Sequential determinations of serum interleukin 6 levels as an immunodiagnostic tool to differentiate rejection from nephrotoxicity in renal allograft recipients

Serum interleukin 6 (IL-6) levels were utilized as an immunologic marker of activation of T cells and macrophages in renal allograft recipients treated with a cyclosporine and prednisone immunosuppressive regimen. IL-6 concentrations were estimated in serum samples selected to correspond to similar timepoints in the clinical courses of renal transplant recipients suffering four types of events: group I, quiescent patients without rejection or infectious disease (n = 16, 147 samples); group II, patients with only rejection episodes (n = 26, 291 samples); group III, patients with only infectious episodes (n = 10, 87 samples); and group IV, patients with CsA-induced nephrotoxicity (n = 15, 117 samples). Serum IL-6 activity measured using an IL-6-dependent cell line (MH60.BSF-2) was specific for this lymphokine based upon the capacity of monoclonal anti-IL-6 antibodies to block target cell proliferation. The control group displayed uniformly elevated IL-6 levels during the first posttransplant day (mean 20.1 +/- 4.1 U/ml range 6.4-64 U/ml), thereafter decreasing by 10-14 days to a mean level of 3.4 +/- 0.9 U/ml (range 1.0-4.2 U/ml). The rejection group showed increased IL-6 levels ranging from 5.3 +/- 0.4 U/ml (range 1.0-64 U/ml) to 56.2 +/- 13.3 U/ml (range 10-300 U/ml, P less than 0.01), occurring at a mean of 2 days (range 0-10 days) before the diagnosis of rejection was established by clinical criteria. Interestingly, all three recipients treated with OKT3 and 5/11 treated with antilymphocyte globulin displayed further significant increases in serum IL-6 levels (OKT3: 46.0 +/- 12.9 U/ml; ALG: 34.6 +/- 7.8 U/ml) one day after inception of treatment. Five of 10 recipients displaying septic events showed elevated serum IL-6 activity--namely, 5.0 +/- 1.2 U/ml to 47.5 +/- 16.2 U/ml, beginning at a mean of 1.2 days before diagnosis. Contrariwise, recipients afflicted with CsA-induced nephrotoxicity displayed reduced IL-6 levels (mean = 1.4 +/- 0.18 U/ml). The ratio (IL-6 activity/CsA trough level) proved to be even more useful than the serum IL-6 level itself to discriminate acute rejection from nephrotoxicity--namely, 0.53 versus 0.006, respectively (P less than 0.01).     

OKT3 treatment of steroid-resistant renal allograft rejection

The monoclonal antibody, Orthoclone OKT3 (OKT3), has been used with great efficacy in a prospective multicenter trial as therapy for first rejection episodes in cadaveric donor (CD) renal allograft recipients treated with azathioprine (AZA) and prednisone (P). However, although almost all rejection episodes were reversed, recurrent rejection occurred in approximately two-thirds of OKT3-treated patients in this earlier trial; infections also occurred in about two-thirds of patients, often related to the additional immunosuppression necessary to reverse the rerejection episodes. In the current series of patients, OKT3 was used to treat rejection in CD renal graft recipients in a protocol differing from the multicenter trial in two respects: baseline immunosuppression was cyclosporine (CsA) and P or CsA, AZA, and P (probably more potent immunosuppressive combinations than the AZA and P in the multicenter trial); and OKT3 treatment was reserved for rejection episodes resistant to 3 bolus infusions of methylprednisolone (MP), 5-10 mg/kg, rather than as primary therapy for first rejection episodes. Using this protocol, 46 of 74 rejection episodes (62%) diagnosed between 3/85 and 3/86 in CD renal allograft recipients were treated successfully with MP. Of the remaining 28 steroid-resistant rejection episodes, 27 (96%) were reversed with a 7-14-day course of OKT3, 5 mg/day. Only 5 recurrent rejection episodes (19%) have been observed in the 2-14-month follow-up period after OKT3 treatment; infections have occurred in 10 patients (36%), and three grafts (11%) have been lost in OKT3 treated patients. These results suggest that recurrent rejection and subsequent infection after OKT3 is used to treat rejection may be reduced in a protocol where CD renal allograft recipients are treated with baseline immunosuppression regimens including CsA and where OKT3 is reserved for steroid-resistant rejection. This approach appears to be both more cost-effective than, and as effective therapeutically as, treating all first rejection episodes with the monoclonal antibody.     

肾移植后测定血清可溶性细胞间粘附分子-1的临床意义

目的　探讨血清可溶性细胞间粘附分子 1(sICAM 1)在肾移植术后免疫学监测中的价值。方法　采用酶联免疫吸附法 (ELISA)动态监测 5 6例肾移植患者术后血清sICAM 1的变化。结果　肾移植患者术后发生排斥反应时 ,其sICAM 1水平 (390 .6 μg/L±91.0 μg/L)明显高于移植肾功能稳定者 (137.3μg/L±16 .8μg/L)和环孢素A(CsA)肾中毒者 (132 .7μg/L±2 4.8μg/L) ,差异有极显著性 (P <0 .0 1) ;抗排斥反应治疗有效后 ,sICAM 1逐渐降至正常水平 ;CsA肾中毒者的sICAM 1水平无明显变化。结论　肾移植术后动态监测患者血清sICAM 1水平的变化 ,有助于急性排斥反应的诊断、鉴别诊断及抗排斥治疗的疗效评价 ,可以作为肾移植术后急性排斥反应的免疫学监测指标。     

Increased serum beta 2 microglobulin during rejection, cyclosporine-induced nephrotoxicity, and cytomegalovirus infection in renal transplant recipients

In 83 renal transplant recipients, serum beta 2 microglobulin (beta 2m) levels were significantly elevated during pretransplant uremia, rejection, cyclosporine-induced nephrotoxicity, and infections. In patients with normal serum creatinine, 74% had elevated serum beta 2m levels. None of the cyclosporine-treated patients had normal levels of beta 2m. Patients with stable renal allograft function receiving cyclosporine showed significantly higher serum beta 2m (P less than 0.001) and serum creatinine (P less than 0.01) levels than azathioprine treated patients. Patients with an irreversible rejection showed significantly higher serum concentrations of beta 2m than patients experiencing a reversible rejection (P less than 0.001). During cytomegalovirus (CMV) infection the serum beta 2m levels were elevated compared with other infections (P less than 0.001), while the serum creatinine was not. However, infected patients had higher serum levels of beta 2m and creatinine than patients with stable renal allograft function (P less than 0.001). Serum beta 2m may therefore be useful in the early diagnosis of CMV infection. To conclude, serum beta 2m levels cannot distinguish between rejection, cyclosporine nephrotoxicity, or infection.     

Immunohistological analysis of renal allograft biopsies from cyclosporin-treated patients

Differentiation of cyclosporin nephrotoxicity from renal allograft rejection is often difficult. Induction of tubular HLA-class II antigens and elevated levels of leucocyte infiltration are associated with allograft rejection but their association with cyclosporin nephrotoxicity is unclear. In order to determine these relationships, transplant biopsies (n=32) from patients considered to have cyclosporin nephrotoxicity, allograft rejection or stable graft function were stained with monoclonal antibodies specific for HLA-class II antigens and infiltrating leucocytes. Leucocyte infiltration was elevated during rejection but not in cyclosporin nephrotoxicity or stable graft function. While HLA-class II antigen expression was induced in 71% of the biopsies obtained during clinical rejection, no increased expression was found in the other 29%. Induced antigens were detected in five of the nine biopsies obtained in the presence of cyclosporin nephrotoxicity 90 days after transplantation. In four of these, induction was attributed to prolongation of increased class II expression following previous rejection episodes. Thus, the presence of induced class II antigens in the renal allograft does not exclude a diagnosis of cyclosporin nephrotoxicity.     

Immunohistological analysis of renal allograft biopsies from cyclosporin-treated patients: Induced HLA-class II antigen expression does not exclude a diagnosis of cyclosporin nephrotoxicity

Abstract. Differentiation of cyclosporin nephrotoxicity from renal allograft rejection is often difficult. Induction of tubular HLA-class II antigens and elevated levels of leucocyte infiltration are associated with allograft rejection but their association with cyclosporin nephrotoxicity is unclear. In order to determine these relationships, transplant biopsies ( n =32) from patients considered to have cyclosporin nephrotoxicity, allograft rejection or stable graft function were stained with monoclonal antibodies specific for HLA-class II antigens and infiltrating leucocytes. Leucocyte infiltration was elevated during rejection but not in cyclosporin nephrotoxicity or stable graft function. While HLA-class II antigen expression was induced in 71% of the biopsies obtained during clinical rejection, no increased expression was found in the other 29%. Induced antigens were detected in five of the nine biopsies obtained in the presence of cyclosporin nephrotoxicity 90 days after transplantation. In four of these, induction was attributed to prolongation of increased class II expression following previous rejection episodes. Thus, the presence of induced class II antigens in the renal allograft does not exclude a diagnosis of cyclosporin nephrotoxicity.     

The selective use of basiliximab versus thymoglobulin in combination with sirolimus for cadaveric renal transplant recipients at low risk versus high risk for delayed graft function

BACKGROUND: We previously reported that the use of basiliximab together with sirolimus permits a window of recovery from delayed graft function before the introduction of reduced-dose cyclosporine. The present study reviews our experience with the substitution of thymoglobulin for basiliximab as induction therapy for recipients at increased risk for early acute rejection episodes. METHODS: We retrospectively reviewed 145 cadaveric renal allograft recipients who received either basiliximab (n=115) or thymoglobulin (n=30) in combination with sirolimus and prednisone, followed by delayed introduction of reduced doses of cyclosporine. Recipients were stratified as high immune responders if they were African American, a retransplant recipient, or a recipient with a panel-reactive antibody greater than 50%. All other recipients were considered low immune responders. RESULTS: Basiliximab-treated high immune responders exhibited a higher incidence of acute rejection episodes (26%) than either basiliximab-treated low immune responders (10%, P=0.04) or thymoglobulin-treated high immune responders (3%, P=0.01). The median time to initiation of cyclosporine was 12 days; cyclosporine was initiated when the serum creatinine level was 2.5 mg/dL or less. Patients with early return of renal function displayed a lower incidence of acute rejection episodes than those with later recovery of function (P=0.003). High immune responders treated with basiliximab expressed a higher mean serum creatinine level at 3 months (P<0.01), 6 months (P=0.02) and 12 months (P=0.01) than either low immune responders treated with basiliximab or high immune responders treated with thymoglobulin. CONCLUSION: A strategy combining sirolimus with basiliximab for low-immunologic risk recipients and thymoglobulin for high-risk recipients leads to prompt recovery of renal function with a low risk of acute rejection episodes.     

Reevaluation of T cell subset monitoring in cyclosporine-treated renal allograft recipients

The predictive value of peripheral blood T cell subset monitoring in renal allograft recipients has been questionable, and there has been no information concerning the correlation of T cell subset changes with the clinical event related to cyclosporine nephrotoxicity. This study was conducted to investigate the clinical usefulness of serial T cell subset monitoring in 34 consecutive renal transplant patients treated with cyclosporine by determining the total peripheral lymphocyte count and T cell subset counts using Leu-4, Leu-3ab, and Leu-2a monoclonal antibodies and flow cytometry up to 6 months after transplantation. The absolute counts of all cells were lower in transplanted patients than those of normal controls, but were not different from those of hemodialysis patients. During infection, the helper/suppressor (H/S) ratio and the cell counts, except for suppressor cells, decreased significantly. Within one week prior to rejection, all cell counts also decreased significantly. Furthermore, cell counts before steroid-resistant rejection were significantly lower than those before steroid-responsive rejection. In contrast, lymphocyte and T cell counts were increased significantly within one week prior to cyclosporine nephrotoxicity being diagnosed; the H/S ratio was not correlated with rejection or toxicity. These results indicate that H/S ratio is not associated with clinical events of renal allograft recipients, but serial lymphocyte and T cell subset counts can provide valuable information for the differentiation of rejection from cyclosporine nephrotoxicity, and also for predicting the outcome of the allograft rejection.     

ICAM-1和VCAM-1测定在肾移植急性排斥反应中的临床意义

目的探讨血清可溶性细胞间粘附分子１（ｓＩＣＡＭ１）和可溶性血管细胞粘附分子１（ｓＶＣＡＭ１）在肾移植急性排斥反应中的临床意义。方法采用酶联免疫吸附法（ＥＬＩＳＡ）动态监测５６例肾移植患者术后ｓＩＣＡＭ１和ｓＶＣＡＭ１水平的变化。结果肾移植患者术后ｓＩＣＡＭ１和ｓＶＣＡＭ１水平呈规律性变化,急性排斥反应组ｓＩＣＡＭ１为（３９０．６±９１．０）ｎｇ／ｍｌ,ｓＶＣＡＭ１为（１９５７．１±４０３．１）ｎｇ／ｍｌ,明显高于移植肾功能稳定组的（１３７．３±１６．８）ｎｇ／ｍｌ、（１１１８．４±２１０．４）ｎｇ／ｍｌ和ＣｓＡ肾中毒组的（１３２．７±２４．８）ｎｇ／ｍｌ、（１２８５．８±２７０．５）ｎｇ／ｍｌ,差异有非常显著性（Ｐ＜０．０１）。结论ｓＩＣＡＭ１和ｓＶＣＡＭ１可以作为肾移植术后急性排斥反应的免疫学监测指标。     

Follow-up of cyclosporine-treated pediatric renal allograft recipients after cessation of prednisone

We attempted cessation of prednisone therapy in 16 pediatric renal allograft recipients who were between the ages of 3 1/2 and 16 years at the time of transplantation. Fourteen had primary grafts and 2 had second grafts. Nine had cadaver and 7 had living-related donor grafts. At the time of cessation of prednisone, cyclosporine was the only other immunosuppressive therapy for 15 of the patients and 1 patient was receiving CsA and azathioprine. All the patients had stable serum creatinines at the time prednisone was stopped, between 7 months and 5 years posttransplantation. Seven patients have had no episodes of rejection, continuing to receive CsA as their only immunosuppressive therapy and have stable renal function between 16 months and 3 1/2 years (mean: 2 years) after stopping prednisone. Stopping the small maintenance dose of prednisone resulted in improved growth in patients whose epiphyses were not fused. They improved their weight:height ratios and lost their cushingoid appearance. Serum cholesterol levels declined significantly. Patients who required antihypertensive drugs to control their blood pressure while receiving prednisone required fewer or no drugs when off prednisone. Nine patients had acute rejection episodes and were put back on maintenance prednisone following a 3-day steroid pulse. All these patients had a prompt improvement in renal function following the steroid pulse. However, only 3 stabilized function at preprotocol baseline Scr. Four currently have functioning grafts with Scr greater than the preprotocol Scr. Two patients have returned to dialysis. Although stopping steroids is a worthy goal in pediatric renal allograft recipients, we cannot recommend this strategy as routine management because of the 56% rate of acute rejection episodes in the patients who had prednisone withdrawn.     

肾移植术后肝细胞生长因子的动态监测及临床意义

目的:探讨肝细胞生长因子(HGF)在急性排斥反应的早期诊断、鉴别诊断中的意义。方法:采用双抗体夹心酶联免疫吸附法,对50例肾移植受者血清HGF水平在手术前后进行动态监测。观察肾移植术后发生急性排斥反应(AR)、急性肾小管坏死(ATN)、环孢素(CsA)中毒时血清HGF的变化。结果:术前组HGF水平与对照组相比有统计学意义(P<0.05)。稳定组术后前3天HGF下降明显,2周左右降至对照组水平。AR组在典型症状出现及血Cr升高前1~3d,HGF即有升高,且峰值出现在抗排斥治疗的当天。经甲基泼尼松龙冲击后AR逆转者HGF迅速下降。ATN组HGF升高,与AR组相比有统计学意义(P<0.05)。CsA中毒组HGF水平升高,与AR相比有统计学意义(P<0.05),但与ATN组相比无统计学意义(P>0.05)。结论:动态监测HGF可能作为急性排斥反应的早期诊断敏感指标,并且对ATN、CsA中毒的鉴别诊断也具有一定临床应用价值。     

Safe conversion from cyclosporine to azathioprine with improved renal function in pediatric renal transplantation

Although cyclosporine has improved allograft survival in renal transplant patients, problems with drug toxicity remain, raising the question whether cyclosporine should be stopped at some point post-transplant. However, the relative safety of converting from cyclosporine to another immunosuppressive agent, or simply stopping cyclosporine remains an issue of debate and has not been evaluated in children. We have developed a protocol to convert children, who are 6 months post-transplant and have stable kidney function, from cyclosporine and prednisone to azathioprine and prednisone. Eleven children have undergone conversion because of suspected/potential nephrotoxicity or because of other difficulties with cyclosporine (expense, hirsutism). These children were compared with a control group of 12 children who met all criteria for conversion at 6 months but remained on cyclosporine. Allograft survival was similar in both groups but the children converted from cyclosporine experienced an improvement in renal function as measured by calculated creatinine clearance. There were no episodes of rejection for a period of 4 months postconversion and all rejection episodes that developed subsequently occurred during or after the change from daily to alternate-day prednisone. We believe that conversion from cyclosporine to azathioprine can be accomplished safely in children with stable allograft function but long-term risks and benefits need further evaluation.     

Serum C-reactive protein concentrations in cyclosporine-treated renal allograft recipients

Acute or persistent elevations in serum C-reactive protein (CRP) concentration have been shown to be of value in diagnosing acute rejection episodes in azathioprine (AZA)-treated renal transplant recipients. To assess whether changes in serum CRP level might assist in differentiating nephrotoxicity from acute rejection in cyclosporine (CsA)-treated renal transplant recipients, we measured changes occurring in serum CRP concentrations in 74 CsA patients in response to transplant operation, acute rejection, cyclosporine nephrotoxicity, and serious infection, and compared these values with changes in AZA patients. Serum CRP concentration rose in response to operation in virtually all patients, regardless of immunosuppressive regimen, from mean baselines of 5.9 +/- 2.7 mcg/ml (AZA) and 6.8 +/- 6.5 mcg/ml (CsA) to mean peak levels of 43.8 +/- 33.4 mcg/ml and 65.1 +/- 39.5 mcg/ml, respectively. CRP rose during 76% of acute rejection episodes in AZA patients by a mean of 29.7 +/- 37.4 mcg/ml. In contrast, in 80% of acute rejection episodes of CsA patients, CRP remained undetectable or failed to rise above a stable, minimally elevated baseline. Similarly, there was no elevation in CRP in 9 of 10 episodes of nephrotoxicity. In 14 CSA patients with serious infections (8 pulmonary, 3 intraabdominal, 3 genitourinary), CRP rose by a mean of 67.7 +/- 50.7 mcg/ml. Thus, although CRP rises significantly with operation or serious infection in CsA patients, CRP fails to rise with nephrotoxicity or acute rejection.     

Increased factor VIII as an index of vascular injury in cyclosporine nephrotoxicity

Very high plasma concentrations of factor-VIII-related antigen (RAG) (VIII-RAG) were found in renal allograft recipients during periods of nephrotoxicity induced by cyclosporine. In eight recipients, who were investigated at weekly intervals, levels of factor-VIII-RAG fell toward normal as the dose of cyclosporine was reduced. Plasma levels of C-reactive protein, an acute phase reactant protein, were never raised in these recipients. These findings are further evidence that toxic doses of cyclosporine are associated with vascular injury.     

肾移植术后血清IL—6水平的动态监测及临床意义

目的：观察肾移植术后发生急性排斥反应、感染、CsA中毒时血清IL-6的变化,以探讨IL-6在急性排斥反应的早期诊断、鉴别诊断中的意义。方法：采用双抗体夹心酶联免疫吸附法,对106例肾移植患者血清IL-6活性水平于肾移植手术前后进行动态监测。结果：肾移植术前,IL-6与对照组比较差别无显著性意义。术后第1天明显升高,2周左右基本降至术前水平。发生急性排斥反应前1-3天。血清IL-6即有升高,峰值出现在抗排斥反应治疗的当天,经甲基本降至术前水平,发生急性排斥反应前1-3天,血清IL-6即有升高,峰值出现在抗排斥反应治疗的当天,经甲基泼尼松尼（MP）冲击有效后迅速下降,治疗无效者,血清IL-6持续在高水平,并发感染时,IL-6也显著升高,与急性排斥反应组相比差别无显著性意义;而CsA中毒时,IL-6变化不明显。结论：动态监测IL-6可以作为急性排斥反应的早期诊断,鉴别诊断的免疫生物学指标。     

Prospective, Pilot, Open-Label, Short-Term Study of Conversion to Leflunomide Reverses Chronic Renal Allograft Dysfunction

Leflunomide (LEF) is a synthetic isoxazole derivative with anti-inflammatory and antiviral properties, which has been reported to prevent acute rejection and delay progression of chronic allograft nephropathy (CAN) in animal models. We performed a pilot, crossover trial in 22 renal transplant recipients who were converted from azathioprine (AZA) or mycophenolate mofetil (MMF) to LEF in an effort to slow progression of renal dysfunction [deteriorating renal function (n = 5), cyclosporine (CyA) nephrotoxicity (n = 4) or biopsy-proven CAN (n = 13)]. Baseline maintenance immunosuppression consisted of CyA, AZA or MMF and prednisone. Six-month postconversion patient and graft survival was 100% and 91%, respectively. Mean serum creatinine 6months preconversion was 2.2 +/- 0.6mg/dL, at initiation was 3.0 +/- 1.1 mg/dL, and 6 months postconversion was 2.8 +/- 1.3 mg/dL. The rate of change in serum creatinine was 35 +/- 39%/6 months preconversion and -5 +/- 21%/6 months postconversion to LEF (p = 0.003). Two patients discontinued LEF for diarrhea and myalgia. No readmissions, increase in liver function tests, infections or acute rejection episodes occurred. Mean CyA levels did not change, 146 +/- 72 ng/ mL pre-LEF vs. 132 +/- 51 ng/mL post-LEF, p = NS. Conversion to LEF reversed progression of chronic renal allograft dysfunction with minimal toxicity.     

CC-chemokine RANTES is increased in serum and urine in the early post-transplantation period of human renal allograft recipients

BACKGROUND: The chemokine RANTES is a potent chemoattractant for T cells and monocytes that has been shown to enhance inflammation. The aim of our study was to investigate whether RANTES is upregulated within the early post-transplantation period that may influence short-time allograft function rate. METHODS: Serum and urine samples from transplanted renal allograft recipients (n = 17) were obtained from specimens taken for diagnostic reasons. Four patients developed biopsy-proven rejection episodes within the first month. Time course of RANTES was studied within the first 12 days after renal transplantation using ELISA technique. Data were tested for significances between patients with rejection and without rejection, compared to healthy volunteers as controls, and correlated with clinical data. RESULTS: In the control group RANTES concentration was 37.2 +/- 2.7 ng/ml (serum) and 8.1 +/- 1.3 pg/ml (urine), respectively. In transplanted recipients serum RANTES was significantly upregulated up to 132 +/- 28 ng/ml on day 1 after transplantation and remained elevated within the first 12 days (n = 17). Time course of urine RANTES demonstrated elevated concentrations with 754 +/- 115 pg/ml on day 1 followed by an continuous decrease to 22.3 +/- 7 pg/ml on day 12 (n = 17). No significant differences could be detected between patients with rejection and without rejection episodes. CONCLUSIONS: In contrast to data of other urinary marker molecules (like IL-6), there are no significant differences between the rejection and non-rejection group. RANTES is therefore not suitable for early detection of rejection. Nevertheless, serum and urine RANTES concentrations were highly elevated in freshly transplanted renal allograft recipients reflecting an activated immune system.     

Delayed acute rejection episodes in cyclosporine-treated renal transplant recipients.

Of 109 cyclosporine-treated cadaveric renal allograft recipients, 45 were free of acute rejection in the first 4 weeks after transplantation. Eleven of 45 (24%) subsequently had delayed, biopsy-proven first rejection episodes 34-61 days after grafting, often after discharge from the hospital. Delayed rejectors had significantly higher plasma creatinine levels at all times during the first posttransplant month than 34 nonrejectors. Trough serum cyclosporine levels were similar in the two groups, although by the 4th week oral cyclosporine dose was significantly lower in the delayed rejection group. Two-thirds of those patients who had serum creatinine levels greater than or equal to 260 mumol/l at 2 weeks and greater than or equal to 225 mumol/l at 3 weeks had a delayed acute rejection episode. Renal transplant recipients treated with cyclosporine who have serum creatinine levels at or above these levels should be aggressively worked up and closely followed for the development of delayed acute rejection.     

Experimental and clinical experience with urine amylase monitoring for early diagnosis of rejection in pancreas transplantation

Pancreas allograft rejection in dogs with pancreaticocystostomy can be predicted in advance of hyperglycemia by monitoring the urinary amylase (UA) concentration (U/L): In initial experiments, UA values declined to less than 1000 1.3 +/- 0.2 days before hyperglycemia in nonimmunosuppressed dogs, 3.3 +/- 1.0 days in dogs treated with cyclosporine (CsA), and 9.3 +/- 0.7 days in dogs treated with CsA, azathioprine (Aza), and prednisone (triple therapy). Autotransplanted control dogs maintained high urine amylase concentrations indefinitely (mean 125,544 +/- 36,931). In a subsequent experiment, in 19 dogs with bladder-drained pancreas allografts on CsA only for prophylactic immunosuppression, a five-day course of antirejection treatment with Aza (5.0 mg/kg) and antilymphocyte globulin ALG (1 mg/kg) was started in group A (n = 10) when a raise in serum glucose was detected, and in group B (n = 9) when a drop of UA below 1000 was observed. The functional allograft survival rate was 9.2 +/- 0.5 days in group A (treatment started after hyperglycemia) and 29.0 +/- 5.7 days in group B (treatment started after drop in UA) (P = .002). The UA dropped in all dogs before hyperglycemia, at a mean of 2.7 days in group A and 20.8 days in group B. Clinically, 8 patients received a whole cadaver pancreas transplant with urinary drainage of the exocrine secretions. All were followed with UA monitoring. Three recipients lost the grafts for technical reasons. Three recipients lost the grafts for technical reasons. One had a primary non-function and UA was below 1000 U/24 hr; two developed abscesses and the grafts were removed while functioning with high UA values. Five grafts are currently functioning; 3 recipients had no rejection episodes and their UA values ranged from 30,000 to 100,000 U/24 hr during their entire postoperative course. The other two had rejection episodes. In both cases UA decreased to baseline levels 1 and 4 days in advance of the hyperglycemia. After antirejection treatment UA rose again to high values and plasma glucose levels declined. Both patients are currently insulin-independent, with UA values ranging from 10,000 to 200,000 U/24 hr. Both experimentally and clinically UA is an early predictor of pancreas allograft rejection. The institution of early treatment of rejection episodes in dogs, based on UA, significantly improved allograft survival. Urine amylase monitoring in pancreas transplant recipients could lead to an early treatment of rejection and improve graft survival.     

Treatment of early mixed cellular and humoral renal allograft rejection with tacrolimus and mycophenolate mofetil

This prospective study investigated the efficiency of the tacrolimus (Tac) combined with mycophenolate mofetil (MMF) alone without immunoadsorption (IA) or plasmapheresis (PPH) as treatment for early (within 2 weeks) acute humoral rejection (AHR) in non-sensitized renal allograft recipients. Of 160 patients enrolled in this prospective study, 11 patients had histologically and clinically confirmed early steroid-resistant acute rejection with an antibody response and received Tac-MMF therapy. No other aggressive rescue methods such as IA, PPH were used, according to the study design. Patients (n=11) were followed for 13.8+/-3.5 months; nine were females. The complement-dependent cytotoxicity crossmatch was negative before transplantation in all patients and only positive for panel-reactive antibody in one patient. Most of the rejection episodes were mixed with cellular rejection (four patients met Banff IIA criteria, five patients met Banff IIB, one patient met Banff IB, and one patient met Banff borderline). After 16.19+/-6.16 days of treatment, all rejection episodes were successfully reversed and all graft functions were stable, with a mean serum creatinine level of 1.12+/-0.32 mg/dl during follow-up. No patient suffered from severe infectious complications (except one case of urinary infection). Our investigation suggests that Tac combined with MMF alone is adequate to reverse early mixed cellular and humoral C4d-positive rejection in non-sensitized renal allograft recipients.