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.     

Renal graft rejection or cyclosporin toxicity? Early diagnosis by a combination of Papanicolaou and immunocytochemical staining of urinary cytology specimens

A method is described for distinguishing between graft rejection and cyclosporin nephrotoxicity in renal allograft recipients by analyzing fresh morning urine samples. The technique combines classic Papanicolaou with immunocytochemical staining and was performed in urine specimens from a series of 42 patients. Early-stage cyclosporin toxicity was usually associated with increased numbers of proximal tubular cells only, whereas in rejection and late-stage toxicity there were increases in both tubular cells and in lymphocytes and monocytes (>2000 cells/ml urine). Differentiation between these two clinical conditions was achieved by immunostaining, which revealed that increased numbers of CD25⁺ and CD8⁺ cells, as well as an increase in the HLA-DR/Lu5 ratio, were typical of rejection. CD25 positivity proved to be the best indicator of rejection, with a sensitivity and specificity of more than 90%. A cytodiagnostic algorithm is presented that is based on cell numbers and types, including immunophenotypes. The proposed method has the advantage of being noninvasive and appears to represent a reliable and rapid adjunct for the monitoring of graft function, especially in high-risk patients on cyclosporin immunosuppression.     

Differential diagnosis of kidney transplant rejection and ciclosporin nephrotoxicity by urine cytology]

To make the differentiation of kidney transplant acute rejection and ciclosporin (CS) nephrotoxicity urine cytology by classical Papanicolaou with immunocytochemical stain has been performed. Increased numbers of renal tubular cells with lymphocytes and monocytes were found in both rejections and CS toxicities. CS toxicities were associated with increased numbers of proximal tubular cells. In immunocytochemical stain, increased numbers of CD25 and CD8 positive cells as well as increased ratio of HLA-DR/cytokeratin positive cells were typically found in rejections. It is concluded that the proposed analysis of urine cytology is a non-invasive and reliable method for daily graft monitoring of acute rejection and CS toxicity.     

Intracellular ATP concentrations of CD4 cells in kidney transplant patients with and without infection

In the field of organ transplantation, overimmunosuppression is associated with severe side effects, such as infection, drug toxicity, and cancer, whereas underimmunosuppression is associated with acute rejection. Intracellular adenosine triphosphate (iATP) concentration following CD4 cell activation provides an assessment of cellular immune function to help monitor the immune status of immunosuppressed patients. This assay has shown to be the first post-transplant test related not only to the risk of acute rejection but also with the appearance of infection. The aim of our study was to compare the iATP concentrations of CD4 cells between healthy adults and kidney transplant recipients from a European population, analyzing the differences according to transplant clinical status. Samples from 81 kidney transplant patients who were admitted to our hospital over a nine-month period were drawn. T-cell activation was measured by determining the increase of iATP from CD4 cells. Results were compared with patient clinical status (rejection, infection, and stability). Three patients suffered an acute rejection episode and they were not included in the analysis (mean iATP concentration 247 +/- 87 ng/mL). iATP concentrations differed significantly between stable and infected patients (313 +/- 193 vs. 197 +/- 114 ng/mL; p = 0.008). iATP concentration values were not related to the length of admission, age, peak and current panel reactive antibodies, mismatches, leukocytes, weight, creatinine, days after transplantation and blood levels of cyclosporin, tacrolimus, and sirolimus. This assay measures global immune responses of CD4 T cells from a whole-blood sample, allowing for the assessment of the impact of immuno- suppressive drugs and of the patient's underlying clinical conditions. This assay identifies transplant patients at risk for infection or rejection, providing information which can guide immunosuppressive therapy.     

Urine macrophage migration inhibitory factor concentrations as a diagnostic tool in human renal allograft rejection.

BACKGROUND: Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine that is a potent activator of macrophages and T cells. Previous studies have shown that local MIF production is increased in acute renal allograft rejection, suggesting that it may play an important role in the rejection process. AIMS: To determine if urine and serum MIF concentrations: (1) are increased in acute rejection, and (2) can be used as noninvasive tools to discriminate between acute rejection (AR) and cyclosporine nephrotoxicity (CyA toxicity). METHODS: In a prospective study of nine renal allograft patients (five acute rejection and four stable), serial urine MIF concentrations were measured by ELISA in the first 14 days after transplantation. In a retrospective study, MIF concentrations in urine and serum were measured in 24 patients who were biopsied for acute renal transplant dysfunction (11 AR, 13 CyA toxicity). Urine and serum MIF were also measured in 23 stable renal transplant patients and 10 normals. RESULTS: MIF was readily detected in the urine of normal healthy controls (106+/-61 pg/micromol creatinine). In the prospective study, the urinary MIF concentration was increased substantially on day 1 posttransplantation and subsequently fell in parallel with the serum creatinine. However, urine MIF increased before episodes of biopsy proven acute rejection. The retrospective study showed that urine MIF concentrations in patients with AR were increased 5-fold compared to normal controls (439+/-313 pg/micromol Cr; P<0.01). In contrast, urine MIF concentrations in CyA toxicity were not significantly different to normal controls (145+/-119 pg/micromol Cr; P=NS). A marked increase in MIF immunostaining was seen in biopsies of AR, but not in CyA toxicity. No significant differences were evident in serum MIF levels between normals and any transplant patient group. CONCLUSIONS: These results suggest that measurement of urine MIF concentration may be useful in monitoring renal transplant patients for acute rejection and as a discriminator from cyclosporine nephrotoxicity.     

Belatacept‐Resistant Rejection Is Associated With CD28+ Memory CD8 T Cells

Recently, newer therapies have been designed to more specifically target rejection in an effort to improve efficacy and limit unwanted toxicity. Belatacept, a CD28‐CD80/86 specific reagent, is associated with superior patient survival and graft function compared with traditional therapy, but its adoption as a mainstay immunosuppressive therapy has been tempered by increased rejection rates. It is essential that the underlying mechanisms associated with this rejection be elucidated before belatacept is more widely used. To that end, we designed a study in a nonhuman primate kidney transplant model where animals were treated with either a belatacept‐ or a tacrolimus‐based immunosuppressive regimen. Interestingly, we found that elevated pretransplant frequencies of CD28⁺CD8⁺T_EMRA cells are associated with rejection on belatacept but not tacrolimus treatment. Further analysis showed that the CD28⁺CD8⁺T_EMRA cells rapidly lose CD28 expression after transplant in those animals that go on to reject with the allograft infiltrate being predominantly CD28^?. These data suggest that CD28⁺ memory T cells may be resistant to belatacept, capable of further differentiation including loss of CD28 expression while maintaining effector function. The unique signaling requirements of CD28⁺ memory T cells provide opportunities for the development of targeted therapies, which may synergize with belatacept to prevent costimulation‐independent rejection.     

Immunocytological determination of lymphocytes and monocytes/macrophages in urinary sediments of renal allograft recipients.

BACKGROUND: Urinary studies using Papanicolaou staining following kidney transplantation led to the conjecture that acute allograft rejection might be accompanied by an increased lymphocyturia. However, it is difficult to distinguish lymphoid cells from other urinary cells using conventional stains. METHODS: Staining of urinary lymphocytes using FITC-labelled antibodies is complicated by a high unspecific fluorescence that limits the evaluation. Therefore, we developed a method to stain urinary lymphocytes using enzyme-linked antibodies. The cells were cytocentrifuged onto microscope slides and were fixed. RESULTS: By means of a combined evaluation of Papanicolaou and immunocytochemical staining, CD3-positive pan T cells, CD4-positive T-helper cells, CD8-positive cytotoxic/suppressor cells, and CD14-positive monocytes/macrophages of urinary sediments were determined in 41 kidney graft recipients following renal transplantation. During periods of normal graft function, neither positive lymphocytes nor positive monocytes/macrophages were found in the urinary sediments. However, in the course of acute allograft rejection a significant increase in positive lymphocytes and positive monocytes/macrophages could be observed. Interestingly, in cases of acute allograft rejection the distribution of urinary lymphocytes and monocytes was comparable to the distribution of infiltrating immunocompetent cells in renal allograft biopsies. CONCLUSION: The present study demonstrates that immunocytochemical staining via enzyme-conjugated antibodies is a reliable method to visualize T lymphocytes and monocytes/macrophages in the urinary sediment, and that this technique may be of special diagnostic value in the diagnosis of acute allograft rejection.     

Glomerular proteinuria as an early sign of renal-transplant rejection

The introduction of cyclosporin gave rise to an additional problem in the surveillance of renal transplant patients, namely the differentiation between cyclosporin toxicity and acute transplant rejection. The development of assays for specific proteins in urine has produced a non-invasive solution to this problem. In 55 renal transplant patients the following proteins were determined daily in 24 h-urine samples: IgG, transferrin (TF), albumin, beta 2-microglobulin (beta 2-MG), retinol binding protein (RBP), alpha 1-microglobulin (alpha 1-MG) and alpha 1-antitrypsin (alpha 1-AT). All proteins were determined quantitatively using immunoluminometric assays and 10 microliters urine in dilutions from 1:1-1:100. The urinary protein excretion was related to the actual creatinine clearance as this index gave the best differentiation between normal and abnormal status. In 24 h-urine, intraindividual peaks of IgG, TF and albumin were seen regularly in acute rejection episodes. However, a peak in the "tubular" proteins (RBP, beta 2-MG, alpha 1-MG) could not be detected. After effective treatment of the rejection episode, the renal function improved and the protein excretion returned to prerejection episode levels. In bacterial infection of the urogenital tract, urinary alpha1-AT levels rose. They returned to normal after successful antibiotic treatment. In two cases of cyclosporin toxicity neither glomerular nor tubular proteins were excreted in abnormal amounts when compared with transplant patients without complications, the only changes being an increase in serum creatinine as a result of reduced renal function.     

Diagnosis of tubular injury in renal transplant patients by a urinary assay for a proximal tubular antigen, the adenosine-deaminase-binding protein

Two murine monoclonal antibodies (URO-4 and URO-4a)--which detect different epitopes of a proximal tubular cell glycoprotein antigen, the adenosine-deaminase-binding protein (ABP)--have been formatted into a sandwich enzyme immunoassay for detection of ABP in the urine. Serial urine samples from 34 renal transplant patients during the first six months posttransplant were analyzed to determine the correlation of this test with clinical rejection and cyclosporin (CsA) nephrotoxicity. In 29/29 acute rejection episodes the ABP level was elevated, beginning 1-7 days prior to treatment of rejection. Eighteen patients were treated for rejection with courses of OKT3 or antithymocyte globulin: 0/6 whose ABP level fell to normal during therapy had rerejection; 10/12 whose ABP level remained elevated had rerejection within 7 days of therapy completion. Of 15 patients treated with CsA, 7 had no rejection or drug toxicity; all 7 had normal ABP levels. The remaining 8 had CsA nephrotoxicity, all in association with elevated ABP levels that rapidly fell to normal with decreased CsA dose. An additional 7 patients with creatinine elevations more than 6 months posttransplant were studied: 5 had chronic vascular changes on biopsy, no response to increased immunosuppression, and normal ABP levels; 2 had a cellular infiltrate on biopsy, response to increased immunosuppression, and elevated ABP levels. We conclude that the urinary ABP assay provides information useful in the management of renal transplant patients with acute and chronic rejection and CsA toxicity.     

Trends in adult post-kidney transplant immunosuppressive use in Australia, 1991-2005

Aim: Kidney transplant outcomes have improved over the past 15 years, partly due to improvements in immunosuppression. We used data from the Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry to examine trends in immunosuppressive use post transplant. Methods: All adult (recipient age 16+ years) kidney‐only transplants performed in Australia from April 1991 to December 2005 were followed to graft loss or December 2005. Immunosuppressive use at induction, 1, 3 and 5 years post transplant were analysed by transplant cohort. Results: Calcineurin‐inhibitors (CNI) were used in most recipients for induction and maintenance immunosuppression, with increasing tacrolimus use. Induction cyclosporin dose increased since 2001 (from 5.8 to 7.9 mg/kg per day), but maintenance cyclosporin and tacrolimus dose decreased (from 3.8 to 3.0 mg/kg per day cyclosporin at 1 year post transplant). CNI‐free induction increased since 2002 (from 1.4% to 8.4%), while CNI‐free maintenance increased throughout the study period. Mycophenolates were the predominant antimetabolite used. Steroid‐free maintenance decreased (from 22.7% to 8.7% at 1 year post transplant), as did median prednisolone doses (from 0.12 to 0.09 mg/kg per day at 1 year post transplant). Sirolimus or everolimus are increasingly used for CNI‐sparing rather than as antimetabolites substitutes. OKT3 or antithymocyte globulin induction decreased, while anti‐CD25 antibody usage increased from 9.5% to 57.1% since 2000. Conclusion: There is a trend to more potent induction immunosuppression with tacrolimus, mycophenolates and anti‐CD‐25 antibodies, but with CNI avoidance or minimization during maintenance phase. While steroid avoidance/cessation decreased, maintenance steroid dose has also decreased. Anti‐CD25 antibodies are now used in >50% of recipients.     

Evaluation of peripheral blood CD4 and CD8 lymphocyte subsets,CD69 expression and histologic rejection grade as diagnostic markers for the presence of cardiac allograft rejection

We investigated the dynamics of the CD4+ and CD8+ lymphocyte subsets, and the expression of activation markers in cardiac transplant recipients. We tested 132 peripheral blood samples from 62 cardiac transplant recipients using fluorescent staining and flow cytometry analysis. The results were correlated with histological rejection grade of concurrently taken biopsies, and 5-year survival of the recipients. A decrease in the total T lymphocyte subset, and in CD4+ lymphocytes was associated with higher rejection grade and lesser survival. An increase (5-11%) of double positive CD4+ CD8+ lymphocytes was observed; these were mostly CD4brightCD8dim. The CD4/CD8 ratio was significantly (P < 0.00) lower in the transplant recipients than in normal individuals. CD69 expression was higher than CD54 and CD154 expression on CD4 and CD8 lymphocytes of cardiac transplant recipients; correlation between these activation markers was excellent (P < 0.001). Fluorescent staining for CD69 was often of low intensity. Multiple regression for % CD8+ CD69+ cells and survival, and for % CD69+ T cells and rejection grade yielded a significant correlation (P < 0.050). Both % CD8+ CD69+ and % CD69+ T cells were significantly higher in samples with severe and moderate rejection grade (grades 3A, 3B and 4) than in samples which showed no, minimal or mild rejection (grades < or = 2); P-values were 0.052 and 0.003, respectively. Preliminary results indicated that false negative results could be contributed to increased immunosuppression. We conclude that CD69 expression on circulating CD4 and CD8 lymphocytes is a useful parameter for the diagnosis of moderate and severe rejection.     

Interleukin-6 and neopterin in renal transplant recipients: a longitudinal study

Serum and urine interleukin-6 (IL-6) levels and serum neopterin/creatinine ratios were longitudinally studied in 86 renal transplant recipients until 4 months after transplantation. During acute rejection and acute tubular necrosis (ATN), serum and urine IL-6 levels were elevated compared to during stable transplant function (P<0.001). During acute rejection, serum IL-6 levels increased at least 2 days before plasma creatinine started to rise (P<0.05), indicating its early involvement in the rejection process. During cytomegalovirus (CMV) disease, serum, but not urine, IL-6 levels were higher (P<0.01), and serum neopterin/creatinine values were higher than during stable transplant function, ATN, or acute rejection (P<0.01). No significant differences with stable transplant function occurred during cyclosporin A toxicity. Measurement of serum IL-6 provided a sensitivity of 84% and a specificity of 85% for the diagnosis of acute rejection episodes not coinciding with ATN. All cases of CMV disease could be diagnosed by measurement of serum neopterin/creatinine, which provided a specificity of 73%.     

Randomized clinical trial of the effect of microemulsion cyclosporin and tacrolimus on renal allograft fibrosis

BACKGROUND: The aim of this study was to compare the effect of Neoral cyclosporin- and tacrolimus-based therapy on the development of renal allograft fibrosis (chronic allograft nephropathy; CAN) in a prospective randomized trial. METHODS: A total of 102 patients undergoing renal transplantation were randomized to immunosuppression with either microemulsion cyclosporin (Neoral; 15 mg per kg per day adjusted to whole-blood trough concentrations of 200-300 ng/ml) or tacrolimus (0.2 mg per kg per day adjusted to whole-blood trough levels of 8-15 ng/ml) in conjunction with steroids, or at a lower dose (7 mg per kg per day and 0.1 mg per kg per day respectively) with the addition of azathioprine for non-heart-beating renal transplant recipients. Renal transplant interstitial fibrosis was quantified using computerized histomorphometric measurement of picrosirius red-stained 1-year protocol renal transplant biopsies. Levels of interstitial fibrosis were compared in relation to observed efficacy and toxicity profiles of the two drugs. RESULTS: There was a significant increase in allograft interstitial fibrosis in the patients treated with Neoral compared with those given tacrolimus. There was no significant difference in the demographic characteristics between the patient groups or in the incidence of acute rejection (Neoral 36 per cent versus tacrolimus 35 per cent) or steroid-resistant rejection (both 10 per cent) between the two drugs. There was a higher incidence of insulin resistance in the tacrolimus group (post-transplant diabetes mellitus, glucose tolerance testing) but this was not statistically significant. Neoral was associated with a significant increase in total cholesterol (P = 0.030) and low-density lipoprotein (P = 0.021) levels, which persisted throughout the study period. CONCLUSION: Despite equivalent efficacy and pretransplantation risk factors for CAN, Neoral was associated with increased allograft fibrosis and significantly higher serum low-density lipoprotein cholesterol levels compared with tacrolimus.     

Activation of nuclear factor-kappa B and macrophage invasion in cyclosporin A-and tacrolimus-treated renal transplants

This retrospective study was designed to compare the efficacy of cyclosporin A (CyA) and tacrolimus (FK506) on chronic rejection (CR) associated with nuclear factor-kappa B (NF-kappaB) activation and macrophage invasion. Non-episodic day 50 protocol renal biopsy was performed in 63 consecutive patients with renal transplants from living donors, treated with either CyA or FK506. Southwestern histochemistry for NF-kappaB, immunostaining for CD68, and Banff classification were performed, and these findings were compared with outcome over 34 +/- 13 months. Compared with specimens from FK506-treated patients (n = 20), specimens from CyA-treated patients (n = 43) showed a significant increase in tubulointerstitial CD68-positive cells (1.5 +/- 0.9 vs. 0.9 +/- 0.8, p < 0.01), although no significant differences were observed in NF-kappaB activation. Specimens with Banff acute rejection (AR) grade > or = 1A (n = 20) showed increased macrophages (p < 0.01) compared with specimens with AR < 1A (n = 43). Specimens from patients with clinical AR prior to day 50 biopsy (n = 23) also showed increased macrophage invasion (p < 0.01) compared with specimens from patients without prior clinical AR (n = 40). The cumulative well-functioning (serum creatinine < 1.5 mg/dL) graft survival rate was significantly lower in patients with increased tubulointerstitial CD68-positive cells (n = 63, p < 0.05). Our findings suggest that tacrolimus is more effective than CyA against CR with respect to macrophage invasion and AR.     

Mononuclear cells infiltrating kidney allografts in the absence of rejection Effect of conversion from cyclosporin to azathioprine therapy

Abstract. Focal small mononuclear cell infiltrates were found in renal allograft biopsies of 13/14 transplant recipients with a stable function after long-term cyclosporin A (CsA) therapy. Phenotypical analysis of the infiltrating cells using monoclonal antibodies showed a slight preponderance of T cells (56%8%), with only small percentages of B cells (5%2%), NK cells (2%1%), and monocytes (2%1%). Within the T-cell population the median calculated CD4/CD8 ratio was 1:3. Thirty-five percent of the infiltrating mononuclear cells remained unidentified with the monoclonal antibody panel used (silent cells). Three months after immunosuppressive therapy had been changed from CsA to azathioprine (AZA), the size of the infiltrates was significantly increased and there was a marked invasion of mononuclear cells between tubular epithelium despite a significant improvement in creatinine clearance ( P < 0.01). The phenotypical composition of these infiltrates was dominated by T cells (84%3%), with a median CD4/CD8 ratio of 2:7 due to an increase in CD4+ cells and a decrease in CD8+ cells after conversion ( P < 0.05). The percentages of B cells, NK cells, and monocytes showed no significant changes after conversion. During AZA therapy nearly all infiltrating mononuclear cells were stained with the monoclonals used, leaving no silent cells postconversion.     

Expression of inducible lymphocyte costimulatory molecules in human renal allograft

Background: CTLA-4/CD28-B7 and CD40-CD40L interactions constitute two key costimulatory pathways in lymphocyte signalling during experimental allograft rejection. Studies on the expression of these molecules in human transplant rejection are still lacking. Methods: The immunohistochemical study was performed on renal biopsies obtained for various clinical complications from 25 renal transplant patients. Expression of B7-1 and B7-2 and their counter-receptor CTLA-4, and of CD40 and its counter-receptor CD40L was examined. Results: In acute rejection a focal intense infiltration of B7-1⁺ and B7-2⁺ cells (mainly CD20^- CD14⁺) and of CTLA-4⁺ T lymphocytes (mainly CD8⁺) was present. In contrast, CD40 and CD40L were rarely expressed. Accumulations of T lymphocytes were found in the interstitium in the same area containing B7-1⁺ and B7-2⁺ cells. The scattered CD40L⁺ cells found in the T-cell infiltrate exhibited the CD4⁺ phenotype. In chronic rejection only a few B7-1⁺, B7-2⁺ or CTLA-4⁺ cells were detectable. In contrast, several CD40L⁺CD4⁺ cells were present both in the interstitium and in glomeruli. Moreover, an intense expression of CD40 on the endothelium was observed. In patients with cyclosporin nephrotoxicity cells positive for B7-1, B7-2, CTLA-4, CD40, or CD40L were absent. Conclusions: These results demonstrate a differential expression of costimulatory molecules in renal biopsies of allograft recipients undergoing acute or chronic rejection. Moreover, their detection may prove useful to discriminate rejection from cyclosporin nephrotoxicity.     

The role of C-reactive protein in graft dysfunction after renal transplantation

PURPOSE: We investigated whether serial daily measurements of serum C-reactive protein could help differentiate episodes of transplant dysfunction due to rejection, infection, cyclosporin A nephrotoxicity or acute tubular necrosis in renal allograft recipients. MATERIALS AND METHODS: Morning serum was obtained daily from 134 patients during the first 30 days after renal transplantation. All episodes of graft dysfunction were recorded and compared to transplant biopsies. C-reactive protein concentrations were correlated with postoperative graft function and the various causes of graft dysfunction. RESULTS: All patients demonstrated an increase in C-reactive protein in response to surgery and a maximum level was reached on day 2 after transplantation. Mean C-reactive protein concentration was significantly increased for delayed (61.50 microg./ml.) compared to primary (mean 38.01) graft function (p = 0.001, Mann-Whitney U test). There were significant increases in C-reactive protein for bacterial infections other than asymptomatic bacteriuria (33.98 microg./ml), interstitial graft rejection (16.43) and acute tubular necrosis (30.50) compared to uneventful courses. C-reactive protein was unchanged for viral infections or cyclosporin A toxicity. CONCLUSIONS: Serial C-reactive protein measurements help to identify renal transplant dysfunction of different origins. However, rejection, infection and acute tubular necrosis show similar patterns of C-reactive protein increase. Thus, C-reactive protein is unable to discriminate the causes of renal graft dysfunction. Biopsy remains the gold standard for the differential diagnosis of renal allograft dysfunction.     

Early steroid withdrawal after liver transplantation: The canadian tacrolimus versus microemulsion cyclosporin a trial: 1-year follow-up

Corticosteroid therapy contributes significant toxicity to liver transplantation. The safety and efficacy of early steroid withdrawal were determined in patients treated with either tacrolimus or microemulsion cyclosporin A (micro-CsA). The primary outcome was the proportion of patients who were steroid-free 1 year posttransplantation. From the seven Canadian adult liver transplant centers, 143 patients were randomly allocated oral treatment with either tacrolimus (n = 71) or micro-CsA (n = 72), together with corticosteroids and azathioprine. Eligibility criteria for steroid withdrawal included freedom from acute rejection for a minimum of 3 months, and prednisone ≤0.15 mg/kg/d. In eligible patients, the daily steroid dose was reduced by 2.5 mg each month until complete discontinuation was achieved. At 1 year after transplantation, 75% of the tacrolimus patients and 63% of the micro-CsA patients were steroid-free (P = .20). Of all of the patients who became eligible for steroid withdrawal, steroid discontinuation was achieved in over 80%. One-year patient survival was 97% with tacrolimus and 89% with micro-CsA (P = .052) . Graft survival was 97% and 86%, respectively (P = .017). The overall incidence of acute rejection during the first year was 35% with tacrolimus and 43% with micro-CsA (P = .26). There was no difference in survival, acute rejection, or rate of steroid withdrawal when adjusting for hepatitis C. All acute rejection episodes experienced during steroid withdrawal were steroid-responsive. Steroid-resistant rejection occurred in 5.6% of the tacrolimus and 9.7% of the micro-CsA patients. One patient, in the micro-CsA group, experienced refractory rejection. Chronic rejection was not observed in either group. The toxicity profiles were similar. Postoperative serum creatinine levels were similar, and dialysis was required in less than 10% of patients in each group. Infectious complications were similar in both groups. Neurotoxicity was a serious adverse event in 13% and 10% of patients receiving tacrolimus and micro-CsA, respectively. Early steroid withdrawal is safe and effective after liver transplantation using either tacrolimus plus azathioprine or micro-CsA plus azathioprine immunoprophylaxis. (Liver Transpl 2003;9:587-595.)     

Objective measurement by ultrasound to distinguish cyclosporin A toxicity from rejection

Measurement of the cross-sectional area of the transplanted kidney with ultrasound has been used to differentiate between cyclosporin A toxicity and rejection both in the immediate post-transplant period and at the time of conversion from cyclosporin A to azathioprine. Of 40 patients studied 21 have been converted from cyclosporin A to azathioprine. There were 12 rejection episodes in 9 patients in the early post-transplant period, and 7 rejection episodes in 7 patients at the time of conversion from cyclosporin A to azathioprine. All of these episodes were correctly diagnosed by ultrasound. Eight episodes of drug induced toxicity in seven patients were, in all but one case, diagnosed correctly. In only 8 of the 19 rejection episodes was the diagnosis suspected clinically at the time ultrasound detected an increase in cross-sectional area.     

Mononuclear cells infiltrating kidney allografts in the absence of rejection

Focal small mononuclear cell infiltrates were found in renal allograft biopsies of 13/14 transplant recipients with a stable function after long-term cyclosporin A (CsA) therapy. Phenotypical analysis of the infiltrating cells using monoclonal antibodies showed a slight preponderance of T cells (56%±8%), with only small percentages of B cells (5%±2%), NK cells (2%±1%), and monocytes (2%±1%). Within the T-cell population the median calculated CD4/CD8 ratio was 1:3. Thirty-five percent of the infiltrating mononuclear cells remained unidentified with the monoclonal antibody panel used (silent cells). Three months after immunosuppressive therapy had been changed from CsA to azathioprine (AZA), the size of the infiltrates was significantly increased and there was a marked invasion of mononuclear cells between tubular epithelium despite a significant improvment in creatinine clearance (P<0.01). The phenotypical composition of these infiltrates was dominated by T cells (84%±3%), with a median CD4/CD8 ratio of 2:7 due to an increase in CD4+ cells and a decrease in CD8+ cells after conversion (P<0.05). The percentages of B cells, NK cells, and monocytes showed no significant changes after conversion. During AZA therapy nearly all infiltrating mononuclear cells were stained with the monoclonals used, leaving no silent cells postconversion.