Delayed graft function in renal transplant recipients: risk factors and impact on 1-year graft function: a single center analysis.

UNLABELLED: Delayed graft function (DGF), a frequent complication after kidney transplantation, occurs among about 60% of recipients of kidneys from deceased donors. DGF has a multifactorial etiology. It is characterized by acute tubular necrosis (ATN) upon biopsy. In this study we sought to identify among a group of recipients of kidneys from deceased donors, the incidence, risk factors, and impacts on patient and graft survivals of DGF. MATERIALS AND METHODS: We retrospectively analyzed medical records from renal transplant recipients aged >18 years who received a deceased donor kidney graft between January 2003 and December 2006. Kidneys lost during the first week posttransplantation were excluded from this series. RESULTS: Among 165 transplants, 111 (67%) displayed DGF, defined as the need for dialysis during the first week posttransplantation. The incidence of DGF was higher among patients with a cold ischemia time (CIT) > 24 hours: 85% vs 60%, DGF vs no DGF (P < .05), as well as for grafts from older donors. After 1-year follow-up, the DGF group showed worse graft function (serum creatinine 1.6 +/- 0.7 vs 1.3 +/- 0.4 mg/dL; P < .05) as well as a greater incidence of graft loss. CONCLUSION: Prolonged cold ischemia and older donor age were associated with a greater incidence of DGF in this series, leading to prolonged hospitalization, increased risk for an acute rejection episode, and reduced graft function and survival after 1 year.

Tuberculosis in renal transplant recipients: a Brazilian center registry.

UNLABELLED: Renal transplant recipients receiving immunosuppression show an increased risk for developing opportunistic infections, such as tuberculosis (TB). TB represents the major cause of morbidity and mortality in the world, mainly in underdeveloped countries. The aim of this study was to analyze the incidence of TB and its presentation among renal transplant recipients over 20 years. PATIENTS AND METHODS: This retrospective analysis included medical records of renal transplant recipients from January 1984 to April 2007. RESULTS: Among 1342 renal transplant recipients, 31 received treatment for TB due to clinical disease (n = 23) or prophylaxis (n = 8). The overall incidence of TB was 1.71%, which was diagnosed at 53 +/- 49 months posttransplantation. The indications for TB prophylaxis were a previous history of TB (n = 6) or direct contact with a TB carrier (n = 1). The most common clinical presentation was extrapulmonary (n = 13). The classical treatment was effective in 16 cases. However, 7 cases of resistant TB required ethambutol added to therapy. Adverse events of treatment included liver toxicity (n = 1) and peripheral neuropathy (n = 1). Three patients died due to TB-related complications. Graft loss was observed in 3 patients after cessation of TB treatment. None of the patients on prophylaxis developed clinical disease. CONCLUSIONS: TB incidence was significantly greater among renal transplant recipients compared with the local population, with a higher incidence of extrapulmonary disease. TB prophylaxis in selected cases was effective, avoiding new infections.

Improved renal function after kidney transplantation is associated with heme oxygenase-1 polymorphism.

Heme oxygenase-1 (HO-1) has a microsatellite polymorphism based on the number of guanosine-thymidine nucleotide repeats (GT) repeats that regulates expression levels and could have an impact on organ survival post-injury. We correlated HO-1 polymorphism with renal graft function. The HO-1 gene was sequenced (N = 181), and the allelic repeats were divided into subclasses: short repeats (S) (<27 repeats) and long repeats (L) (>/=27 repeats). A total of 47.5% of the donors carried the S allele. The allograft function was statistically improved six months, two and three yr after transplantation in patients receiving kidneys from donors with an S allele. For the recipients carrying the S allele (50.3%), the allograft function was also better throughout the follow-up, but reached statistical significance only three yr after transplantation (p = 0.04). Considering only those patients who had chronic allograft nephropathy (CAN; 74 of 181), allograft function was also better in donors and in recipients carrying the S allele, two and three yr after transplantation (p = 0.03). Recipients of kidney transplantation from donors carrying the S allele presented better function even in the presence of CAN.

Skin malignancies in renal transplant recipients: a Brazilian center registry.

UNLABELLED: Renal transplant recipients have an increased risk of malignancies, especially nonmelanoma skin cancers, compared with the normal population. The aim of the present study was to analyze the incidence of skin malignancies in a setting of renal transplant recipients over 20 years follow-up. PATIENTS AND METHODS: This retrospective analysis of medical records included posttransplant patients with biopsy-proven skin cancer. Recipients of pancreas kidney transplants or with suspected but not biopsy-proven skin malignancy were excluded from this series. RESULTS: Among 1300 renal transplant recipients from January 1984 to December 2006, 33 (2.5%) were diagnosed with skin malignancies during follow-up. The majority of patients were men (70.2%), of white race (97%), and with a mean posttransplant follow-up of 65 months. The most frequent skin cancer was squamous cell carcinoma (46.2%), in single or multiple lesions (50% each group). Basal cell carcinoma was diagnosed in seven patients; most presented as a single lesion (71.3%). Eight patients presented with more than one histologic type of skin cancer; most frequently squamous and basal cell carcinomas. Kaposi sarcoma was diagnosed in four patients, one of whom also had a basal cell carcinoma. CONCLUSION: The incidence of skin malignancies in this series was 2.5%. The most frequent tumor was squamous cell carcinoma, isolated or in association with basal cell carcinoma. An higher frequency was observed in white male patients, at a mean follow-up of 5 years posttransplantation.

Posttransplant diabetes mellitus: incidence and risk factors.

UNLABELLED: Posttransplant diabetes mellitus (PTDM) is common post transplantation and is associated with tacrolimus (TAC) and steroid therapy. The aim of the present study was to analyze the incidences of PTDM and associated risk factors. METHODS: We selected renal transplant recipients treated with TAC, mycophenolate mofetil (MM), and steroids. Exclusion criteria were recipients <18 years old, history of diabetes, recipients of kidney/pancreas, and/or those receiving cyclosporine or sirolimus. PTDM was defined as glucose >126 mg/dL, with or without drug therapy. RESULTS: Among 67 patients who fulfilled the inclusion criteria, 18 (26.8%) developed PTDM within 2 months of transplantation. Compared with normal glucose patients, the PTDM group was older, male, received a kidney from deceased donors, and showed higher pretransplant glucose levels. No differences were noticed in renal function or daily dose of TAC or steroids. However, TAC trough levels in the first month were higher among the PTDM group, despite the lower dose per kilogram. After 1 year of follow-up, weight gain as well as daily TAC per kilogram dose was less among PTDM patients. Analysis of potential risk factors showed a higher incidence of hepatitis C virus infection in the PTDM group, as well as a higher frequency of HLA DR13. CONCLUSION: The incidence of PTDM diagnosed in the early posttransplant period in the present series was 26.8%. Risk factors included older age, male gender, recipients of kidneys from deceased donors, hepatitis C virus infection, higher pretransplant glucose levels, and higher TAC trough levels during the first month posttransplant.

Systemic lupus erythematosus after renal transplantation: is complement a good marker for graft survival?

BACKGROUND: Renal transplantation is considered a safe procedure for patients with systemic lupus erythematosus (SLE). However, the recurrence of disease and its impact on graft survival remains controversial. METHODS: To analyze the presence of lupus serology activity during dialysis and its impact on lupus recurrence after transplantation, we performed a retrospective analysis of 23 lupus patients who received 26 kidney transplantations. RESULTS: Twenty-three patients received 26 renal transplantations from 1984 to 2003. Twelve patients presented pretransplant lupus activity (low complement and ANA > 1/40), without correlation with length of dialysis, but associated with proliferative glomerulonephritis (class IV) pretransplant. Among 26 grafts, 6 were lost in the first 6 months posttransplant. Among the remaining 20 functioning grafts, low complement activity occurred in 8, being associated with recurrence of immune deposits in 3 cases. Analysis of lupus activity showed that only one patient with a normal complement level posttransplant presented SLEDAI > 4, associated with persistent proteinuria and a graft biopsy without immune deposits. Graft survival was reduced in the presence of low complement posttransplantation. CONCLUSION: Low complement levels after renal transplantation, in association with proteinuria may be considered to be a risk factor for recurrence of immune deposits, with a negative impact on graft survival.

Changes in serological markers of hepatitis B virus after renal transplantation.

An estimated 350 million persons worldwide are chronically infected with hepatitis B virus (HBV). Immunosuppression after renal transplantation seems to enhance viral replication and increase the risk of developing cirrhosis and hepatocellular carcinoma. This retrospective study was performed to assess the prevalence among and serological status of HBV infection after renal transplantation at a single university Brazilian center. Thirty six (4.2%) patients among 850 kidney recipients showed positive HBsAg for more than 6 months; 31 were hepatitis B surface antigen (HBsAg) positive at transplantation. Of the 15 hepatitis B e antigen (HbeAg) positive patients, six had spontaneous HBeAg seroconversion and three also had HBsAg clearance. An additional two showed HBeAg clearance with Lamivudine without seroconversion. Among 15 HBeAg-negative patients, three developed HBeAg reversion with no elevation of alanine transferase (ALT) levels and one had HBsAg clearance. Only one patient had acute exacerbation of hepatitis B (ALT > 20 times normal range) but remained HbeAg negative. During follow-up, five patients became HBsAg positive; two reactivations of resolved hepatitis B, two with previous anti-HBS induced by vaccination, and one with no serological marker for HBV. Lamivudine was prescribed for 16 patients, two of whom had HbeAg clearance without seroconversion and five who developed viral resistance to Lamivudine after a mean of 29.2 months. No hepatocellular carcinoma or deaths related to hepatitis B were seen in this group. In summary, prevalence of HBV in kidney transplant patients was 4.2%. Immunosuppression after renal transplantation in HBV infection led to an increased risk of liver complications and changes in HBV serological status.

Effects of a Physiotherapeutic Protocol in Respiratory Function, Aerobic Capacity and Quality of Life After Kidney Transplantation.

INTRODUCTION: Chronic kidney disease can lead to dysfunction of the respiratory, cardiac, and musculoskeletal systems, altering the body's metabolism. Renal transplantation and hospital physiotherapy, through specific protocols, can improve these dysfunctions. OBJECTIVES: This study evaluates the impact of a hospital physiotherapeutic protocol in quality of life (QoL), respiratory muscle strength, peak expiratory flow, and 6-minute walk test (6MWT) in the preoperative, first, and fifth days after renal transplantation. METHODS: We evaluated 39 patients who received a renal transplant at Clinics Hospital of University of Campinas for respiratory muscle strength, expiratory peak flow, and functional capacity by the 6MWT. The short form-36 quality of life questionnaire was applied to 12 patients. RESULTS: We observed a significant reduction in respiratory muscle strength and peak expiratory flow in the first postoperative day. On postoperative day 5, there was improvement in respiratory muscle strength and expiratory peak flow. However, aerobic capacity measured by 6MWT remained below predicted. Analysis of QoL showed an improvement in almost all analyzed domains after transplantation. CONCLUSION: A specific physiotherapeutic protocol applied early after transplantation provided recovery of respiratory muscle strength and QoL. However, longer training is necessary to obtain adequate aerobic rehabilitation.

Effect of panel-reactive antibody in predicting crossmatch selection of cadaveric kidney recipients.

AIM: The influence of panel-reactive antibody level (%PRA) on crossmatch results was evaluated among 866 patients on the waiting list for cadaveric renal allografting from January 2001 to August 2005. We evaluated the results for 124 potential donors for a kidney, including 2008 crossmatches. Four hundred eighteen patients were tested against only 1 donor. METHODS: Serum samples were screened for anti-HLA antibodies using immunoglobulin (Ig)G enzyme-linked immunosorbent assay (ELISA) PRA kit and the %PRA of the most reactive sample (peak) was used for patient stratification, according to sensitization level. Crossmatches were performed on fresh donor T lymphocytes from peripheral lymph nodes, using classical and anti-human-globulin enhanced complement-dependent cytotoxicity (CDC-T) methods. The tests were performed using peak and current patient sera before and after dithiothreitol treatment. The crossmatch was assumed to be negative when no reactivity was observed in all tests. RESULTS: The incidences of positive crossmatch were as follows: 72.3%, 14.6%, and 7.2%, among patients with PRA >50%, PRA

The effects of rapamycin in the progression of renal fibrosis.

UNLABELLED: Renal fibrosis is a hallmark of end-stage renal diseases and of chronic allograft nephropathy (CAN). Rapamycin, besides its action through blockade of lymphocyte proliferation, also has antiproliferative, antiviral, and antitumor actions. Its use in clinical in patients with CAN has recently been advocated. OBJECTIVES: Our goal was to evaluate the effect of rapamycin in an established model of renal fibrosis, unilateral ureteral obstruction. MATERIALS AND METHODS: C57BL/6 mice were divided into two groups, treated or not with daily doses of rapamycin (0.2 mg/kg) beginning on day-1. The obstruction was performed as day 0. Blood and kidney tissues were collected at 1, 4, 7, and 14 days after the surgery to quantify bone morphogenic protein (BMP)-7 and transforming growth factor (TGF)-beta mRNA by real time PCR. RESULTS: Daily treatment with rapamycin caused a significant reduction in serum creatinine at day 1 (0.57 +/- 0.03 vs 0.95 +/- 0.15 mg/dL, P = .002) and at day 14 (0.56 +/- 0.04 vs 0.73 +/- 0.07 mg/dL, P = .040). This profile was corroborated by histological morphometric analyses showing less fibrosis at day 14. However, rapamycin surprisingly induced an upregulation of TGF-beta at day 4 (3.05 +/- 0.46 vs 1.85 +/- 0.41, P = .006) and at day 7 (6.33 +/- 0.55 vs 4.97 +/- 0.38, P = .024) with a reduced expression by day 14 (4.03 +/- 1.07 vs 7.89 +/- 0.83, P < .001). Surprisingly, rapamycin also promoted an increment in BMP-7, completely reversing the ratio of TGF-beta to BMP-7, allowing a more protective phenotype. CONCLUSION: Rapamycin slightly ameliorated the renal dysfunction and, at later time points, induced less fibrosis and less decrease in the TGF-beta to BMP-7 ratio.

Early Vascular Thrombosis After Kidney Transplantation: Can We Predict Patients at Risk?

BACKGROUND: Renal transplant is the therapy of choice for patients with chronic renal disease. In recent years, improvement in immunosuppressive drugs reduced early graft loss associated with acute rejection. However, vascular thrombosis, accounting for 5% of early graft loss, can sensitize the recipient for human leukocyte antibodies, reducing the chance for a second transplant. The aim of this study was to identify risk factors for vascular thrombosis in a single transplant center, to design specific prevention protocol. METHODS: This was a retrospective, case-control study. From the Renal Transplant Unit database, we identified 21 cases of vascular thrombosis in recipients of kidneys from deceased donors. Recipients from the contralateral kidney from the same donor, without vascular complications, were assigned to the control group. Data analyzed included donor, recipient, transplant surgery, and post-operative follow-up. The local ethics committee approved the protocol. RESULTS: Thrombosis and control groups were comparable for recipient characteristics, cold ischemia time, organ side (right or left), and site of arterial anastomosis. We observed an increased risk for vascular thrombosis in kidneys with multiple veins (odds ratio, 11.32; P = .03). Organ retrieval surgery complications, such as vascular lesions or heterogeneous perfusion, despite normal pre-implantation biopsy, were considered risk factors for vascular thrombosis within the first post-operative day (odds ratio, 7.1; P = .03). CONCLUSIONS: In this series, multiple renal vein and organ retrieval surgery complications were risk factors for early vascular thrombosis.

Spironolactone in Post-Transplant Proteinuria: A Safe Alternative Therapy.

BACKGROUND: Aldosterone is involved in the process of renal allograft fibrosis, clinically manifest by proteinuria and allograft dysfunction, with increased risk for cardiovascular death. The treatment with aldosterone antagonists appears to be effective in controlling proteinuria, with a protective effect on progression of renal fibrosis. METHODS: This retrospective, cohort study included kidney transplant recipients from January 1993 to June 2015. Inclusion criteria were persistent proteinuria >0.5 g/d, longer than 6 months, and spironolactone therapy. RESULTS: One hundred forty transplant recipients fulfilled the inclusion criteria and were divided into 3 groups, according to proteinuria levels at the beginning of spironolactone therapy: low (<1 g/24 h), intermediate (1-3 g/24 h), and nephrotic (>3 g/24 h). Groups were comparable in demographic data, with a higher incidence of living related donors in the nephrotic group. In patients with proteinuria ≥1 g/d, we observed a significant reduction in proteinuria after 6 months of therapy that persisted over time. Blood pressure and glomerular filtration rate persisted stable over time. Adverse events were not severe to withdrawal therapy. CONCLUSIONS: Spironolactone can be a safe alternative to control post-transplant proteinuria, especially in patients with mild to moderate allograft dysfunction with proteinuria ≥1 g/day.

Nosocomial infections in renal transplant patients: risk factors and treatment implications associated with urinary tract and surgical site infections.

A prospective cohort study was conducted from January 2000 to December 2001 to determine the rate of bacterial nosocomial infections in renal transplant recipients. The patients were divided into two groups according to the origin of the allograft, namely deceased or living related donors. One hundred and sixty-three renal transplant recipients were reviewed during hospitalization; 110 (67.5%) kidneys were from deceased donors and 53 (32.5%) kidneys were from living related donors. The median length of hospitalization was 12 days for transplants from living related donors and 26 days for transplants from deceased donors (P<0.0001). Twenty-one (39.6%) recipients of kidneys from living related donors and 68 (61.8%) recipients of kidneys from deceased donors had bacterial nosocomial infectious episodes (P=0.019). The post-transplant nosocomial infections diagnosed during hospitalization included urinary tract infections (UTIs) (44.8%), surgical site infections (SSIs) (11%), pneumonia (6.1%), catheter-related bloodstream infections (4.2%) and others (1.8%). Risk factors for UTI included: recipient of kidney from a deceased donor, substitution of the initial immunosuppressive regimen, duration of urinary bladder catheterization, and length of hospitalization before the infection. Six Enterobacter cloacae strains with multiple resistances to antibiotics were identified in UTIs, and hospital dissemination was documented using molecular typing. UTI was the single most important hospital infection and was significantly higher in recipients of kidneys from deceased donors (P=0.001).

Use of aminophylline and enalapril in posttransplant polycythemia.

BACKGROUND: Posttransplant polycythemia (PTP) affects 6-30% of renal transplant recipients and can result in thromboembolic disease. The pathogenesis of PTP remains unknown and may be multifactorial. Although phlebotomy has previously been the treatment for PTP, drugs such as adenosine receptor antagonists or angiotensin-converting enzyme inhibitors can be used to control PTP. METHODS: The authors performed a prospective study of two different drugs to treat PTP: aminophylline and enalapril. Twenty-seven patients with PTP lasting more than 6 months were evaluated. During phase 1, aminophylline was compared with enalapril. The patients sequentially received aminophylline and enalapril during 12-week periods, intercalated by 12-week periods of no drugs. During phase 2, enalapril was administered for 12 weeks. RESULTS: From January 1984 to December 1993, 110 of 333 patients with PTP lasting more than 6 months (33%) developed polycythemia, and 27 patients were included in the present study. In phase 1, aminophylline had no effect on PTP. Enalapril promoted an erythropoiesis inhibition, characterized by a decrease in hematocrit and an increase in iron stores and ferritin levels. After withdrawal of enalapril, the hematocrit increased and the iron stores decreased. In phase 2, there was a progressive reduction in hematocrit after the 4th week of therapy. The lowest hematocrit was observed in the 12th week and then enalapril was stopped, leading to a subsequent rise in hematocrit. Erythropoietin levels and renal function remained constant during all periods of both phases of the study. CONCLUSION: The use of adenosine antagonists was ineffective to treat PTP in our series. However, treatment with enalapril promoted an erythropoiesis inhibition, demonstrated by a reduction in hematocrit, hemoglobin, red blood cell count, and reticulocyte count, associated with an increase in iron stores. This response occurred independently from erythropoietin levels or hemodynamic graft changes.

Hyperuricemia exacerbates chronic cyclosporine nephropathy.

BACKGROUND: Hyperuricemia frequently complicates cyclosporine (CSA) therapy. The observation that longstanding hyperuricemia is associated with chronic tubulointerstitial disease and intrarenal vasoconstriction raised the hypothesis that hyperuricemia might contribute to chronic CSA nephropathy. METHODS: CSA nephropathy was induced by the administration of CSA (15 mg/kg/day) for 5 and 7 weeks to rats on a low salt diet (CSA group). The effect of hyperuricemia on CSA nephropathy was determined by blocking the hepatic enzyme uricase with oxonic acid (CSA-OA). Control groups included rats treated with vehicle (VEH) and oxonic acid alone (OA). Histological and functional studies were determined at sacrifice. RESULTS: CSA treated rats developed mild hyperuricemia with arteriolar hyalinosis, tubular injury and striped interstitial fibrosis. CSA-OA treated rats had higher uric acid levels in association with more severe arteriolar hyalinosis and tubulointerstitial damage. Intrarenal urate crystal deposition was absent in all groups. Both CSA and CSA-OA treated rats had increased renin and decreased NOS1 and NOS3 in their kidneys, and these changes are more evident in CSA-OA treated rats. CONCLUSION: An increase in uric acid exacerbates CSA nephropathy in the rat. The mechanism does not involve intrarenal uric acid crystal deposition and appears to involve activation of the renin angiotensin system and inhibition of intrarenal nitric oxide production.

Urine cytology as a screening method for polyoma virus active infection.

Polyoma virus nephropathy (PVN) occurs in 3% to 4% of renal transplants, causing graft loss in about 50% of cases. The presence of viral cytopathic changes in graft epithelial cells is the only diagnostic tool for PVN. However, identification of cells with viral inclusions (decoy cells) in urine can be used as a screening tool for viral replication of or for active infection with PV. The aim of the present study was to identify the occurrence of PV active infection in renal transplant recipients. Two hundred forty urine cytology samples, collected from 80 transplant patients with stable renal function, were collected on a monthly basis and stained with the Pap smear for decoy cells. Active infection with polyoma virus was confirmed by urine immunostaining. All samples were analyzed blindly and classified as negative or positive (>1 decoy cell/sample). Among 240 urine cytologies collected from 48 men and 32 women, decoy cells were identified in 37.5%. No differences were observed in serum creatinine or immunosuppressive regimen between patients with positive versus negative cytology. No graft losses occurred secondary to PVN in the present study setting. The incidence of decoy cells in this series (37.5%) was consistent with previous reports (20% to 40%), suggesting that active infection may be confirmed by PV immunohistochemistry. The absence of PVN in this group may be attributed to the low doses of immunosuppressive drugs in the late posttransplant transplant period, but also to the unknown incidence of polyoma virus infection in Brazil.

Percutaneous renal graft biopsy: a clinical, laboratory and pathological analysis.

CONTEXT: Renal allograft biopsies have been used as a good method for monitoring the evolution of kidney transplants for at least 20 years. Histological analysis permits differential diagnosis of the causes of allograft dysfunction to be made. OBJECTIVES: To correlate the data of urinalysis and serum creatinine with histological diagnosis of renal graft in a group of renal transplant patients. DESIGN: Accuracy study, retrospective analysis. SETTING: A university terciary referral center. SAMPLE: 339 percutaneous allograft biopsies obtained from 153 patients. Blood and urine samples were obtained before the graft biopsy. MAIN MEASUREMENTS: Laboratory evaluation and hystological analysis (light microscopy, immunofluorescent electronic microscopy). RESULTS: Most of the biopsies (58.9%) were performed during the first month post-transplant. An increase in serum creatinine was associated with acute tubular and/or cortical necrosis. Proteinuria and normal serum creatinine were associated with glomerular lesions. Non-nephrotic range proteinuria and an increase in serum creatinine were associated with chronic rejection. CONCLUSION: Evaluation of serum creatinine and urinalysis can be useful in suggesting the histological graft diagnosis.

[Spontaneous spinal extradural hematoma. A rare complication during anticoagulant therapy]. / Hematoma espinhal extradural espontâneo. Rara complicação durante terapia anticoagulante.

A 42-year-old woman with metallic valve prosthesis in aortic position, in use of oral anticoagulant, presented a sudden syndrome of medullary compression, characterized by intense dorsal pain and partial paralysis of the inferior portion of the body, progressing to flaccid paraplegia of the arms and legs with level of sensibility in T-2. Large extradural spinal hematoma of the thoracic spine was diagnosed by magnetic resonance with medulla compression in the proximal portion. The patient was underwent to surgery (decompressive laminectomy), however with little motricity improvement and the level of sensibility. Due to respiratory insufficiency the patient died.

C4d deposits in borderline rejection: an early marker for chronic renal dysfunction?

The impact of borderline rejection in renal graft remains controversial. The aim of this study was to analyze the presence of C4d deposits in peritubular capillaries and macrophage infiltration in renal biopsies with diagnosis of borderline rejection ant its effect on graft function. Thirty-one renal transplant recipients with a diagnosis of borderline rejection were included. Initial and sequential biopsies were analyzed for morphology, C4d, and macrophage staining and compared with clinical data. Initial biopsies showed 12 samples to be C4d positive, associated with a higher incidence of delayed graft function, earlier post-transplantation time, higher acute tubular necrosis score, capillaritis, and glomerular macrophage infiltration, and a lower level of tubulitis, interstitial fibrosis, and tubular atrophy compared with the C4d-negative samples. In sequential biopsies, 5 patients from the negative group turned C4d positive. Patients with ≥1 positive C4d biopsy (n = 17) showed lower renal graft function at 6 months (1.8 ± 0.8 vs 1.4 ± 0.5 mg/dL; P < .01), 1 year (2.1 ± 1 vs 1.5 ± 0.5 mg/dL; P < .01), and 2 years (2.3 ± 1.3 vs 1.5 ± 0.7 mg/dL; P < .05) of follow-up. The expression of C4d in peritubular capillaries of renal biopsies classified as borderline rejection was associated with a worse prognosis for the renal allograft.

Urinary tract infection in renal transplant recipients: incidence, risk factors, and impact on graft function.

INTRODUCTION: Urinary tract infection (UTI) is the most common infection posttransplant. However, the risk factors for and the impact of UTIs remain controversial. The aim of this study was to identify the incidence of posttransplant UTIs in a series of renal transplant recipients from deceased donors. Secondary objectives were to identify: (1) the most frequent infectious agents; (2) risk factors related to donor; (3) risk factors related to recipients; and (4) impact of UTI on graft function. PATIENTS AND METHODS: This was a retrospective analysis of medical records from renal transplant patients from January to December 2010. Local ethics committee approved the protocol. RESULTS: The incidence of UTI in this series was 34.2%. Risk factors for UTI were older age, (independent of gender), biopsy-proven acute rejection episodes, and kidneys from deceased donors (United Network for Organ Sharing criteria). For female patients, the number of pretransplant pregnancies was an additional risk factor. Recurrent UTI was observed in 44% of patients from the UTI group. The most common infectious agents were Escherichia coli and Klebsiella pneumoniae, for both isolated and recurrent UTI. No difference in renal graft function or immunosuppressive therapy was observed between groups after the 1-year follow-up. CONCLUSIONS: In this series, older age, previous pregnancy, kidneys from expanded criteria donors, and biopsy-proven acute rejection episodes were risk factors for posttransplant UTI. Recurrence of UTI was observed in 44%, with no negative impact on graft function or survival.