Living donor kidney transplant recipients and clinical trials: participation profiles and impact on post-transplant care

Many transplant physicians believe that transplant candidates who enroll in clinical trials may have better outcomes than those who do not enroll. We examined a 7-year cohort (1997-2003) of adult primary, non-HLA identical, living donor kidney transplant (LDKT) recipients to determine whether demographic characteristics predisposed to enrollment and whether participation affected posttransplant care intensity and/or allograft function. Overall, 146 of 512 (28.5%) LDKT recipients enrolled in clinical trials. LDKT recipients who were male and those who lived <100 miles from our transplant center were significantly more likely to participate. During the first post-transplant year, study patients (SPs) had more clinic visits (p < 0.0001) and more allograft biopsies (p = 0.024) compared to nonstudy patients (NSPs), but comparable numbers of hospital readmissions and allograft ultrasounds. SPs and NSPs did not differ in 1-year creatinine clearance, delta creatinine or rejection incidence. Overall graft and patient survival were comparable. We conclude that clinical trial participants were disproportionately male, had increased intensity of post-transplant care but comparable outcomes to nonparticipants.

Developments in clinical islet, liver thoracic, kidney and pancreas transplantation in the last 5 years

Although organ transplantation has matured into a proven therapy for end-stage organ failure, the many notable developments of the past 5 years speak to the multitude of remaining challenges. Two new procedures, islet transplantation and adult-to-adult living donor liver transplantation, have emerged to enlarge our therapeutic armamentarium for Type 1 diabetes mellitus and end-stage liver disease, respectively. In cardiac transplantation, the acceptance of ventricular assist devices as destination therapy is a notable event in light of critical shortage of deceased donor organs. Both liver and lung allocation policies have made a dramatic paradigm shift away from waiting time toward the survival benefit of transplantation. Finally, primary threats to post-transplant longevity have gained an increasing share of the spotlight. Recognition of the impact of renal insufficiency for all nonrenal transplant recipients, of recurrent hepatitis C virus for liver recipients, and of accelerated vasculopathy for cardiac have identified novel end points for clinical trials.

Development of an effective sample preparation approach for proteomic analysis of silkworm eggs using two-dimensional gel electrophoresis and mass spectrometry

Sample preparation is still the first and important step toward successful two-dimensional gel electrophoresis (2DE) and identification in proteomics study. The 2DE profiling of eggs of silkworm species by using conventional one-step extraction, however, is unsatisfactory because high-abundance proteins such as egg-specific protein (ESP) and No 30 family (30 KP) in the extract lead to difficulties in detecting most of biologically relevant proteins. Based on the tendency of these abundant proteins to be soluble in Tris-HCl buffer, we report herein a robust approach in which the extract enriched in ESP and 30 KP was fractionationed and mixed with the re-extract of residual pellet in an optimal proportion. In comparison with the one-step method, the 2DE pattern was improved by this new method with over one-third enhancement in spots. A total of 48 unique proteins obtained have been furthermore identified by mass spectrometry (MS) and MS/MS. The identified proteins are found to include heat shock proteins families, ribosomal proteins, disulfide isomerase proteins, Glutathione S-transferase, and elongation factor, etc., which are mainly involved in some important processes. To our knowledge, this is the first time that the several proteins have been detected in silkworm eggs by proteomics means. This simple and reproducible approach would raise the opportunity of discovering and identifying more biomarkers and determining their possible roles in further studies.

Effect of mycophenolate mofetil on rat kidney grafts with prolonged cold preservation

The impact of mycophenolate mofetil (MMF) on initial renal transplant function is not well characterized. We tested how MMF may modulate graft function and survival in a syngeneic rat kidney transplantation model after prolonged cold preservation. Donor kidneys were preserved in University of Wisconsin for either 24 or 39 h prior to transplantation into nephrectomized rats. Recipients received MMF (20 mg/kg/day) or vehicle. Mycophenolic acid (MPA) blood concentrations were measured by high-performance liquid chromatography. The inflammatory response, tubular epithelial proliferation, and histologic damage 3 days post-transplantation were assessed microscopically. In the 24 h cold storage (c.s.) group serum-creatinine was measured. In the 39 h c.s. group 1-week recipient survival was determined. After 24 h of c.s., recipient survival was 100%. The number of T-cell infiltrates was low and not influenced by MMF, whereas renal ED1+ cell infiltration was significantly suppressed by MMF. Tubular cell proliferation was enhanced by MMF. Serum-creatinine levels and renal histology were comparable between MMF and vehicle-treated animals. In the 39 h c.s. group, recipient survival was 20% in MMF-treated vs 90% in vehicle-treated animals (P=0.001). MMF effectively suppressed inflammatory cell infiltration and inhibited tubular cell proliferation. MMF-induced structural damage was most striking in the renal papilla. In rat kidney grafts with moderate preservation injury (24 h c.s.), MMF, given at an immunosuppressive dose, showed predominantly antiinflammatory effects without compromising graft function. In grafts with severe preservation injury (39 h c.s.), MMF caused irreversible structural damage and inhibited tubular cell regeneration resulting in renal failure.

Livin promotes Smac/DIABLO degradation by ubiquitin-proteasome pathway

Livin, a member of the inhibitor of apoptosis protein (IAP) family, encodes a protein containing a single baculoviral IAP repeat (BIR) domain and a COOH-terminal RING finger domain. It has been reported that Livin directly interacts with caspase-3 and -7 in vitro and caspase-9 in vivo via its BIR domain and is negatively regulated by Smac/DIABLO. Nonetheless, the detailed mechanism underlying its antiapoptotic function has not yet been fully characterized. In this report, we provide, for the first time, the evidence that Livin can act as an E3 ubiquitin ligase for targeting the degradation of Smac/DIABLO. Both BIR domain and RING finger domain of Livin are required for this degradation in vitro and in vivo. We also demonstrate that Livin is an unstable protein with a half-life of less than 4 h in living cells. The RING domain of Livin promotes its auto-ubiquitination, whereas the BIR domain is likely to display degradation-inhibitory activity. Mutation in the Livin BIR domain greatly enhances its instability and nullifies its binding to Smac/DIABLO, resulting in a reduced antiapoptosis inhibition. Our findings provide a novel function of Livin: it exhibits E3 ubiquitin ligase activity to degrade the pivotal apoptotic regulator Smac/DIABLO through the ubiquitin-proteasome pathway.

Liver and intestine transplantation in the United States, 1995-2004

Three years of survival data are now available and the impact of the model for end-stage liver disease (MELD) allocation system is becoming clear. After a decline in new registrants to the waiting list in 2002, the number increased to 10 856 new patients in 2004. Since the implementation of MELD, the percentage of patients who have been on the list for 1-2 years has declined from 24% to 19%. There has been a shift upward in the percentage of patients with higher MELD scores on the waiting list. An increasing percentage of adult living donor liver recipients are over the age of 50 years; from 1% in 1997 to 51% in 2004. Parents donating to children (93% of living donors in 1995), represented only 14% in 2004. Long-term adjusted patient survival declined with increasing recipient age in adults following either DDLT or LDLT. Cirrhosis caused by chronic hepatitis C virus (HCV) is the leading indication for liver transplantation and is associated with reduced long-term survival in recipients with HCV compared to those without HCV, 68% at 5 years compared to 76%. Although the intestine waiting list has more than doubled over the last decade, an increasing number of centers now perform intestinal transplantation with greater success.

Characteristics associated with liver graft failure: the concept of a donor risk index

Transplant physicians and candidates have become increasingly aware that donor characteristics significantly impact liver transplantation outcomes. Although the qualitative effect of individual donor variables are understood, the quantitative risk associated with combinations of characteristics are unclear. Using national data from 1998 to 2002, we developed a quantitative donor risk index. Cox regression models identified seven donor characteristics that independently predicted significantly increased risk of graft failure. Donor age over 40 years (and particularly over 60 years), donation after cardiac death (DCD), and split/partial grafts were strongly associated with graft failure, while African-American race, less height, cerebrovascular accident and 'other' causes of brain death were more modestly but still significantly associated with graft failure. Grafts with an increased donor risk index have been preferentially transplanted into older candidates (>50 years of age) with moderate disease severity (nonstatus 1 with lower model for end-stage liver disease (MELD) scores) and without hepatitis C. Quantitative assessment of the risk of donor liver graft failure using a donor risk index is useful to inform the process of organ acceptance.

The Art and Science of Immunosuppression: the Fifth Annual American Society of Transplant Surgeon's State-of-the-Art Winter Symposium

The 2005 American Society of Transplant Surgeons (ASTS) Winter Symposium entitled 'The Art and Science of Immunosuppression' explored ways to maximize existing immunosuppressive protocols and to develop new strategies incorporating novel agents and emerging diagnostic technologies to customize immunosuppression and reduce side effects. Several presentations evaluated steroid withdrawal or avoidance protocols reflecting the significant difficulties of bone loss, glucose control and growth retardation in children associated with long-term steroid use. Calcineurin-inhibitor related renal dysfunction of both native and transplanted kidneys was identified as significant, but no consensus was reached concerning effective prevention. Similarly, recurrence of Hepatitis C following liver transplantation was identified as problematic without identifying a preferred immunosuppressive regimen in this setting. Control of T-cell mediated rejection was found to be excellent, but recognition and treatment of non-T cell causes of allograft damage (i.e. B- or NK-cell mediated) was identified as an area of current interest. Immunosuppressive agents under development, such as those blocking co-stimulation or cytokine signals, and JAK-3 inhibitors were discussed. Finally, the available technologies for molecular and genetic diagnostics and the clinical correlation in the post-transplant setting were discussed.

Detection breadth and limits for potential adventitious/endogenous contaminants in biopharmaceutical processes: a reality check for innovative methods

In this presentation we address the "gold standards" among diagnostic tests used to detect some potential adventitious and endogenous contaminants in human biologics and vaccines, reflecting on the breadth as well as limits of detection of these assays. This perspective may help developers of innovative diagnostics to address the unique needs of this highly regulated industry.

Parathyroid reoperation with use of technetium 99m sestamibi radiolocalization and an intraoperative gamma counter

OBJECTIVE

To describe a new intraoperative technique for localization of abnormal parathyroid tissue.

METHODS

We report a case and discuss the difficulties encountered in reexploration of the neck area.

RESULTS

Parathyroid reoperation remains a formidable challenge to even the most experienced endocrine surgeon. Despite the advances in radiographic imaging and localization techniques, accurate intraoperative identification of abnormal parathyroid tissue in a scarred field with obliterated anatomic planes is frequently tedious and occasionally unsuccessful. In a 48-year-old woman with hyperparathyroidism, extensive exploration of the area identified (on the basis of preoperative magnetic resonance imaging and technetium 99m sestamibi scans) as suspicious for the presence of abnormal parathyroid tissue revealed only an aberrant vein. With use of a handheld gamma counter to provide intraoperative guidance during parathyroid reexploration after preoperative intravenous injection of technetium 99m sestamibi, quick identification of a small, intrathyroidal, fifth gland adenoma responsible for persistent primary hyperparathyroidism was facilitated.

CONCLUSION

Because of suboptimal precision and specificity, current preoperative localization studies can occasionally provide misleading information. Particularly in difficult cases of parathyroid reexploration, an instrument capable of localizing abnormal parathyroid tissue, which can be used intraoperatively with ease, can be an invaluable tool to ensure a safe, expedient, and successful surgical outcome.

Ischemic preconditioning improves rat kidney graft function after severe ischemia/reperfusion injury

Ischemic preconditioning (IP) has been shown to ameliorate renal ischemia reperfusion injury. Using a rat kidney transplantation model we determined if IP improves graft function after prolonged cold storage.

MATERIALS AND METHODS

Syngeneic rat kidneys were divided into two groups. Prior to 42 hours of cold storage in UW and transplantation, one group (n = 10) received IP (15 minutes of warm ischemia/10 minutes of reperfusion), whereas another group (n = 10) received no treatment. Early graft function and 1-week recipient survival were assessed.

RESULTS

Recipient survival was not significantly different between groups [70% (IP) vs 40% (non-IP); P = .28]. IP treatment led to a quicker recovery of renal function. On PODs 3 and 6, serum creatinine levels in the IP group were significantly lower compared with the untreated group. In conclusion, one cycle of IP (15/10) accelerates recovery of renal graft function after severe ischemia reperfusion injury. This simple treatment modality may improve outcomes of renal transplants with prolonged cold storage.

Technical Note: A Rapid Lipid Separation Method for Determining Fatty Acid Composition of Milk

A rapid method for milk lipid separation followed by transmethylation to produce fatty acid methyl esters from bovine milk samples is presented. Fat is separated by a nonsolvent method using centrifugation. The method was compared with the popular hexane:isopropanol solvent extraction method, and fatty acid proportions were statistically identical for both methods. In 108 replicates, variance accounted for by using the 2 methods was of a similar magnitude to variance due to repeat separations or repeat injections onto the gas chromatography column. It is concluded that the proposed method is accurate, simple, rapid, safe, economical, and especially suitable for large numbers of samples.

Experience with steroid-free maintenance immunosuppression in simultaneous pancreas-kidney transplantation

INTRODUCTION

Steroid avoidance is possible in simultaneous pancreas-kidney transplantation with the use of newer immunosuppressive agents and induction therapy. We undertook a retrospective consecutive case review of patients treated at a university tertiary referral center.

METHODS

Medical records of 44 consecutive patients receiving a pancreas-kidney transplant from November 2000 to September 2002 were reviewed. The immunosuppression protocol used in this series of patients consisted of thymoglobulin induction, combined with mycophenolate mofetil, tacrolimus, and sirolimus for maintenance immunosuppression. Steroids were used only while thymoglobulin was given and were typically discontinued by postoperative week 1. Main outcome measures included graft and patient survival rates, rejection rates of the kidney or pancreas, infection rates, and surgical complication rates.

RESULTS

All 44 patients received a kidney-pancreas transplant with systemic venous anastomosis and enteric drainage of the pancreas. Patient kidney, and pancreas survival rates were 95.6%, 93.2%, and 88.7%, respectively. Biopsy-proven pancreas rejection rates at 1 and 6 months posttransplant were 2.3% and 2.3%. Kidney rejection rates at 1 and 6 months were 2.3% and 4.6%. Reasons for patient loss included one death from sepsis and one cardiovascular death. Reasons for kidney loss besides death included a thrombotic microangiopathy. Reasons for pancreas loss included three thromboses, one mild rejection/infection, and one duodenal segment leak with infection. All patients who have been free of rejection have been off steroids for the duration of follow-up.

CONCLUSIONS

Newer immunosuppression protocols without maintenance steroids are possible with minimal rejection in the first 3 months and equivalent patient and graft survival rates compared with earlier protocols utilizing steroids. The potential beneficial long-term impact of steroid avoidance will require further study.

Polyomavirus-Associated nephropathy in simultaneous Kidney-Pancreas transplant recipients: a Single-Center experience

BACKGROUND

With the introduction of more potent immunosuppressive agents, rejection rates have decreased markedly in simultaneous pancreas-kidney transplant (SPK) recipients. However, with more intense immunosuppression, opportunistic infections such as polyoma virus have been more frequent. The purpose of this article is to outline the clinical course of SPK patients who developed documented polyoma infection in the transplanted kidney.

METHODS

A retrospective review of 146 consecutive SPK recipients from 1996 to 2002 was performed. Induction and maintenance immunosuppression, surgical complications, rejection episodes, and opportunistic infections were reviewed. Patients who developed biopsy-proven polyoma virus infection in the renal allograft were identified.

RESULTS

Nine patients (6%) were identified who developed polyoma. All had received induction therapy with either OKT3 (5 mg/d for 10.5 days) or thymoglobulin (5.7 mg/kg). Patients without polyoma had received similar induction. Maintenance immunosuppression included Prograf/MMF in six patients, CsA/MMF in two, and CsA/azathioprine in one. Time to diagnosis was an average of 359.3 days (range 136 to 836) after transplantation. Two patients had undergone treatment for kidney rejection prior to the diagnosis of polyoma. Immunosuppression was decreased in all patients when polyoma was identified, and more recently Cidofovir has been administered. Despite these interventions, five of the nine lost kidney function (creatinine > 5.0 or resumption of dialysis). However, none of the nine developed pancreatic abnormalities as demonstrated by normal blood glucose and amylase and no requirement for exogenous insulin. Two patients underwent LRRT more than 1 year after polyoma diagnosis; both have normal kidney function (Cr < 1.5 mg/dL) at 4 years of follow-up. Polyoma virus was the leading cause of renal loss in this cohort of patients.

CONCLUSIONS

Polyoma is a serious concern for SPK transplant recipients. The pancreas, however, is spared from clinical evidence of infection, and no rejection was noted when immunosuppression was decreased. These graft losses appear to be a penalty of more potent immunosuppression, and a better treatment strategy is needed to prevent renal graft loss when polyoma is diagnosed. Retransplantation can be considered based on our limited experience.

von Willebrand factor binding to platelet glycoprotein Ib-IX-V stimulates the assembly of an alpha-actinin-based signaling complex

BACKGROUND

Pathological shear stress induces platelet aggregation that is dependent on von Willebrand factor (VWF) binding to glycoprotein (Gp)Ib-IX-V and phosphatidylinositol 3-kinase activation. We tested the hypothesis that pathological shear stress stimulates phosphatidylinositol 3,4,5-trisphosphate (PIP3) synthesis by directing the assembly of a molecular signaling complex that includes class IA phosphatidylinositol 3-kinase (PI 3-KIA).

METHODS

Platelets were subjected to 120 dynes cm-2 shear stress in a cone-plate viscometer. Resting and sheared platelets were lyzed, immunoprecipitations of PI 3-KIA performed, or lipids extracted for PIP3 measurements. alpha-Actinin was incubated with phosphatidylinositol 4,5-bisphosphate (PIP2), immunoprecipitated, and used as a substrate for in vitro PI 3-KIA activity.

RESULTS

Pathological shear stress induces biphasic PIP3 production. In resting platelets, PI 3-KIA associates with alpha-actinin and PIP2. After exposure to shear stress, alpha-actinin and PIP2 rapidly disassociate from PI 3-KIA. PI 3-KIA then gradually re-associates with PIP2 and alpha-actinin, and this complex becomes linked to GpIb alpha through the cytoskeleton. PIP3 production and the observed changes in the association between alpha-actinin, PIP2, and PI 3-KIA are inhibited when VWF binding to GpIb alpha is blocked. In a cell-free system, alpha-actinin binds PIP2 and when the alpha-actinin-PIP2 complex is added to platelet PI 3-KIA, PIP3 production is stimulated.

CONCLUSIONS

These results suggest that pathological shear-induced VWF binding to GpIb-IX-V stimulates PIP3 production through the assembly of an alpha-actinin-based complex that colocalizes PI 3-KIA with substrate PIP2.

Prognostic indicators for outcome following rotator cuff tear repair

PURPOSE

To examine the prognostic indicators associated with outcome following rotator cuff surgery.

METHODS

A retrospective evaluation of records on 1120 shoulders (1067 patients) with rotator cuff tear treated by surgery was performed. Preoperative, intra-operative and postoperative factors were analysed by Kendall's Tau-b correlation analysis and logistic regression analysis.

RESULTS

Positive correlations were seen between the type of tear and the number of tendons involved, retraction, age, degeneration, subacromial bone spur, surgical technique, preoperative and postoperative muscle power, surgical outcome, and preoperative abduction on Kendall's Tau-b analysis. There was a positive correlation seen between degenerative change and age, number of tendons involved, retraction, preoperative pain, tear type, and preoperative musclepower on logistic regression analysis. Additionally, positive correlations were seen between good surgical postoperative outcome and postoperative activities of daily living, preoperative pain, postoperative muscle power, preoperative activities of daily living, tear type, preoperative external rotation, preoperative muscle power, number of tendons involved, preoperative pain, and duration of symptoms.

CONCLUSION

Ageing was found to be the major factor in progressive degeneration of the rotator cuff, and should be considered the single most important contributing factor in the pathogenesis of rotator cuff tears. In addition, degenerative tendonopathy appeared the primary pathology in rotator cuff tear, preceding hypertrophic spur formation. Rotator cuff tears are therefore unlikely to be initiated by impingement; rather, they develop as an intrinsic degenerative tendonopathy.