Proposal of categorization of expanded criteria donors in renal transplantation.

INTRODUCTION: Transplantation of renal allografts that have been procured from expanded criteria donors (ECD) have prevailed in an attempt to expand the donor pool. Even though ECD is an acceptable source of donors, the wide range of age along with the presence or not of risk factors necessitates further categorization. The aim of this study was to analyze the allograft and recipient survival of the ECD renal grafts and to propose an ECD categorization model. PATIENTS AND METHODS: We reviewed the medical records of renal transplant recipients from January 2002 to July 2012, who received renal allografts from expanded and standard criteria donors (SCD) without risk factors such as hypertension, cerebrovascular disease or impaired renal function. RESULTS: During the study period, 310 renal transplantations were performed in our Transplant Unit, of which 86 and 114 renal grafts were procured from ECD and SCD respectively. ECD renal graft survival the first, third and fifth year was 92%, 82% and 70% while respective recipient survival was 95%, 87% and 82%. Comparison with the control group of SCD showed that ECD renal graft survival after the third post-transplant year was significantly inferior (P < .0001). Donor age was a considerable prognostic factor of long-term renal graft function. Serum creatinine of ECD grafts was the first and third year 1.86 ± 0.6 mg/dL and 1.91 ± 0.8 mg/dL, respectively, showing significant difference to that of SCD grafts (P < .0001). Further categorization of ECD showed that renal allografts procured from donors above 60 years old without risk factors had better renal graft survival and function compared to grafts procured from donors aged 50-59 with 2 or 3 risk factors. CONCLUSIONS: Renal transplantation from ECD offers acceptable graft survival rates, however they are inferior compared to renal grafts from optimal kidney donors. ECD kidney grafts have to be categorized, taking into consideration the independent risk factors.

Immunologic prognostic factors of renal allograft survival.

INTRODUCTION: Successful outcome of renal transplantation depends on various factors, of which immunologic is one of the most important. Accumulated experience of a single center, with the same surgical and immunological team contributes significantly to safe conclusions. Purpose of this study was the evaluation of potential factors, in particular immunologic, that influence renal allograft survival. PATIENTS AND METHODS: During the period 1991-2013, 20,784 surgical operations have been performed in our Department of Surgery - Transplant Unit, of which 575 were renal transplantations. We examined donor and recipient demographic factors, immunologic characteristics along with patient and graft survival. RESULTS: Renal allograft was retrieved from living-related donor in 103 cases and in 472 from cadaveric donor. Donor age was 46.7 ± 18.5 years old and 49.9% (287) were male. Recipient age was 48 ± 12.3 years old and 402 were male. HLA histocompatibility was carefully matched resulting in 85.5% renal transplants with 2-4 HLA mismatches and 93.8% renal transplants with at least one HLA-DR. Renal graft survival the first, fifth and tenth year was 89%, 76%, and 67% and patient survival was respectively 95%, 89% and 83%. Statistical analysis revealed that only donor age influenced renal graft survival (P < .05). HLA mismatches were not correlated with graft survival (log rank P = .495), but identification of panel reactive antibodies (PRA) class I and class II post transplantation had a statistically significant impact on long term renal graft survival (log rank P < .001 and P = .021, accordingly). CONCLUSIONS: Analysis of potential prognostic factor showed that only donor age was correlated with allograft survival. Development of PRA following renal transplantation influenced long term graft survival. Good HLA matching with at least one HLA DR resulted in excellent graft and patient survival.

Effect of transient BK viremia and viruria on long-term renal allograft survival and function.

INTRODUCTION: The purpose of this study is to present the five-year survival and function of the renal allograft of recipients who were diagnosed with BK viremia and viruria during the first year after renal transplantation. PATIENTS AND METHODS: BK virus was studied in 32 new renal allograft recipients, from the first postoperative day until 18 months after the transplantation. Real-time polymerase chain reaction was used to detect and quantitate BK viral load in serum and urine samples. RESULTS: Qualitative analysis with PCR for the DNA of BK virus showed 31 (31/228, 14%) positive serum samples originating from 20 (20/32, 62%) renal allograft recipients and 57 (57/228, 25%) positive urine samples originating from 23 (23/32, 72%) recipients. During the follow up period of 5 years, renal allograft function remained stable (eGFR 18(th) month: 53.9 ± 23.9 mL/min/1.73 m(2) and eGFR 5(th) year: 52.6 ± 20.6 mL/min/1.73 m(2)). Comparison of recipients that presented with either BK viremia or viruria with a group that did not present viral reactivation did not reveal a statistically significant difference in eGFR. Furthermore, recipients with significantly high viral load in serum or urine did not present renal allograft dysfunction. CONCLUSION: BK virus is potentially pathogenic in renal allograft recipients. It is certain that there is a reactivation of the virus in a high percentage of transplanted patients mostly in the first year after the surgery, without however a negative effect of the transient viremia and viruria in renal allograft function.

Blood stream infections in renal transplant recipients: a single-center study.

INTRODUCTION: Bacteremias among renal transplant recipients are more frequent as a result of immunosuppression. They are considered extremely high-risk because they are correlated with decreased allograft and recipient survival. PATIENTS AND METHODS: All episodes of bacteremia among renal transplant recipients were documented following review of medical records, from January 2010 to May 2013. RESULTS: In total 26 episodes of bacteremia were observed in 22 patients. Gram negative bacteremia was identified in 73% (19/26) cases. Pathogens according to their frequency were the following Escherichia coli (6/26, 23%), Klebsiella pneumonia (5/26, 19%), Pseudomonas aeruginosa (3/26, 11%), Staphylococcus epidermidis (3/26, 11%), Acinetobacter baumanni (2/26, 7.7%), Enterococcus faecalis (2/26, 7.7%). The first trimester post renal transplantation 18 episodes (69%) of bacteremia were presented that were not correlated to indwelling urinary catheter or stent. Positive urinary culture with the same pathogen was recognized in 13 patients. All recipients manifested fever, eight recipients had leucocytosis and three cases were complicated by septic shock. Immediate resuscitation with intravenous fluids and non-nephrotoxic antibiotic regimen was initiated. Acute renal allograft dysfunction (defined as an increase in serum creatinine more than 0.5 mg/dL from baseline) was observed in five patients and was restored following infection resolution. CONCLUSION: Increased prevalence of bacteremia in renal transplant recipients is attributed to immunosuppression and usually bacteremic episodes follow urinary tract infection. The commonest pathogens are Gram negative bacteria with E. coli the most frequent. Early detection and proper management are important as bacteremia affects renal allograft and recipient survival.

Acute prostatitis caused by Raoultella planticola in a renal transplant recipient: a novel case.

We present a unique case of acute bacterial prostatitis caused by a very rare human pathogen, Raoultella planticola, in a renal allograft recipient 3.5 months post transplantation. Only a few cases of human infection by this pathogen have been reported worldwide. The present study reports the case of a 67-year-old man who was admitted to our transplant unit 3.5 months post transplantation with fever, dysuria, suprapubic pain, symptoms and signs of acute prostatitis, and elevated markers of inflammation and prostate-specific antigen. R. planticola was isolated in the urine culture. The patient was treated with ciprofloxacin (based on the antibiogram) and had a full recovery, with satisfactory renal function. To the best of our knowledge, this is not only the first reported case of R. planticola prostatitis, but also the first report of such an infection in a solid organ transplant recipient or in a patient on immunosuppressive medication.

Small bowel obstruction caused by inflammatory cytomegalovirus tumor in a renal transplant recipient: report of a rare case and review of the literature.

Cytomegalovirus (CMV) infection in renal transplant recipients can present as asymptomatic viremia or CMV syndrome or, in more severe cases, as tissue-invasive disease. CMV enteritis, a common manifestation of CMV invasive disease, usually presents with fever, abdominal pain, anorexia, nausea, and diarrhea, and can be rarely complicated by colon perforation, hemorrhage, or megacolon. CMV infection occurs primarily in the first 6 months post transplantation, when immunosuppression is more intense. We describe the case of a female renal transplant recipient with small bowel obstruction caused by CMV disease 7 years post renal transplantation. The patient presented with diarrhea and abdominal pain. Because of elevated CMV viral load, she was initially treated with antiviral therapy with transient response. Endoscopy and imaging tests showed obstruction of the terminal ileum and, subsequently, the patient underwent exploratory laparotomy when a right hemicolectomy was performed. Biopsy results confirmed the diagnosis of CMV enteritis. Epidemiologic characteristics, clinical presentation, diagnostic workup, therapeutic options, and morbidity-mortality rates of CMV infection/disease, in renal transplant recipients, are reviewed.

Ezetimibe is effective in the treatment of persistent hyperlipidemia of renal allograft recipients.

INTRODUCTION: Ezetimibe is a hypolipidemic agent acting via inhibition of cholesterol absorption from the small intestine. The effectiveness and safety of long-term administration of ezetimibe was evaluated in renal allograft recipients with persistent hyperlipidemia. PATIENTS AND METHODS: 67 renal allograft recipients with post-transplantation hyperlipidemia resistant to statins were included in the study; 11 were treated with ezetimibe (10 mg/day) alone and 56 with ezetimibe and statin. The effectiveness of ezetimibe was assessed by determination of total cholesterol (TC), LDL cholesterol (LDL-C), HDL cholesterol (HDL-C) and triglycerides (TR). Its safety was determined by liver enzymes (ALT, AST), LDH, CPK, serum creatinine and blood levels of immunosuppressive drugs (cyclosporine, tacrolimus, everolimus, sirolimus) over the follow-up period of 18±6 months. RESULTS: A significant reduction of TC and LDL-C blood levels by 25% and 34% respectively, was observed during the first month of treatment with ezetimibe (p<0.001). This reduction was maintained for the whole period of ezetimibe administration. Renal function remained stable over the follow-up period, while no changes of the blood levels of immunosuppressive drugs were observed. Liver enzymes, LDH and CPK remained normal in all patients except for one diabetic patient who developed rhabdomyolysis. Apart from gastrointestinal symptoms in 2 patients, no other side effects were observed. CONCLUSION: Combination of ezetimibe with statins represents an effective and safe regimen for treatment of persistent hyperlipidemia in renal allograft recipients.

Prospective monitoring of BK virus replication in renal transplant recipients.

BACKGROUND: BK virus-associated nephropathy (BKVAN) can be diagnosed only with renal graft biopsy. Definitive diagnosis of BKVAN requires demonstration of BK virus (BKV) replication in renal allograft tissues. Non-invasive analysis of urine and blood is considered essential in screening renal transplant recipients. PATIENTS AND METHODS: This study evaluated prospectively the replication of BKV in plasma and urine with qualitative and quantitative real-time polymerase chain reaction in 32 de novo (group A) and 34 chronic (group B) renal transplant recipients and the long-term impact on graft function. RESULTS: In group A, 456 samples (228 plasma, 228 urine) were examined and BKV was detected in 31 (31/228, 14%) samples of plasma and 57 (57/228, 25%) samples of urine in 20 (20/32, 62.5%) and 23 (23/32, 72%) recipients, respectively. Incidence of viremia and viruria increased during the first 6 months presenting a peak the third postoperative month (viremia: 28% and viruria: 31%). Immune suppressive treatment with tacrolimus showed significant relation with viremia. Renal graft function in de novo renal transplant recipients remained stable throughout the follow-up period without influence of BKV replication. In group B, incidence of viremia and viruria were 3% (1/34) and 9% (3/34) correspondingly, indicating that after the first post-transplant year the risk of BKV re-activation is diminished. CONCLUSION: The highest incidence of BK viremia and viruria is observed the third post-transplantation month, confirming previously published studies in Europe and the United States, and long-term follow up shows that BKV replication decreases significantly after the third post-transplant month and even transient viremia or viruria does not have an impact on renal function.

Ureteral complications in renal transplant recipients successfully treated with interventional radiology.

INTRODUCTION: Ureteral complications in renal transplantation occur in approximately 8% of renal transplant recipients, occasionally leading to graft loss. This retrospective study presents a single-center experience in managing ureteral complications with interventional radiology as well as the long-term graft function and recipient survival. PATIENTS AND METHODS: We analyzed 21 renal transplant recipients with ureteral problems. RESULTS: Nine patients experienced urinary leak, six patients had ureteric obstruction, and six patients had obstruction preceded by leak. Median recipient age was 48 (range, 20-63) years; 71% (15/21) of the patients were male and 66.6% (14/21) of transplants were derived from cadaveric donors. Ureteral complications were diagnosed at a mean of 18 days (range, 12-47) after renal transplantation. Initially a percutaneous nephrostomy was performed, followed by antegrade placement of a nephroureteral stent. In cases with ureteral obstruction, ureteral balloon dilation was performed prior to placement of the stent. Median time to the procedure was 53 days, and median follow-up for the purposes of this study was 57 months. Renal graft function improved following treatment of the ureteral complication. Mean serum creatinine values prior to and after the intervention were 4.8 +/- 2.12 and 1.79 +/- 0.58 mg/dL, respectively (P < .0001). Functional renal grafts were observed at the first, third, and fifth posttransplantation year among 100%, 95.2% and 80.9% of patients, respectively. It should be further noted that no graft was lost due to a ureteral complication. CONCLUSIONS: Interventional radiology was successful in treating immediate and long-term ureteral problems among renal transplant recipients with preservation of good renal function and patient survival.

Prospective study of urine cytology screening for BK polyoma virus replication in renal transplant recipients.

OBJECTIVE: BK virus (BKV) may be associated with interstitial nephritis in renal transplant recipients and this can lead to irreversible chronic allograft dysfunction. Early diagnosis of BKV nephropathy determines its progress because no specific antiviral therapy exists. Urine cytology, detection of viral DNA in urine or blood and renal biopsy are the main diagnostic tools. The purpose of this study was to evaluate the use of urine cytology for diagnosis of BKV replication in renal graft recipients. PATIENTS AND METHODS: We studied 32 de novo renal transplant recipients prospectively with sequential urine samples for a period of 1 year. Thin-Prep methodology was used to prepare the slides. Cytology results were correlated with polymerase chain reaction (PCR) in urine and blood. RESULTS: Decoy cells indicative of BKV infection were detected in 14 (7.3%) of the 190 urine samples derived from 11 recipients. In three cases with positive decoy cells, BK viraemia and viruria were simultaneously identified. In a further three cases, BKV active replication was confirmed in urine by both cytology and PCR. CONCLUSIONS: Urine cytology is an easy and rapid method of detecting decoy cells in cases where renal biopsy is not possible. However, the low incidence of detection of decoy cells in the present study, together with poor correlation with PCR results, questions its sensitivity and specificity in diagnosing BKV reactivation.

Transplantation of pediatric kidneys to adult recipients: an analysis of 13 cases.

INTRODUCTION: The shortage of cadaveric donors for kidney transplantation has prompted many centers to expand the criteria used for donor selection to increase the organ supply. The use of cadaveric pediatric kidneys has been suggested as a means to overcome the shortage. However, some studies indicate that kidneys from pediatric donors show inferior results to those from adult donors. In this retrospective study we examined the outcome of kidney transplantation using cadaveric pediatric donors. MATERIALS AND METHODS: From October 1990 to May 2002, 13 adult patients received pediatric renal transplants including two that were transplanted en bloc. The patients were divided into two groups based upon donor age: group I donors were 18 months to 6 years old; the seven recipients were of mean age 47.3 years. Group II donors were 7 to 15 years old; the six recipients were of mean age 43.6 years old. Cyclosporine-based immunosuppressive regimens were used in both groups. RESULTS: The patient survival rate was 85.7% in group I and 100% in group II. The graft survival rates at the first and third posttransplant year in group I were 71.4% (5/7) and 57.1% (4/7) and in group II, 66.7% and 50%, respectively. The frequency of urinary complications in group I was 28.5% (2/7) and in group II 33.3% (2/6). There was one case of venous thrombosis in group II. CONCLUSION: Pediatric renal grafts may be used with reasonable safety. However, surgical complications remain a significant problem especially with younger pediatric grafts.