Efficacy of early biopsy in kidney allograft recipients with delayed graft function

It is accepted that kidney transplants that display delayed graft function (DGF) show poorer survival and function, particularly when an acute rejection episode (ARE) occurs. A diagnostic biopsy to establish the reason for DGF, or acknowledge an ARE, even if borderline, can improve short- and long-term graft survivals. From January 2002 to September 2006 we retrospectively evaluated 358 kidney transplant recipients. We performed a biopsy to evaluate the cause of DGF in all patients who required dialysis, or had serum creatinine levels that increased, remained unchanged, or decreased less than 10% per day on three consecutive days during the first week after transplantation. An ARE was found in 18.8% (n = 19) of the biopsies. Early biopsy for patients with DGF is a safe method that allows uncovering of an ARE that would otherwise be undetected. The immediate recognition and treatment of rejection episodes can certainly increase long-term survival and function of renal transplants.     

Pretransplant calcium levels have no predictive value for delayed graft function, long-term graft function, cardiovascular events, or graft and patient survival in renal transplantation

BACKGROUND: Disorders of calcium homeostasis are one of the most common problems in patients with end-stage renal disease (ESRD). Elevated calcium levels increase the incidence of cardiovascular mortality in ESRD patients, and appear to be a risk factor for the occurrence of delayed graft function (DGF) after kidney transplantation. Therefore, we investigated the impact of pretransplant serum calcium levels on outcomes after kidney transplantation: DGF, acute rejection, graft function, and survival, as well as the incidence of cardiovascular events. METHODS: We studied 285 patients (96.9% of all transplanted patients) who underwent their first transplantation between 1995 and 2004. Demographic data were extracted from hospital records or were documented during follow-up; serum samples were collected at the time of transplantation. RESULTS: In our cohort the incidence of DGF was 16.5% and 35.4% of acute rejection episodes (ARE). However, pretransplant calcium levels were not related to DGF or ARE in our patient cohort. Furthermore, there was no correlation between pretransplant serum calcium level with the incidence of cardiovascular events or mortality, as well as graft function or survival. CONCLUSION: In our study population pretransplant calcium levels showed no effect on DGF, ARE rate, the occurrence of cardiovascular events or death, renal graft function, or survival. Therefore, pretransplant calcium level is not a helpful marker for risk stratification at the time of transplantation.     

Addition of isradipine (Lomir) results in a better renal function after kidney transplantation: a double-blind, randomized, placebo-controlled, multi-center study

BACKGROUND: After successful kidney transplantation patients may suffer from the adverse effects due to the use of calcineurin inhibitors. Calcium channel blockers are effective in the treatment of hypertension and may ameliorate cyclosporine- (CsA) induced impairment of renal function after kidney transplantation. Calcium channel blockers may also modulate the immune-system which may result in reduction of acute rejection episodes. PATIENTS AND METHODS: From June 1995 till 1997 the effect of isradipine (Lomir) on renal function, incidence and severity of delayed graft function (DGF), and acute rejection after kidney transplantation, was studied in 210 renal transplant recipients, who were randomized to receive isradipine (n=98) or placebo (n=112) after renal transplantation in a double-blind fashion. RESULTS: In the isradipine group renal function was significantly better at 3 and 12 months (P=0.002 and P=0.021) compared with the placebo group. DGF was present in both groups: isradipine: (28+6)/98 (35%); placebo: (35+9)/112 (40%), P=0.57. Severity of DGF was comparable in both groups (isradipine: 9.1+/-8.7 vs. placebo: 9.3+/-8.1 days). No statistical difference was found in incidence or severity of biopsy-proven acute rejection [isradipine: (42+6)/98 (49%) versus placebo: (46+9)/112 (49%), P=1.00]. Renal vein thrombosis was observed in eight patients. This proved to be associated with the route of administration of the study medication [6/45 (13%) on i.v. medication versus 2/165 (1%) on oral medication, P<0.001]. CONCLUSIONS: Addition of isradipine results in a better renal function after kidney transplantation, without effect on incidence or severity of DGF or acute rejection.     

Clinical Implications of Initial Renal Function After Deceased Donor Transplant

The aim of this study was to investigate whether slow graft function (SGF) after transplantation of deceased-donor kidneys affected the prevalence of anemia or the glomerular filtration rate (GFR). We retrospectively evaluated the records of 534 kidney transplant patients who were classified based on their initial renal function, namely, immediate graft function (IGF), slow graft function (SGF), or delayed graft function (DGF). Among the 534 kidney transplant patients studied, the occurrences of each condition were IGF 104, SGF 133, and DGF 297. Six months after transplantation, a greater percentage of DGF patients were anemic compared with the others (P = .028). However, at 12 months after transplantation, SGF patients showed more anemia than the IGF group. DGF and SGF patients displayed similar GFR values at 18 and 24 months after transplantation. However, IGF patients displayed higher GFRs, even when subjects who experienced acute rejection episodes were censored (P = .004). The incidence of acute rejection episodes was similar among SGF and DGF patients. Patients displaying SGF after deceased-donor transplantation showed a greater tendency to be anemic than those displaying IGF. This study also suggested that SGF patients were at risk for acute rejection episodes and/or significantly reduced kidney function as measured by GFR.     

Ischemia-reperfusion injury-induced abnormal dendritic cell traffic in the transplanted kidney with delayed graft function

Delayed graft function (DGF) in kidney transplantation is associated with an increased risk of acute rejection. Myeloid dendritic cells (DCs) are involved in graft rejection, whereas plasmacytoid DCs may play a role in inducing tolerance. We evaluated the presence and phenotype of the DCs in renal graft biopsies of 15 patients with DGF collected before and 7-15 days after transplantation. Biopsies taken from normal patients and from transplant recipients with acute calcineurin inhibitors (CNIs) nephrotoxicity served as a control group. Specific markers of myeloid, plasmacytoid, and mature DCs were imaged by confocal microscopy and immunohistochemistry. In normal kidneys and pre-transplant biopsies, sparse niches of myeloid and plasmacytoid cells were found but these were significantly increased with few mature cells during DGF. This same pattern was seen in acute rejection but with overall higher cell numbers. In CNI nephrotoxicity, myeloid cells were slightly increased but plasmacytoid cells were significantly higher than in DGF. Using a pig model, we found that a short period of warm ischemia followed by reperfusion led to myeloid cell infiltration of the kidney. Our data suggest that ischemia-reperfusion injury may cause an imbalance between intragraft myeloid and plasmacytoid DCs, which might be related to DGF and acute rejection.     

Predictors of renal transplant histology at three months.

BACKGROUND: The quality of a damaged kidney, the complexity of the surgery, and the events in the first weeks after transplantation, such as delayed graft function (DGF) and acute rejection, may influence its histological appearance and long-term survival. The aim of this study was to evaluate the importance of these factors in predicting renal allograft histology at 3 months. METHODS: Prospective, protocol kidney biopsy specimens (n=112), obtained 3 months after transplantation, were scored for chronic damage by the Banff schema and evaluated by multivariate analysis against donor factors, implantation histology, prior recipient sensitization, ischemia, perioperative factors, and subsequent clinical events, such as DGF and acute rejection. RESULTS: Adequate samples were obtained in 102 of 112 biopsies and classified as chronic Banff grade 0 (n=22), grade I (n=56), grade II (n=23), or grade III (n=1). Acute Banff scores were minimal. DGF occurred in 49% and was the strongest predictor of tubulointerstitial damage at 3 months. DGF correlated with acute tubular necrosis on the implantation biopsy specimen and with the number of acute rejection episodes; DGF also correlated with the Banff grades of chronic glomerulitis, chronic interstitial fibrosis, and tubular atrophy scores (P<0.05-0.001) in the 3-month biopsy specimen. By multivariate analysis, chronic tubular atrophy was independently predicted by the presence of vascular disease in the donor biopsy specimen, DGF, and vascular rejection occurring within the first 3 months (P<0.05-0.001). Chronic interstitial fibrosis was unrelated to fibrosis in the donor biopsy specimen but was independently predicted by DGF, donor age, and vascular rejection (P<0.05-0.001). Vascular disease in the donor biopsy specimen correlated with chronic intimal thickening (r=0.36, P<0.01) and arteriolar hyalinosis score (r=0.54, P<0.001) on the 3-month biopsy specimen. Banff chronic intimal vascular thickening was independently predicted by donor biopsy specimen vascular grade, prior vascular rejection episodes, and renal cold ischemia time (P<0.05-0.01). There were no correlates with the mean cyclosporine (CsA) dose, blood levels, diagnosis of CsA toxicity, or cellular rejection within the first 3 months. CONCLUSIONS: This study has demonstrated that the quality of the donor organ at implantation was strongly predictive of subsequent renal histology in grafts functioning at 3 months. Vascular rejection and DGF had a significant long-term effect on graft damage, but cellular rejection and simple measures of CsA exposure did not.     

Effects of Ischemia-Reperfusion Injury in Kidney Transplantation: Risk Factors and Early and Long-Term Outcomes in a Single Center

Introduction

Ischemia-reperfusion injury (IRI) causes a high rate of delayed graft function (DGF), the most frequent complication in the immediate postoperative period after cadaveric donor kidney transplantation. Herein we evaluated the impact of donor and recipient characteristics on DGF development in terms of the incidence of acute rejection episodes, hospital stay, renal function, and long-term graft and patient survivals.

Materials and Methods

Between February 1998 and July 2011, 761 patients underwent cadaveric donor kidney transplantations. DGF was defined as the need for dialysis in the first week. Patients were subdivided according to initial graft function as immediate graft function (IGF) or DGF.

Results

DGF observed in 241 patients (31.6%) was associated independently with expanded criteria donors, extended cold ischemia time, Karpinsky histological score, and prior dialysis duration both univariate and multivariate analysis. The incidence of acute rejection episodes was 18.1% among the DGF group versus 1.3% in the IGF group (P < .01). DGF significantly reduced both graft and patient survivals at 6, 12, 36, and 60 months.

Conclusion

DGF was responsible for a longer hospital stay, worse early and long-term renal function, a higher incidence of acute rejection episodes as well as reduced graft and patient survivals.     

Delayed graft function requiring more than one‐time dialysis treatment is associated with inferior clinical outcomes

Delayed graft function (DGF) is a common complication of deceased donor kidney transplantation with negative impact on clinical outcomes. In a single‐center retrospective analysis, we compared patient and kidney survival, early renal function, and the incidence of acute rejection during the first year among all adult deceased donor kidney transplant patients without DGF, with DGF requiring one‐time and/or more than one‐time dialysis treatment between January 1, 2000, and December 31, 2008. Of 831 adult kidney transplant patients, 74 (8.9%) required one‐time and 134 (16.1%) more than one‐time dialysis treatment post‐transplantation, respectively. While DGF patients with one‐time dialysis treatment had comparable clinical outcomes to that of patients without DGF, patients with DGF requiring more than one‐time dialysis treatment had a 45% increased risk for death (HR 1.45, 95% CI 1.02, 2.05, p = 0.04) after adjustment for the differences in demographic and baseline characteristics. Furthermore, DGF patients with more than one‐time dialysis requirement displayed significantly lower renal function after recovery (OR 0.32, 95% CI 0.21, 0.49, p < 0.001, for eGFR ≥ 60 mL/min) and higher incidence of acute rejection during the first year (OR 1.66, 95% CI 1.11, 2.49, p = 0.015). Additional studies of therapeutic approaches to manage patients with prolonged DGF are needed.     

The impact of delayed graft function of the kidney on the pancreas allograft in simultaneous kidney-pancreas transplantation

It is unclear whether delayed graft function (DGF) of the kidney has any influence on pancreas graft function following simultaneous kidney-pancreas transplantation (SKPT). A subgroup analysis was conducted using data from a multicenter study to determine the impact of DGF of the kidney on pancreas graft function following SKPT. METHODS: Of the 297 SKPT patients, 24 (8%) had DGF of the kidney, defined as the need for dialysis during the first week posttransplant. Clinical parameters including patient and graft survival, incidence of acute rejection, and pancreas and renal function were compared between patients with and without DGF at 1 week, and at 1, 3, 6, and 12 months posttransplant. RESULTS: Demographic and transplant characteristics were similar between the two groups except for longer kidney and pancreas cold ischemia times, more males, and more primary cytomegalovirus (CMV) exposure in the DGF group (P <.05). No differences were seen in patient and graft survival rates, but the incidence of acute renal rejection was higher in patients with DGF (42%) than in those without DGF (15%, P =.001). More patients with DGF (25%) received oral hypoglycemic agents at 1-year posttransplant than in those without DGF (5%, P <.01). At 1 year, the mean serum creatinine was 1.8 mg/dL and 1.4 mg/dL in patients with and without DGF, respectively (P <.01). CONCLUSIONS: Patients with DGF of the kidney had a higher incidence of acute renal rejection and received oral hypoglycemic agents more often during the first year posttransplant compared to those who did not have DGF following SKPT.     

Delayed graft function in living-donor renal transplantation: 10-year experience

Background

Delayed graft function (DGF), a dialysis requirement within a week after transplantation, can occur in deceased-donor renal transplantation. DGF is rare, in living-donor renal transplantation (LDRT) and its incidence and risk factors have not been established.

Methods

We investigated the incidence and clinical characteristics of DGF in LDRT over 10 years. We compared HLA mismatches, panel reactive antibody status, frequency of nonrelated donors, donor age, sex match, recipient-donor body weight ratio, total ischemia time, and transplanted kidney weight between DGF and non-DGF patients.

Results

The incidence of DGF in LDRT was 1.6%, which differed from earlier reports. HLA mismatch, female recipient frequency, and nonrelated donors were higher among the DGF group, but no risk factor for DGF was significant after multivariate logistic regression analysis. Biopsy findings showed 2 cases to be associated with rejection, 1 with acute pyelonephritis and 1 with acute tubular necrosis. The cases with rejection resulted in graft failure within 3 years after transplantation, but the other cases were followed with favorable graft function.

Conclusions

The incidence of DGF among LDRT was lower than that reported earlier studies, and the factors previously reported to cause DGF were not associated with DGF herein. Because DGF with rejection responses has a poor prognosis, strenuous strategies, including biopsy, should be performed in cases of DGF after LDRT.     

Silent acute rejection during prolonged delayed graft function reduces kidney allograft survival

BACKGROUND: The relationship between the effects of early, silent, acute rejection (AR) and delayed graft function (DGF) on kidney allograft survival remain controversial, and the role of protocol biopsies during DGF is unclear. We hypothesized that protocol biopsies during DGF would reveal a high incidence of silent AR that may adversely affect long-term allograft survival. METHODS: We routinely carried out protocol biopsies in patients requiring dialysis 7 to 10 days posttransplant. We retrospectively examined the extent to which silent AR, diagnosed by protocol biopsies during prolonged DGF, may mediate the adverse effects of DGF on graft survival in 410 consecutive transplants using Cox proportional hazards analysis. RESULTS: By 40 days posttransplant, the cumulative incidence of AR was 57.2% among 65 patients who had a protocol biopsies during DGF, while it was only 15.1% among the 345 who did not need a protocol biopsy. Mild DGF (n=30) requiring one or two dialysis treatments had no effect on graft survival, but the unadjusted risk ratio (and 95% confidence interval) associated with more prolonged DGF (n=104) was 3.08 (2.09-4.52, P<0.0001). The risk for graft failure from AR detected on protocol biopsy was 2.91 (1.60-5.27, P=0.0004) and was similar to the risk from early AR in patients without DGF, 2.95 (1.72-5.07, P<0.0001). After taking the effects of AR into account, the risk of graft failure attributable to prolonged DGF was reduced to 1.76 (1.06-2.94, P=0.0294), suggesting that much of the risk of DGF was because of the risk of AR. CONCLUSIONS: Silent AR is common during DGF. Prolonged DGF is associated with reduced graft survival after kidney transplantation, and much of this association can be explained by silent AR. In the absence of data from randomized trials, protocol biopsies and treatment of silent AR during prolonged DGF appear to be warranted.     

Histopathologic evaluation of pretransplant biopsy as a factor influencing graft function after kidney transplantation: a 1-year observation

INTRODUCTION: Many factors affect long-term results in kidney transplantation including histologic damage as a independent predictor, such as chronic allograft/nephropathy in protocol biopsies and age-dependent lesions. Histopathologic findings correlate with the incidence of delayed graft function, renal function, and allograft survival, allowing a rather precise prediction of graft outcome. MATERIALS AND METHODS: We analyzed 92 renal thick needle preimplantation and 29 postexplantation biopsies. Biopsies were preserved in 4% formalin and immersed in paraffin. Optimal biopsies contained at least 10 glomeruli and at least 2 cross-sections of arteries. We analyzed tubulitis, intensity of acute tubular necrosis, inflammatory infiltration, glomerulonephritis, arterial hyalinization, arteritis, fibrosis, tubular atrophy, arterial intimal fibrosis, increase of mesangial matrix, and percentage of glomerulosclerosis. During the postoperative course we analyzed patients condition, exigency of postoperative dialysis, urine output, as well as serum concentrations of creatinine, urea, uric acid, and ions. During a 1-year observation period, we analyzed living recipients, graft loss, death with a functioning graft, incidence of nephropathy (CAN), and acute rejection episodes (ARE). RESULTS: We observed a significant correlation between immediate graft function (IGF) and lack of ATN in the pre-0 biopsy. We observed no correlation between renal function and arterial hyalinization and fibrosis, inflammatory infiltration, tubular atrophy. In the postoperative period, we observed a significant correlation between IGF and lack of interstitial fibrosis with significantly lower levels of creatinine, urea, and potassium and higher urine output early after transplantation. IGF and better function of the right kidney was correlated with shorter time to reach a creatinine level of 2 mg%. In the postoperative periods, we also observed a difference between renal function depending on gender. The presence of acute tubular necrosis, arterial fibrosis, lack of inflammatory infiltration in the pre-0 biopsy correlated with worse late renal function. Among explantation biopsies 65.5% showed signs of CAN, and 37.93%, histologic marks of ARE.     

Posttransplantation acute tubular necrosis: risk factors and implications for graft survival

Previous studies aimed at identifying the causes, risk factors, and outcome of kidney transplant recipients with delayed graft function (DGF) have yielded controversial results. We retrospectively analyzed the causes and risk factors for DGF in 263 cadaveric kidney transplantations from November 1988 to March 1997 in one center. Causes of DGF were assessed by postoperative graft evolution and graft biopsy. Univariate and multivariate analysis were used to investigate the risk factors for DGF induced by acute tubular necrosis (ATN). Seventy-six patients (29%) had DGF, which was caused by ATN in 70 patients (92.1%) and acute rejection (AR) in 6 patients (7.9%). Therefore, we focused on risk factors and consequences for ATN-induced DGF. In monofactorial analysis, ATN was significantly associated with greater weight and presence of an atheromatous disease in both donor and recipient. Other risk factors for ATN were older age of donor, recipient American Society of Anesthesiology (ASA) physical status category IV, cold ischemia time (CIT), and transplantation using the right kidney. The multivariate analysis showed that donor and recipient weight, donor age, transplantation using the right kidney, preservation in Eurocollins solution, ASA score, and CIT were associated with ATN. The incidence of rejection and renal function were not different at 3 months or 1 and 5 years. ATN is the main cause of DGF in kidney transplant recipients. ATN is caused by donor and recipient vascular background, grafting the right kidney, and CIT. ATN does not appear to have an adverse effect on long-term kidney function.     

Effect of histological damage on long-term kidney transplant outcome

BACKGROUND: Chronic renal allograft failure remains a major challenge to overcome. Factors such as donor quality, delayed graft function (DGF), acute rejection, and immunosuppression are known to affect long-term outcome, but their relationship to histological damage to graft outcome is unclear. METHODS: Protocol kidney biopsies (n=112) obtained at 3 months after transplantation yielded 102 with adequate tissue. Histology was scored by the Banff schema, and compared with implantation biopsies (n=91), repeat 12-month histology (n=39), decline in serum creatinine and serial isotopic glomerular filtration rate, onset of chronic allograft nephropathy (CAN), and actuarial graft survival censored for death with a functioning graft. RESULTS: At a median follow-up of 9.3 years, 20 patients had graft failure and 26 died with a functioning graft. Banff chronic nephropathy was present in 24% of 3-month biopsies, and was predicted by microvascular disease in the donor, cold ischemia, DGF, and acute vascular rejection (P<0.001). Acute glomerulitis at 3 months correlated with segmental glomerulosclerosis at 12 months, subsequent recurrent glomerulonephritis, and graft failure (P<0.01). Subclinical rejection at 3 months occurred in 29% of biopsies, correlated with prior acute rejection and HLA mismatch, and led to chronic histological damage by 12 months (r=0.25-0.67, P<0.05-0.001). Subclinical rejection, arteriolar hyalinosis, and tubulitis present at 3 months had resolved by 12 months. The 10-year survival rates for Banff chronic nephropathy were 90.4% for grade 0, 81.0% grade 1, and 57.9% for grades 2 or greater (P<0.01). Early tubulointerstitial damage at 3 months profoundly influenced graft survival beyond 10 years. CAN was predicted by kidney ischemia, 3-month chronic intimal vascular thickening, tubular injury, proteinuria, and late rejection. Chronic fibrointimal thickening of the small arteries and chronic interstitial fibrosis at 3 months independently predicted graft loss and decline in renal function (P<0.05-0.001). CONCLUSIONS: Early transplant damage occurs in the tubulointerstitial compartment from preexisting donor kidney injury and discrete events such as vascular rejection and DGF. Subsequent chronic damage and graft failure reflect accumulated previous injury and chronic interstitial fibrosis, vascular impairment, subclinical rejection, and injury from late rejection. CAN may be conceptualized as the sequelae of incremental and cumulative damage to the transplanted kidney. The duration of graft survival is dependent and predicted by the quality of the transplanted donor kidney combined with the intensity, frequency, and irreversibility of these damaging insults.     

Hypertension is an independent predictor of delayed graft function and worse renal function only in kidneys with chronic pathological lesions

BACKGROUND: Delayed graft function (DGF) has been identified as one of the principal correlates of poor graft survival in cadaveric renal transplantation. However, its risk factors and clinical predictors have been poorly elucidated. METHODS: We analyzed the risk factors of DGF with a specific emphasis on the role of histological damage of donor kidney. Then, we also studied the impact of DGF, and donor factors affecting DGF, on kidney graft function over the first year after engraftment in 100 consecutive cadaveric renal transplant (Tx) recipients. RESULTS: The organs displaying DGF (n=48) had a significantly higher degree of glomerular sclerosis and tubular atrophy (P<0.01), as well as of interstitial fibrosis and vascular damage (P<0.02) in time-zero biopsies. In patients who received an "ideal" organ for Tx (total histological score < or = 4), DGF showed a strong relationship with Deltaage D-R (70% increase of risk for donors 10 years older than recipients), and with the histological score (odds ratio 1.34). In contrast, donor hypertension was the most relevant variable independently associated with DGF (odds ratio 19.4) in patients receiving a suboptimal organ (histological score >4). Moreover, DGF and donor hypertension adversely affected graft function at 1 year, but only in Tx patients with a histological score >4 in time-zero biopsy. Of note, both patients with and those without DGF showed a very low incidence of biopsy-proven acute rejection (8.5 and 6.8%, respectively) and a rather short cold ischemia time (<16 hr). CONCLUSION: Our findings suggest that the quality of the transplanted organ and the occurrence of DGF are strictly related to each other and can influence graft function through apparently nonimmune mechanisms. In addition, long-standing donor hypertension is a strong independent variable affecting both DGF and graft function of suboptimal cadaveric kidneys, at least up to 1 year.     

Recurrent lupus nephritis in a rejected renal allograft

SUMMARY: The case of a 48-year-old female patient who underwent renal transplantation because of an end-stage renal disease after membranous glomerulonephritis (WHO class V) in systemic lupus erythematosus (SLE) is presented. the patient lost one cadaveric allograft immediately after transplantation because of renal vein thrombosis, presumably caused by anti-Cardiolipin antibodies. A second cadaveric allograft showed a stable function for several years before slowly deteriorating. an abrupt increase of serum creatinine led to the suspicion of a final episode of acute rejection. A biopsy was performed, which showed an overlap of rejection and recurrent iupus nephritis in an advanced chronically damaged allograft. the lupus nephritis recurred as the same WHO class V as in the native kidney, but without significant predictive clinical or serological signs of SLE activity. the case presented and a review of the literature indicate that the frequency of recurrent lupus nephritis might be underestimated, and earlier surveillance biopsies in transplanted SLE patients should be considered.     

Clinical significance of eosinophils in suspicious or borderline renal allograft biopsies

AIMS: Renal allograft biopsies play a critical role in renal transplantation. Acute rejection characterized by tubulitis and intimitis is of primary concern. There is an association between eosinophilic infiltrates and irreversible acute rejection; however, the significance of eosinophils in biopsies that fall short of the diagnostic threshold for acute rejection has not been well studied. This report describes clinical course, treatment and long-term outcome of 5 transplant recipients with biopsy histology that showed borderline changes associated with eosinophilic infiltrates. METHODS: Clinical records were selected for review on the basis of biopsy histology satisfying the following criteria: presence of interstitial infiltrates with eosinophils, absence of definitive criteria for acute rejection and absence of findings suggestive of infection or cyclosporine toxicity. RESULTS: All identified biopsies occurred within the first month of transplantation, and histology showed varying degrees of patchy mononuclear cell infiltrates composed of lymphocytes, with eosinophilic infiltrates, but no evidence of acute rejection based on Banff criteria. These patients were taking trimethoprim-sulfamethoxazole and ranitidine at the time of biopsy. Serum creatinine returned to baseline levels in each case after stopping both drugs, and remained stable during the duration of follow-up without any documented episode of acute rejection. No patient received specific therapy for acute rejection. CONCLUSION: This report suggests that independent of decisions on treatment with high-dose steroids or anti-lymphocyte antibody preparations, the management algorithm should include stopping drugs associated with acute interstitial nephritis when non-diagnostic biopsies show eosinophilic infiltrates.     

Utility of protocol biopsy for the early diagnosis of transplanted kidney dysfunction

Abstract:  We performed protocol kidney biopsies for the early diagnosis of asymptomatic histopathological acute rejection (AR), commonly defined as subclinical rejection and drug nephrotoxicity. Forty-seven kidney recipients that had asymptomatic and stable kidney function underwent protocol biopsies both one month and one yr after kidney transplantation. The protocol biopsies one month after transplantation revealed borderline change in 13 of 47 cases (27.6%). AR 1a was observed in eight cases (17.2%) and AR 1b was observed in three cases (6.4%). The AR 1a and AR 1b groups were treated with methyl prednisolone pulse and deoxyspergualin. Toxic tubulopathy was found in four cases (8.5%). In the cases of nephrotoxicity, cyclosporine or tacrolimus was reduced. The borderline change group was observed without any additional treatment. Every case diagnosed with acute rejection one month after transplantation improved histopathologically one yr after transplantation, and the borderline change group partially remained borderline change and partially improved histopathologically one yr after transplantation. The nephrotoxicity group improved histopathologically one yr after transplantation. In our institution, protocol biopsies one month and one yr after kidney transplantation proved useful in screening for subclinical rejection and toxic tubulopathy and subsequently effective in improving long-term graft survival.     

Delayed graft function: risk factors, consequences and parameters affecting outcome-results from MOST, A Multinational Observational Study

BACKGROUND: Delayed graft function (DGF) is a common complication after renal transplantation, and may affect graft function. The aim of this analysis was to evaluate risk factors for DGF, as well as parameters and events influencing graft function after DGF. We analyzed data collected in an ongoing international, prospective; observational study, the Neoral-MOST (Multinational Observational Study in renal Transplantation), and included in the analysis all patients with cadaveric kidney transplants for whom renal function at 1 year posttransplantation was documented (N = 8950). Logistic regression was used to evaluate the risk factors for DGF occurrence, and multifactorial analysis of variance (ANCOVA) to assess the relevance of different factors for GFR at 1 year. RESULTS: Higher donor age, longer CIT, male recipients, Caucasian recipients, high recipients body mass index, and PRA were all associated with a higher risk for DGF. Renal function of former DGF kidneys at 1 year was lower in kidneys of elder donors, or which had experienced rejection or CMV infection. Variations of the maintenance regimen at 1 year posttransplantation were not associated with better graft function. Multifactorial analysis showed donor age and acute rejection as significant independent factors. CONCLUSIONS: Most factors increasing the risk for DGF or having a negative impact on renal function at 1 year in grafts with DGF are predetermined. Additional posttransplant damage by acute rejection was associated with further reductions in GFR. Preventing acute rejection is an important step in achieving optimal function of DGF grafts.     

Is patchy tubular injury a histopathological marker of acute rejection?

Abstract:  Renal allograft specimens often show patchy tubular injury (PTI), or patches of injured tubular sections. PTI reflects damage to the proximal tubules, and the histologic findings consist of tubular cell necrosis and tubular regeneration without tubulitis. Unlike acute tubular necrosis (ATN) in cadaveric donors, PTI can be observed in kidneys from living donors when there is no history of acute renal failure after transplantation. In this study, we examined the clinicopathological importance of PTI in acute rejection. Between April 2000 and May 2007, 2252 biopsies of living kidney grafts were performed at least one d after the transplant operation. Acute rejection was observed in 877 biopsies. Of these cases, 78 (8.9%) biopsies from 43 patients showed PTI. The severity of the PTI was graded semiquantitatively as follows: grade 1 cases had three or four damaged tubular sections, grade 2 cases had >5 sections, and grade 3 cases had >10 sections. The incidence of PTI was significantly higher in vascular rejection (VR) and antibody-mediated rejection (AMR) patients than in those experiencing tubulointerstitial rejection (TIR). The mean PTI score was significantly higher (2.00 ± 0.12) in VR than in TIR (1.39 ± 0.10) and AMR (1.68 ± 0.08) patients. The mean serum creatinine (sCr) at the time of biopsy was higher in VR patients than in AMR and TIR patients. Moreover, in VR patients, those with severer PTI developed higher sCr levels. These data suggest that PTI has a strong relationship with local ischemic damage delegated by VR, and the severity of PTI could be a practical histological marker in acute vascular rejection.