 in grade 2; 27.34 +/- 17.96 in grade 3; and 50.90 +/- 17.36 in grade 4. In group B, the number of TRXh cells was 1.82 +/- 1.01. There was a significant difference between each rejection grade in group A and group B (p < 0.01), and we could observe TRXh cells in the early stage of rejection. These results suggest that analysis of TRXh cells in lung tissues may be useful in the early diagnosis of rejection.

Expression of adult T-cell leukemiaderived factor in bronchoalveolar lavage cells after canine lung transplantation

Lung transplantation is now an accepted therapeutic option for patients with end-stage lung disease, and an early diagnosis of rejection is essential in the management of these patients. Adult T-cell leukemia-derived factor (ADF), known as a human homolog of thioredoxin, has been shown to be induced by a variety of stresses. In this study we examined ADF expression in lung tissues and bronchoalveolar lavage cells after canine lung transplantation to determine whether it could be induced by allogenic stimulations and could be used to diagnose early rejection. Allotransplantations were performed in adult mongrel dogs, and immunosuppression was performed from the day of operation to the fifth postoperative day. No immunosuppressant was given from the sixth to the tenth postoperative days. Animals were put to death on the tenth postoperative day. Bronchoalveolar lavage was performed on the fifth and tenth postoperative days, and the lavage cells and lung tissues were examined immunohistochemically with anti-ADF antibody. The grades of rejection were as follows: grade 1 in two animals, grade 2 in three animals, and grade 3 in two animals. The percentages of ADF high-producer cells in bronchoalveolar lavage cells on the fifth and tenth postoperative days were 4.29% +/- 2.65% and 26.6% +/- 3.99%, respectively (p < 0.01). The percentages of ADF high-producer cells in normal healthy dogs and in those with grade 1, grade 2, and grade 3 rejection were 3.00% +/- 1.64%, 20.5% +/- 9.00%, 25.5% +/- 6.06%, and 34.5% +/- 6.50%, respectively. The percentage in each rejection group was significantly higher than that in normal healthy dogs (p < 0.05). These results suggest that examination of bronchoalveolar lavage cells with ADF staining may be useful in the early diagnosis of rejection.

Diagnosis of rejection in the allografted rat lung: using monoclonal antibodies to T cell subsets for immunologic monitoring.

Early diagnosis of rejection and timely immunosuppression are absolutely important in clinical lung transplantation. We studied surface markers of peripheral blood lymphocytes (PBL), graft infiltrating lymphocytes (GIF) and bronchoalveolar lavage fluid (BALF) in a rat using flow cytometric monitoring to diagnose rejection. Left lung transplantation was performed on Brown Norway (BN) rats and Lewis (LEW) rats in the following groups; Group 1: LEW-LEW (isograft), Group 2: BN-LEW (allograft; no immunosuppression), Group 3: BN-LEW (allograft; treated with Cyclosporine A at a dose of 15 mg/kg/day i.m.). In each group, rats were killed 3, 5, 7 days postoperatively (n = 6 on each day). Monoclonal antibodies investigated in this study were W3/25 (anti-helper T lymphocyte), OX8 (anti-suppressor/cytotoxic T lymphocyte), and OX39 (anti-interleukin 2 receptor). Histological classification of rejection in Group 2 showed vascular phase at 3 days, alveolar phase at 5 days, and destructive phase at 7 days, respectively. No evidence of rejection was found in Group 1 or 3. In Group 2, W3/25 positive cell proportion in GIL and BALF significantly decreased as the rejection progressed, but OX8 positive and OX39 positive cell proportion increases were significantly greater than in Groups 1 and 3 as the rejection progressed. These results lead us to speculate that the studies of T cell subsets in GIL and BALF lymphocytes are useful for diagnosis of rejection in lung transplantation.

Early diagnosis of kidney transplant rejection and cyclosporin nephrotoxicity by urine cytology.

A total of 2000 urine samples from 53 kidney transplant recipients were studied to develop a routine method for the early diagnosis of rejection and cyclosporin (CSA) nephrotoxicity in urine. New-Sternheimer staining and an immunocytochemical technique were used together with classical Papanicolaou staining to differentiate cells in the urine. After cell count and differentiation of second morning urine samples with New-Sternheimer and Papanicolaou stains, immunocytochemistry was performed using antibodies against the following antigens: CD2, CD4, CD8, CD25, CD71 (transferrin receptor), HLA-DR and cytokeratin (Lu-5). Cell counts were obtained for the positively-reacting cells per millilitre of urine. By New-Sternheimer and Papanicolaou staining, CSA nephrotoxicity was characterized by the predominance of proximal tubular cells. During rejection episodes, increased numbers of mononuclear cells and renal epithelial cells were found. Immunocytochemical analysis showed a significant increase in CD2-, CD4-, CD8-, CD25-, CD71-, and HLA-DR-positive epithelial cells and in the ratio HLA-DR/cytokeratin-positive epithelial cells in rejection. CD25-positive cells had the highest sensitivity and specificity for the diagnosis of rejection. Our urine cytology technique proved to be a useful and non-invasive method for the early diagnosis of rejection and CSA nephrotoxicity.

Pancreas function index: An early monitor of allograft rejection

The lack of reliable markers for the early diagnosis of allograft rejection is a major obstacle preventing improved results in clinical pancreas transplantation. Using a vascularized whole-pancreas transplant model in the rat, with exocrine ductal drainage into the lower urinary tract, we explored the possibility that a change in an index of pancreatic function (IPF), viz., urine volume, urine pH, and urine amylase (UA) in composite, may provide an earlier and more specific indicator of rejection than a decline in UA levels alone. Six Lewiston Lewis rat isograft and 12 ACI-to-Lewis allograft recipients were studied. Ten nontransplanted diabetic Lewis rats served as a control group. Euglycemia was restored in all the recipients of isografts, and was maintained for over a year. In the allograft group, rejection occurred on Days 7–9, with a mean graft survival time of 8.1 ± 0.1 days. Peak UA levels and IPF during normal allograft function were 2422 ± 353 U/ml and 100 ± 14, respectively, whereas levels heralding rejection were 600 U/ml and 25 ( P < 0.05). The diagnosis of rejection based on the IPF resulted in significantly greater specificity and an earlier prediction time compared with UA alone (2.4 ± 0.3 vs 1.6 ± 0.2 days); the IPF permitted the successful prediction of rejection 3 or more days prior to hyperglycemia in 6 of 12 (50%) grafts, whereas only 1 of 12 (8%) rejection episodes was successfully predicted when the rejection criterion was based on UA. In conclusion, early diagnosis of rejection was achieved by a composite index of pancreatic function, improving the ability to predict pancreas-allograft rejection 24 to 48 hr prior to a fall in UA levels.