Gene Expression in Biopsies of Acute Rejection and Interstitial Fibrosis/Tubular Atrophy Reveals Highly Shared Mechanisms That Correlate With Worse Long-Term Outcomes

Interstitial fibrosis and tubular atrophy (IFTA) is found in approximately 25% of 1-year biopsies posttransplant. It is known that IFTA correlates with decreased graft survival when histological evidence of inflammation is present. Identifying the mechanistic etiology of IFTA is important to understanding why long-term graft survival has not changed as expected despite improved immunosuppression and dramatically reduced rates of clinical acute rejection (AR) (Services UDoHaH. http://www.ustransplant.org/annual_reports/current/509a_ki.htm). Gene expression profiles of 234 graft biopsy samples were obtained with matching clinical and outcome data. Eighty-one IFTA biopsies were divided into subphenotypes by degree of histological inflammation: IFTA with AR, IFTA with inflammation, and IFTA without inflammation. Samples with AR (n = 54) and normally functioning transplants (TX; n = 99) were used in comparisons. A novel analysis using gene coexpression networks revealed that all IFTA phenotypes were strongly enriched for dysregulated gene pathways and these were shared with the biopsy profiles of AR, including IFTA samples without histological evidence of inflammation. Thus, by molecular profiling we demonstrate that most IFTA samples have ongoing immune-mediated injury or chronic rejection that is more sensitively detected by gene expression profiling. These molecular biopsy profiles correlated with future graft loss in IFTA samples without inflammation.

Observations on the use of cidofovir for BK virus infection in renal transplantation

BACKGROUND

In renal transplantation, BK virus infection can result in significant graft nephropathy and loss. While reduction in immunosuppression (IS) is considered standard therapy, adjunct agents may be warranted. Data are suggestive of a possible role of cidofovir for the management of BK. This study aims to describe the course of BK viremia (BKV) in a large cohort of renal transplant patients receiving adjunct cidofovir.

METHODS

We evaluated kidney and kidney-pancreas recipients who received cidofovir combined with reduced IS for management of high-level BKV or BK virus nephropathy (BKVN). We examined the rate and timing of BKV clearance, and performed a multivariate analysis to identify risk factors associated with long-term (>6 months) viremia.

RESULTS

In total, 75 patients received a median of 13 doses of cidofovir in conjunction with reduced IS; 32 patients (43%) had short-term BKV (≤6 months), and 43 (57%) had long-term BKV. Overall, 53 of 75 patients (71%) eventually cleared BKV at a median of 4.2 months (interquartile range 2.1-9.3 months). Independent factors associated with long-term BKV included older age (odds ratio [OR] 1.1, P = 0.02), delayed graft function (OR 31.4, P = 0.01), and higher peak BKV (OR 12.8, P = 0.02), while BKV reduction by at least 1 log(10) copies/mL at 1 month of treatment was associated with clearance within 6 months (OR 49.3, P < 0.01). Patients with earlier clearance maintained stable graft function and no graft losses, while long-term BKV was associated with a 15% decline in estimated glomerular filtration rate.

CONCLUSIONS

Adjunct cidofovir resulted in preservation of renal function when viral clearance occurred within 6 months of initiation. This retrospective review defines factors predicting response to cidofovir in conjunction with reduced IS for BKVN or high-level BKV. Still, considering cost, frequency of administration, and treatment duration, a randomized trial is necessary to define the exact utility of cidofovir in the setting of BK virus infection.

De novo donor specific antibodies and patient outcomes in renal transplantation

Single antigen identification of HLA antibodies is used to detect donor specific antibodies (DSAs). However, the impact of DSA elements such as class, relative strength, duration, and longitudinal effect on graft function and survival, remains unclear. Routine DSAs (LabScreen, One Lambda, Inc., Canoga Park, CA) and metabolic studies were performed at 1, 3, 6, 9, and 12 months post-transplant, and every 6 months for renal transplant recipients from 7/2007-7/2010 (n = 389). Biopsies were evaluated by updated Banff 2005 guidelines after two consecutive positive DSAs. Based on these tests, 25% of recipients developed de novo DSA. Those with DSA had increased acute rejection episodes (AR), higher creatinine (Scr), and worse graft survival. Three subgroups of these patients were identified based on duration: persistent DSA (> 1), isolated DSA, or no DSA. Persistent DSA patients were more likely to be African American, and have higher mean fluorescence intensity (MFI) and AR rates. Persistent DSA patients, with or without AR, had elevated Scr. Recipients with DQ-only DSA had higher rates of antibody mediated rejection (AMR). From this, we conclude that routine posttransplant DSA monitoring identifies recipients at risk for graft damage or loss. Persistent de novo DSAs correlated with inferior graft outcomes and AMR. With or without AR, DSA persistence was associated with worse outcomes, possibly warranting intervention. De novo DQ-DSA may be a biomarker for chronic damage and/or AMR, while an isolated DSA determination appears clinically insignificant.

A review of the evidence for use of thymoglobulin induction in renal transplantation

Depleting antilymphocyte, or antithymocyte antibodies, have long been an integral part of induction regimens and continue today to be used in the management of patients at risk of early rejection or those in whom the introduction of calcineurins or other immune suppressants must be delayed. Registry data demonstrate that the most commonly used depleting antibody, rabbit anti-human thymocyte globulin (rATG), is associated with improved outcomes following renal transplantation in high-risk patients, particularly in conjunction with steroid-avoidance regimens. Two prospective randomized trials in high-risk renal allograft patients have also demonstrated an advantage of r-ATG induction compared to the nondepleting interleukin receptor (IL2RA) antibodies. In low-immunologic-risk patients, however, r-ATG induction and IL2RA induction appear to be equivalent in terms of rejection prophylaxis and long-term function. Other studies have shown that sequential rATG-containing regimens were superior to no induction and allowed for successful late introduction of calcineurin inhibitors. The side effect profile of the depleting antibody included increased incidence of fever, hematologic abnormalities, cytomegalovirus infections when prophylaxis was not employed, and in some studies, increased incidence of posttransplant lymphoproliferative disease. This review describes the evidence supporting the use of depleting ATGs in kidney transplantation.

Analgesic nephropathy selectively affecting a unilateral non-functioning hypoplastic kidney

Analgesic nephropathy results from chronic abuse of non-narcotic analgesics, most frequently with the use of phenacetin and mixed analgesic preparations. Renal papillary necrosis and chronic interstitial nephritis with progressive scarring are characteristic of the histopathology of analgesic nephropathy. Typically, papillary necrosis in these patients is bilateral and affects almost all renal papillae. This report describes a case of severe analgesic nephropathy that discriminantly affected a unilateral non-functioning kidney and spared the contralateral normally developed kidney. The patient herein consumed therapeutic doses of acetaminophen and naproxen daily and for several years. We estimated the cumulative doses of acetaminophen and naproxen used by the patient during that period to be approximately 1.0 and 0.4 kg, respectively. The cumulative dose of acetaminophen is at the threshold of doses that were traditionally associated with an increased risk for end-stage kidney failure. Simultaneous intake of both analgesics could have had a synergetic adverse effect on renal function. This case also demonstrates that preexisting renal insufficiency is prerequisite to the development of analgesic nephropathy. Conversely, kidneys with normal function are resistant to the chronic nephrotoxicity associated with habitual analgesic use.

Changes in Abdominal Wounds Following Treatment With Sirolimus and Steroids in a Rat Model

Wound healing complications have been observed in patients receiving sirolimus (SLR). This study examined the degree and duration of delayed healing in various protocols using SLR. Sprague-Dawley rats underwent a standard midline abdominal incision and wound closure. Groups of 6 rats each were randomized to receive different doses of SLR (2 and 5 mg/kg) with or without loading dose (10 mg/kg x3 days), and with or without steroids (20 mg/kg x3 days followed by 5 mg/kg for 2 weeks). Rats were humanely killed on postoperative days 5, 10, or 15. Wound breaking force was measured using the EHMI BIAX-II instrument and tensile strength was calculated. Wounds in control animals had gradual increase in tensile strength during the 15-day observation. In contrast, high and loading doses of SLR caused reduction in wound strength until day 10, but the wounds' tensile strength became equivalent to control by day 15. The addition of steroids prolonged wound recovery with low doses of SLR until day 15 and had very profound effects on healing in high-dose SLR-treated animals (>50% reduction) that continued beyond the 2 weeks of observation. Low doses of SLR in non-steroid-treated animals had a short-term (5-day) impact on wound healing; high dose and loading doses delayed healing for 10 to 15 days. The addition of steroids had a synergistic effect on delayed wound healing, particularly in animals receiving high-dose SLR, which demonstrated prolonged wound weakness. These results may provide practical guidelines for postoperative introduction of SLR in the context of various clinical protocols.

Serial Peripheral Blood Cytotoxic Lymphocyte Gene Expression Measurements for Prediction of Pancreas Transplant Rejection

Acute rejection after pancreas transplantation remains a significant problem and contributes to immunological graft loss. No clinical markers of pancreas rejection have been universally accepted. The purpose of this study was to investigate the use of genetic markers; granzyme B, perforin, and HLA-DRA in the peripheral blood of pancreas transplant recipients. These genes have been identified in renal and islet cell transplant recipients as noninvasive tools to predict acute rejection. Blood samples were collected weekly for up to 1 year posttransplant. Surveillance biopsies of the pancreas were scheduled at weeks 2, 4, 8, and 12 as part of the typical posttransplant protocol for patients with pancreas alone or pancreas after kidney transplantation. Exclusion criteria included a diagnosis of biopsy-proven chronic rejection alone, pancreatitis, or kidney rejection within 2 months after pancreas biopsy. Gene expression levels of granzyme B, perforin, and HLA-DRA were compared in patients with (n = 7) and without biopsy proven acute rejection (n = 7). Recipients with acute rejection showed increased expression of granzyme B, HLA-DRA, as well as perforin genes compared to patients without biopsy-proven rejection. In addition, we observed that elevation of these genes occurred as early as 4 weeks before the traditional biopsy diagnosis, while the recipients with no rejection showed no change in gene expression. Our data indicated that serial measurements of peripheral blood granzyme B, perforin, and HLA-DRA gene expression can be a useful tool to predict pancreas rejection in its earliest stage.

Pediatric IgA nephropathy: clinical features at presentation and outcome for African-Americans and Caucasians

AIM

To determine the disease severity at onset and outcome for African-American and Caucasian pediatric patients with IgA nephropathy diagnosed at the Le Bonheur Children's Medical Center since 1990.

DESIGN/METHODS

The study population included all patients diagnosed with IgA nephropathy at the Le Bonheur Children's Medical Center from January 1990 through February 2004. All were below age 18 at biopsy. Clinical features assessed at diagnosis were age, gender, presence of hypertension, history of macroscopic hematuria, degree of proteinuria, severity of renal histology and pattern for immunofluorescent reactants.

STATISTICS

Student's t-test was used to compare age at biopsy and length of follow-up between the 2 groups. Fisher's exact test was used to compare features at presentation and patterns of immunofluorescence. Kidney survival was predicted by the Kaplan-Meier method.

RESULTS

Forty-seven patients (17 African-American, 29 Caucasian) were studied. Clinical features at diagnosis and pattern for all immunofluorescent reactants did not differ significantly between the 2 groups. Mesangial deposition of C1q occurred in 4/17 African-Americans as compared to 1/27 Caucasians (p = 0.06). Four patients (2 African-Americans, 2 Caucasians) progressed to end-stage renal disease. Predicted kidney survival was 96% (94% in African-Americans and 97% in Caucasians) at 1 year and 91% (94% in African-Americans and 89% in Caucasians) at 5 years from diagnosis. Mean time from diagnosis to end-stage renal disease or last follow-up was 3.3 years (3.8 for African-Americans, 3.0 for Caucasians). Macroscopic hematuria occurred prior to diagnosis for 90% of the Caucasian as compared to 61% of the African-American patients (p = 0.03). Urinalysis was normal at last follow-up visit for 24% of African-American patients and 32% of Caucasian patients.

CONCLUSION

In a relatively small sample from a single center, except for the difference in macroscopic hematuria, clinical features at diagnosis and outcome of IgA nephropathy appear similar for African-American and Caucasian pediatric patients.

Renal pathology and clinical presentations of polyomavirus nephropathy in simultaneous kidney pancreas transplant recipients compared with kidney transplant recipients

INTRODUCTION

The purpose of this study was to describe and compare the renal histopathology and clinical course of simultaneous kidney-pancreas transplant (SKP) recipients with kidney transplant (KT) recipients with polyomavirus nephropathy (PVN).

METHODS

Between 1997 and 2002, 20 patients (7 SKP, 13 KT) were diagnosed with PVN. Clinical characteristics and outcomes of PV-N were correlated with histopathologic examinations of renal allograft biopsy and compared between SKP and KT recipients.

RESULTS

There were no differences in demographics between SKP and KT recipients with PV-N. The mean time to PVN was 611 (172 to 1174) days posttransplant in SKP and 343 (83 to 720) days posttransplant in KT (P =.05). The serum creatinine at the time of diagnosis was similar between SKP and KT recipients. All patients were treated with reduction in immunosuppression. After a median follow-up of 2 years, the patient survival was 71% in SKP and 100% in KT. Four grafts (57%) were lost owing to PVN in SKP group and three grafts (23%) were lost owing to PVN in the KT group. More patients (43%) in SKP had a history of acute rejection prior to diagnosis of PVN compared to KT (8%) and biopsy-proven tacrolimus nephrotoxicity prior to PVN was more common in SKPT (86%) than in KT (8%) patients (P <.05). SKP patients with evidence of diffuse fibrosis and high total sum scores at time of presentation all subsequently lost their grafts.

CONCLUSIONS

SKP recipients with PVN had a worse clinical course than KT recipients.

Borderline changes in the banff schema: rejection or no rejection?

The relationship between acute renal allograft rejection and histopathologic biopsy alterations recognized by the Banff Schema as "borderline changes" is not clear. Some evidence supports the contention that about one third of patients with borderline infiltrates and clinical evidence of graft dysfunction do indeed have acute rejection, which, if left untreated, progresses to a histologically more advanced stage of rejection. Several investigators recognize that not all patients with mild tubulitis respond clinically to antirejection therapy; a significant number of these biopsy specimens display additional histological alterations. The most common concurrent lesions are chronic allograft nephropathy, arteriolar lesions consistent with calcineurin inhibitor toxicity, acute tubular necrosis, and obstructive nephropathy. Management of patients with borderline changes must tightly correlate the pathologic features and the clinical information.

Observations on the use of sirolimus and tacrolimus in high-risk renal transplant recipients

Sirolimus is the first of a group of mammalian target of rapamycin inhibitors to be introduced for clinical use in the United States. At the University of Tennessee in Memphis, we have evolved strategies for the use of sirolimus in kidney transplant recipients; which utilize the drug as a primary immunosuppressant and exploit its potential for preserving renal function. Conversions from the calcineurins to sirolimusbased immunosuppression established the efficacy of calcineurin-free immunosuppressants in selected high-risk patients. The conversion experience stimulated the design of protocols for primary use of sirolimus. Posttransplant use of sirolimus was associated with low incidence of rejection whether sirolimus was used with low-dose Prograf or in calcineurin-free protocols. Primary use with full-dose Prograf was associated with a high incidence of calcineurin-related nephrotoxicity and was abandoned in our program. Hematologic and lipid side effects were manageable, as was an observed increase in wound-healing problems and lymphocele formation. Continuous modifications of the sirolimus protocols to increase our benefit-to-risk ratio are ongoing and indicate a continued role for the drug in posttransplant immune suppression.

Polyomavirus in kidney and kidney-pancreas transplant recipients

PURPOSE

To report the incidence and clinical characteristics of polyomavirus (PV) nephritis in kidney (KTX) and kidney-pancreas transplant (KPTX) recipients.

METHODS

Single center retrospective analysis of all cases of PV nephritis in KTX and KPTX patients transplanted between 1994 and 1999.

RESULTS

Thirteen (5 KTX and 8 KPTX) patients (2.1%) had PV nephritis diagnosed on multiple biopsies (n = 22) among 504 KTX and 106 KPTX recipients. The incidence of PV nephritis was higher in cadaver donor transplants (2.6% cadaver vs. 0.7% living donors), after KPTX (1% KTX vs. 7.5% KPTX), in males (3.3% male vs. 0.7% female), and in diabetic patients (4.4% diabetic vs. 0.8% nondiabetic). The mean time to diagnosis of PV nephritis was 18 (range 6-48) months after KTX and 17 (range 9-31) months after KPTX. Three KTX patients and 5 KPTX patients had calcineurin inhibitor toxicity on biopsy prior to developing PV nephritis. Reduction in immunosuppression occurred in 100% of KTX and 63% of KPTX patients. Three patients (23%) developed rejection within 3 months of diagnosis of PV, 1 after a reduction in immunosuppression. Despite multiple antiviral treatment regimens, renal allograft failure requiring dialysis occurred in 60% of KTX and 50% of KPTX patients. All KPTX patients remain insulin independent and 2 were successfully retransplanted with living donor kidneys. 2 patients (15%) died but there was no mortality directly related to the virus.

CONCLUSIONS

Polyomavirus nephritis may be increasing in incidence and appears to be unresponsive to either conventional antiviral agents or a reduction in immunosuppression. Most of our cases occurred in male diabetic patients undergoing cadaveric donor transplantation and were preceded by biopsy-proven nephrotoxicity. Further studies are needed to better define the pathogenesis of PV and effective antiviral treatment.

Initial clinical experience with interleukin-2 receptor antagonist induction in combination with tacrolimus, mycophenolate mofetil and steroids in simultaneous kidney-pancreas transplantation

Since 1996, our standard immunosuppressive protocol for simultaneous kidney-pancreas transplantation (SKPT) has been tacrolimus (TAC), mycophenolate mofetil (MMF) and steroids without antibody induction. When basiliximab and daclizumab, monoclonal antibodies directed against the interleukin-2 receptor (IL-2R), became available, we selectively added these agents to our standard protocol. The purpose of this prospective, open-label study was to evaluate the safety and efficacy of IL-2 receptor antagonists in SKPT. From April 1998 to August 1999, 35 SKPTS were performed. One patient with delayed graft function received Thymoglobulin and was excluded; 17 received no induction, and 17 received IL-2R antagonists (9 basiliximab, 8 daclizumab) as induction. Demographic- and transplant characteristics were similar between the two groups. At 6 months, patient survival was 88 % (15/17) in the induction arm compared to 100 % (17/17) in the no-induction arm, P = NS. The 2 causes of death were sepsis and hemolytic uremic syndrome, and both patients died with functioning grafts. Death-censored pancreas and kidney graft survival rates in the induction and the no-induction groups were 88 % vs. 100 % respectively, in both groups. The incidence of acute rejection (kidney or pancreas) at 6 months did not differ between the two groups (35 % in both groups). Biopsy proven pancreas and kidney acute rejections were 35 % vs. 24 % and 12 % vs. 12 % in the induction- and no-induction groups, respectively. The incidences of major infection and readmission did not differ between groups. TAC trough levels and mean daily doses of TAC, MMF and steroids did not differ between the two groups at 1, 3, and 6 months. The incidence of event-free survival (no death, rejection, or graft loss) at 6 months was 59 % (10/17) in the induction and 65 % (11/17) in the no-induction group. Basiliximab and daclizumab appear to be safe in SKPT. However, the preliminary results of this study do not demonstrate a significant benefit in either reducing the incidence of acute rejection or improving outcomes at 6 months. Larger studies with longer follow-up are needed to confirm these findings.

Initial clinical experience with interleukin-2 receptor antagonist induction in combination with tacrolimus, mycophenolate mofetil and steroids in simultaneous kidney-pancreas transplantation

Since 1996, our standard immunosuppressive protocol for simultaneous kidney-pancreas transplantation (SKPT) has been tacrolimus (TAC), mycophenolate mofetil (MMF) and steroids without antibody induction. When basiliximab and daclizumab, monoclonal antibodies directed against the interleukin-2 receptor (IL-2R), became available, we selectively added these agents to our standard protocol. The purpose of this prospective, open-label study was to evaluate the safety and efficacy of IL-2 receptor antagonists in SKPT. From April 1998 to August 1999, 35 SKPTS were performed. One patient with delayed graft function received Thymoglobulin and was excluded; 17 received no induction, and 17 received IL-2R antagonists (9 basiliximab, 8 daclizumab) as induction. Demographic- and transplant characteristics were similar between the two groups. At 6 months, patient survival was 88 % (15/17) in the induction arm compared to 100 % (17/17) in the no-induction arm, P = NS. The 2 causes of death were sepsis and hemolytic uremic syndrome, and both patients died with functioning grafts. Death-censored pancreas and kidney graft survival rates in the induction and the no-induction groups were 88 % vs. 100 % respectively, in both groups. The incidence of acute rejection (kidney or pancreas) at 6 months did not differ between the two groups (35 % in both groups). Biopsy proven pancreas and kidney acute rejections were 35 % vs. 24 % and 12 % vs. 12 % in the induction- and no-induction groups, respectively. The incidences of major infection and readmission did not differ between groups. TAC trough levels and mean daily doses of TAC, MMF and steroids did not differ between the two groups at 1, 3, and 6 months. The incidence of event-free survival (no death, rejection, or graft loss) at 6 months was 59 % (10/17) in the induction and 65 % (11/17) in the no-induction group. Basiliximab and daclizumab appear to be safe in SKPT. However, the preliminary results of this study do not demonstrate a significant benefit in either reducing the incidence of acute rejection or improving outcomes at 6 months. Larger studies with longer follow-up are needed to confirm these findings.

A 9-year experience with 126 pancreas transplants with portal enteric drainage

HYPOTHESIS

A novel technique of pancreas transplantation (PTX) with portal venous delivery of insulin and enteric exocrine drainage (portal enteric) was developed at our center to improve the PTX procedure.

DESIGN

Case series.

SETTING

Single-center experience at a university hospital.

PATIENTS AND INTERVENTION

From October 1990 through December 1999, we performed 126 PTXs with portal enteric drainage, including 90 simultaneous kidney PTXs (SKPT) and 36 solitary PTXs (18 sequential PTXs after kidney transplantation and 18 PTXs alone).

MAIN OUTCOME MEASURES

Patient and graft survival rates; medical and surgical morbidity. Three groups, representing 3 eras of immunosuppression, were compared. Thirty patients underwent SKPT with muromonab-CD3 induction and cyclosporine-based therapy in era 1 (October 1990 through June 1995); 42 SKPTs received tacrolimus and mycophenolate mofetil-based immunosuppression without antibody induction in era 2 (July 1995 through May 1998); and 18 SKPTs were performed in era 3 (June 1998 through December 1999) with either basiliximab or daclizumab induction.

RESULTS

One-year patient survival rates after SKPT were 77% in era 1, 93% in era 2, and 100% in era 3 (P =.03). The 1-year kidney graft survival rates were 77% in era 1, 93% in era 2, and 94% in era 3 (P =.08). The 1-year pancreas graft survival rates after SKPT were 60% in era 1, 83% in era 2, and 83% in era 3 (P =.06). The incidences of rejection (63% vs. 33% vs. 39%; P<.001) and thrombosis (20% vs. 7% vs. 6%; P<.001) were decreased in eras 2 and 3.

CONCLUSION

Simultaneous kidney PTXs with portal enteric drainage can be performed with improved outcomes.

Renal allograft outcomes in African American versus Caucasian transplant recipients in the tacrolimus era

METHODS

Between January 1995 and December 1999, 185 kidney transplants were performed with tacrolimus (TAC)-based immunosuppression including 120 African American (AA, 65%) and 65 Caucasian recipients (C, 35%). Mean follow-up was 34 months. The AA group was characterized by a higher incidence of renal disease due to hypertension (72% AA vs 37% C, P <.001), pretransplant dialysis (95% AA vs 82% C, P =.003), waiting time (1.9 years AA vs 1.1 years C, P =.02), cadaveric donation (88% AA vs 68% C, P =.01), HLA mismatching (mean 3.5 AA vs 2.4 C, P <.001), and delayed graft function (DGF; 50% AA vs 22% C, P =.001).

RESULTS

The 5-year actuarial patient and graft survival rates were 96% AA versus 83% C (P = NS) and 83% AA versus 75% C, (P = NS), respectively. The incidence of acute rejection (21% AA vs 12% C, P = NS) and mean time to acute rejection (12 months AA vs 11 months C) were similar. Although the incidence of chronic allograft nephropathy (CAN) was comparable (7% AA vs 5% C), the mean time to CAN was shorter in AA recipients (18 months AA vs 37 months C, P =.03).

CONCLUSIONS

These results suggest marked improvement in post-transplant outcomes in the TAC era in patients with multiple immunologic risk factors including AA ethnicity, cadaveric donor source, DGF, and HLA mismatching.

Portal-enteric pancreas transplantation at the University of Tennessee, Memphis

The UT Memphis group has made a number of important contributions to the field of PTX, including: 1) pioneering studies on the effects of PTX on autonomic neuropathy, 2) comprehensive reports dealing with quality of life after PTX, 3) seminal studies on the metabolic effects of PTX with portal venous delivery of insulin, 4) refining and perfecting a novel technique of PTX with portal venous drainage of insulin and primary enteric drainage of the exocrine secretions, 5) describing a safe outpatient percutaneous technique of pancreas allograft biopsy, 6) developing the use of glucose tolerance for rejection surveillance, and 7) managing PTX patients with biopsy-directed immunosuppression and no anti-lymphocyte induction therapy. The P-E technique has the potential to become the standard of care in the near future because it is more physiologic, normalizes carbohydrate and lipid metabolism, and minimizes complications attributed to the transplant procedure. In addition, we have been actively involved in studying new immunosuppressive regimens in order to improve and simplify the care of the PTX recipient. We believe that PTX will remain an important treatment option for IDDM until other strategies are developed that can provide equal glycemic control with less or no immunosuppression and less overall morbidity.

A prospective comparison of simultaneous kidney-pancreas transplantation with systemic-enteric versus portal-enteric drainage

OBJECTIVE

To compare pancreas transplantation with systemic-enteric (SE) versus portal-enteric (PE) drainage in a prospective fashion.

SUMMARY BACKGROUND DATA

To improve the physiology of pancreas transplantation, the authors developed a new technique of portal venous delivery of insulin and enteric drainage of the exocrine secretions.

METHODS

During a 26-month period, the authors prospectively alternated 54 consecutive simultaneous kidney and pancreas transplants to either SE (n = 27) or PE (n = 27) drainage. The two groups were well matched for numerous characteristics. Maintenance immunosuppression in both groups consisted of tacrolimus, mycophenolate mofetil, and steroids.

RESULTS

Patient survival rates were 93% SE versus 96% PE; kidney graft survival rates were 93% in both groups. Pancreas transplantation survival (complete insulin independence) was 74% after SE versus 85% after PE drainage with a mean follow-up of 17 months. The mean length of initial hospital stay was 12.4 days in the SE group and 12.8 days in the PE group. The SE group was characterized by a slight increase in the number of readmissions. The incidences of acute rejection (33%) and major infection (52%) were similar in both groups. The incidence of intraabdominal infection was slightly higher in the SE group. However, the early relaparotomy rate was similar between groups. The composite endpoint of no rejection, graft loss, or death was attained in 56% of SE versus 59% of PE patients.

CONCLUSIONS

These results suggest that simultaneous kidney and pancreas transplantation with SE or PE drainage can be performed with comparable short-term outcomes.

Patterns of cytomegalovirus infection in simultaneous kidney-pancreas transplant recipients receiving tacrolimus, mycophenolate mofetil, and prednisone with ganciclovir prophylaxis

BACKGROUND

The impact of tacrolimus (TAC), mycophenolate mofetil (MMF) and steroid immunosuppression on cytomegalovirus (CMV) infection in combination with ganciclovir prophylaxis in simultaneous kidney-pancreas transplantation (SKPT) has not been well studied.

METHODS

A retrospective analysis was made of 75 SKPTs performed between 1 January 1996 and 7 January 1999. All patients received ganciclovir for 3 months, but CMV donor (D)+ / recipient (R)- patients received ganciclovir for 6 months.

RESULTS

16/74 (22%) were CMV D+/R-, 25 (33%) D+/R+, 16 (22%) D-/R+, and 17 (23%) D-/R- (1 patient with unknown donor serology was excluded). The mean time to CMV infection was 198 days post-transplant. The incidence of either CMV infection or tissue invasive CMV disease was 16/74 (22%), including 9 (12%) with CMV infection and 7 (10%) CMV disease. The one-year patient, kidney, and pancreas graft survival rates were 91%, 89%, and 83%, respectively. The mean follow-up was 29 months (minimum of 12 months). CMV infection was not associated with an increased incidence of graft failure or mortality. The D+/R- group had the highest incidence of CMV infection (44%) compared with the other serologic groups (17%, P=0.02). Concurrent CMV and rejection occurred more frequently in the D+/R- than the other serologic groups (25% vs. 7%, P=0.03). The D-/R- group had the best outcomes, with no CMV infection, improved kidney graft survival at the end of follow-up (82% vs. 72%, P=0.04) and the highest event-free survival (no CMV infection, rejection, or graft loss) when compared to the other groups (76% vs. 33%, P<0.01).

CONCLUSIONS

Compared to previous studies, ganciclovir prophylaxis delayed the onset and reduced the severity of CMV infection in patients receiving TAC, MMF, and steroids. Despite ganciclovir prophylaxis, CMV seronegative patients receiving CMV D+ organs had worse outcomes than seronegative recipients receiving CMV D- organs.

Outcomes of simultaneous kidney-pancreas transplantation in African-American recipients: a case-control study

INTRODUCTION

Previous studies have suggested that African-American (AA) ethnicity is a risk factor for rejection and graft loss after kidney transplantation. However, little data is available regarding outcomes after simultaneous kidney pancreas transplantation (SKPT) in AA recipients. The objective of this study was to compare the outcomes of SKPT in AA patients to matched Caucasian patients as controls.

METHODS

From January 1996 to September 1999, we performed 79 SKPTs, including 10 in AA recipients. Ten Caucasian controls were selected and matched for age, gender, weight, timing and technique of transplantation, and immunosuppressive regimen. Clinical outcomes were collected and compared between the two groups.

RESULTS

The two groups were well matched for donor and recipient demographic, immunologic and transplant characteristics, including 2 patients in each group with type 2 diabetes. All patients received tacrolimus (TAC), mycophenolate mofetil (MMF) and steroids, and about half in each group received antibody induction therapy. Patient survival was 100% in both groups with a mean follow-up of 18 months (range 6 47). Kidney and pancreas graft survival rates were both 80% in the AA and 100% in the Caucasian groups, respectively (p = 0.14). All but one kidney (in the AA group) and all pancreas grafts experienced immediate function. There were two immunologic kidney and two immunologic pancreas graft losses in the AA group. No grafts were lost due to technical problems. The mean length of initial hospital stay was 16 d in the AA group compared to 10 d in the Caucasian group (p = 0.07). The AA group had a slight increase in the number of readmissions (mean 2.2 AA vs. 1.6 Caucasian, p = 0.08). The incidence of biopsy-proven pancreas acute rejection was significantly higher in the AA group (50%) compared to the Caucasian group (10%) (p = 0.05). The incidence of either kidney or pancreas acute rejection was also higher in the AA group (60% AA vs. 20% Caucasian, p = 0.06). TAC levels were comparable at specific times after transplantation, al-though there was a trend toward higher doses of TAC in the AA group to achieve therapeutic levels. The incidences of relaparotomy (30% AA vs. 20% Caucasian) and major infection (40% AA vs. 60% Caucasian) were similar between groups. Renal and pancreas allograft functions were comparable between groups at specific times after transplantation.

CONCLUSIONS

These results suggest that SKPT in AA recipients may be associated with a higher incidence of rejection and immunologic graft loss compared to matched Caucasian controls.

Temporal correlation of tumor necrosis factor-alpha release, upregulation of pulmonary ICAM-1 and VCAM-1, neutrophil sequestration, and lung injury in diet-induced pancreatitis

Lung injury is a major cause of patient morbidity in acute pancreatitis. The purpose of this study was to examine the mechanism of pulmonary infiltration and lung injury in acute pancreatitis. Mice were fed a choline-deficient/ethionine-supplemented (CDE) diet for 144 hours to induce severe acute pancreatitis. Serum samples were collected for measurement of biochemical markers of disease and for the detection of tumor necrosis factor-alpha (TNF-alpha). Cell surface adhesion molecule expression was quantified by the sensitive radiolabeled dual monoclonal antibody technique. Neutrophil sequestration in lung tissue was measured by the myeloperoxidase assay. Lung injury was determined histologically and lung edema was assessed by wet/dry ratios. Pancreatic injury was demonstrated to occur in all CDE-fed mice, which developed significant hyperamylasemia and hypoglycemia by 48 hours (P <0.0001). Serum TNF-alpha levels increased significantly by 48 hours over baseline values (P <0.02). Expression of intracellular adhesion molecule (ICAM-1) in pulmonary endothelia was significantly increased above baseline by 30% at 48 hours (P <0.02) and peaked at 120 hours by 100% (P <0.0001). Vascular cellular adhesion molecule (VCAM-1) was constitutively expressed at baseline and was upregulated threefold by 48 hours (P <0.0001). Neutrophil infiltration increased gradually 24 hours after ICAM-1 and VCAM-1 were upregulated with significant elevation of myeloperoxidase activity over baseline at 72 hours (7.2 +/- 1.2 vs. 18.1 +/- 2.2 activity units/gram tissue; P <0.05). Neutrophil infiltration peaked at 144 hours (26.24 +/- 10.49 activity units/gram tissue P <0.0001), and its kinetics correlated with the onset and progression of morphologic injury as well as increased lung edema. These results show that acute pancreatitis is associated with a systemic release of inflammatory cytokines, followed by increased expression of pulmonary ICAM-1 and VCAM-1, neutrophil infiltration, and histologic lung injury. The adhesion molecule axis may be a potential target for practical intervention to ameliorate lung injury and morbidity in acute pancreatitis.

A prospective comparison of systemic-bladder versus portal-enteric drainage in vascularized pancreas transplantation

BACKGROUND

Most pancreas transplants are performed with systemic venous delivery of insulin and bladder drainage of the exocrine secretions (systemic-bladder [S-B]). To develop a more physiologic procedure, we performed pancreas transplantations with portal venous delivery of insulin and enteric drainage of the exocrine secretions (portal-enteric [P-E]).

METHODS

During an 11-month period, we prospectively alternated 32 consecutive pancreas transplant recipients to either S-B (n = 16) or P-E (n = 16) drainage with standardized immunosuppression.

RESULTS

Patient, kidney, and pancreas graft survival rates after simultaneous kidney-pancreas transplantation were 91% S-B versus 92% P-E, 91% S-B versus 92% P-E, and 82% S-B versus 92% P-E, respectively. Pancreas graft survival rates after solitary pancreas transplantation were 80% S-B versus 75% P-E. There were no graft losses either to immunologic or infectious complications in either group, but the incidence of acute rejection was slightly higher in the S-B group (44% S-B vs 31% P-E, P = NS). The cost and length of the initial hospital stay were similar between groups. The incidence of operative complications, major infections, and cytomegalovirus infections were likewise comparable. However, the S-B group was characterized by a slight increase in the number of readmissions, urinary tract infections, and urologic complications. Furthermore, metabolic acidosis and dehydration were more common in the S-B group.

CONCLUSIONS

Pancreas transplantation with P-E drainage can be performed with short-term results comparable to those of transplantation with S-B drainage.

Simultaneous kidney-pancreas transplantation without antilymphocyte induction

BACKGROUND

The introduction of potent new immunosuppressive agents may allow simultaneous kidney-pancreas transplantation to be performed without antilymphocyte induction.

METHODS

We analyzed 30 simultaneous kidney-pancreas transplantations receiving tacrolimus, mycophenolate mofetil, and steroids without without antilymphocyte induction. Eighteen patients underwent pancreas transplantation with portal-enteric (P-E) drainage and the remaining 12 had systemic bladder (S-B) drainage. Target 12 hr trough tacrolimus levels for the first 3 months after simultaneous kidney-pancreas transplantation were 15-20 ng/ml. The oral mycophenolate mofetil dose was 2-3 g/day begun immediately posttransplant in two to four divided doses. Steroids were tapered according to protocol.

RESULTS

All patients experienced immediate function of both kidney and pancreas grafts. One-year actuarial patient, kidney, and pancreas graft survival rates are 93, 93, and 90%, respectively. Nine patients (30%) had a total of 13 rejection episodes (12 biopsy proven) including 4 within 2 weeks, 6 between 2 weeks and 3 months, and 3 beyond 3 months after simultaneous kidney-pancreas transplantation. Three rejection episodes were treated with steroids alone and 10 were treated with antilymphocyte therapy (5 OKT3 and 5 ATGAM). A total of seven patients (23%) received antilymphocyte therapy. Three patients (10%) had more than one rejection episode. Two pancreas grafts (7%) and one kidney graft (3%) were lost from rejection. Four patients (13%) developed cytomegalovirus infection, but none had tissue-invasive cytomegalovirus. At present, 22 surviving patients (81%) remain on triple immunosuppression with tacrolimus, mycophenolate mofetil, and prednisone with excellent dual graft function.

CONCLUSION

Tacrolimus, mycophenolate mofetil, and prednisone immunosuppression without without antilymphocyte induction is safe and effective after simultaneous kidney-pancreas transplantation.

Experience with portal-enteric pancreas transplant at the University of Tennessee-Memphis

The UT-Memphis Group has made a number of important contributions to the field of PTX including: 1. Pioneering studies on the effects of PTX on autonomic neuropathy;(15, 16) 2. Comprehensive reports dealing with quality of life after PTX;(17, 18, 38) 3. Seminal studies on the metabolic effects of PTX with portal venous delivery of insulin;(33,34) 4. Refining and perfecting a novel technique of PTX with portal venous drainage of insulin and primary enteric drainage of the exocrine secretions;(2,6,11,19) 5. Describing a percutaneous technique of pancreas biopsy;(20) and 6. Pioneering the use of glucose tolerance for rejection surveillance.(24) The P-E technique has the potential to become the standard of care in the near future because it is more physiologic, normalizes carbohydrate and lipid metabolism, and minimizes complications attributed to the transplant procedure. In addition, we have been actively involved in studying new immunosuppressive regimens in order to improve and simplify the care of the PTX recipient. We believe that PTX will remain an important option in the treatment of IDDM until other strategies are developed that can provide equal glycemic control with less or no immunosuppression or less overall morbidity.

Correlation of histology to clinical rejection reversal: a thymoglobulin multicenter trial report

Correlation of histology to rejection reversal: A Thymoglobulin Multicenter Trial report

BACKGROUND

Histology may provide a link between clinical response to antirejection therapy and graft function. In a subset of centers, renal biopsy was a secondary end point for the Thymoglobulin Multicenter Trial.

METHODS

Thirty-eight patients had a protocol biopsy one to two weeks following the end of therapy. Inclusion and post-treatment biopsies were graded and scored according to Banff criteria by a central pathologist who was blinded to the type and outcome of therapy and the timing of the biopsy.

RESULTS

The majority of patients (31 of 38) had moderate rejection on their inclusion biopsy. An improvement of at least one Banff grade occurred in 58% of the patients. The treatment was clinically successful in 33 patients, but two thirds of the patients (25 out of 38) demonstrated residual inflammation in the graft. The degree of improvement of inflammation was proportionate to rejection severity (P = 0.006). Banff scoring indicated that residual inflammation was less in Thymoglobulin-treated patients than in those receiving Atgam (P < 0.05) and correlated with the incidence of recurrent rejection (P = 0.015).

CONCLUSIONS

These data demonstrate a discrepancy between clinical and histological resolution of acute renal allograft rejection. Residual infiltrates in the graft following rejection therapy are common and, despite clinical improvement, may indicate an increased risk for recurrent rejection.

The US multicenter double-blind, randomized, phase III trial of thymoglobulin versus atgam in the treatment of acute graft rejection episodes following renal transplantation: rationale for study design

In this study intended to establish equivalence between two antibody therapies for acute rejection in kidney transplant recipients, it was important to develop a rigorous protocol. Assurance of the presence of acute rejection was imperative. Therefore, due to the lack of literature support for clinical assessment of renal dysfunction, histologic diagnosis of acute rejection was required for enrollment in the study. Likewise, supportive literature for a correlation between response to anti-rejection therapy and the severity of rejection lead to the decision that the study should be stratified by a measurement of rejection severity for which Banff criteria were used. Finally, quantification of the response to therapy was also measured against the available literature and a large, newly developed international database of kidney transplant rejection episodes (the Efficacy Endpoints database) where serum creatinine, expressed as a percentage of the baseline level at the time of rejection was shown to be the most effective, available clinical marker of rejection response. Therefore, the US Multicenter Phase III Trial for comparing Thymoglobulin to Atgam in the treatment of acute rejection exhibits a unique and detailed study design that could be implemented in future trials as well as in clinical practice to improve assessment of outcomes.

Evolution in pancreas transplantation techniques: simultaneous kidney-pancreas transplantation using portal-enteric drainage without antilymphocyte induction

OBJECTIVE

To report initial experience with the combination of a novel technique of portal-enteric pancreas transplantation with newer immunosuppressive strategies that eliminate antilymphocyte induction therapy.

BACKGROUND

A new surgical technique of pancreas transplantation has been developed with portal venous delivery of insulin and enteric drainage of the exocrine secretions (portal-enteric). The introduction of potent immunosuppressive agents may allow simultaneous kidney and pancreas transplants (SKPT) to be performed without antilymphocyte induction.

METHODS

From September 1996 to November 1998, the authors performed 28 primary SKPTs with portal-enteric drainage and no antilymphocyte induction. All patients received triple immunosuppression with tacrolimus, mycophenolate mofetil, and steroids. The study group had a mean age of 38 years and a mean preoperative duration of diabetes of 25 years. Four patients (14%) had prior kidney transplants.

RESULTS

All patients had immediate renal allograft function. Actual patient, kidney, and pancreas graft survival rates were 86%, 82%, and 82%, respectively, after a mean follow-up of 12 months. Four patients died, three as a result of cardiac events unrelated to SKPT. Five kidney and five pancreas grafts were lost, including five deaths with function and three cases of chronic rejection. The mean length of stay and total charges for the initial hospital stay were 12.5 days and $99,517. The mean number of readmissions was 2.9, and 10 patients (36%) had no readmissions. Six patients (21 %) developed acute rejection, with five (18%) receiving antilymphocyte therapy. Seven patients (25%) underwent relaparotomy, including two (7%) for intraabdominal infection. Nine patients (32%) had major infections, including three (11%) with cytomegaloviral infection. Of the 24 surviving patients, 22 (92%) are both dialysis- and insulin-free.

CONCLUSION

These preliminary results suggest that SKPT with portal-enteric drainage without antilymphocyte induction can be performed with excellent outcomes.

The use of positive B cell flow cytometry crossmatch in predicting rejection among renal transplant recipients

We performed retrospective flow cytometry crossmatch (FCXM) on 106 renal graft recipients who were transplanted based on current T cell negative serologic crossmatch. T and B cell FCXMs were performed on current and historical peak reactive post-transplant sera using 1024-channel flow cytometer and the shift in median channel fluorescence (SMCF) over the negative control was calculated. Cut-off values for a positive T and B crossmatch, > 40 and > 80 SMCF, respectively, were determined based on previous retrospective analysis of the data in the context of clinical outcome in our center, and were 1.5 times the standard deviation (SD) above the mean median channel fluorescence (MCF) of normal sera controls. The 1-yr graft survival was 95% for the total group of patients studied, and 87% for the recipients who had a positive T cell FCXM. To focus on the influence of a positive B cell FCXM on the incidence of rejection, primary transplant recipients who had a negative T cell FCXM (n = 81) were studied. Fifteen of 30 (50%) recipients with a positive B cell FCXM experienced at least one rejection episode within the first year. By contrast, only 15 of 51 (29.4%) of patients with a negative B cell FCXM experienced rejection (p = 0.05). The mean B cell SMCF in the group of patients who had no rejections was 45 +/- 59, while that of the group of patients who experienced at least one rejection was 97 +/- 97 (p = 0.012). By comparison, the rejection rate among the retransplant patients was 44.4%, and the mean B cell SMCF in the group with rejection was 94 +/- 75 while it was 5 +/- 7 among retransplant patients who did not have rejection (p = 0.031). Eighty-six percent of sensitized (panel reactivity antibodies (PRA) > 10%) patients who had a B positive/T negative FCXM experienced rejection, compared to 33% (n = 6 out of 16) of the B negative/T negative sensitized patients (p = 0.03). Furthermore, 62% (n = 13 out of 21) of donor-recipient mismatched patients with a B positive/T negative FCXM experienced rejection, compared to 38% (n = 13 out of 35) of patients with T negative/B negative FCXM who were similarly mismatched (p = 0.064). These data demonstrate the value of a positive B cell FCXM for predicting post-transplant rejections particularly when evaluated in the context of prior sensitization and/or DR mismatching. Our results suggest that B cell FCXM may have significant clinical implications, justifying its use in post-transplant management of recipients who have other risk factors of rejection.

The Banff 97 working classification of renal allograft pathology

BACKGROUND

Standardization of renal allograft biopsy interpretation is necessary to guide therapy and to establish an objective end point for clinical trials. This manuscript describes a classification, Banff 97, developed by investigators using the Banff Schema and the Collaborative Clinical Trials in Transplantation (CCTT) modification for diagnosis of renal allograft pathology.

METHODS

Banff 97 grew from an international consensus discussion begun at Banff and continued via the Internet. This schema developed from (a) analysis of data using the Banff classification, (b) publication of and experience with the CCTT modification, (c) international conferences, and (d) data from recent studies on impact of vasculitis on transplant outcome.

RESULTS

Semiquantitative lesion scoring continues to focus on tubulitis and arteritis but includes a minimum threshold for interstitial inflammation. Banff 97 defines "types" of acute/active rejection. Type I is tubulointerstitial rejection without arteritis. Type II is vascular rejection with intimal arteritis, and type III is severe rejection with transmural arterial changes. Biopsies with only mild inflammation are graded as "borderline/suspicious for rejection." Chronic/sclerosing allograft changes are graded based on severity of tubular atrophy and interstitial fibrosis. Antibody-mediated rejection, hyperacute or accelerated acute in presentation, is also categorized, as are other significant allograft findings.

CONCLUSIONS

The Banff 97 working classification refines earlier schemas and represents input from two classifications most widely used in clinical rejection trials and in clinical practice worldwide. Major changes include the following: rejection with vasculitis is separated from tubulointerstitial rejection; severe rejection requires transmural changes in arteries; "borderline" rejection can only be interpreted in a clinical context; antibody-mediated rejection is further defined, and lesion scoring focuses on most severely involved structures. Criteria for specimen adequacy have also been modified. Banff 97 represents a significant refinement of allograft assessment, developed via international consensus discussions.

Results of the double-blind, randomized, multicenter, phase III clinical trial of Thymoglobulin versus Atgam in the treatment of acute graft rejection episodes after renal transplantation

BACKGROUND

Thymoglobulin, a rabbit anti-human thymocyte globulin, was compared with Atgam, a horse anti-human thymocyte globulin for the treatment of acute rejection after renal transplantation.

METHODS

A multicenter, double-blind, randomized trial with enrollment stratification based on standardized histology (Banff grading) was conducted. Subjects received 7-14 days of Thymoglobulin (1.5 mg/kg/ day) or Atgam (15 mg/kg/day). The primary end point was rejection reversal (return of serum creatinine level to or below the day 0 baseline value).

RESULTS

A total of 163 patients were enrolled at 25 transplant centers in the United States. No differences in demographics or transplant characteristics were noted. Intent-to-treat analysis demonstrated that Thymoglobulin had a higher rejection reversal rate than Atgam (88% versus 76%, P=0.027, primary end point). Day 30 graft survival rates (Thymoglobulin 94% and Atgam 90%, P=0.17), day 30 serum creatinine levels as a percentage of baseline (Thymoglobulin 72% and Atgam 80%; P=0.43), and improvement in posttreatment biopsy results (Thymoglobulin 65% and Atgam 50%; P=0.15) were not statistically different. T-cell depletion was maintained more effectively with Thymoglobulin than Atgam both at the end of therapy (P=0.001) and at day 30 (P=0.016). Recurrent rejection, at 90 days after therapy, occurred less frequently with Thymoglobulin (17%) versus Atgam (36%) (P=0.011). A similar incidence of adverse events, post-therapy infections, and 1-year patient and graft survival rates were observed with both treatments.

CONCLUSIONS

Thymoglobulin was found to be superior to Atgam in reversing acute rejection and preventing recurrent rejection after therapy in renal transplant recipients.

Acute pancreatitis induces cytokine production in endotoxin-resistant mice

OBJECTIVE

The purpose of this study was to determine whether pathologic progression and cytokine responses in acute pancreatitis (AP) are altered in the absence of endotoxemia.

SUMMARY BACKGROUND DATA

Previous studies have demonstrated that AP is characterized by rapid production and release of inflammatory cytokines, which play a major role in the local pancreatic and systemic complications of this disease. Infection and endotoxemia have been implicated as a major source of morbidity and death in AP and as possible stimuli for the overwhelming cytokine response seen in this disease.

METHODS

AP was induced by a choline-deficient and ethionine-supplemented diet for 4 days in normal C57BL/6J mice (controls, n = 23) and in CD14 knockout mice (CD14KO, n = 23), which cannot produce circulating cytokines in response to endotoxin. Control and endotoxin-resistant mice were killed at time 0, then at 24, 48, 72, and 96 hours after the start of the diet. At each time point serum was collected for amylase, glucose, and cytokine measurements (tumor necrosis factor-alpha [TNFalpha] and interleukin-1beta [IL1beta]), and the pancreas was removed for histologic examination. TNFalpha was measured with a bioassay using WEHI-2F cells and IL1beta with a bioassay using D10.G4.1 cells.

RESULTS

CD14KO mice developed biochemical manifestations of AP with alterations in amylase levels, hypoglycemia, weight loss, and histologic changes of pancreatitis similar to the pattern seen in control mice. TNFalpha and IL1beta production had similar kinetics in both groups, with significant peak TNFalpha serum levels at 72 hours and a progressive rise of IL1beta levels throughout the study period. Histologic changes appeared earlier and were more pronounced in the control versus the CD14KO mice. However, the mortality rate was identical (20% at 96 hours) for both groups.

CONCLUSIONS

These results demonstrate that the progression of AP, the cytokine response associated with the disease, and early death are independent of endotoxin action. These findings, which suggest that an uncharacterized stimulus is responsible for triggering the cytokine cascade in this disease, may have significant implications for the management of patients with AP.

Role of renal allograft biopsy in multicenter clinical trials in transplantation

There is current agreement that in the design of prospective clinical trials, patients should be assigned to various treatment groups based on histological diagnosis of acute renal allograft rejection. The Banff schema is satisfactory in reporting and grading histology for patient entry into clinical trials, particularly in multicenter studies because it standardizes the entry and randomization criteria and maintains reproducibility of the histological Interpretation between the different centers. It should be emphasized that for biopsy specimens to be effective tools for either clinical practice or clinical trials, they need to be obtained before therapeutic intervention and handled by experienced histopathology laboratory technicians. Adequate tissue sampling is necessary for diagnosis and for proper grading of rejection. It is recommended that a minimum of two cores of renal tissue are needed to avoid underestimation of rejection grade. Banff classification considers a biopsy specimen to be adequate if it contains seven or more glomeruli and at least a single artery. Examination of serial step sections through the tissue samples is crucial to identify focal lesions of toxicity and to properly score intimal arteritis and tubulitis. In addition, fast interpretation of the biopsy by an experienced nephropathologist or a transplant pathologist within 24 hours optimizes the utilization of the biopsy-acquired information. At the present time, it is premature to decide on the role of graft histology as an endpoint in clinical trials, but posttreatment biopsies should be encouraged in large, multicenter, prospective trials because they may be our only tools to study postrejection changes. Semiquantitative biopsy reporting systems should be routinely included in clinical databases to allow for the prospective examination of structure-function relationships and long-term outcomes following acute rejection.

Patterns of acute rejection in portal-enteric versus systemic-bladder pancreas-kidney transplantation

Portal-enteric (PE) transplantation of the pancreas allograft provides maintained physiologic drainage, and theoretically the portal delivery of transplantation antigens may have beneficial effects on the graft acceptance leading to improved graft survival. To determine whether the technique of pancreas placement affects the incidence of acute rejection we reviewed our experience in technically successful PE and systemic-bladder (SB) drained simultaneous pancreas and kidney (SPK) transplants performed between 1989 and 1994. Forty-seven recipients were included (SB = 30, PE = 17). All patients received cyclosporine based quadruple immunosuppression and survived at least 1 month. The two groups were comparable in HLA mismatches, cold ischemia time and level of immunosuppression at time of rejection. In the SB group the incidence of rejection was 1.04 kidney rejection/patient and 0.90 pancreas rejection/patient whereas the PE group experienced 0.53 kidney rejection/patient and 0.47 pancreas rejection/patient. The two groups were compared using incidence density statistics due to great variation in follow-up time. The SB group had a significant higher density of both kidney and pancreas rejections (p < or = 0.037 for kidney rejection and 0.058 for pancreas rejection). In addition, while 6 of 30 (20%) pancreas grafts and 4 of 30 (13%) kidney grafts were lost to irreversible rejection in the SB group, only 1 of 17 (6%) pancreas graft and 1 of 17 (6%) kidney graft were lost in the PE group. These data demonstrate, that the PE placement of pancreas allograft affects the rates of acute rejection and graft loss, and imply that there exist some important immunological advantages when the pancreas graft is drained into the portal circulation.

Utility of standardized histological classification in the management of acute rejection. 1995 Efficacy Endpoints Conference

BACKGROUND

Standardized histological grading of transplant kidney biopsies has become a primary criterion for diagnosis of rejection in immunosuppression clinical trials.

METHODS

A consortium of 19 transplant centers from North America, Europe, and Australia convened in 1995 to examine kidney transplant rejection. Data from the 1995 Efficacy Endpoints Conference were examined for frequency of adoption of Banff schema. Biopsy grading was correlated with clinical parameters of rejection and therapy response.

RESULTS

Histological confirmation of rejection episodes occurred in 73% of 953 cases, with Banff criteria adoption increasing in frequency between 1992 and 1995. Banff grading significantly correlated with clinical rejection severity (rejection creatinine: grade I, 2.8+/-0.2 mg/dl; grade II, 3.5+/-0.2 mg/dl; grade III, 4.1+/-0.3 mg/dl; P < 0.001), although nadir creatinines were similar. Response rates of Banff grades I and II to steroid therapy were not different, but only 42% of grade III rejections responded to steroids (P < 0.003. Banff grading also correlated with postrejection creatinine, day 15: grade I, 2.2+/-0.2 mg/dl; grade II, 3.0+/-0.2 mg/dl; grade III, 3.8+/-0.4 mg/dl (P < 0.001), and day 30: grade I, 2.1+/-0.1 mg/dl; grade II, 2.2+/-0.2 mg/dl; grade III, 2.7+/-0.2 mg/dl (P < 0.06). Banff grade III correlated with reduced graft survival at 1 year: grade I, 86%; grade II, 88%; grade III, 70% (P < 0.01).

CONCLUSIONS

This multicenter review of rejection severity confirms that standardized histologic classifications such as the Banff schema provide a reliable means for stratifying patient risk of treatment success or failure. These data support the use of Banff criteria in clinical trial design.

Use of glucose disappearance rates (kG) to monitor endocrine function of pancreas allografts

We have reported that a decline in glucose disappearance rate (kG) in pancreas transplant recipients is associated with pancreatic rejection. The purpose of this study was to determine test-retest reliability of kG monitoring and to establish the kG criteria for diagnosing abnormal graft function. Six healthy non-diabetic volunteers and 14 stable pancreas recipients underwent 2 intravenous glucose tolerance tests 7 d apart. All kG values in non-diabetic volunteers had < 15% variation between the two determinations (r = 0.96, P < or = 0.0006). Similarly, 13/14 recipients experienced < 20% variation in kG with one patients experiencing a 23% variation (r = 0.90, P < or = 0.0001). Using a 20% change from baseline as the reference value, we monitored 28 pancreas recipients for 2-36 months post-transplant. Of 253 kG values, 160 (64%) did not exceed the 20% change from baseline, 65 (26%) declined > 20% and 28 (11%) increased > 20%. Of 160 stable kG values, 154 (96%) were associated with normal graft function while 6 (4%) occurred in the context of rejection. Of 65 kG values declining by > or = 20%, 47 (72%) accurately identified acute rejections diagnosed by biopsy (70%) or response to treatment (30%), 12 (19%) were associated with identifiable causes of increased insulin resistance and only in 6 (9%) cases a cause for the decline was unidentifiable. The kG values with > 20% rise from baseline were, in 15%, associated with identifiable causes of decreased insulin resistance. The sensitivity of the kG as a marker for rejection was 88.7%, specificity 91%, positive predictive value 72.3%, negative predictive value 96.8%, and accuracy 90.5%. These data confirm that a > 20% deterioration of glucose disappearance rate is associated with pancreas allograft rejection, and confirms the utility of kG monitoring in clinical follow-up of pancreas transplant recipients.

Recovery from ischemic acute renal failure is improved with enteral compared with parenteral nutrition

OBJECTIVE

To compare measurements of renal function after acute ischemic renal failure in rats fed enterally or parenterally.

DESIGN

Prospective, randomized, animal trial.

SETTING

University research laboratory.

SUBJECTS

Male Sprague-Dawley rats (n = 21).

INTERVENTIONS

Animals were randomized to receive isocaloric (160 nonprotein kcal/kg/day), or isonitrogenous (1.4 g of nitrogen/kg/day [100 mmol/kg/day]) enteral (n = 10), or parenteral nutrition (n = 11) through either a gastrostomy tube or a catheter placed in the jugular vein. After the animals received 7 days of assigned feedings, baseline blood samples were collected. A right nephrectomy and 45-min left renal pedicle occlusion were then performed. One hour after the ischemic injury, assigned feedings were resumed and continued for 3 days. After ischemic injury, daily blood samples were obtained and 24-hr urine collections were performed. On day 11, animals were killed and the kidney was harvested and fixed for subsequent microscopic examination.

MEASUREMENTS AND MAIN RESULTS

Urine was analyzed for concentrations of total urea nitrogen, creatinine, protein, and calcium. Serum was analyzed for creatinine and urea nitrogen concentrations. Fixed kidney sections were examined for mitotic figures, tubular calcifications, and casts using light microscopy by an investigator blinded to the nutritional regimen. Data are presented as mean +/- SD or median (range). Percent increase in creatinine clearance from the nadir on day 9 to day 11 was approximately 2.5-fold greater in the enteral compared with the parenteral nutrition group (490 +/- 221% vs. 208 +/- 130%; p = .003). Histologic evaluation demonstrated greater dystrophic tubular calcifications per ten high-power fields in the parenteral compared with the enteral nutrition group (50 [four to 85] vs. three [0 to 37]; p = .001). No differences in urine calcium concentration or 24-hr calcium excretion were seen.

CONCLUSION

Rats given continuous enteral nutrition 7 days before and for 3 days after ischemic acute renal failure have improved renal function compared with rats given parenteral nutrition.

Increased recognition of IgA nephropathy in African-American children

Based upon the percentage of cases of IgA nephropathy (IgAN) in biopsy series, a lower prevalence has been assumed for African-Americans compared with Americans of European descent. This may be due to a racial difference in the basic underlying pathology of IgAN or to racial differences in patterns of referral and biopsy selection practices. Over the past decade (1985-1994), we have found similar incidences of IgAN in Caucasian and African-American children from Shelby County, Tennessee. The incidence was 3.0 cases per million per year for Caucasian and 5.7 cases per million per year for African-American children. IgAN may be more common in African-American children than previously appreciated. Population-based incidence studies will be necessary to determine whether or not our experience has become a more widespread phenomenon.

Routine early biopsy of allografts with delayed function: correlation of histopathology and transplant outcome

Approximately 25-30% or our cadaveric renal transplant recipients have required post-transplant dialysis. In an attempt to discern the etiology, routine biopsies were performed 7-10 d post-transplant and repeated weekly. All patients received a triple-therapy cyclosporine-based regimen with (N = 61) or without (N = 10) antilymphocyte induction. Rejection was classified as 'early' when it appeared on the first biopsy (8.9 +/- 0.3 d), 'delayed' when it appeared only on the second biopsy (17.9 +/- 1.0 d) and persistent when present on both biopsies. Adequate biopsy material was obtained from 71 patients who provided a total of 117 biopsies. Acute tubular necrosis was the most common finding (50%) in the first biopsy, while rejection occurred in 30% of biopsies. Rejection on the first biopsy was strongly associated with primary nonfunction (PNF) (8 of 21 vs. 1 of 40, p < or = 0.0001). In contrast, eight patients without rejection on Biopsy 1 developed delayed rejection on Biopsy 2; only one was associated with PNF. DGF persisted beyond the second week in 38 patients; 17 (38%) of which had rejection. Nine patients had persistent rejection 55% of whom experienced PNF compared to 6% without persistent rejection (p < or = 0.001). The occurrence of early rejection was associated with pretransplant peak PRA levels > 50% (p < or = 0.01). Graft survival for all patients was 79% and 65% at 1 and 2 yr. Rejection influenced 1-yr graft survival for patients with persistent rejection who had 55% incidence of primary nonfunction and 1- and 2-yr graft survival rates of 42% and 37%. These data indicate that early biopsies are useful in unmasking rejection during DGF and at predicting primary nonfunction. Based on these data we recommend the routine utilization of biopsies for all patients with DGF.

Calcium channel blockade inhibits release of TNF alpha and improves survival in a rat model of acute pancreatitis

Tumor necrosis factor-alpha (TNF alpha) has been implicated as one of the numerous likely mediators of the systemic complications of acute pancreatitis. Recent suggestions that calcium (Ca2+) acts as a signal not only for TNF alpha release but also for TNF alpha action at distant sites led us to hypothesize that the calcium channel blocker diltiazem could inhibit TNF alpha release in acute pancreatitis, ameliorating the severity of the disease and improving overall survival. A rat model of acute pancreatitis induced by retrograde ductal infusion of bile was used for two experiments (n = 120). Experiment 1 was designed to determine the effects of calcium channel blockade using diltiazem on the severity of pancreatitis as measured by changes in biochemistry, pathology, and serum TNF alpha levels. In experiment 2, effects of calcium channel blockade on animal survival were measured over 72 h. Calcium channel blockade was associated with a significant reduction in serum TNF alpha levels as well as amelioration of pancreatitis by biochemical and pathological criteria. Overall survival from bile-induced pancreatitis was dramatically improved in rats pretreated with diltiazem (80%) compared to untreated animals (40%). Our data suggest that calcium channel blockade is associated with TNF alpha inhibition and improved outcome in a rat model of acute pancreatitis.

The correlation of Banff scoring with reversibility of first and recurrent rejection episodes

Recurrent acute rejection remains a significant problem for recipients of renal allografts, with a large proportion of patients progressing to graft loss. The newly introduced Banff schema was used to determine whether the histologic pattern of acute rejection (severity and renal compartment scoring) could discriminate recurring from nonrecurring rejections and to examine whether objective rejection scoring had predictive value for rejection reversal and outcome. A total of 67 biopsies obtained from 50 patients with acute rejection were examined for the occurrence of recurrent allograft rejection. All patients were maintained on a cyclosporine-based triple immunosuppressive protocol and had biopsy-proven acute rejection without chronic changes. Rejection recurred in 13 patients (26%), of whom 4 further developed a third rejection. The majority of the patients developed this first rejection within 2 months posttransplantation. Demographics, prebiopsy renal function, immunosuppression, and peak serum creatinine level at the time of biopsy were similar in patients with multiple and single rejection. Peak levels of reactivity to panel of lymphocytes seemed higher in the group of patients with recurrent rejection, whereas HLA matching was similar for all patients. Banff scores for acute rejection did not discriminate patients at risk of rejection recurrence who had lower vascular (0.6 vs. 1.2), tubular (0.6 vs. 1.1), and lower cumulative SUM (3.0 vs. 4.5) scores on their first rejection when compared with patients with one rejection. Histological scoring was, however, significantly different when first and third episodes were compared in the same patient, indicating increased rejection severity with recurrence. Moreover, the rate of reversal of recurrent rejection by anti-lymphocyte therapy was significantly less than that of first rejection (P<0.05). In conclusion, these data demonstrate that Banff scoring correlated with rejection reversal and steroid responsiveness, yet rejection recurrence was independent of histological score of the first rejection. Furthermore, Banff schema provided an objective histological correlation to the poor clinical outcome seen with recurrent rejection. The data also suggest that patients with early mild rejection continue to be at risk for recurrence and graft loss.

Intragraft angiotropic large-cell lymphoma of T cell-type in a long-term renal allograft recipient

Chronic immune suppression is a risk for the development of post-transplantation lymphoproliferative disorders, which are frequently caused by a B-cell dyscrasia. We report a unique primary presentation of the rare angiotropic lymphoma in a kidney allograft, 18 years after transplantation. The diagnosis was made by a percutaneous allograft biopsy specimen when the recipient presented with renal dysfunction and intermittent hematuria. Immunostaining of the biopsy specimen revealed a T-cell lineage of the neoplastic cells rather than the more common B-cell source. At the time of biopsy, there was no evidence of systemic dissemination of lymphoma. The intragraft lymphoma resolved completely after chemotherapy, but the patient died 6 months later as a result of an intracerebral hemorrhage. At autopsy, intravascular lymphoma was only found in the cerebral vessels. To the authors' knowledge, this is the first report of angiotropic T-cell lymphoma in a kidney allograft. A description of the clinical, pathologic, and immunohistochemical features of this case is provided, as well as reviews of previous reports of renal angiotropic lymphoma and post-transplantation T-cell lymphomas.