Application of TruGraf v1: A Novel Molecular Biomarker for Managing Kidney Transplant Recipients With Stable Renal Function

TruGraf v1 is a laboratory-developed DNA microarray-based gene expression blood test to enable proactive noninvasive serial assessment of kidney transplant recipients with stable renal function. It has been previously validated in patients identified as Transplant eXcellence (TX: stable serum creatinine, normal biopsy results, indicative of immune quiescence), and not-TX (renal dysfunction and/or rejection on biopsy results). TruGraf v1 is intended for use in subjects with stable renal function to measure the immune status as an alternative to invasive, expensive, and risky surveillance biopsies.

MATERIALS AND METHODS

In this study, simultaneous blood tests and clinical assessments were performed in 192 patients from 7 transplant centers to evaluate TruGraf v1. The molecular testing laboratory was blinded to renal function and biopsy results.

RESULTS

Overall, TruGraf v1 accuracy (concordance between TruGraf v1 result and clinical and/or histologic assessment) was 74% (142/192), and a result of TX was accurate in 116 of 125 (93%). The negative predictive value for TruGraf v1 was 90%, with a sensitivity 74% and specificity of 73%. Results did not significantly differ in patients with a biopsy-confirmed diagnosis vs those without a biopsy.

CONCLUSIONS

TruGraf v1 can potentially support a clinical decision enabling unnecessary surveillance biopsies with high confidence, making it an invaluable addition to the transplant physician's tool kit for managing patients. TruGraf v1 testing can potentially avoid painful and risky invasive biopsies, reduce health care costs, and enable frequent assessment of patients with stable renal function to confirm the presence of immune quiescence in the peripheral blood.

Investigator Assessment of the Utility of the TruGraf Molecular Diagnostic Test in Clinical Practice

BACKGROUND

TruGraf v1 is a well-validated DNA microarray-based test that analyzes blood gene expression profiles as an indicator of immune status in kidney transplant recipients with stable renal function.

METHODS

In this study, investigators assessed clinical utility of the TruGraf test in patient management. In a retrospective study, simultaneous blood tests and clinical assessments were performed in 192 patients at 7 transplant centers, and in a prospective observational study they were performed in 45 subjects at 5 transplant centers.

RESULTS

When queried regarding whether or not the TruGraf test result impacted their decision regarding patient management, in 168 of 192 (87.5%) cases the investigator responded affirmatively. The prospective study indicated that TruGraf results supported physicians' decisions on patient management 87% (39/45) of the time, and in 93% of cases physicians indicated that they would use serial TruGraf testing in future patient management. A total of 21 of 39 (54%) reported results confirmed their decision that no intervention was needed, and 17 of 39 (44%) reported that results specifically informed them that a decision not to perform a surveillance biopsy was correct.

CONCLUSIONS

TruGraf is the first and only noninvasive test to be evaluated for clinical utility in determining rejection status of patients with stable renal function and shows promise of providing support for clinical decisions to avoid unnecessary surveillance biopsies with a high degree of confidence. TruGraf is an invaluable addition to the transplant physician's tool kit for managing patient health by avoiding painful and invasive biopsies, reducing health care costs, and enabling frequent assessment of patients with stable renal function to confirm immune quiescence.

New-Onset Diabetes After Transplantation: Results From a Double-Blind Early Corticosteroid Withdrawal Trial

New-onset diabetes after transplantation (NODAT) is an important complication following kidney transplantation. Data from the 5-year early steroid withdrawal double-blind randomized trial were analyzed to determine if steroid avoidance reduced the NODAT risk. Incidence, timing and risk factors for NODAT were evaluated using eight definitions. By American Diabetes Association definition, 36.3% of patients on chronic corticosteroids (CCS) and 35.9% on early corticosteroid withdrawal (CSWD) were diagnosed with NODAT by 5 years. The definition combining fasting blood glucose ≥126 mg/dL on two occasions or treatment identified slightly more cases of NODAT: CCS (39.3%) and CSWD (39.4%). Through 5 years posttransplant, the proportion of NODAT patients requiring treatment were similar (CSWD 22.5% vs. CCS 21.5%); however, insulin therapy was lower with CSWD (3.7% vs. 11.6%; p = 0.049). By multivariate analysis, only age, but not corticosteroid use, was a significant risk factor for NODAT for more than one definition. Numerical, but not statistically significant trends toward lower NODAT rates with CSWD were observed through 5 years for insulin use, HbA1c ≥6.0% and ≥6.5% on two occasions. This prospective, randomized trial of CSWD indicates that CSWD has a limited impact in reducing NODAT when compared to low-dose prednisone (5 mg/day from month 6 to 5 years).

Physiochemical properties of generic formulations of tacrolimus in Mexico

Tacrolimus is an important immunosuppressive agent used to prevent allograft rejection after transplantation. Tacrolimus has a narrow therapeutic index; therefore, it is essential that the physicochemical properties of generic formulations be identical to the brand-name formulation, Prograf. In this study, the physicochemical properties of generic tacrolimus formulations were compared with Prograf. The drug dissolution profiles of generic formulations of tacrolimus were different from that of Prograf. Tacrobell and T-Inmun exhibited faster dissolution than Prograf, and Tenacrine, Framebin, and Talgraf showed slower and incomplete drug dissolution, releasing 24% to 51% of tacrolimus within 2 hours. Generic formulations of tacrolimus demonstrated decreased solubility compared with Prograf. The solubility of Prograf was 35.7 microg/mL at 2 hours and 29.5 microg/mL at 24 hours. The solubility of Tenacrine, Framebin, and Talgraf at 2 hours was 5.5, 12.6, and 7.8 microg/mL, respectively, and the solubility decreased to 0.5, 2.3, and 2.1 microg/mL, respectively, at 24 hours. Whereas Prograf demonstrated content uniformity, the content of the generic tacrolimus formulations varied widely. The standard deviation of content for Tenacrine, Tacrobell, and T-Inmun were high at 29.3, 6.9, and 5.6, respectively. Furthermore, the mean percentage of labeled amount of T-Inmun was 84.2% with a relative standard deviation of 6.7% (minimum value; 72.7%; maximum value; 100.7%). These results indicate that generic formulations of tacrolimus tested in this study are not bioequivalent to Prograf, which suggests that their use may be of potential risk to transplant patients.

Once-daily tacrolimus extended-release formulation: 1-year post-conversion in stable pediatric liver transplant recipients

The pharmacokinetics, safety and tolerability of a once-daily formulation of tacrolimus (tacrolimus extended-release formulation; XL formerly referred to as MR or MR4) were assessed in 18 stable pediatric liver transplant recipients who were converted from the twice-a-day formulation of tacrolimus (TAC) to XL. Patients received their twice-a-day dose of TAC on study days 1 through 7. Beginning on the morning of study day 8, patients were converted to XL on a 1:1 (mg:mg) basis for their total daily dose, and were maintained on a once-daily AM dosing regimen using the same therapeutic monitoring and patient care techniques employed with TAC. Based on pharmacokinetic profiles obtained on study days 7 (TAC) and 14 (XL), steady state exposure (AUC(0-24)) was equivalent between XL and TAC; the mean XL/TAC ratio for lnAUC(0-24) was 100.9% (90% CI: 90.8%, 112.1%). AUC(0-24) and C(min) were strongly correlated at steady state (correlation coefficient: XL 0.90, TAC 0.94). During the first year post-conversion, there were no cases of acute rejection, discontinuation of XL, graft loss or death. The safety profile of XL was consistent with that known for TAC. These results support the safe and convenient conversion of pediatric liver transplant recipients from twice-a-day TAC to once-daily XL.

Posttransplant lymphoproliferative disorder: significance of central nervous system involvement

BACKGROUND

Few data exist regarding central nervous system (CNS) involvement in patients with posttransplant lymphoproliferative disorder (PTLD). The purpose of this study was to review the Israel Penn International Transplant Tumor Registry (IPITTR) experience with CNS involvement by PTLD.

METHODS

Nine hundred ten PTLD cases from the United States were reported to the IPITTR and reviewed for CNS involvement.

RESULTS

One hundred thirty-six transplant recipients with PTLD (15%) had CNS involvement. The highest incidence of CNS involvement occurred in pancreas (3 of 11; 27%) and kidney transplant recipients (76 of 429; 18%). Fifteen cases occurred in children and 121 cases in adults. For both children and adults, isolated CNS disease was associated with better survival when compared with multiple-site involvement (children: 29% vs 0%; adults: 12% vs 6%; P < .05). Three-year survival in PTLD patients with CNS involvement was 9.4% and without CNS involvement was 49.4% (P < .01). Radiation therapy alone appeared to provide the best survival rates (25%).

CONCLUSIONS

CNS involvement in transplant recipients with PTLD carries an ominous prognosis; however, isolated CNS involvement has a better prognosis than CNS plus extracranial involvement. Radiation therapy alone provides the best results, but this may be a reflection of isolated CNS disease.

Conversion of stable liver transplant recipients from a twice-daily Prograf-based regimen to a once-daily modified release tacrolimus-based regimen

INTRODUCTION

Modified release (MR) tacrolimus is an extended release formulation administered once daily. The purpose of this pharmacokinetic (PK) study was to evaluate tacrolimus exposure in stable liver transplant recipients converted from Prograf twice a day to MR tacrolimus once daily.

METHODS

This was an open-label, multicenter study with a single sequence, four-period crossover design. Eligible patients were 18 to 65 years of age, >6 months posttransplant with stable renal and hepatic function and receiving stable doses of Prograf twice a day for >2 weeks prior to enrollment. Patients received Prograf twice a day on days 1 to 14 and 29 to 42. Patients were converted to the same milligram-for-milligram daily dose of MR once daily on days 15 to 28 and 43 to 56. Twenty-four-hour PK profiles were obtained on days 14, 28, 42, and 56. Laboratory and safety parameters were also evaluated.

RESULTS

Of 70 patients, 62 completed all four PK profiles. The AUC0-24 of tacrolimus was comparable for Prograf twice a day (days 14 and 42) and MR tacrolimus once daily (days 28 and 56). The 90% confidence intervals for MR tacrolimus versus Prograf at steady state (days 28 and 56 vs days 14 and 42) was 0.85 to 0.92 for AUC0-24. MR tacrolimus was well tolerated with a safety profile comparable to that of Prograf. AUC0-24 was highly correlated to Cmin for Prograf (day 14, r = .93; Day 42, r = .89) and for MR tacrolimus (day 28, r = .93; day 56, r = .92). Renal and liver function remained stable. One patient experienced acute rejection.

CONCLUSION

The steady-state tacrolimus exposure of MR tacrolimus once daily is equivalent to Prograf twice a day after a milligram-for-milligram conversion in stable liver transplant recipients.

Chemotherapy for posttransplant lymphoproliferative disorder: the Israel Penn International Transplant Tumor Registry experience

INTRODUCTION

Very little published data exist regarding the results of chemotherapy treatment of posttransplant lymphoproliferative disorder (PTLD). The purpose of the study was to review the Israel Penn International Transplant Tumor Registry experience with PTLD treated with chemotherapy.

METHODS

Patients with PTLD who received chemotherapy were identified and data collected regarding demographics, tumor characteristics, recurrence rates, and survival.

RESULTS

One hundred ninety three solid organ transplant recipients with PTLD who received chemotherapy were identified. Most patients were male (142:51) and Caucasian (148; 16 AA, 29 unspecified). Most PTLD were B-cell predominant (81%), monoclonal (71), and CD 20+ (60% of patients tested). Organ transplanted included: kidney, 92 (48%); heart, 54 (28%); liver, 30 (16%); pancreas, 8 (4%); and lung, 9 (5%). Median time to presentation posttransplant was 24.5 months (range 0.8 to 226.5 months). Ninety patients received CHOP, 12 ProMACE, 65 other multidrug regimens, and 23 patients received single-agent chemotherapy. Five-year survival for these four regimens were: 24%, 25%, 32%, and 5%. PTLD-specific death rates were 34%, 34%, 40%, and 48%.

CONCLUSIONS

Single-agent chemotherapy appears to be inferior to other chemotherapy regimens for PTLD as it is associated with lower survival.

Conversion of stable kidney transplant recipients from a twice daily Prograf-based regimen to a once daily modified release tacrolimus-based regimen

Modified release (MR) tacrolimus is an extended release formulation administered once daily (qD). The purpose of this pharmacokinetic (PK) study was to evaluate tacrolimus exposure in stable kidney transplant recipients converted from Prograf twice a day to MR tacrolimus qD.

METHODS

This was an open-label, multicenter study with a crossover design. Eligible patients were 18 to 65 years of age, more than 6 months posttransplant with stable renal function, and received stable Prograf doses more than 2 weeks prior to enrollment. Patients received Prograf twice a day through day 7; 24-hour PK profiles were obtained on days 1 and 7. Patients were converted to the same milligram-for-milligram daily dose of MR tacrolimus qD in the morning on day 8; 24-hour PK profiles were obtained for MR tacrolimus on days 8, 14, and 21. Laboratory and safety parameters were also evaluated.

RESULTS

Most patients (67 of 70) completed all 5 PK profiles. The 90% confidence intervals (CI) for the MR tacrolimus vs Prograf comparison at steady state (days 14 and 21 vs days 1 and 7) were 90.7 and 99.4 for AUC0-24 and 82.7 and 91.9 for Cmin. MR tacrolimus was well tolerated with a safety profile comparable to that of Prograf. AUC0-24 was highly correlated to Cmin for Prograf (day 1, r = 0.80; day 7, r = 0.84) and MR tacrolimus (day 14, r = 0.92; day 21, r = 0.86). Renal function remained stable after conversion to MR tacrolimus.

CONCLUSION

The steady state PK of MR tacrolimus are equivalent to Prograf after a milligram-for-milligram conversion in stable kidney transplant recipients. The results provide evidence to support a safe 1:1 conversion from Prograf twice a day to MR tacrolimus.

Donor Kidneys With Small Renal Cell Cancers: Can They Be Transplanted?

INTRODUCTION

The purpose of this study was to determine whether incidentally discovered, small renal cell cancers (RCC) in donor kidneys can be excised and safely transplanted.

METHODS

The Israel Penn International Transplant Tumor Registry database was searched and all small RCC that were identified and resected prior to transplantation of deceased and living donor kidneys were reviewed. Patient demographics, tumor characteristics, recurrence, and survival were examined.

RESULTS

Fourteen kidneys were identified in which small RCC were noted at the time of procurement and where the tumors were excised ex vivo and then transplanted. Eleven kidneys were obtained from living related donors and three were from deceased donors. Median tumor size was 2 cm (range 0.5 to 4 cm). All 14 tumors were of histological Furhman grade II/VI (n = 8) or Furhman grade I/VI (n = 6). All kidneys had pathologically confirmed negative margins. The mean age of the recipients was 40.8 +/- 9.2 years, with the majority being men (11 men; 3 women). Median follow-up for this group was 69 months (range 14 to 200 months). There have been no recurrences of tumor in these recipients and the 1-, 3-, and 5-year patient and graft survivals are 100%, 100%, and 93%.

CONCLUSIONS

These data represent the only data available (to our knowledge) on this issue. This experience indicates that donor kidneys with small, incidental RCC and low histological grade (Furhman grade I and II/IV) can be managed with excision and transplantation, with a low risk of tumor recurrence in the recipient.

Prostate Cancer Prior to Solid Organ Transplantation: The Israel Penn International Transplant Tumor Registry Experience

INTRODUCTION

Prostate adenocarcinoma (PCA) is the second leading cause of cancer-related deaths in men, and with routine prostrate specific antigen (PSA) screening, is being diagnosed with increasing frequency. To date, reported experiences with transplantation in men with a history of PCA are limited to only a few patients. This study presents the first series of transplant recipients with a history of PCA.

METHODS

Analysis of transplant recipients with a history of pretransplant PCA was performed on the Israel Penn International Transplant Tumor Registry database. PCA were staged using American Joint Committee on Cancer criteria. Statistics analysis was performed by chi-square and Student t tests.

RESULTS

Ninety patients with preexisting PCA were identified: 77 renal, 10 heart, and three liver transplant recipients. Mean age at PCA diagnosis was 61.3 +/- 6.3 years. Median interval between diagnosis and transplantation was 19.3 months, and median follow-up after transplantation was 20.5 months. Median time to PCA recurrence was 10.6 months after transplantation and median survival time with recurrent PCA was 49.2 months after transplant. Patient mortality was 28.8%, and PCA-related death rate was 7.8%. PCA recurrence rate was 17.7%. Tumor recurrence rates in stage I and II disease (14 and 16%) were lower than in stage III disease (36%).

CONCLUSIONS

In conclusion, death rate to disease other than PCA is three times that due to PCA. PCA recurrence rates are relatively low in patients who initially presented with stage I and II disease, and are half that of patients with stage III disease.

African American Renal Transplant Recipients Benefit From Early Corticosteroid Withdrawal Under Modern Immunosuppression

African Americans have historically been considered high-risk renal transplant recipients due to increased rejection rates and reduced long-term graft survival. Modern immunosuppression has reduced rejections and improved graft survival in African Americans and may allow successful corticosteroid withdrawal. Outcomes in 56 African Americans were compared to 56 non-African Americans enrolled in early withdrawal protocols. Results are reported as African American versus non-African American. Acute rejection at 1 year was 23% and 18% (P = NS), while patient and graft survival was 96% versus 98% and 91% versus 91% (P = NS), respectively. In conclusion, early withdrawal in African Americans is associated with acceptable rejection rates and excellent patient and graft survival, indicating that the risks and benefits of early withdrawal are similar between African Americans and non-African Americans. Additional followup is needed to determine long-term renal function, graft survival, and cardiovascular risk in African Americans with early steroid withdrawal.

Transmission of donor cancer into cardiothoracic transplant recipients

BACKGROUND

The demand for transplantable organs exceeds donor supply. Patients with central nervous system (CNS) or other tumors are controversial donors, and the donor cancer transmission rates in cardiothoracic transplant recipients have not been determined. The Israel Penn International Transplant Tumor Registry (IPITTR) was queried to define the risk of donor cancer transmission in cardiothoracic transplant recipients.

METHODS

All heart, lung, or heart-lung recipients of organs from donors with a history of malignancy were reviewed. Donor and recipient demographics, histologic findings, and recurrence were reviewed.

RESULTS

Twenty-two patients received 17 hearts, 3 lungs, and 2 heart-lung transplants from donors with known CNS or other malignancies. No malignancy transmissions were noted with astrocytomas (n = 3) or glioblastomas (n = 1), except a medulloblastoma that recurred at 6 months. The transmission rate for CNS tumors was 17% (1 of 6), and 1- and 3-year survivals were 67% and 50%, respectively. The most common non-CNS donor cancer was renal cell carcinoma (n = 5). Two renal cell cancer transmissions occurred, both when vascular extension was present. The most aggressive tumor transmission was choriocarcinoma (n = 2) and melanoma (n = 2). Two of 3 choriocarcinomas metastasized with 67% mortality, and both melanomas were transmitted and resulted in death. Other donor cancers included angiosarcoma (n = 2), cervical (n = 1), lung (n = 1), prostate (n = 1), and a liver adenocarcinoma. The transmission rate for all non-CNS groups was 56% (9 of 16) with a 2-year survival of 40%.

CONCLUSIONS

The IPITTR experience indicates that tumor transmission is high (10 of 22, 45%) in cardiothoracic transplant recipients. Similar to intra-abdominal organ recipients in the IPITTR, (1) renal cell carcinomas without capsular invasion appear safe with no transmission, (2) vascular invasion in renal cell carcinoma appears to result in early tumor transmission, and (3) melanoma and choriocarcinoma have high rates of transmission with early and almost universal death.

Strategies to minimize immunological and nonimmunological risk factors in the renal transplant population

To improve long-term outcome after renal transplantation, attention should be placed on the tailored use of immunosuppressive regimens that have a more favorable impact on the immunological and nonimmunological risk profiles of an individual recipient. Tacrolimus is widely used for maintenance and rejection immunosuppression in solid organ transplantation, and compared with cyclosporine, its use in renal transplantation is associated with a reduced incidence and severity of acute rejection and a more positive effect on known cardiovascular risk factors. Recent experience with tacrolimus-based therapy has demonstrated an improved lipid profile and lower arterial blood pressure, with less requirement for lipid-lowering and antihypertensive medication compared with cyclosporine, without significantly increasing the risk of long-term insulin-dependent posttransplant diabetes mellitus. The advantageous effects of tacrolimus on both immunological and nonimmunological risk factors offer potential benefits for long-term graft function and survival.

Oral arginine improves blood pressure in renal transplant and hemodialysis patients

BACKGROUND

Hypertension in kidney transplant (KT) patients may result from attenuated whole-body nitric oxide (NO) content and abnormal NO-mediated vasodilation. Increasing NO bioavailability with L-arginine (ARG) could theoretically restore the NO-mediated vasodilatory response and lower blood pressure.

METHODS

In a prospective pilot study, 6 normotensive volunteers and 10 KT patients received oral supplements of ARG (9.0 g/d) for 9 days, then 18.0 g/d for 9 more days. Six hemodialysis (HD) and 4 peritoneal dialysis patients received the same dose for 14 days. Five KT patients received 30 mL/d of canola oil (CanO) in addition to ARG. Systolic (SBP) and diastolic (DBP) blood pressure, creatinine clearance (CCr), and serum creatinine (Cr) were measured at baseline, day 9, and day 18. In a subsequent study, 20 hypertensive KT patients with stable but abnormal renal function were randomized in a crossover study to start ARG-only or ARG+CanO supplements for two 2-month periods with an intervening month of no supplementation. SBP, DBP, CCr, and Cr were measured monthly for 7 months.

RESULTS

In the pilot study, ARG reduced the SBP in HD patients from 171.5 +/- 7.5 mmHg (baseline) to 142.8 +/- 8.3 mmHg (p = .028). In the crossover study, SBP was reduced from baseline (155.9 +/- 5.0 mmHg), after the first 2 months (143.2 +/- 3.2 mmHg; p = .03) and subsequent 2 months (143.3 +/- 2.5 mmHg; p = .014) of supplementation. DBP was also reduced after supplementation in both studies. CanO had no effect on blood pressure. Renal function did not change.

CONCLUSIONS

Oral preparations of ARG (+/-CanO) were well tolerated for up to 60 consecutive days and had favorable effects on SBP and DBP in hypertensive KT and HD patients.

Recent advances in immunosuppressive therapy for renal transplantation

Recent advances in immunosuppression have focused on more effective, safer, and targeted therapies that have resulted in improved short- and intermediate-term renal allograft survival. During the past decade there has been a marked decrease in acute rejection rates following renal transplantation because of the use of newer immunosuppressive agents. Recent data indicate that the average yearly reduction in the relative hazard of graft failure beyond 1 year was 4.2% for all recipients (0.4% for those recipients who had an acute rejection episode and 6.3% for those who did not have an acute rejection). Despite these improvements the currently available immunosuppressive agents are associated with significant cardiovascular risk factors, an increased risk of infection, and the development of malignancies in the long term. Predictive parameters of donor-specific hyporesponsiveness are needed so as to allow identification of patients in whom immunosuppressive therapy can be safely reduced. Immunosuppressive agents that have recently been approved for use in the United States and those that are in clinical and preclinical studies are discussed.

Immediate allograft dysfunction due to atheroembolic disease

Atheroembolic disease is a known cause of renal failure following invasive vascular procedures in patients with atherosclerosis. It is, however, not generally associated with renal transplant dysfunction. We report on a case of donor-transmitted atheroembolic renal disease, which led to an immediate loss of the transplant kidney in the operating room. Risk factors associated with this condition and methods to prevent this complication are discussed.

HPV subtype analysis in lower genital tract neoplasms of female renal transplant recipients

OBJECTIVE

Immunocompromised patients, such as female renal transplant recipients, have an increased incidence of neoplasms involving the lower genital tract (i.e., cervix, vagina, vulva). The relationship between lower genital tract neoplasms and human papillomavirus (HPV) infection has been established and high-risk oncogenic subtypes have been identified (HPV 16, 18, 45, and 56). The purpose of this study is to evaluate HPV subtypes present in lower genital tract neoplasms of post renal transplant women and compare HPV subtypes found in these patients with immunocompetent patients having similar neoplasms and normal immunocompetent controls.

METHODS

Twenty specimens from lower genital tract neoplasms of 16 renal transplant patients, 13 specimens from 13 immunocompetent patients with similar histology, and 13 patients with normal lower genital tract histology were analyzed for the presence of HPV using polymerase chain reaction. HPV primers including the L1 (late) region consensus primers and primers specific for the HPV E6 (early) region for subtypes 6, 11, 16, and 18 were amplified with DNA from the above patient samples.

RESULTS

Overall, HPV was detected in 21/46 specimens tested. Thirteen of the HPV-positive specimens were from transplant patients, and 8 were from immunocompetent patients (5 immunocompetent with disease and 3 normal patients). This difference in the total number of HPV-positive cases was statistically significant between the transplant and immunocompetent group (P = 0.02). Although no difference in HPV 6 and/or 11 was detected between the two groups, HPV subtypes 16 and/or 18 approached statistical significant difference (P = 0.06).

CONCLUSIONS

High-risk oncogenic HPV subtypes 16 and/or 18 were found at a higher rate in transplant patients compared with their immunocompetent counterparts. The combination of immunocompromise and increased HPV 16 and/or 18 positivity may place these patients at increased risk for aggressive lower genital tract neoplastic progression.

Economic cost of expanded criteria donors in cadaveric renal transplantation: analysis of Medicare payments

BACKGROUND

The use of expanded criteria donors (ECDs) in cadaveric renal transplantation is increasing in the US. We assess the economic impact of the use of ECDs to the Medicare end stage renal disease program.

METHODS

The United Nations for Organ Sharing renal transplant registry was merged to Medicare claims data for 42,868 cadaveric renal transplants performed between 1991-1996 using USRDS identifiers. Only recipients for whom Medicare was the primary payer were considered, leaving 34,534 transplants. An ECD was defined as (1) age < or =5 or > or =55 years, (2) nonheart-beating donors, donor history of (3) hypertension or (4) diabetes. High-risk recipients (HRR) were age >60 years, or a retransplant. Medicare payments from the pretransplant dialysis period were projected forward to provide a financial "breakeven point" with transplantation.

RESULTS

There were 25,600 non-HRR transplants, with 5,718 (22%) using ECDs, and 8,934 HRR transplants, of which 2,200 (25%) used ECDs. The 5-year present value of payments for non-ECD/non-HRR donor/recipient pairings was $121,698 vs. $143,329 for ECD/non-HRR pairings (P<0.0001) and, similarly was $134,185 for non-ECD/HRR pairings vs. $165,716 for ECD/HRR pairings (P<0.0001). The break even point with hemodialysis ranged from 4.4 years for non-ECD/ non-HRR pairings to 13 years for the ECD/HRR combinations but was sensitive to small changes in graft survival. Transplantation was always less expensive than hemodialysis in the long run.

CONCLUSIONS

The impact of ECDs on Medicare payments is most pronounced in high-risk recipients. Cadaveric renal transplantation is a cost-saving treatment strategy for the Medicare ESRD program regardless of recipient risk status or the use of ECDs.

Recommendations for bioequivalence testing of cyclosporine generics revisited

The immunosuppressant cyclosporine is generally considered a critical-dose drug. The validity of standard criteria to establish bioequivalence between cyclosporine formulations has recently been challenged. Recommendations included establishment of individual bioequivalence rather than average bioequivalence, establishment of bioequivalence in transplant patients and in subgroups known to be poor absorbers, as well as long-term efficacy and safety studies in transplant patients. However, at the moment individual bioequivalence is a theoretical concept, the practical benefits of which have not statistically been proven. The proposed patient pharmacodynamic studies can be expected to require an unrealistically high number of subjects to achieve sufficient statistical power. It is well established that the common practice of blood-concentration-guided dosing of cyclosporine efficiently compensates for interindividual and intraindividual variability and allows for safely switching cyclosporine formulations as bioinequivalent as Sandimmune and Neoral. Recent studies comparing the generic cyclosporine formulation SangCya with Neoral, including individual bioequivalence, bioequivalence in transplant patients, and long-term safety after switching from Sandimmune to SangCya, confirmed that it was valid to conclude bioequivalence of both cyclosporine formulations based on standard average bioequivalence criteria. Present FDA guidelines for approving bioequivalence can be considered adequate and sufficient for generic cyclosporine formulations.

Merkel's cell carcinoma in organ recipients: report of 41 cases

In the general population Merkel's cell carcinoma (MCC) is an aggressive neuroendocrine skin cancer. More than 600 cases have been reported. MCC seems to be common in transplant recipients, with 41 cases being reported to the Cincinnati Transplant Tumor Registry, and another 11 in the transplant literature. In the general population, it is a disease of older adults, with only 51% of cases occurring below the age of 50 years. In transplant patients, the mean age at diagnosis was 53 (range 33-78) years, and 29% of recipients were <50 years old. The tumor appeared from 5 to 286 (mean 91.5) months after the transplant. Of 44 lesions that occurred in 41 patients, the distribution was similar to that seen in the general population, with 36% occurring on the head and neck, 32% on the upper extremities, 16% on the trunk, 9% at unknown sites, and 7% on the lower extremities. Twenty of the patients (49%) had 22 other malignancies, the great majority of which (91%) were other skin cancers. Treatment depended on the stage of the disease and included wide surgical excision, radical lymph node dissection, radiation therapy, and chemotherapy. In transplant patients, MCC probably proved to be more aggressive than in the general population in that 68% of patients developed lymph node metastases and 56% died of their malignancies. Furthermore, one third of surviving patients still have active cancers from which they may die. Also, follow-up of survivors has been relatively short, with a mean of only 18 (range 0-135) months.

Evaluation of pre- and posttransplant donor-specific transfusion/cyclosporine A in non-HLA identical living donor kidney transplant recipients. Cooperative Clinical Trials in Transplantation Research Group

BACKGROUND

The beneficial effects of donor specific transfusion (DST) have become controversial in the cyclosporine era. This study was performed to evaluate the potential benefits of a new protocol for administering DSTs in the perioperative period.

METHODS

Non-HLA identical living donor kidney transplant recipients were randomized prospectively to control or to receive a DST 24 hr before transplant and 7-10 days posttransplant. All patients received similar immunosuppression according to protocol.

RESULTS

The protocol had 212 evaluable patients (115 transfused and 97 control). There were no differences in 1- and 2-year graft and patient survival, causes of graft failure, incidence and types of infection, repeat hospitalization, or the ability to withdraw steroids. Immunological hyporesponsiveness (by mixed lymphocyte culture) occurred more frequently in transfused patients (18%) than controls (3%) (P = 0.04). Blood stored for > or =3 days was associated with fewer early rejections than blood stored < or =2 days. Overall, class II antigen mismatches were associated with more rejection episodes than class I antigen mismatches. However, transfused patients, but not control patients, with more class I antigen mismatches were more likely to have rejections.

CONCLUSIONS

Administration of DSTs by the method described had no practical influence on patient or graft survival for up to 2 years. However, donor-specific hyporesponsiveness was more common in transfused patients (18 vs. 3%). Longer follow-up will be needed to determine whether DST will be associated with long-term benefit.

A blinded retrospective analysis of renal allograft pathology using the Banff schema: implications for clinical management

BACKGROUND

We sought to determine whether diagnoses established through the Banff schema for evaluation of renal allograft pathology have implications for clinical management, compared with diagnoses established using descriptive terminology.

METHODS

All patients included in this study had mild to severe allograft rejection diagnosed, and, as part of a therapeutic protocol, they received OKT3 as primary anti-rejection therapy. We conducted a retrospective review of their renal allograft biopsy specimens and reclassified them, using the Banff schema, without knowledge of clinical information, laboratory data, or previous biopsy interpretation. Although there is no strict correspondence between descriptive diagnostic terminology and the criteria used in the Banff schema, for the purpose of comparisons, the following approximation was used: mild and mild to moderate rejection=Banff borderline and Banff grade 1, moderate and moderate to severe rejection=Banff grades 2A and 2B, and severe rejection=Banff grade 3. The diagnosis was considered concordant when the diagnosis by descriptive terminology and Banff grading were within the adopted approximation.

RESULTS

Of 96 biopsies specimens with mild to severe allograft rejection, 10 were insufficient for diagnosis, and three had changes of chronic allograft rejection. Of the remaining 83 biopsy specimens, 34 (41%) were concordant in interpretation of rejection grades, whereas 49 (59%) were discrepant. The greatest degree of concordance was in grades 2A (66.7%, 18 of 27) and 2B (64.7% 11 of 17), and the lowest was in the borderline category (11.8%, 2 of 17). The greatest degree of discrepancy was in normal and grade 3 (100%, 3 of 3 and 2 of 2, respectively), and the lowest was in grade 2A (33.3%, 9 of 27). Although primary anti-rejection therapy with OKT3 resulted in a high reversal rate of rejection (98%), there were 5 deaths, 12 graft loses, six episodes of serious infections, and three malignancies in this group of patients during a mean follow-up period of approximately 38 months.

CONCLUSIONS

Because patients with borderline changes and grades 1 and 2A rejection may be treated differently from patients with higher grades (2B and 3), the use of the Banff schema may allow for better adjustment of immunosuppressive therapy in response to specific grades of acute allograft rejection and may result in decreased complications of immunosuppressive therapy.

Recurrent and de novo glomerular disease after renal transplantation: a report from Renal Allograft Disease Registry (RADR)

INTRODUCTION

Short-term and long-term results of renal transplantation have improved over the past 15 years. However, there has been no change in the prevalence of recurrent and de novo diseases. A retrospective study was initiated through the Renal Allograft Disease Registry, to evaluate the prevalence and impact of recurrent and de novo diseases after transplantation.

MATERIALS AND METHODS

From October 1987 to December 1996, a total of 4913 renal transplants were performed on adults at the Medical College of Wisconsin, University of Cincinnati, University of California at San Francisco, University of Louisville, University of Washington, Seattle, and Washington University School of Medicine. The patients were followed for a minimum of 1 year. A total of 167 (3.4%) cases of recurrent and de novo disease were diagnosed by renal biopsy. These patients were compared with other patients who did not have recurrent and de novo disease (n=4746). There were more men (67.7% vs. 59.8%, P<0.035) and a higher number of re-transplants (17% vs. 11.5%, P<0.005) in the recurrent and de novo disease group. There was no difference in the rate of recurrent and de novo disease according to the transplant type (living related donor vs. cadaver, P=NS). Other demographic findings were not significantly different. Common forms of glomerulonephritis seen were focal segmental glomerulosclerosis (FSGS), 57; immunoglobulin A nephritis, 22; membranoproliferative glomerulonephritis (GN), 18; and membranous nephropathy, 16. Other diagnoses include: diabetic nephropathy, 19; immune complex GN, 12; crescentic GN (vasculitis), 6; hemolytic uremic syndrome-thrombotic thrombocytopenic purpura (HUS/TTP), 8; systemic lupus erythematosus, 3; Anti-glomerular basement membrane disease, 2; oxalosis, 2; and miscellaneous, 2. The diagnosis of recurrent and de novo disease was made after a mean period of 678 days after the transplant. During the follow-up period, there were significantly more graft failures in the recurrent disease group, 55% vs. 25%, P<0.001. The actuarial 1-, 2-, 3-, 4, and 5-year kidney survival rates for patients with recurrent and de novo disease was 86.5%, 78.5%, 65%, 47.7%, and 39.8%. The corresponding survival rates for patients without recurrent and de novo disease were 85.2%, 81.2%, 76.5%, 72%, and 67.6%, respectively (Log-rank test, P<0.0001). The median kidney survival rate for patients with and without recurrent and de novo disease was 1360 vs. 3382 days (P<0.0001). Multivariate analysis using the Cox proportional hazard model for graft failure was performed to identify various risk factors. Cadaveric transplants, prolonged cold ischemia time, elevated panel reactive antibody, and recurrent disease were identified as risk factors for allograft failure. The relative risk (95% confidence interval) for graft failure because of recurrent and de novo disease was 1.9 (1.57-2.40), P<0.0001. The relative risk for graft failure because of posttransplant FSGS was 2.25 (1.6-3.1), P<0.0001, for membranoprolifera. tive glomerulonephritis was 2.37 (1.3-4.2), P<0.003, and for HUS/TTP was 5.36 (2.2-12.9), P<0.0002. There was higher graft failure (64.9%) and shorter half-life (1244 days) in patients with recurrent FSGS.

CONCLUSION

In conclusion, recurrent and de novo disease are associated with poorer long-term survival, and the relative risk of allograft loss is double. Significant impact on graft survival was seen with recurrent and de novo FSGS, membranoproliferative glomerulonephritis, and HUS/TTP.

An individual bioequivalence approach to compare the intrasubject variability of two ciclosporin formulations, SangCya and Neoral

A novel bioequivalence testing approach was used to determine intrasubject variability and switchability of two ciclosporin formulations, SangCya (test) and Neoral (reference). Twenty healthy volunteers were enrolled into a single-dose, randomized, open-label, 4-period, 2-sequence study with a crossover replicate design. Subject-by-formulation interaction variances were compared using a mixed effects linear model. Intrasubject variability for ln AUC(0-infinity) and ln C(max) of SangCya and Neoral were not significantly different. The 95% confidence intervals of the intrasubject variability of AUC(0-infinity) (0.94) and C(max) (1.28) as determined using the bootstrap nonparametric percentile method (n = 2,000) were below the individual bioequivalence limit estimated at 2.25. We concluded equivalent intrasubject variability of ciclosporin pharmacokinetics and switchability between SangCya and Neoral.

The evaluation of the safety and tolerability of two formulations of cyclosporine: neoral and sandimmune. A meta-analysis

BACKGROUND

Neoral, a microemulsion formulation of cyclosporine, was approved for use in the United States in 1995. Many studies comparing Neoral and Sandimmune have been conducted, and although most state that Neoral is the superior cyclosporine formulation, results have failed to conclusively demonstrate this claim. The aim of this meta-analysis was to compare the safety and efficacy of Neoral and Sandimmune.

METHODS

Publications comparing the use of Neoral and Sandimmune were reviewed for demographic variables, adverse events, rejection incidence, graft losses, and serum creatinine. Neoral and Sandimmune were compared in all patients and in the following subgroups: (1) age (adult or pediatric), (2) transplant type (kidney, liver, or heart), (3) indication (de novo or stable), and (4) study design (randomized prospective trials versus nonrandomized, blinded versus open-labeled studies).

RESULTS

The rate of graft loss was similar when comparing Neoral and Sandimmune in all analyses. The incidence of rejection was lower in Neoral-treated de novo renal, liver, and cardiac transplants (P<0.05). There were significantly more adverse events in Sandimmune-treated de novo liver transplants than Neoral-treated de novo liver transplants (P<0.00001). When considering only randomized prospective trials, the incidence of rejection was lower in Neoral-treated de novo and stable patients (P<0.05). However, there were more adverse events in Neoral-treated stable patients (P<0.00001). When considering only blinded studies, there were more adverse events in Neoral-treated patients (P<0.05), whereas in open-labeled studies there was no difference in adverse events comparing Neoral and Sandimmune (P=NS).

CONCLUSIONS

Considering all published trials, the data seem to indicate that Neoral therapy is preferred because of a lower rejection incidence, with a trend toward less adverse events. However, when limiting the analysis to only randomized prospective trials, and specifically assessing blinded studies, the data become less clear. Neoral use was associated with more adverse events in blinded studies, and Sandimmune use was associated with more adverse events in open-labeled studies. Careful individual consideration must be given in choosing the best possible cyclosporine formulation.