Comprehensive Complication Index to Monitor Morbidity and Mortality After Liver Transplantation in Primary Sclerosing Cholangitis

OBJECTIVE

The objective of this study was to investigate the short-term and long-term morbidity after liver transplantation (LTx) in patients with primary sclerosing cholangitis (PSC).

BACKGROUND

PSC is a common indication for LTx in Scandinavia. Recently, research has focused on long-term survival and morbidity. The Comprehensive Complication Index (CCI) precisely describes postsurgical complications, by considering both number and severity.

PATIENTS AND METHODS

Two patient groups were compared: those with classical PSC symptoms (n=148) and those with increased risk of cholangiocarcinoma (n=51, premalignant group). Two CCI scores were calculated, at 1-year post-LTx and a cumulative overall score at the latest follow-up. In addition, we investigated factors potentially related to high CCI.

RESULTS

The 1-year median CCI were 29.6 and 26.2 in the classical and premalignant groups, respectively ( P =0.308). The median overall CCI were 43.2 and 46.8 ( P =0.765), respectively. Patient survival was significantly lower in patients with 1-year CCI>42. The most common complications associated with low survival were cholangitis, infections, and hypertension. One-year and overall CCI were similar between sexes and different types of biliary anastomosis. Patients with pre-LTx Model for End-stage Liver Disease scores >20 had higher 1-year and overall CCI (36.2 and 52.6, respectively) than those with lower Model for End-stage Liver Disease scores. Both low (<22) and high (>25 kg/m 2 ) body mass indices were associated with high overall 1-year and overall CCI (50.9 and 41.8, respectively), but median body mass indices were associated with significantly lower 1-year and overall CCI (38.4, P =0.023).

CONCLUSIONS

The previously determined 1-year CCI cutoff of 42 could significantly predict survival post-LTx. Mortality and morbidity were not significantly different between the PSC groups analyzed.

Association Between Pre-Transplant Oral Health and Post-Liver Transplant Complications

Oral disease is linked with systemic inflammation and various systemic conditions, including chronic liver disease. Liver transplantation (LT) candidates often need dental infection focus eradication, and after LT, there is high risk of many inflammation-related complications. We studied whether pre-LT dental status is associated with the occurrence of post-LT complications. This study included 225 adult LT recipients whose teeth were examined and treated before LT, and 40 adult LT recipients who did not have pre-LT dental data available. Data on post-LT complications were collected from the national liver transplant registry and followed up until the end of July 2020. Worse pre-LT dental status was associated with a higher risk of acute rejection post-LT compared to patients with good dental status. Worse dental status was also associated with higher 1-year-post-LT ALT levels and lower albumin levels. In conclusion, poor pre-LT oral health seems to associate with an increased risk of post-LT acute rejection and with elevated ALT levels and decreased albumin levels, suggesting an effect on post-LT liver health. Therefore, prevention and treatment of oral and dental diseases should be promoted early in the course of liver disease.

The first 10 years of simultaneous pancreas-kidney transplantation in Finland

INTRODUCTION

Simultaneous pancreas-kidney transplantation (SPK) is an option for patients with type 1 diabetes (T1D) and kidney failure but can be associated with a high complication rate. Here we describe our 10-year experience since the launch of the SPK program.

METHODS

This retrospective study included consecutive patients with T1D receiving SPK from March 14, 2010 to March 14, 2020 at Helsinki University Hospital. Portocaval anastomosis (i.e., systemic venous drainage) and enteric exocrine drainage were used. A specific team was trained for both pancreas retrieval and transplantation, postoperative care was standardized to include somatostatin analogues, antimicrobial treatment, and preoperatively initiated chemothrombopropylaxis. During program maturation donor criteria were expanded and logistical processes improved to minimize cold ischemia time. Clinical data were collected from a nationwide transplantation registry and patient records.

RESULTS

A total of 166 SPKs were performed (median 2 per year in the first 3 years, 17.5 per year for the following 4 years, and 23 per year for the past 3 years). Seven patients (4.1%) died with a functioning graft with a median 43 months follow-up. One-year pancreas graft survival was 97.0%, 3-year pancreas graft survival was 96.1% and 5-year was 96.1%. Mean HbA1c was 36 mmol/mol (SD 5.57) and creatinine was 107 μmol/L (SD 34.69) at 1-year after transplantation. All kidney grafts were functioning at the end of follow-up. Complications required re-laparotomy in 39 (23%) patients, mostly due to a pancreas graft related problem (N = 28). No pancreas or kidney graft failure from thrombosis occurred.

CONCLUSION

A planned, step-wise development of an SPK program offers a safe and effective treatment for patients with T1D and kidney failure.

Gamma-glutamyltransferase predicts macrovesicular liver graft steatosis - an analysis of discarded liver allografts in Finland

OBJECTIVE

Liver-transplantation activity is limited by the shortage of grafts. Donor-liver macrovesicular steatosis predisposes to ischemia-reperfusion injury and is associated with reduced graft survival. The increasing prevalence of fatty-liver disease underlines the importance of identifying macrovesicular steatosis in potential donor livers. We analyzed liver grafts discarded for transplantation, and particularly the role of gamma-glutamyltransferase (GGT) in predicting graft steatosis.

METHODS

One-hundred sixty rejected cadaveric-donor liver grafts were studied. Donor selection was based on clinical data, and macroscopic graft inspection. Discarded grafts were biopsied at procurement of non-liver organs.

RESULTS

The most common reasons for discarding the graft were abnormal liver tests, ultrasound-verified steatosis and history of harmful alcohol use. GGT correlated moderately with macrovesicular steatosis (r = 0.52, p < 0.001), but poorly with microvesicular steatosis (r = 0.36, p < 0.001). Increased correlation between GGT and macrovesicular steatosis was observed among alcohol abusers (r = 0.67, p < 0.001). Area under the curve (AUC) of GGT for predicting >30% macrovesicular steatosis was 0.79 (95% CI 0.71-0.88), and for >60% steatosis, 0.79 (95% CI 0.68-0.90). The optimal GGT-cut off for detecting >30% and >60% macrovesicular steatosis were, respectively, 66 U/L (sensitivity 76% and specificity 68%) and 142 U/L (sensitivity 66% and specificity 83%). Among alcohol users, a GGT value >90 U/L showed 100% sensitivity for >60% macrovesicular steatosis. AUC for GGT in predicting fibrosis Stages 2-4 was 0.82 (95% CI 0.71-0.92, p < 0.001, optimal cut off 68, sensitivity 92%, specificity 61%).

CONCLUSIONS

Abnormal liver values, steatosis and harmful alcohol use were the main reasons for discarding liver-graft offers in Finland. GGT proved useful in predicting moderate and severe liver graft macrovesicular steatosis.

Histopathological Helsinki score of colorectal liver metastases predicts survival after liver resection

AIM

Several perioperative scoring systems have been created to predict outcomes in metastatic colorectal cancer; however, these rarely include histological parameters. We evaluated histological factors used for patients with liver metastases operated between 2000 and 2019 and compared the results with the Fong score.

EXPERIMENTAL DESIGN

Many scoring models for overall disease-free survival (DFS) were established and compared using multivariate Cox proportional hazard models. Statistically significant predictors at a 5% level in the univariate analysis were included in the multivariate models using the backward and forward selection methods. Per these models, we established a score of eight histological factors. We defined low-, intermediate-, and high-risk groups and compared them using the Kaplan-Meier survival and receiver operating characteristics (ROC) analyses. The histological score's accuracy was compared with the modified Fong clinical risk score.

RESULTS

The following factors constituted the Helsinki score: advanced pT stage, node-positive primary, ≥2 metastases, size >50 mm, vitality >30%, margin <5 mm, vascular invasion, and biliary invasion. The high-risk group had significantly worse DFS and overall survival. In ROC analyses, the Helsinki score was slightly better than the modified Fong clinical risk score.

CONCLUSIONS

Helsinki score challenges physicians to acknowledge histological factors as important outcome measures.

Enhanced recovery protocol in laparoscopic liver surgery

Introduction

Enhanced recovery protocols (ERP) accelerate recovery and shorten postoperative hospital stay. This increased knowledge of ERPs has also gradually implemented into liver surgery. However, in laparoscopic liver surgery (LLS), the experience of optimized perioperative care protocols is still limited.

Methods

We prospectively studied the implementation of multimodal ERP principles to LLS in the first 100 consecutive patients. Opioid-sparing multimodal pain management was applied together with early mobilization already in the postoperative care unit (PACU). Drains and catheters were avoided and per oral intake was initiated promptly. Primary pain control was achieved with iv NSAIDS, low-dose opioid and corticosteroids. Combination of per oral ibuprofen and long-acting tramadol was routinely administered shortly after operation. The multiprofessional adherence to the protocol was also evaluated.

Results

Investigated LLS was performed during Aug 2016–Apr 2019. Operations were done due to malignancy in 83 (83%) of cases, mostly for colorectal liver metastases (n = 52, 52%). Forty-eight (48%) of the operated patients were female. Median age was 65 years (range 17–91). The American Society of Anaesthesiologists Physical Status (ASA) classification median was three. Median postoperative hospital stay was 2 days (range 1–8 days). More than seventy percent of patients were discharged by the second postoperative day and nearly ninety percent by the third postoperative day. Complications after surgery were few. The new ERP elements were adopted in most of the cases.

Conclusions

ERP was introduced safely and effectively after LLS. The adherence to the ERP was good. Routine discharge 1–2 days after LLS is realistic and achievable.

Implementing eHealth in Kidney Transplantation in Finland

Digitalization of health care processes is currently under rapid development. In Finland, a nationwide project called Health Village is coordinating digital health care processes. It is a digital health platform that enables health care organizations to create digital extensions of their clinics. In the Helsinki area, a new electrical medical record (EMR) system named Apotti is being developed. Apotti is based on Epic Systems, and its transplantation module Phoenix was chosen for the basement for the new EMR in transplantation. Both digital services in the Kidney Hub of the Health Village and in Apotti are combined to form the basis of upcoming digital patient care process in kidney transplantation. The Health Village project started in February 2017 to develop eHealth processes in nephrology and kidney transplantation. The decision for Phoenix was made in January 2018. Multidisciplinary teams have developed digital pathways in nephrologic patient care and kidney transplantation since then. The basic structure for eHealth pathways in kidney transplantation will be launched in October 2018. The development of the EMR system is under construction and should be finished by November 2019. Digitalization of health systems in kidney transplantation will harmonize patient care in all parts of Finland. In addition, new models of patient care are providing savings in health care costs. However, the implementation of new systems should be started ahead of time, and the whole process must be well planned to achieve the desired final purpose.

Severe allograft rejection in an intestinal transplant patient following oral immunoglobulin treatment for chronic norovirus infection: a case report

In an intestinal transplant patient under triple immunosuppression therapy with tacrolimus levels >10 ng/L, a 2-day oral immunoglobulin therapy given as treatment for chronic norovirus infection was temporally closely associated with the development of severe steroid-resistant acute graft rejection, thus suggesting that oral immunoglobulin might be able to promote a rejection response.

Optimized recovery programs in gastrointestinal surgery

Optimized or enhanced recovery programs have been applied to intestinal surgery already for a long time. They are being widely initiated also within bariatric, hepatic and pancreatic surgery. The programs aim at an increasingly better well-being of surgical patients by avoiding procedures which slow down the recovery and favoring those that promote it. Informing the patient is also an essential part of the programs. Effective pain management avoiding opioids, early started oral nutrition, and mobilization immediately after the operation prevent postoperative decreased intestinal motility and nausea. At best, the programs will guarantee the patients' excellent recovery and shorten the length of stay on the ward.

Epidermal growth factor receptor inhibition with erlotinib ameliorates anti-Thy 1.1-induced experimental glomerulonephritis

BACKGROUND

Mesangial proliferative glomerulonephritis is a common glomerular disorder that may lead to end-stage renal disease. Epidermal growth factor (EGF) plays an important role in the regulation of cell growth, proliferation, and differentiation and in the pathology of various renal diseases. Erlotinib is a novel, oral, highly selective tyrosine kinase inhibitor of the EGF receptor. It is clinically used to treat non-small cell lung and pancreatic cancers. Here, we investigated the effect of erlotinib on the progression of mesangioproliferative glomerulonephritis in an experimental model.

METHODS

Mesangial glomerulonephritis was induced with anti-rat Thy-1.1 antibody in male Wistar rats weighing 150-160 g. Rats were treated with erlotinib (10 mg/kg/day p.o.) or vehicle only (polyethylene glycol). Native Wistar rat kidneys were used as histological controls. Serum creatinine levels were measured at day 7. Kidneys were harvested 7 days after antibody administration for histology.

RESULTS

Native controls showed no histological signs of glomerular pathology. In the vehicle group, intense glomerular inflammation developed after 7 days and prominent mesangial cell proliferation and glomerular matrix accumulation was seen. Erlotinib was well tolerated and there were no adverse effects during the follow-up period. Erlotinib significantly prevented progression of the glomerular inflammatory response and glomerular mesangial cell proliferation as well as matrix accumulation when compared with the vehicle group. Erlotinib also preserved renal function.

CONCLUSION

These results indicate that erlotinib prevents the early events of experimental mesangial proliferative glomerulonephritis. Therefore, inhibition of the EGF receptor with erlotinib could prevent the progression of glomerulonephritis also in clinical nephrology.

Enhanced recovery protocol after liver resection

BACKGROUND

Enhanced recovery protocols (ERPs) accelerate patient recovery and shorten hospital stay by optimization of perioperative care. However, experience with ERPs is still limited in liver surgery.

METHODS

The implementation of a multimodal ERP was studied in patients who underwent open and laparoscopic liver surgery. An opioid-sparing pain treatment was chosen together with early mobilization and oral feeding, as well as restricted use of abdominal drains and catheters. Date to discharge, postoperative complications and patient satisfaction were assessed. A historical cohort of patients who underwent liver resection served as a control group.

RESULTS

Some 134 liver resections (126 open, 8 laparoscopic) were performed between April 2013 and March 2014. Operations were carried out mostly for malignant liver tumours. One hundred and six (79.1 per cent) of the 134 patients were discharged by the fifth postoperative day. The median (range) postoperative hospital stay was 4 (2-11) days, compared with 6 (4-16) days for the control group (P < 0.001). Only four patients in the ERP group were readmitted and the 30-day mortality rate was zero.

CONCLUSION

An ERP for perioperative care after liver surgery was introduced safely and effectively. Discharge within 4 days is achievable with no increase in adverse events and good patient satisfaction.

Intensive perioperative simvastatin treatment protects from chronic kidney allograft injury

BACKGROUND/AIMS

Ischemia-reperfusion injury (IRI) and innate immune response augment adaptive immunity and may also trigger repair processes that lead to uncontrolled fibrosis and atherosclerosis as seen in chronic allograft injury. Simvastatin has been shown to protect from renal IRI in several experimental studies. The aim of this study was to examine the effect of donor simvastatin pretreatment and early initiation of recipient simvastatin treatment on chronic kidney allograft injury.

METHODS

A rat renal transplantation model was used. Simvastatin was administered perorally for donor (5 mg/kg) and/or for recipient (2 mg/kg) 2 hours before transplantation and/or as daily treatment starting on the first postoperative day (2 mg/kg/day). The study included 5 groups: (1) no simvastatin, (2) donor pretreatment, (3) daily recipient treatment, (4) donor pretreatment + daily recipient treatment and (5) donor pretreatment + recipient pretreatment + daily recipient treatment. The grafts were recovered at day 90 for histopathological and immunohistochemical analysis. Kidney function was followed weekly with serum creatinine, and 24-hour urine protein was measured 60 and 90 days after transplantation.

RESULTS

We found that donor and recipient simvastatin pretreatment combined with daily recipient treatment reduced graft inflammation and chronic allograft injury. Treatment using only statins started after transplantation reduced inflammation to some extent, but did not affect chronic kidney allograft injury. Pretreatment using only donor statins impaired graft function and increased proteinuria.

CONCLUSION

Our data suggest that perioperative recipient statin treatment reduces inflammation and may protect the graft in the long term.

[Incarcerated Spigelian hernia]

Incarcerated Spigelian hernia is a rare cause of abdominal pain requiring emergency surgery. It occurs in the lower abdomen between abdominal musculature in the region of Spigelian aponeurosis. On the basis of incidental findings in laparoscopy the frequency of this hernia is less than 2%. Spigelian hernias are often completely symptomless, but they are associated with the risk of intestinal incarceration. Owing to its rare occurrence, incarcerated Spigelian hernia is difficult to diagnose, which may delay the treatment.

Early short-term platelet-derived growth factor inhibition prevents the development of chronic allograft nephropathy in experimental rat kidney transplantation

Chronic allograft nephropathy (CAN) remains the primary reason for late allograft loss in kidney transplantation. Platelet-derived growth factor (PDGF) is a major mitogen mediating mesenchymal cell proliferation in CAN. When administered continuously the PDGF receptor tyrosine kinase inhibitor imatinib prevents the development of CAN and restores kidney function in experimental kidney transplantation. Herein we investigated whether early short-term imatinib treatment prevented CAN. Kidney transplantations were performed from DA to WF rats and syngenic controls were done between DA rats. Allograft recipients were immunosuppressed with cyclosporine (CsA; 1.5 mg/kg/d sc). One group of allografts was also treated with imatinib (10 mg/kg/d po). Serum creatinine levels were measured once a week. Grafts were harvested 90 days after transplantation for histology and immunohistochemistry (PDGF-AA, -BB, PDGFR-alpha, -beta). Histological changes were scored according to the Chronic Allograft Damage Index (CADI). Among syngenic grafts, no signs of CAN were observed, namely, CADI 0.3 +/- 0.2 (mean +/- SEM). Control allografts showed moderate to intense chronic changes, CADI 6.5 +/- 1.3. Early short-term imatinib treatment significantly prevented the development of CAN compared with control allografts. Only a few histological changes were seen, namely, CADI 3.3 +/- 1.4. Compared with control allografts PDGF ligand and receptor induction was significantly inhibited by imatinib to nearly the same level as in syngenic grafts. Creatinine values of imatinib-treated allografts were also lower than control allografts. Our results demonstrated that early short-term imatinib treatment significantly prevented CAN. This indicated that early PDGF induction has an important role in the pathogenesis of CAN.

Sirolimus attenuates chronic allograft nephropathy in an experimental rat kidney transplantation model

Chronic allograft nephropathy (CAN) is the primary reason for late allograft loss in kidney transplantation. The use of calcineurin inhibitors is suggested to be a risk factor for the development of CAN. Thus, calcineurin-inhibitor-free immunosuppressive protocols are needed to improve long-term graft outcome. Sirolimus affects the immune response by interfering with postreceptor interleukin-2 signaling. Safety profile of sirolimus is different from that of calcineurin inhibitors. We investigated the long-term effects of sirolimus on kidney allografts and fibrogenic growth factor expression and compared it to cyclosporine A. Kidney transplantations were performed from DA to WF rats and syngenic controls were done between DA rats. Allograft recipients were immunosuppressed daily with sirolimus 2 p.o. or CsA 1.5 mg/kg s.c. In addition, sirolimus-treated animals were treated with cyclosporine 1.5 mg/kg s.c. for the first 7 days after transplantation. Serum creatinine levels were measured once a week. Grafts were harvested 90 days after transplantation for histology and immunohistochemistry. Histological changes were scored according to the chronic allograft damage index (CADI). No signs of CAN were seen in syngenic grafts, CADI 0.8 +/- 0.2 (mean +/- SEM). In cyclosporine-treated allografts moderate to intense chronic changes were seen; CADI 10.3 +/- 0.6. Sirolimus significantly ameliorated the development of CAN compared to cyclosporine, CADI 3.0 +/- 0.5 (P < .05). Creatinine values of sirolimus-treated allografts were lower compared to the cyclosporine-treated allografts and were nearly similar to the syngenic grafts. Our results demonstrate that sirolimus attenuates the development of CAN and restores kidney function. Based on our findings, sirolimus improves the long-term kidney graft outcome.

The Effect of Leflunomide Analogue FK778 on Development of Chronic Rat Renal Allograft Rejection and Transforming Growth Factor-BETA Expression

BACKGROUND

Chronic allograft nephropathy (CAN) remains the primary reason for late allograft loss in kidney transplantation. Transforming growth factor beta (TGF-beta) is a major mitogen mediating mesenchymal cell proliferation and epithelial to mesenchymal cell transition in CAN. FK778, an analogue of an active metabolite of leflunomide, is a promising immunosuppressive drug that inhibits de novo pyrimidine biosynthesis. Herein we investigated the effect of FK778 on development of chronic rejection and TGF-beta expression in combination with calcineurin inhibitors cyclosporine (CsA) and tacrolimus (Tac).

METHODS

Kidney transplantations were performed from DA to WF rats and syngeneic control transplantations between DA rats. Allografts were immunosupressed alone with CsA (1.5 mg/kg/d subcutaneously) or Tac (1.5 mg/kg/d orally) or with combinations of FK778 (10 mg/kg/d orally) and CsA or Tac. No immunosuppression was given to syngeneic grafts. Grafts were harvested 90 days after transplantation for histology and immunohistochemistry (TGF-beta, TGF-betaR1). The chronic changes in allografts were scored according to the Chronic Allograft Damage Index (CADI).

RESULTS

No histological signs of chronic rejection were seen in syngeneic grafts. According to CADI, moderate chronic changes were seen in grafts treated only with CsA or Tac. In both groups the changes typically associated with CAN were significantly ameliorated with FK778. CsA-treated grafts showed intense posttransplant expression of TGF-beta and TGF-betaR1 after 90 days. In grafts treated with Tac monotherapy this expression was substantially lower. FK778 markedly reduced the expression of TGF-beta and TGF-betaR1 when combined with calcineurin inhibitors and lesser expression was demonstrated with the combination of FK778 and Tac.

CONCLUSIONS

Our results demonstrated that FK778 is a potent immunosuppressive drug having synergistic effects with calcineurin inhibitors. When combined with CsA or Tac, it decreased posttransplant TGF-beta ligand and receptor expression. Our data also showed that FK778 prevented chronic changes typically associated with CAN. Taken together our results suggested that FK778 could be a promising therapy for CAN in clinical kidney transplantation.

Vascular Endothelial Growth Factor (VEGF) Ligand and Receptor Induction in Rat Renal Allograft Rejection

BACKGROUND

Acute rejection is the single most important risk factor for the subsequent development of chronic allograft nephropathy (CAN), which is still the primary reason for late allograft loss in kidney transplantation. Vascular endothelial growth factor (VEGF) is a proangiogenic factor that has an important role in the development and maintenance of physiological endothelium. While its role has been characterized in the pathology of diabetic nephropathy and preeclampsia, its role in the development of acute and chronic allograft rejection remains unclear.

METHODS

Kidney transplantations were performed from DA to WF rats and syngeneic control transplantations were performed between DA rats. Normal kidneys were used as controls to evaluate physiological VEGF and VEGFR-1 expression. Allografted rats were immunosuppressed with cyclosporine (CsA) (1.5 mg/kg/d subcutaneously); and no immunosuppression was given to syngeneic grafts. Grafts were harvested at 5 and 90 days after transplantation for histology and immunohistochemistry (VEGF, VEGFR-1).

RESULTS

In normal kidneys VEGF ligand and receptor expression was almost nonexistent. Only mild glomerular, arterial, and tubular VEGF expression was seen. In syngeneic grafts, no histological signs of acute or chronic rejection were seen, whereas characteristics of both acute and chronic rejection were seen in CsA-treated allografts. Altough VEGF expression was increased in syngenic grafts when compared to controls it still remained mild in both the early and the late posttransplant period. In CsA-treated allografts moderate VEGF expression was seen already 5 days after transplantation; the expression increased at 90 days after transplantation. The same pattern was also discovered for VEGFR-1 expression although the difference was not as remarkable after 5 days.

CONCLUSIONS

Our results demonstrated that VEGF ligand and receptor expression was increased in both acute and chronic rejection. Our data suggested that VEGF may have an important role in the pathology of chronic rejection. Based on our findings VEGF inhibition could be a potential intervention to prevent CAN in clinical kidney transplantation.

The Effect of FK778 on Acute Rat Renal Allograft Rejection and Expression of Platelet-Derived Growth Factor and Transforming Growth Factor-Beta

BACKGROUND

Acute rejection is the single most important risk factor for the development of subsequent chronic allograft nephropathy (CAN). Both platelet-derived growth factor (PDGF) and transforming growth factor-beta (TGF-beta) are major mitogens mediating mesenchymal cell proliferation and epithelial to mesenchymal cell transition. Early posttransplant induction of these growth factors may start molecular mechanisms leading to CAN. A new promising immunosuppressive drug, FK778, is an analogue of the active metabolite of leflunamide, which inhibits de novo pyrimidine biosynthesis. Herein we investigated the effect of FK778 on acute rejection and on the expression of PDGF and TGF-beta both alone and in combination with cyclosporine (CsA) or tacrolimus (Tac).

METHODS

Kidney transplantations were performed from Dark Agouti (DA) to Wistar-Furth (WF) rats with syngeneic controls between DA rats. No immunosuppression was given to syngeneic grafts. Allografts were immunosuppressed with FK778 alone or in combination with CsA or Tac. Grafts were harvested on day 5 for histology and immunohistochemistry (PDGF-A, -B, PDGFR-alpha, -beta, TGF-beta1, and TGF-betaR1).

RESULTS

FK778 ameliorated the inflammatory response and reduced PDGF and TGF-beta expression in a dose-dependent manner. It also showed synergy with calcineurin inhibitors, an effect that was stronger with Tac than with CsA.

CONCLUSIONS

Our results indicated that FK778 decreased PDGF and TGF-beta expression early in acute rejection, suggesting it to be a promising therapy for CAN.

Human polyoma virus in kidney transplants: SV40 T-antigen demonstration in the urine

We wanted to develop an immunostaining method of urine cytopreparations to detect polyoma virus infection by using fresh urine samples and staining with the monoclonal SV40 antibody and to compare the findings to the demonstration of decoy cells in the urine or to kidney histology. Routine urine samples from pediatric kidney transplant patients were collected either early after transplantation or later, cytocentrifuged, and immunostained with SV40-T-antibody. The number of SV40-T-antigen-positive epithelial cells was counted in the cytopreparations and compared to the findings in routine urine cytology and transplant histology. Immunostaining of urine cytology with SV40-T-ab demonstrated clearly that the infected epithelial cells and the rate of infection could be estimated by semiquantitative counting. There was strong correlation between the findings in the urine and in the biopsies, but in the urine preparations the number of infected cells was much higher than in the biopsies. The high number of SV40-positive cells in the urine also correlated to the severity of clinical infection and to the state of transplant. Immunostaining of urine cytology with SV40-T-antibody seems to be useful in the diagnosis and follow-up of polyoma virus reactivation disease in transplant patients, especially in children with renal transplants.

Leflunomide analogue FK778 is vasculoprotective independent of its immunosuppressive effect: potential applications for restenosis and chronic rejection

BACKGROUND

Leflunomide (LFM) inhibits experimentally both acute and chronic allograft rejection. The inhibition of dihydroorotate dehydrogenase (DHODH) in pyrimidine synthesis is suggested to be the major immunosuppressive mechanism. The mechanism of its vasculoprotective effect is not known, although it may be linked to inhibition of receptor tyrosine kinases (RTK). Here, we have investigated whether sufficient vasculoprotective effect could be obtained upon administration of FK778, a LFM analogue with shorter half-life, and compared the dose response with that of a known platelet-derived growth factor RTK inhibitor, imatinib, after endothelial injury in vivo.

METHODS AND RESULTS

Wistar rats were used for aorta denudations. The rats remained untreated or received either FK778 or imatinib (STI571) at decreasing oral doses from 10 mg/kg per day. Half of the animals in both treatment groups also received uridine to reverse DHODH activity. Morphometric analysis was done after 14 day follow-up. In the untreated group, moderate neointima formation was detected. FK778 almost completely inhibited intimal formation, with or without uridine addition (P<0.05). Imatinib also inhibited neointima formation (P<0.05), whereas exogenous uridine reversed its effect.

CONCLUSIONS

Our results demonstrate that FK778 inhibits neointima formation by way of a mechanism that is independent of DHODH inhibitory activity on vascular smooth muscle cell. Interestingly, the effect of imatinib was inhibited by uridine, suggesting that part of its action on vascular stenosis could be mediated through inhibition of pyrimidine synthesis.

Chronic allograft nephropathy is prevented by inhibition of platelet-derived growth factor receptor: tyrosine kinase inhibitors as a potential therapy

BACKGROUND

Chronic allograft nephropathy (CAN) is the primary reason for late allograft loss in kidney transplantation, and currently there is no treatment available for it. Platelet-derived growth factor (PDGF) is suggested to be a major mitogen mediating mesenchymal cell proliferation in CAN. It has been shown that PDGF is already induced at acute renal allograft rejection, indicating a link between acute rejection and subsequent development of CAN. However, the definite effect of PDGF on the pathogenesis of CAN is still unknown. We investigated the role of PDGF in CAN by inhibiting PDGF by imatinib (STI571), a selective PDGF receptor tyrosine kinase inhibitor.

METHODS

Kidney transplantations were performed from Dark Agouti (DA) to Wistar-Furth rats, and syngenic control transplantations were performed from DA to DA rats. All allograft recipients were immunosuppressed with cyclosporine A (1.5 mg/kg/day subcutaneously). One group of the animals was also treated with imatinib (10 mg/kg/day orally). Serum creatinine levels and cyclosporine A concentrations were measured once per week until the animals were killed. Grafts were harvested 5 and 90 days after transplantation for histology and immunohistochemistry.

RESULTS

Only very few histologic chronic changes, similar to syngenic grafts, were seen in imatinib-treated allografts compared with control allografts. Creatinine values of imatinib-treated allograft recipients and infiltration of inflammatory cells, PDGF ligand, and receptor induction were also at the same level as in syngenic grafts.

CONCLUSIONS

Our results demonstrate that imatinib prevents CAN almost completely, indicating that PDGF plays an important role in its pathogenesis. On the basis of our findings, imatinib could be a potential intervention in preventing CAN in clinical kidney transplantation.

Expression of insulin-like growth factors IGF-I and IGF-II, and their receptors during the growth and megakaryocytic differentiation of K562 cells

Insulin-like growth factors (IGFs) I and II are critical regulators of cell proliferation and differentiation and most of the growth promoting properties of both ligands are mediated by IGF-I receptor (IGF-IR). In the present study we have investigated the role of IGFs in K562 cell line during normal growth and 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-induced megakaryocytic differentiation. Abundant expression of IGF-I, IGF-II and IGF-IR was demonstrated in resting cells and exogenous IGF-I and IGF-II increased 3H-thymidine incorporation in a dose dependent manner. In contrast, we found that basal growth of the cells was inhibited by using anti-IGF-IR mAb. Furthermore, also IGF-I and IGF-II induced DNA synthesis was significantly suppressed by anti-IGF-IR mAb. During megakaryocytic differentiation, expression of IGF-IR increased during first 12h, but after that the expression started to decrease together with IGF-I. Taken together, our data suggest that autocrine production of IGF-I and IGF-II may via IGF-IR play a significant role in the growth and megakaryocytic differentiation of K562 cells.

The effect of acute rejection and cyclosporin A-treatment on induction of platelet-derived growth factor and its receptors during the development of chronic rat renal allograft rejection

BACKGROUND

In the development of chronic kidney allograft rejection acute rejection (AR) is the single most important risk factor. Although Cyclosporin A (CsA) medication has decreased the incidence of AR, chronic rejection (CR) is still the major reason for late allograft loss. Platelet-derived growth factor (PDGF) is a major mitogen mediating mesenchymal cell proliferation in CR. We have investigated the impact of AR and different doses of CsA on the expression of PDGF ligands and receptors in the development of CR.

METHODS

Kidney transplantations were performed from DA to WF rats and syngenic controls were done from DA to DA rats. Two groups of allografts were treated daily with CsA either at low dose (1.5 mg/kg) or high dose (5 mg/kg). Third group of allografts was treated with CsA 5 mg/kg/day for 1 week and then left untreated until the development of AR. AR episodes were treated with CsA 5 mg/kg/day. Grafts were harvested 3 months after transplantation for histology and immunohistochemistry (PDGF-AA, -BB and PDGFR-alpha, -beta).

RESULTS

In syngenic grafts no histological signs of CR were seen and the expression of PDGF ligands and receptors remained almost nonexistent. AR episodes increased the chronic rejection changes. High-dose CsA-treatment ameliorated inflammation compared to low-dose CsA-treatment, although it failed to inhibit the development of chronic changes. More fibrosis was even seen in high-dose than in low-dose CsA-treated grafts. CR in each allograft group was associated with induction of all PDGF ligands and receptors (P<0.05 compared with syngenic controls) in interstitial inflammatory cells, capillary endothelium, and arterial smooth muscle cells. In the group with AR episodes the expression was further increased.

CONCLUSIONS

Our results demonstrate that CsA treatment cannot inhibit the expression of PDGF ligands and receptors in the development of chronic kidney allograft rejection and that AR episodes induce even more PDGF and its receptors in the graft indicating a link between AR and subsequent development of CR.

Early induction of platelet-derived growth factor ligands and receptors in acute rat renal allograft rejection

BACKGROUND

Acute rejection is the single most important risk factor for the development of subsequent chronic rejection. Platelet-derived growth factor (PDGF) is a major mitogen that mediates mesenchymal cell proliferation in chronic rejection. Therefore, we investigated whether PDGF ligands and receptors are induced during acute renal allograft rejection in rat.

METHODS

Kidney transplantations were performed from Dark Agouti (DA) to Wistar-Furth (WF) rats, and syngenic controls were performed from DA to DA rats. Allografts were immunosuppressed with cyclosporine (CsA) 1.5 mg/kg/d subcutaneously or left untreated. Grafts were harvested at 1, 3, 5, and 7 days for histology and immunohistochemistry.

RESULTS

In syngenic grafts, no histological signs of acute rejection were seen and the expression of PDGF ligands and receptors remained almost nonexistent. In nontreated allografts, intense rejection resulted in graft necrosis in 7 days. Acute rejection was associated with the induction of all PDGF ligands and receptors (P<0.05 compared to syngenic controls). The expression of PDGF ligands and receptors was located mainly to graft-infiltrating macrophages but also to capillary endothelium and arteriolar smooth muscle cells. CsA significantly ameliorated acute rejection but failed to inhibit the induction of PDGF and its receptors in CsA-treated allografts.

CONCLUSIONS

Our results demonstrate that PDGF ligands and receptors are induced during acute rejection. PDGF may be induced directly as a reparative response to graft injury in acute rejection or indirectly by various inflammatory mediators released by graft-infiltrating inflammatory cells. This study indicates that PDGF ligands and receptors are already induced in acute rejection, which suggests a link between acute rejection and the subsequent development of chronic rejection.

Prevalence, morphology, and topography of blood vessels in herniated disc tissue. A comparative immunocytochemical study

STUDY DESIGN

Ninety disc herniations removed during surgery were studied by immunocytochemistry, using two different endothelial cell markers, to study the prevalence, morphology, and topography of blood vessels in disc herniations.

OBJECTIVES

To increase the specific localization of even very small blood vessels present in disc herniations by using specific antibodies to endothelial cells; to study blood vessels comparatively with two different endothelial cell antibodies, comparing their prevalence; and to study blood vessel morphology and topographic relationships of blood vessels to other tissue elements, particularly disc cells.

SUMMARY OF BACKGROUND DATA

In many previous macroscopic studies and in studies using conventional histologic methodology, blood vessels have been observed in degenerated and injured intervertebral discs. In a smaller patient sample, the authors previously observed blood vessels in approximately 80% of disc herniations by immunocytochemistry, the blood vessels co-localizing with macrophage cells. Many of these blood vessels are the product of very active neovascularization after disc tissue injury. The presence of such blood vessels has not, however, been studied in greater detail or in larger patient samples. Immunocytochemistry offers superior visualization and more specific localization and was thus used in the present study.

METHODS

Thin frozen sections from 90 disc herniations were immunostained in parallel with von Willebrand factor and Ulex europaeus antibodies, both of which localize endothelial cells specifically. Indirect immunocytochemistry by avidin-biotin-peroxidase complex or alkaline phosphatase-antialkaline phosphatase were used for immunolocalization. Blood vessels were classified as being: +, abundant: (+), very few; or +, totally absent.

RESULTS

The prevalence of blood vessels in disc herniations was found in 82 of 90 (91%) disc herniations with von Willebrand factor antibody and in 75 of 90 (83%) disc herniations with Ulex europaeus antibody. In 59 disc herniations (66%), blood vessels were observed with both antibodies in parallel, whereas they were observed with neither antibody in only six of 90 disc herniations. Furthermore, the ratio of abundant to very few blood vessels was 73:9 with von Willebrand factor antibody and 63:12 with Ulex europaeus antibody, further supporting the abundance of blood vessels in disc herniations. Blood vessels were most prevalent in sequestrated discs, but they were also observed in six of eight protrusions. Dense blood vessel networks were observed to penetrate the disc tissue, and blood vessels were also present in areas of inflammatory cell infiltration. Topographically, blood vessels were, on several occasions and with both antibodies, seen to pass close by or to surround disc cells.

CONCLUSIONS

By immunocytochemistry with endothelial cell markers, blood vessels can be observed to be numerous, and their prevalence in herniated discs is very high, presumably as a result of a very intense neovascularization process after the disc injury. A close apposition to disc cells may suggest attempts to increase the nutrition of these cells and will influence the metabolism of the cells.