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V Scantlebury

Publications and source records attributed to V Scantlebury.

At least 19 recordsLinked to original sources
PubMed2006

Differential pharmacokinetic interaction of tacrolimus and cyclosporine on everolimus.

OBJECTIVE: We characterized the pharmacokinetics of tacrolimus and everolimus in a combined immunosuppressive regimen. METHODS: This was an open-label exploratory trial in eight maintenance renal transplant patients with calcineurin inhibitor intolerance initially receiving mycophenolate mofetil (MMF) and tacrolimus. At enrollment, MMF was discontinued and replaced with everolimus 1.5 mg twice a day in study period 1 (days 1 to 10). In period 2 (day 11 to month 3), tacrolimus dose was reduced by half. RESULTS: At study entry tacrolimus trough level (C0) was 7.9 +/- 3.9 ng/mL and area under the curve over a dosing interval (AUC) was 132 +/- 56 ng x h/mL. The addition of everolimus in period 1 did not change tacrolimus exposure: C0 8.4 +/- 4.0 ng/mL, AUC 134 +/- 70 ng x h/mL. Everolimus pharmacokinetics in the presence of tacrolimus in period 1 were: C0 3.3 +/- 1.2 ng/mL, Cmax 10.4 +/- 5.1 ng/mL, AUC 58 +/- 20 ng x h/mL. When compared to pharmacokinetic data from a previous study in 47 renal transplant patients receiving everolimus at the same fixed dose (1.5 mg twice a day) with cyclosporine, everolimus exposure was 2.5-fold higher with cyclosporine relative to the data in this study with tacrolimus. After tacrolimus dose reduction in period 2, there was no clinically relevant change in everolimus exposure: C0 3.0 +/- 1.1 ng/mL, Cmax 8.2 +/- 1.3 ng/mL, AUC 49 +/- 10 ng x h/mL. CONCLUSIONS: Tacrolimus appears to have a minimal effect on everolimus blood levels compared with the influence of cyclosporine. The dose of everolimus when combined with tacrolimus needs to be higher than when combined with cyclosporine in order to reach a given everolimus blood level.

Adrenal Cortex Hormones↗
PubMed2001

Results of simultaneous and sequential pediatric liver and kidney transplantation.

BACKGROUND: The indications for simultaneous and sequential pediatric liver (LTx) and kidney (KTx) transplantation have not been well defined. We herein report the results of our experience with these procedures in children with end-stage liver disease and/or subsequent end-stage renal disease. PATIENTS AND METHODS: Between 1984 and 1995, 12 LTx recipients received 15 kidney allografts. Eight simultaneous and seven sequential LTx/KTx were performed. There were six males and six females, with a mean age of 10.9 years (1.5-23.7). One of the eight simultaneous LTx/KTx was part of a multivisceral allograft. Five KTx were performed at varied intervals after successful LTx, one KTx was performed after a previous simultaneous LTx/KTx, and one KTx was performed after previous sequential LTx/KTx. Immunosuppression was with tacrolimus or cyclosporine and steroids. Indications for LTx were oxalosis (four), congenital hepatic fibrosis (two), cystinosis (one), polycystic liver disease (one), A-1-A deficiency (one), Total Parenteral Nutrition (TPN)-related (one), cryptogenic cirrhosis (one), and hepatoblastoma (one). Indications for KTx were oxalosis (four), drug-induced (four), polycystic kidney disease (three), cystinosis (one), and glomerulonephritis (1). RESULTS: With a mean follow-up of 58 months (0.9-130), the overall patient survival rate was 58% (7/12). One-year and 5-year actuarial patient survival rates were 66% and 58%, respectively. Patient survival rates at 1 year after KTx according to United Network of Organ Sharing (liver) status were 100% for status 3, 50% for status 2, and 0% for status 1. The overall renal allograft survival rate was 47%. Actuarial renal allograft survival rates were 53% at 1 and 5 years. The overall hepatic allograft survival rate was equivalent to the overall patient survival rate (58%). Six of seven surviving patients have normal renal allograft function, and one patient has moderate chronic allograft nephropathy. All surviving patients have normal hepatic allograft function. Six (86%) of seven sequentially transplanted kidneys developed acute cellular rejection compared with only two (25%) of eight simultaneously transplanted kidneys (P<0.04). CONCLUSIONS: Simultaneously transplanted kidneys were less likely to develop rejection than sequentially transplanted kidneys in this series. This did not have any bearing on patient or graft survival rates. Mortality correlated directly with the severity of United Network of Organ Sharing status at the time of kidney transplantation. Candidates for simultaneous or sequential LTx/KTx should be prioritized based on medical stability to optimize distribution of scarce renal allografts.

Adolescent↗
PubMed2001

Kidney transplantation for end-stage renal failure in liver transplant recipients with hepatitis C viral infection.

BACKGROUND: End-stage renal failure after successful liver transplantation (LTx) has been described in up to 5% of patients. Kidney transplantation (KTx) has been the treatment of choice in these cases. However, in recipients infected with hepatitis C virus (HCV), the augmentation of immunosuppression after KTx may result in an increased viral load. This, in turn, may adversely affect the liver allograft. METHOD: The present study retrospectively examined the outcome in 17 patients (3 females and 14 males, mean age 51.1+/-11.3 years) who received KTx after LTx. The mean interval from LTx to KTx was 57.6+/-32.1 months. The mean follow-up was 41.7+/-20.5 months after KTx, and 99.6+/-37.7 months after LTx. Sixteen of the 17 patients received tacrolimus-based immunosuppression at the time of KTx. RESULTS: During the follow-up period, one patient underwent combined liver and kidney retransplantation 3.7 years after KTx and 12.7 years after LTx. She subsequently died secondary to primary nonfunction. Four other patients died, two of lung cancer, one of pancreatitis/sepsis, and one of severe depression leading to noncompliance. A total of 29 episodes of biopsy-proven acute renal allograft rejection (1.7 episodes/ patient) were encountered and treated with steroids. Seven patients experienced a rise in liver function tests during the period of increased steroid dosage. Four patients received no treatment, and their liver function returned to baseline. The remaining three were treated with interferon. Overall 1- and 3-year actuarial patient and liver allograft survival was 88% and 71% (after renal transplantation); corresponding 1- and 3-year actuarial graft survival was 88% and 61%. Twelve patients are alive with normal liver function. One patient is on dialysis, because of renal allograft loss to noncompliance. CONCLUSION: In this series, LTx recipients with HCV infection were able to undergo KTx with a reasonable degree of success. KTx should be offered for end-stage renal failure after LTx, even in the presence of HCV infection, to individuals with stable liver function and no signs of liver failure.

Adult↗
PubMed2000

Biopsy of marginal donor kidneys: correlation of histologic findings with graft dysfunction.

BACKGROUND: Kidney biopsies are being used to evaluate marginal donors, but rigorous statistical validation of this practice with multivariate analysis has not been performed. METHODS: To analyze histologic parameters in 78 donor biopsies for their ability to predict graft dysfunction, we used a proportional odds model that included both donor and recipient factors. Glomerulosclerosis was categorized into grades 0, 1, 2, and 3, corresponding to 0, 1-10%, 11-20%, and 21-30% global sclerosis, respectively. The degrees of interstitial fibrosis, tubular atrophy, arteriosclerosis, and arteriolar hyalinosis were graded from 0 to 3+, using definitions suggested by the Banff Schema of allograft pathology. RESULTS: Increasing donor age was associated with higher glomerulosclerosis, tubular atrophy, and arteriosclerosis. Kidneys with any degree of interstitial fibrosis were 2.6 times [odds ratio (OR)] more likely to experience a worse outcome at 6 months (P = 0.02). This association held up after correction for acute rejection (OR 2.5, P = 0.03) and high panel-reactive antibody (OR 3.4, P = 0.006), However, the OR was reduced to 1.9 (P = 0.15) after controlling for recipient age. With each increment in the grade of glomerulosclerosis, the odds for a worse outcome at 12 months increased to 2.3 (P = 0.005). The value for OR became 2.0 (P = 0.03) when controlling for recipient age (P = 0.01), 2.4 (P = 0.005), when controlling for acute rejection, and 2.3 (P = 0.006) when controlling for high panel-reactive antibody. CONCLUSIONS: Histopathological parameters present in donor biopsies can independently predict post-transplant graft function. Implications for the pool of donor organs available for transplantation are discussed.

Adolescent↗
PubMed2000

Acute renal allograft rejection with severe tubulitis (Banff 1997 grade IB).

Recent studies have correlated renal allograft function with individual histologic lesions defined in the Banff schema of kidney transplantation pathology. The clinical significance of severe tubulitis (Banff 97 grade t3) has not been specifically examined. We compared the clinical course and response to antirejection therapy in 36 patients with t3 tubulitis, and 137 patients with milder grades of tubulitis and varying grades of intimal arteritis. Rejection associated with severe tubulitis (grade t3) was associated with graft outcome that was worse than mild to moderate tubulitis (grades t1 or t2) and approached that seen in grade v1 intimal arteritis. Rejection characterized by grade v2 or v3 intimal arteritis had worse prognosis than v1 intimal arteritis and all grades of tubulitis without coexisting intimal arteritis. These observations validate the Banff 97 recommendation that the severity of both tubulitis and intimal arteritis needs to be graded in renal allograft biopsies. In addition, grade t3 tubulitis is identified as a lesion which should be a cause for clinical concern.

Acute Disease↗
PubMed1999

Epstein-Barr virus-related disorders in children undergoing renal transplantation with tacrolimus-based immunosuppression.

In children undergoing renal transplantation, Epstein-Barr virus- (EBV) related disorders, including posttransplant lymphoproliferative disorder, constitute a major complication associated with tacrolimus-based immunosuppression. In this study, we reviewed the EBV complications in 81 children, all of whom had EBV serological studies before renal transplantation. We also highlight the data in a subgroup of 30 children transplanted more recently who were monitored sequentially for EBV symptoms and signs and with immunological studies, and in whom the donor EBV serology was also determined. During a mean follow-up time of 3.9+/-2.3 years, 19 children developed symptomatic Epstein-Barr virus (EBV*) infection. This consisted of the clinical syndrome of infectious mononucleosis in 7 children; in addition, 10 children developed posttransplant lymphoproliferative disorder (PTLD), which was histologically confirmed in 8, and 2 others developed malignant lymphoma. Recipient seronegativity (EBV-) and donor EBV seropositivity (EBV+) predicted a high probability for seroconversion (P=0.0072) and for developing PTLD or malignancy (P<0.01). In the subgroup of 30 children studied prospectively, seroconversion occurred in 15 of 19 seronegative recipients of EBV seropositive grafts at 6.6+/-2.6 months (mean+/-SD) after transplantation. Seven children developed symptomatic EBV infection (including three with PTLD) in association with seroconversion and a rise in EBV viral load in the peripheral blood, demonstrated by an EBV-specific polymerase chain reaction (EBV-PCR). Of 15 seroconverters, 7 who developed symptomatic infection had received EBV+ grafts; 8 others with EBV+ grafts seroconverted but did not become symptomatic. These two subgroups did not differ in age, rejection rate, antiviral prophylaxis, or level of immunosuppression. In the overall group of 81 children, only the two with malignant lymphoma who were managed with chemotherapy had substantial morbidity. The 10 individuals with PTLD received a regimen combining i.v. ganciclovir and CytoGam, and stopping or reducing the tacrolimus. Four children with associated marked tonsilar growth underwent tonsillectomy. All 19 individuals with EBV disorders resolved their symptoms and signs, and all have maintained good allograft function during a follow-up time of 3.0+/-2.5 years (mean+/-SD) after the development of symptomatic EBV infection, PTLD, or malignancy. We conclude that seronegative recipients of EBV+ grafts are at high risk for developing EBV-related disorders after renal transplantation under tacrolimus-based immunosuppression, although the ultimate clinical outcomes have been remarkably good. These data form the basis for formulating strategies for early identification of children at risk for EBV complications, and for instituting preventive and treatment strategies that permit these children to realize the substantial benefits offered by tacrolimus-based immunosuppression.

Adolescent↗
PubMed1999

Clinical significance of renal biopsies showing concurrent acute rejection and tacrolimus-associated tubular vacuolization.

BACKGROUND: The clinical significance of biopsies showing both rejection and isometric tubular vacuolization has not been well defined in the literature. METHODS: The clinical picture, sequential histopathologic findings, and response to therapy were compared between 24 renal allograft biopsies showing both tubular vacuolization and rejection and 14 biopsies showing vacuolization alone. RESULTS: The rejection was categorized as grade 1 in 4/24 (16.6%), grade 2A in 10/24 (41.6%), and grade 2B in 10/24 (41.6%) cases (Banff schema, 1993-1995). Treatment with additional steroids and tacrolimus led to a decrease in the interstitial inflammation score (2.6+/-0.1 to 1.3+/-0.1, P<0.001), tubulitis score (2.6+/-0.1 to 1.1+/-0.1, P<0.001), and serum creatinine (4.4+/-2.2 mg/dl to 3.3+/-2.6 mg/dl, P=0.001). Complete response, partial response and no response to antirejection therapy were observed in 16/24 (66.7%), 3/24 (12.5%), and 5/24 (20.8%) patients, respectively. Although there was a rise in the plasma (1.4+/-0.2 ng/ml to 2.8+/-0.3 ng/ml, P<0.001) and whole blood (16.5+/-2.8 ng/ml to 31.2+/-5.7 ng/ml, P<0.001) tacrolimus levels, repeat biopsy showed no change in the size or extent of tubular vacuolization (mean score 2.88+/-0.19 vs. 2.83+/-0.21). The morphologic characteristics of the tubular vacuoles in these cases did not differ from those observed in 14 cases of tacrolimus nephrotoxicity not complicated by rejection. CONCLUSION: Patients with concurrent acute rejection and tubular vacuolization usually benefit from increased immunosuppression. The pathogenesis of the vacuolization in this clinical setting is not clear, but may reflect immune-mediated tubular injury.

Acute Disease↗
PubMed1999

Human polyoma virus-associated interstitial nephritis in the allograft kidney.

BACKGROUND: Asymptomatic polyoma virus infection documented by urine cytology or serology is well known, but the clinical course of biopsy-proven interstitial nephritis is not well defined. METHODS: Twenty-two cases were identified by histology, immunostaining, in situ hybridization, electron microscopy, or polymerase chain reaction. RESULTS: The clinical features mimicked acute rejection (n=19), chronic rejection with incidental diagnosis at nephrectomy (n=2), or drug toxicity (n=1). Histology showed homogenous intranuclear inclusions. In situ hybridization showed BK virus (BKV) to be the predominant species, but polymerase chain reaction documented JC virus co-infection in one of five cases so tested. Electron microscopy in seven cases showed 20-51-nm virions. The two cases diagnosed at nephrectomy received no therapy. Initial antirejection therapy in 12 cases led to clearance of the virus in 1/12 (8%), partial therapeutic response in 3/12 (25%), and graft loss in 8/12 (67%) cases. The last recorded creatinine in patients with functional grafts ranged from 1.9 to 7.0 (median: 4.5) mg/dl, 0.4-45 (median: 4.0) months after initial diagnosis. The remaining eight cases treated by reduction of immunosuppression at the outset have been free of graft loss for 0.2-10.0 (median: 4.8) months since diagnosis, and clearance of virus has been documented in three of six (50%) cases. The serum creatinine in these patients is 1.7-6.0 (median: 2.4) mg/dl, 0.2-10 (median: 4.8) months after diagnosis. Follow-up biopsies performed 1-23.5 months after diagnosis show chronic allograft nephropathy. CONCLUSIONS: Polyoma virus tubulo-interstitial nephritis-associated graft dysfunction usually calls for judicious decrease in immunosuppression and monitoring for acute rejection. Development of methods to serially quantify the viral load in individual patients could potentially improve clinical outcome.

Adolescent↗
PubMed1999

Cytomegalovirus infection of the native ureter after liver-kidney transplantation.

We report a case of invasive cytomegalovirus (CMV) infection in the native ureter of a patient 7 years after liver-kidney transplantation. Previous reports of CMV ureteritis in transplant patients have involved only the allograft ureter, usually within 3 months of transplantation. The common characteristics of these patients, the possible risk factors, and the diagnostic findings of CMV ureteritis are discussed. Combined surgical and medical intervention are required for successful treatment.

Adult↗
PubMed1997

HLA and cross-reactive antigen group matching for cadaver kidney allocation.

BACKGROUND: Allocation of cadaver kidneys by graded human leukocyte antigen (HLA) compatibility scoring arguably has had little effect on overall survival while prejudicing the transplant candidacy of African-American and other hard to match populations. Consequently, matching has been proposed of deduced amino acid residues of the individual HLA molecules shared by cross-reactive antigen groups (CREGs). We have examined the circumstances under which compatibility with either method impacted graft survival. METHODS: Using Cox proportional hazards regression modeling, we studied the relationship between levels of conventional HLA mismatch and other donor and recipient factors on primary cadaver kidney survival between 1981 and 1995 at the University of Pittsburgh (n=1,780) and in the United Network for Organ Sharing (UNOS) Scientific Registry during 1991-1995 (n=31,291). The results were compared with those obtained by the matching of amino acid residues that identified CREG-compatible cases with as many as four (but not five and six) HLA mismatches. RESULTS: With more than one HLA mismatch (> 85% of patients in both series), most of the survival advantage of a zero mismatch was lost. None of the HLA loci were "weak." In the UNOS (but not Pittsburgh) category of one-HLA mismatch (n=1334), a subgroup of CREG-matched recipients (35.3%) had better graft survival than the remaining 64.7%, who were CREG-mismatched. There was no advantage of a CREG match in the two- to four-HLA incompatibility tiers. Better graft survival with tacrolimus was observed in both the Pittsburgh and UNOS series. CONCLUSIONS: Obligatory national sharing of cadaver kidneys is justifiable only for zero-HLA-mismatched kidneys. The potential value of CREG matching observed in the one-HLA-mismatched recipients of the UNOS (but not the Pittsburgh) experience deserves further study.

Adolescent↗
PubMed1997

Clinical significance of renal allograft biopsies with "borderline changes," as defined in the Banff Schema.

BACKGROUND: The Banff Schema suggests the term "borderline changes" for biopsies showing changes insufficient for a diagnosis of mild acute rejection. The appropriate clinical management for patients showing such changes on biopsy is controversial. METHODS: We reviewed the clinical course and response to antirejection therapy of 24 patients with borderline changes, and compared our findings with those obtained from 14 patients with mild acute rejection. Patients were classified as showing complete response, partial response, or no response to antirejection treatment, depending on whether the posttreatment fall in serum creatinine was >70%, 30-70%, or <30% of the pretreatment rise, respectively. Renal allograft biopsies were systematically evaluated in accordance with the Banff schema. RESULTS: Complete response to antirejection therapy was seen in 15/24 (63%), partial response in 3/24 (13%), and nonresponse in 6/24 (25%) patients with borderline change. Compared with patients showing complete response, nonresponse was associated with higher scores of acute tubular necrosis and chronic allograft nephropathy (P<0.05). By comparison, 12/14 (86%) cases of mild acute rejection showed complete response to antirejection therapy (P=0.25 vs. patients with borderline change), and lack of response was associated with a higher score for chronic allograft nephropathy. CONCLUSION: When biopsies are done in the context of renal allograft dysfunction, borderline changes frequently require increased immunosuppression. These findings should not be extrapolated to protocol biopsies performed in the setting of stable graft function.

Adult↗
PubMed1997

Clinical features of acute reversible tacrolimus (FK 506) nephrotoxicity in kidney transplant recipients.

This study was designed to (a) estimate the contribution of tacrolimus nephrotoxicity to episodes of renal allograft dysfunction investigated by needle biopsy, (b) describe the temporal evolution of nephrotoxicity and its response to therapy, and (c) ascertain how often renal dysfunction is associated with concurrent extra-renal toxicity. Patients were selected based on a rising serum creatinine, normal ultrasound, and biopsy findings leading to a reduction in the dose of tacrolimus and a fall in serum creatinine. Twenty two (17%) cases of nephrotoxicity were identified amongst 128 consecutive kidney transplant biopsies with sufficient clinical data for analysis. There were 13 males and 9 females, 17-75 yr in age. Tacrolimus was administered initially as a 0.075-0.1 mg/kg/d IV continuous infusion followed by an oral dose of 0.15 mg/kg twice daily. The onset of nephrotoxicity in this study occurred 1-156 wk post-operatively. The mean baseline creatinine was 212.2 +/- 168.0 mumol/l (range 88.4-875.2) and rose 40.6% +/- 14.2% (range 11-66) during episodes of nephrotoxicity (p < 0.001). The highest recorded plasma and whole-blood tacrolimus levels during the toxic episodes were respectively 2.7 +/- 0.8 ng/ml (range 1.1-3.5) and 31.6 +/- 10.6 ng/ml (range 14.5-50.5). The drug levels were considered to be beyond the therapeutic range in 18/22 (82%) patients. The highest tacrolimus level preceeded the rise in serum creatinine in 20 cases by an interval of 1.6 +/- 1.8 d. A mean reduction in tacrolimus dosage of 41% +/- 21% (range 11-89) led to a 86% +/- 18% (range 45-100) fall in the serum creatinine within 1-14 d (p < 0.001). Interactions between tacrolimus and clarithromycin, diltiazem, or itraconazole modified the pharmakokinetic parameters in three cases. Serum potassium > 5.0 mequiv/l was recorded in 9/22 (41%) cases. Three or more elevations in blood glucose > 7.7 mmol/l (140 mg/dl) were recorded in 4/11 (36%) non-diabetic patients. Hand tremors were seen in two (9%) cases and elevated diastolic blood pressure > 90 mmHg in seven (32%) patients. In conclusion, tacrolimus nephrotoxicity accounted for 17% of graft dysfunction episodes investigated by biopsy. Concurrent hyperglycemia, hyperkalemia, or tremors were noted in several patients. Nephrotoxicity responded well to reduction in the drug dosage.

Acute Disease↗