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B Kiberd

Publications and source records attributed to B Kiberd.

At least 19 recordsLinked to original sources
PubMed2006

Access to the kidney transplant wait list.

The study examines selection for kidney transplantation and determines who are referred, how many had contraindications and whether comorbidity indices predict transplant status. Of 113 consecutive adult incident end-stage renal disease (ESRD) patients at this single center 47 (41.6%) were referred. Using published guidelines, 48 (42.5%) had a specific contraindication. However 26 (23%) were neither referred nor had contraindications. An ESRD mortality score, acute renal failure status and albumin were independent predictors of referral but only the mortality score was predictive of contraindication status. The Charlson and ESRD comorbidity indices were less predictive of contraindication or referral status. In a comparison of patients who were Candidates (referred and no contraindication, n = 39) compared to those who were Neither (not referred and no contraindications, n = 26), age was the most discriminating factor (c = 0.99, 95% CI 0.97-1.00). Comorbidity and mortality indices were inferior. Neither patients were older (75 +/- 7 years) and had comorbidity scores that were higher than Candidates but similar to those with contraindications (ESRD index; Neither 3.3 +/- 2.5, Candidate 1.4 +/- 1.8, and contraindication 4.1 +/- 3.4). Comorbitity indices do not help explain selection practices whereas age is an important discriminator. How many Neither patients would benefit from transplantation is not known.

Acute Kidney Injury↗
PubMed2005

Hypertension-based clinical risk strategies for detecting microalbuminuria in diabetes.

BACKGROUND: Microalbuminuria screening to identify patients at risk of diabetic nephropathy is widely accepted. AIM: To investigate whether blood-pressure-based strategies can identify such patients without the need for microalbuminuria testing. METHODS: Spot urine for albumin/creatinine ratios was performed in all patients over an 18-month period. The performance of four combinations of clinical models, based on existing triggers for anti-hypertensive intervention (prior use and/or existing systolic BP exceeding 140 or 160 mmHg and/or dipstick proteinuria exceeding 1+ or 2+) was evaluated at microalbuminuria thresholds of 3.5 and 10 mg/mmol. The models were ranked 1 to 4, based on their escalating relative strengths in predicting need for intervention. RESULTS: Of 3748 patients, 1257 (34%) or 739 (20%) exceeded microalbuminuria thresholds of 3.5 or 10 mg/mmol. All four models predicted microalbuminuria risk (areas under ROC curves 0.60-0.77, all p < 0.001). The models (1-4) identified 2220, 2465, 2803 or 2937 for intervention, respectively, irrespective of microalbuminuria status, and missed 368, 232, 194 or 126 at 3.5 mg/mmol and 164, 87, 81 or 45 at 10 mg/mmol. DISCUSSION: Clinical models using routinely measured parameters reduced the target population for microalbuminuria screening by 60-80%, missing 3-10% of patients with albumin/creatinine ratios exceeding 3.5 mg/mmol or 1-4% of those exceeding 10 mg/mmol.

Albuminuria↗
PubMed2005

Basiliximab lowers the cyclosporine therapeutic threshold in the early post-kidney transplant period.

Early adequate cyclosporine exposure has been shown to predict low acute rejection rate in kidney transplantation. The aim of this study is to determine the importance of exceeding the early cyclosporine therapeutic exposure threshold with basiliximab induction. A retrospective analysis of 166 first cadaveric and non-identical live donor transplant recipients treated with or without basiliximab induction, Neoral, mycophenolate mofetil and prednisone, was performed. Adequate exposure was defined as a 2-h post-Neoral dose cyclosporine level (C2) >1700 ng/mL at day 3. The primary outcome was acute rejection within the first 6 months. In the no basiliximab (control) group (n = 74), rejection occurred in 23% (17 of 74) of recipients and was strongly associated with low cyclosporine exposure on day 3. Acute rejection occurred in 38% (11 of 29) with C2 <1700 ng/mL compared with 13% (six of 45) with C2 >/=1700 ng/mL (p = 0.014). In the basiliximab group (n = 92), rejection occurred in only 11% (10 of 92) of recipients and did not correlate with cyclosporine exposure. Acute rejection occurred in 10% (four of 40) with C2 <1700 ng/mL compared with 12% (six of 52) with C2 >/=1700 ng/mL (p = 0.81). Therefore achieving cyclosporine therapeutic targets by day 3 may not be required when anti-IL2 receptor antibody induction is used.

Acute Disease↗
PubMed2004

Therapeutic monitoring of cyclosporine in kidney transplantation: the Halifax experience.

Appropriate dosing of an immunosuppressive agent is critical to its efficacy and tolerability. Finding a simple and effective method of monitoring cyclosporine (CsA/CyA) has been formidable despite a long history of widespread usage. Earlier reports linked CsA dosing to trough levels (C0), whereas later more elaborate systems have evaluated efficacy linked to 12-hour area-under-the-curve (AUC(0-12)) as a measure of total drug exposure. Recent work done at our center and elsewhere has shown that the 2-hour postdose concentration (C2) to be simple and more effective than the C0 or the AUC. With C2 monitoring as a guide to CsA dosing, acute rejection (AR) and nephrotoxicity (NT) can be effectively reduced. Furthermore, absorption profile as per C2 levels further emphasizes the importance of achieving the targeted peak concentration in the first week of transplantation. The C2 concentration strategy is discussed in light of newer induction agents and other immunosuppression.

Administration, Oral↗
PubMed2003

Basiliximab widens the therapeutic window for AUC-monitored neoral therapy early after kidney transplantation.

Early adequate cyclosporine exposure has been shown to predict low acute rejection. Recently basiliximab induction has been added to immunosuppressive regimens to further reduce rejection. The aim of this study was to determine the importance of achieving the early cyclosporine therapeutic threshold with basiliximab induction. A retrospective analysis of first cadaver and nonidentical living donor transplant recipients treated with or without basiliximab induction was performed. All patients (n = 170) received neoral, mycophenolate mofetil, and prednisone. The cyclosporine absorption profile was measured on day 3. Adequate cyclosporine exposure was defined as area under the curve (AUC) 0-4: >4400 microg x h/L at day 3. The primary outcome was acute rejection (AR) within the first 6 month. In the no basiliximab (control) group, AR occurred in 22% (17/78) of recipients and was strongly associated with low cyclosporine exposure on day 3. AR occurred in 39% (9/23) with cyclosporine AUC0-4 < 4400 microg x h/L compared with 15% (8/55) with AUC0-4 > 4400 microg x h/L (P =.016). In the basiliximab group, AR occurred in only 9% (8/92) of recipients and did not correlate with cyclosporine exposure. AR occurred in 8% (2/24) with cyclosporine AUC0-4 < 4400 microg x h/L compared with 9% (6/68) with AUC0-4 > 4400 microg x h/L (P =.94). Achieving cyclosporine therapeutic targets by day 3 may not be required when anti-IL2 induction is used.

Antibodies, Monoclonal↗
PubMed2003

Tacrolimus monitoring by simplified sparse sampling under the concentration time curve.

The purpose of this study was to determine which tacrolimus pharmacokinetic parameters best predicted efficacy in kidney transplantation. Blood tacrolimus levels at 0, 1, 2, 3, and 4 hours postdose were measured in 28 kidney transplants. All received tacrolimus-based triple-drug therapy with mychophenolate mofetil and prednisone. Associations between blood concentrations at each sampling time point and the area under the curve (AUC) 0-4 were measured by Pearson's correlation coefficients. Tacrolimus dosing was based on C0 not AUC. AUC and blood concentrations at each sampling time were retrospectively compared with C0 as predictor of acute rejection and nephrotoxicity. Although tacrolimus C0 correlated with AUC0-4 (r =.86), correlations were higher with C2 and C3 (r =.96 and r =.94, respectively). C0 levels were not significantly different in six patients with acute rejection and 23 patients without. There was a trend toward lower tacrolimus C3 in patients with AR than without AR (P =.06). C2 and C3 correlate better with AUC0-4 than C0. Early tacrolimus C3 levels may be a better than C0 as a predictor of efficacy.

Adult↗
PubMed2003

Diabetes mellitus in transplantation: 2002 consensus guidelines.

Diabetes mellitus is a serious complication following organ transplantation that is underdiagnosed, possibly due to the inadequate definitions used in published literature and the lack of standardized screening. Diabetes in transplantation amplifies the already increased risk of cardiovascular disease among transplant patients, and increases the risk of graft loss and death. Patients at risk of developing diabetes in transplantation should therefore be prospectively identified and given individualized immunosuppressive therapy to minimize the risk of developing this disease. These guidelines are intended to: (1) help identify patients at risk for diabetes after transplantation; (2) set down a standard definition of posttransplant diabetes mellitus (PTDM); (3) create a standard monitoring protocol for the diagnosis of PTDM; and (4) optimize the management of patients at risk of developing or who develop diabetes after transplantation. With improved diagnosis, individualization of therapy, and proper early management, the incidence of diabetes in transplantation, and the accompanying additional burden of illness the disease carries, may be diminished. In turn, this will help achieve the therapeutic goals of reducing the risk of graft complications, improving quality of life, and reducing postoperative morbidity and mortality in transplant patients.

Consensus↗
PubMed2001

A pilot study of steroid-free immunosuppression in the prevention of acute rejection in renal allograft recipients.

BACKGROUND: Corticosteroids have been a mainstay of rejection prophylaxis for several decades, despite the multiple adverse effects of long-term use, including weight gain, hyperlipidemia, diabetes, hypertension, and bone disease. The detrimental effect of steroids on the metabolic profile begins in the early posttransplantation period, and the complete avoidance of steroids in transplantation would therefore be optimal. We hypothesized that the addition of mycophenolate mofetil (MMF) and a humanized monoclonal anti-CD25 antibody (daclizumab) to a cyclosporine (CsA microemulsion)-based immunosuppression protocol would permit transplantation without steroids. METHODS: Steroid-free renal transplantation was attempted in 57 patients treated with daclizumab, MMF, and CsA. Twenty-eight patients received kidneys from living donors; the remaining 29 received cadaveric grafts. RESULTS: At 1 year, patient and graft survival were 95% and 89%, respectively. Fourteen patients (25%) experienced rejections, of which 13 were readily reversed with steroids; 1 patient required OKT3. Mean serum creatinine at 12 months for patients not experiencing rejection was 149+/-58 micromol/L, compared with 158+/-102 micromol/L for those experiencing rejection. Five patients required hospitalization for infection; no patients developed lymphoproliferative disease. At baseline, 17 patients required 3 or more antihypertensive medications, compared with 2 patients at 1 year. Three of 43 nondiabetic patients developed diabetes during the study. There was no significant reduction in lumbar or femoral bone density. CONCLUSIONS: On the basis of these positive results, we believe steroid avoidance with this immunosuppressive regimen merits further study.

Acute Disease↗
PubMed2001

International Child Care Practices Study: infant sleeping environment.

BACKGROUND: The International Child Care Practices Study (ICCPS) has collected descriptive data from 21 centres in 17 countries. In this report, data are presented on the infant sleeping environment with the main focus being sudden infant death syndrome (SIDS) risk factors (bedsharing and infant using a pillow) and protective factors (infant sharing a room with adult) that are not yet well established in the literature. METHODS: Using a standardised protocol, parents of infants were surveyed at birth by interview and at 3 months of age mainly by postal questionnaire. Centres were grouped according to geographic location. Also indicated was the level of SIDS awareness in the community, i.e. whether any campaigns or messages to "reduce the risks of SIDS" were available at the time of the survey. RESULTS: Birth interview data were available for 5488 individual families and 4656 (85%) returned questionnaires at 3 months. Rates of bedsharing varied considerably (2-88%) and it appeared to be more common in the samples with a lower awareness of SIDS, but not necessarily a high SIDS rate. Countries with higher rates of bedsharing appeared to have a greater proportion of infants bedsharing for a longer duration (>5 h). Rates of room sharing varied (58-100%) with some of the lowest rates noted in centres with a higher awareness of SIDS. Rates of pillow use ranged from 4% to 95%. CONCLUSIONS: It is likely that methods of bedsharing differ cross-culturally, and although further details were sought on different bedsharing practices, it was not possible to build up a composite picture of "typical" bedsharing practices in these different communities. These data highlight interesting patterns in child care in these diverse populations. Although these results should not be used to imply that any particular child care practice either increases or decreases the risk of SIDS, these findings should help to inject caution into the process of developing SIDS prevention campaigns for non-Western cultures.

Beds↗
PubMed2000

Conversion to rapamycin immunosuppression in renal transplant recipients: report of an initial experience.

BACKGROUND: The aim of this study is to evaluate the effects of RAPA conversion in patients undergoing cyclosporine (CsA) or tacrolimus (Tac) toxicity. METHODS: Twenty renal transplant recipients were switched to fixed dose rapamycin (RAPA) (5 mg/day) 0 to 204 months posttransplant. Drug monitoring was not initially used to adjust doses. The indications for switch were chronic CsA or Tac nephrotoxicity (12), acute CsA or Tac toxicity (3), severe facial dysmorphism (2), posttransplant lymphoproliferative disorder (PTLD) in remission (2), and hepatotoxicity in 1. Follow-up is 7 to 24 months. RESULTS: In the 12 patients switched because of chronic nephrotoxicity there was a significant decrease in serum creatinine [233+/-34 to 210+/-56 micromol/liter (P<0.05) at 6 months]. Facial dysmorphism improved in two patients. No relapse of PTLD was observed. Five patients developed pneumonia (two Pneumocystis carinii pneumonia, one infectious mononucleosis with polyclonal PTLD lung infiltrate) and two had bronchiolitis obliterans. There were no deaths. RAPA was discontinued in four patients, because of pneumonia in two, PTLD in one, and oral aphtous ulcers in one. RAPA levels were high (>15 ng/ml) in 7 of 13 (54%) patients. CONCLUSIONS: RAPA conversion provides adequate immunosuppression to enable CsA withdrawal. However, when converting patients to RAPA drug levels should be monitored to avoid over-immunosuppression and adequate antiviral and Pneumocystis carinii pneumonia prophylaxis should be given.

Adult↗
PubMed2000

Is routine ureteric stenting needed in kidney transplantation? A randomized trial.

BACKGROUND: Whether routine ureteric stenting in low-urological-risk patients reduces the risk of urological complications in kidney transplantation is not established. METHODS: Eligible patients were recipients of single-organ renal transplants with normal lower urinary tracts. Patients were randomized intraoperatively to receive either routine stenting or stenting only in the event of technical difficulties with the anastomosis. All patients underwent Lich-Gregoire ureteroneocystostomy. RESULTS: Between June 1994 and December 1997, 331 kidney transplants were performed at a single center, 305 patients were eligible, and 280 patients were enrolled and randomized. Donor and recipient age, sex, donor source, whether first or subsequent grafts, ureteric length, native renal disease, and immunosuppression were similar in each group. In the no-routine-stenting group 6 of 137 patients (4.4%) received stents after randomization for intraoperative events that in the surgeon's opinion required use of a stent. In an intention-to-treat analysis there was no difference between groups in the primary outcome cluster of obstruction or leak [routine stenting 5 of 143 (3.5%) vs. no routine stenting 9 of 137 (6.6%); P=0.23], or in either of these complications analyzed separately. All urological complications were successfully managed without major morbidity. Living donor organs and shorter ureteric length (after trimming) were univariate risk factors for leaks, although increasing donor age was associated with obstruction. CONCLUSIONS: Routine ureteric stenting is unnecessary in kidney transplantation in patients at low risk for urological complications. Careful surgical technique with selective stenting of problematic anastomoses yields similar results.

Adult↗
PubMed2000

Intravenous mycophenolate mofetil: safety, tolerability, and pharmacokinetics.

An intravenous (i.v.) formulation of mycophenolate mofetil (MMF; CellCept, Roche Pharmaceuticals, Inc., Palo Alto, CA) that will enable its administration to patients unable to tolerate oral medication is available. Two separate studies, an open-labeled pharmacokinetic (PK) study and a double-blind safety study, were performed. Within 24 h after transplant, 153 (safety study) and 45 (PK study) first or second renal transplant recipients were started on i.v. MMF 1 g Q12h or placebo (used in the safety study only, 2:1 MMF:placebo), given over 2 h via a dedicated peripheral venous catheter. In the safety study, per os (p.o.) MMF (1g Q12h) or placebo was administered, starting within 72 h after transplant, whereas in the PK study, p.o. MMF was started on the evening of day 5. Sequential blood samples obtained on study days 5 (i.v. MMF) and 6 (p.o. MMF) before and up to 12 h after the AM dose were analyzed for mycophenolic acid (MPA) and MPA glucuronide (MPAG) concentrations by high-performance liquid chromatography. The area under the concentration curve (AUC) was calculated using the linear trapezoidal rule. The MPA AUC(0-12) was higher for i.v. MMF than p.o. MMF (40.8 +/- 11.4 microg x h/ mL vs. 32.9 +/- 15, p < 0.001). There were no other significant PK differences for plasma MPA or MPAG. In the safety study (n = 98 i.v. MMF vs. n = 55 placebo), 11 patients (11%, i.v. MMF) and 4 patients (7%, placebo) discontinued their use of the drug because of an adverse event (AE). Overall, AEs were similar between i.v. MMF and placebo. Injection site phlebitis (4%) and thrombosis (4%) were observed only with i.v. MMF. MMF i.v. 1 g twice daily (b.i.d.) should provide efficacy at least equivalent to p.o. MMF without increased toxicity, and it provides an acceptable alternative dose form in the immediate period after transplant.

Administration, Oral↗
PubMed2000

Effect of recipient sensitization (peak PRA) on graft outcome in haploidentical living related kidney transplants.

OBJECTIVE: To evaluate the influence of pre-transplant recipient sensitization on the outcome of 1-haploidentical live related donor (LRD) kidney transplants. METHOD: We reviewed 141 consecutive cyclosporine-treated adult haploidentical first transplants for which panel reactive antibody (PRA) levels were available. Patients were divided into three groups according to their peak PRA levels: group I, PRA = 0 (n = 97); group II, PRA = 1-50% (n = 24); and group III, PRA = 51-100% (n = 20). RESULTS: Differences in PRA were associated with significant differences in short- and longer-term graft survival, unrelated to patient survival. Graft survival at 1, 3, and 5 yr was only 74, 40, and 27% in group III, compared to 92, 87, and 52% in group II, and 96, 91, and 85% in group I (p < 0.001). Increasing PRA was associated with shorter time-to-graft failure. In group III, 20% lost their transplant from acute rejection in the first 6 months, versus 4% in group II and 3% in group I (p < 0.01). Graft survival in group II diverged from that of group I only after 3 yr, due to an increase in loss from chronic rejection. Hospitalization was longer in group III, in association with a significantly higher incidence of acute rejection during the first 3 months after transplantation (p < 0.02). Serum creatinine was higher in sensitized than nonsensitized patients at all time points. CONCLUSIONS: Sensitization has a significant negative impact on the outcome of haploidentical LRD kidney transplants. Sensitized potential recipients and their potential donors should be aware of this in arriving at informed decision-making for transplantation. These patients may benefit from more sensitive cross-match testing, more intense or more novel immunosuppression, or immunomodulation to modify their immune responsiveness.

Adult↗
PubMed2000

Concentrations of antimony in infants dying from SIDS and infants dying from other causes.

OBJECTIVES: Raised concentrations of antimony have been found in infants dying of sudden infant death syndrome (SIDS). The presumed source of this antimony is toxic gases generated from fire retardants that are present in cot mattresses. The aim of this study was to determine the role of antimony in SIDS. DESIGN: Samples of liver, brain, serum, and urine were collected from all patients dying from SIDS and a group of aged matched control infants who had died of other causes. SETTING: Nationwide study in Ireland. SUBJECTS: 52 infants dying from SIDS and 19 control infants aged > 7 days and < 1 year. RESULTS: The median concentration of antimony in the liver and brain of infants dying of SIDS was < 1 ng/g, with no difference detected between the infants dying from SIDS and the control infants. The range of antimony in the serum of infants dying of SIDS was 0.09-0.71 microg/litre (median, 0.26). Although no difference was found between infants dying from SIDS and control infants, SIDS infants were found to have higher concentrations when compared with healthy infants in the 1st year of life, probably as a result of release of antimony into serum after death. Urine antimony concentrations in infants dying from SIDS were < 3.91 ng/mg (corrected for creatinine) and similar to values found both in control infants and healthy infants. CONCLUSION: There is no evidence to support a causal role for antimony in SIDS.

Antimony↗
PubMed2000

Is 3-hour cyclosporine blood level superior to trough level in early post-renal transplantation period?

PURPOSE: Cyclosporine dose is traditionally based on trough blood levels. Cyclosporine trough blood level correlates poorly with acute rejection and cyclosporine nephrotoxicity after renal transplantation. We determined whether cyclosporine blood level at any other time point is superior to cyclosporine trough blood level as a predictor of acute rejection and cyclosporine nephrotoxicity. MATERIALS AND METHODS: Cyclosporine blood level was measured before (trough), and 1, 2, 3 and 4 hours after the dose in 156 initial renal transplant cases 2 to 4 days after the initiation of cyclosporine micro-emulsion formula administration. The cylosporine micro-emulsion dose was based on cyclosporine trough blood level targeting 250 to 400 microg./l. RESULTS: Regression analysis revealed that only delayed graft function (p = 0.007) and cyclosporine blood level after 3 hours (p = 0.008) predicted acute rejection. Mean cyclosporine trough blood level plus or minus standard error was not significantly different in patients with and without acute rejection (293+/-21 versus 294+/-11 microg./l.). Mean cyclosporine blood level after 3 hours was significantly lower in patients with acute rejection (1,156+/-90 versus 1,421+/-50, p = 0.008). Cases were divided into tertiles at levels after 3 hours (1,100 and 1,500 microg./l.). The group in which the level after 3 hours was less than 1,100 microg./l. had the highest acute rejection rate (22 of 50 patients, 44%) and a cyclosporine nephrotoxicity rate of 13% (7 of 52 patients). The group in which the level after 3 hours was 1,100 to 1,500 microg./l. had the lowest acute rejection rate (5 of 46 patients, 11%) without increased cyclosporine nephrotoxicity (7 of 52 patients, 13%). A level after 3 hours of greater than 1,500 microg./l. was associated with a rejection rate of 15% (7 of 47 patients) but significantly higher cyclosporine nephrotoxicity (16 of 52 patients, 30%). CONCLUSIONS: Cyclosporine blood level after 3 hours in the early post-transplantation period is associated with acute rejection and cyclosporine nephrotoxicity. A cyclosporine blood level range after 3 hours of 1,100 to 1,500 microg./l. is associated with an optimal outcome. Our data suggest that cyclosporine blood level after 3 hours may represent a better method of monitoring cyclosporine micro-emulsion dose than cyclosporine trough blood level. This hypothesis must be further studied in randomized trials.

Cyclosporine↗