A meta-analysis of intervention effects on challenging behaviour among persons with intellectual disabilities

BACKGROUND

Persons with intellectual disabilities (ID) often show challenging behaviour. We review distinct interventions that are applied to treat these challenging behaviours, and analyse intervention effects and moderating variables.

METHODS

A literature search was conducted using the databases ERIC, PsycINFO, Web of Science and Medline. A random-effects meta-analysis was carried out, supplemented with sensitivity, subgroup, meta-regression and publication bias analyses.

RESULTS

Eighty potential articles were identified, from which 30 contained sufficient data to enable statistical meta-analysis. From these 30 studies, 18 described a biological, 13 a psychotherapeutic and nine a contextual intervention, either applied alone or combined. The overall standardised mean difference was 0.671 (SD = 0.051). As shown by sensitivity analysis, this summary effect size is robust. Assessed through subgroup and meta-regression analysis, all tested moderators showed no statistically significant association with the treatment effects. After applying a funnel plot-, a fail-safe N-, and Duval's and Tweedie's trim and fill-analysis, we conclude that our meta-analysis does not suffer much from publication bias effects.

CONCLUSIONS

Several biological, psychotherapeutic and contextual interventions effectively reduce challenging behaviours among persons with ID.

Acral myxoinflammatory fibroblastic sarcoma in a renal transplant patient: a case report

Herein, we have reported a case of a 62-year-old patient who presented at 10 months after renal transplantation with a nodular mass on the dorsum of his foot. Local excision was performed and an acral myxoinflammatory fibroblastic sarcoma was diagnosed. This is a rare, low-grade sarcoma with a high rate of local recurrence, sometimes leading to amputation. Metastasis to the lungs and liver has been reported, but is rare. Since our patient received triple immunosuppressive therapy, our major concern was a much more aggressive behavior. However, more than 2 years after excision of the tumor, the patient is still free of disease.

Usefulness of the Supports Intensity Scale (SIS) for persons with other than intellectual disabilities

In response to the shift from a system-centred care model to a person-centred support model, the Supports Intensity Scale (SIS) has been developed as an instrument to assess the support needs of persons with intellectual disabilities. The instrument is used as a tool for constructing individual support plans, as well as a tool for resource allocation. The aim of the present study was to evaluate the usefulness of the SIS for persons with other than intellectual disabilities. Therefore, the psychometric properties of the SIS were investigated in a sample of 1303 persons with other than intellectual disabilities. Confirmatory factor analysis failed to support the originally proposed six-factor model within this sample. However, an explorative examination of the underlying structure resulted in a shortened version of the SIS, including four subscales and 22 items. Further analyses revealed satisfying results for reliability, construct validity, and criterion validity of the shortened assessment tool (SIS-NID).

Guidelines for an integrated diagnostic approach of chronic lymphoproliferative disorders in the routine laboratory of haematology in Belgium

This paper summarizes the minimal workout of chronic lymphoproliferative disorders in a routine laboratory of haematology as recommended by a team of experienced laboratory supervisors in Belgium, taking into account the specific organisation of healthcare in Belgium, the innovations in the field of molecular analyses and related reimbursement. The starting point was essentially based upon clinical and/or haematological indications and it is emphasized that conclusions should be drawn in close dialogue with the clinician and experts in cytogenetics and histopathology. Reports made in the laboratory should be based upon an integration of cytomorphological, immunophenotypical and molecular data. These guidelines are not intended to be used as universal 'diagnostic pathways', but should be useful in developing local diagnostic pathways. It is well understood that this consensus, being valid anno 2009, may rapidly change with new technologies being introduced and new targets discovered.

Staff variables associated with the challenging behaviour of clients with severe or profound intellectual disabilities

BACKGROUND

Previous research has identified that staff-client interactions play an important role in the origin and maintenance of challenging behaviour. Particularly, the reciprocity between staff behaviour and client behaviour has been considered a key issue. Furthermore, severe challenging behaviour has been found to elicit negative emotional reactions from staff which in turn may influence staff's behaviour. Another variable that has been associated with staff behaviour are staff's attributions regarding clients' challenging behaviour. The present study tested several hypotheses about associations between staff variables and challenging behaviour.

METHOD

Questionnaires were used to investigate associations between the attributions, emotional reactions and behavioural reactions of 51 staff members towards challenging behaviour of clients with severe or profound intellectual disabilities who displayed self-injurious behaviour, stereotyped behaviour and/or aggressive/destructive behaviour.

RESULTS

Staff members reported that reactions to challenging behaviour differed according to the type of challenging behaviour. Negative emotional reactions were positively associated with challenging behaviour. Associations between emotional reactions, staff beliefs and staff reactions were inconsistent.

CONCLUSIONS

The findings suggest that there is a need to look for a better conceptualization and assessment of the variables under investigation.

Aggressive cutaneous squamous cell carcinoma associated with prolonged voriconazole therapy in a renal transplant patient

A 69-year-old man, with a history of end-stage renal disease due to polyarteritis nodosa, followed by invasive pulmonary aspergillosis secondary to cyclophosphamide and corticosteroids, received a renal transplant 2 years ago under prophylactic treatment with voriconazole. Because of the severity of the aspergillosis, it was decided to continue voriconazole for a prolonged period. Eighteen months after transplantation, the patient developed a severe facial phototoxic reaction. A few months later, he developed multiple actinic keratoses and a large, rapidly expanding, poorly differentiated squamous cell carcinoma (SCC) with perineural invasion and metastatic lymph nodes, necessitating radical surgery and radiotherapy. Voriconazole therapy has been suggested to be involved in the development of multi-focal invasive SCC when complicated by a phototoxic reaction. Therefore, an alternative antifungal prophylaxis regimen (for instance with posaconazole) should be considered when evaluating patients for solid organ transplantation who are at high risk for the development of cutaneous malignancies.

Influenza vaccination is efficacious and safe in renal transplant recipients

Whether influenza vaccination in solid-organ transplant recipients is efficacious remains a controversial issue. Furthermore, theoretical concerns have been raised regarding the safety of vaccination as it might trigger rejection of the allograft. The present prospective trial is aimed at investigating the antibody response and safety of influenza vaccination in renal transplant recipients (RTR). A total of 165 RTR and 41 healthy volunteers were vaccinated with a standard trivalent inactivated influenza vaccine. Hemagglutination-inhibiting (HI) antibodies were quantified before and 1 month after vaccination. Seroprotection (SP) and seroresponse (SR) were defined as a titer > or =40 and a 4-fold rise in HI titer, respectively. Similar SR rates were observed in both groups. Postvaccination SP rates in RTR amounted to 92.7%, 78.7% and 82.9% for A/H1N1, A/H3N2 and B, respectively. High baseline SP rates, most probably reflecting frequent preimmunizations, explain partly the high postvaccination SP rates. SR rate was independently and inversely associated with baseline SP rate. Mycophenolate mofetil (MMF) usage was associated with a 2.6-5-fold lower SR. Nonetheless, these patients showed good postvaccination SP rates. A booster dose did not enhance SP or SR rates. Influenza vaccination neither affected allograft function nor caused rejection episodes. In conclusion, influenza vaccination is efficacious and safe in renal transplantation.

Living donor kidney transplantation: analysis of the first 40 cases performed in UZ Leuven

Living donation kidney transplantation has been popular worldwide to try to increase the donor pool. In Belgium, the rate of living donation kidney transplantation has been traditionally relatively low compared to other countries. This is--in part--due to the relatively higher cadaveric organ offer that is available in Belgium (around 25 donors per million inhabitants), compared to other countries. However, the increasing waiting times on cadaveric waiting list and the superiority of the results of live donation versus cadaveric kidney transplantation have led to a reappraisal of this strategy. In our center a living donation kidney transplant programme was started in 1997. Since then 40 cases of live donation kidney transplantation have been performed and are reported herein.

Operationalizing quality of life for people with profound multiple disabilities: a Delphi study

BACKGROUND

In a recent study, we constructed an item pool that contains items on the quality of life (QOL) and related aspects of support of people with profound multiple disabilities (PMD). In the present study, a panel of experts assessed the content and the structure of this item pool in order to enhance its validity and usefulness.

METHOD

A two-round Delphi study was set up. The panel consisted of 45 experts, of whom 12 were theory-experts, 12 practice-experts and 12 experience-experts from Belgium (n = 12), Germany (n = 12), the Netherlands (n = 11) and the UK/Ireland (n = 10). Both quantitative and qualitative methods of analysis were applied to the data.

RESULTS

The majority of the items were considered relevant for the QOL of people with PMD. In the first round, 91% of the items reached the 80% criterion of consensus. In the second round, 78.7% of the items reached the 85% criterion of consensus. There were no significant differences in opinion neither between types of experts nor between countries. Several items were reported as missing in the item pool and were added.

CONCLUSIONS

The results provide some evidence that the item pool is a valid operationalization of QOL of people with PMD and can be used in an instrument to measure the QOL of this target group.

Severe diarrhea in renal transplant patients: results of the DIDACT study

Diarrhea is common in transplant recipients. While the majority of cases are mild and transient, some are severe and prolonged, which can threaten graft survival through dehydration. While it is known that some immunosuppressive agents can elicit diarrhea, there does not appear to be any consensus on the role that other nonimmunosuppressive causes can play in transplant patients. The aim of the present open, nonrandomized, multicenter study was to identify nonimmunosuppressive factors involved in severe diarrhea in renal transplant patients. Patients (n = 108) with severe diarrhea (>/=3 stools/day for >/=7 days) were enrolled from 16 Belgian transplant centers. Patients were diagnosed according to an agreed flowchart that consisted of identification of possible infections, followed by changes in empirical and immunosuppressive treatment. Approximately 50% of patients experienced resolution of severe diarrhea following treatment for infections, dietary problems or diarrhea-causing concomitant medications. In conclusion, a large proportion of the severe diarrhea observed in renal transplant recipients is not associated with immunosuppressive therapy and can be treated through anti-infectives, changes to concomitant medication and other empirical treatments. Correct diagnosis of the cause of severe diarrhea in such patients should help to protect graft survival in transplant recipients.

Long-term cardiac outcomes in renal transplant recipients receiving fluvastatin: the ALERT extension study

Renal transplant recipients (RTR) have an increased risk of premature cardiovascular disease. The ALERT study is the first trial to evaluate the effect of statin therapy on cardiac outcomes following renal transplantation. Patients initially randomized to fluvastatin or placebo in the 5-6 year ALERT study were offered open-label fluvastatin XL 80 mg/day in a 2-year extension to the original study. The primary endpoint was time to first major adverse cardiac event (MACE). Of 1787 patients who completed ALERT, 1652 (92%) were followed in the extension. Mean total follow-up was 6.7 years. Mean LDL-cholesterol was 98 mg/dL (2.5 mmol/L) at last follow-up compared to a pre-study level of 159 mg/dL (4.1 mmol/L). Patients randomized to fluvastatin had a reduced risk of MACE (hazards ratio [HR] 0.79, 95% CI 0.63-0.99, p = 0.036), and a 29% reduction in cardiac death or definite non-fatal MI (HR 0.71, 95% CI 0.55-0.93, p = 0.014). Total mortality and graft loss did not differ significantly between groups. Fluvastatin produces a safe and effective reduction in LDL-cholesterol associated with reduced risk of MACE in RTR. The lipid-lowering and cardiovascular benefits of fluvastatin are comparable to those of statins in other patient groups, and support use of fluvastatin in RTR.

Alkaline encrusted pyelitis

Alkaline encrusted pyelitis is an infectious disease characterised by encrustations in the wall of the upper urinary tract, surrounded by severe inflammation. Destruction of native kidneys and kidney grafts may occur, resulting in end stage renal failure. Corynebacterium group D2, an urea splitting microorganism, is nearly exclusively associated with this disease. The most important predisposing factors are previous urological procedures and an immunosuppressed state. In a suggestive clinical context, diagnosis should be made with unenhanced computed tomography findings and bacteriologic isolation of the responsible microorganism. The treatment is threefold: appropriate antibiotic therapy, by preference with glycopeptides, acidification of urine and chemolysis, and if needed, surgical removal of encrustations. We report the case of a patient who was diagnosed with this rare condition and could escape maintenance dialysis after correct diagnosis was made and conservative treatment was started using antibiotics and combined oral and local acidification.

Optimization of a genotypic assay applicable to all human immunodeficiency virus type 1 protease and reverse transcriptase subtypes

Genotypic assays are used often to guide clinicians in decisions concerning the treatment of patients. An optimized sequence-based genotypic assay was used to determine the whole protease and reverse transcriptase (RT) gene, including the gag cleavage site region and RNase H region. Since non-B subtypes are increasing in countries where subtype B was the most prevalent subtype, and treatment becomes more available in developing countries where the epidemic is characterized by a high prevalence of non-B subtypes, it was important that the genotypic test was evaluated using a panel of different subtypes. Amplification was successful for different subtypes: A, B, C, D, F, G, H, J, CRF01_AE, CRF02_AG, CRF11_cpx, CRF13_cpx and an uncharacterized recombinant sample. The detection limit of the PCR was 1000 copies/ml, except for 1 subtype C sample (PL3) and 1 CRF02_AG sample (PL8). The detection limit for these samples was 5000 copies/ml. A sequence could be obtained in both directions for most of the samples.

Renal dysfunction is a strong and independent risk factor for mortality and cardiovascular complications in renal transplantation

Renal transplant recipients (RTR) have shortened life expectancy, primarily due to premature cardiovascular disease (CVD). Traditional CVD risk factors are highly prevalent. In addition, several non-traditional risk factors may contribute to the high risk. The aim of the study was to evaluate the effects of renal dysfunction on mortality and cardiovascular complications in 1052 placebo-treated patients of the Assessment of LEscol in Renal Transplantation (ALERT) trial. Follow-up was 5-6 years and endpoints included cardiac death, non-cardiovascular death, all-cause mortality, major adverse cardiac event (MACE), non-fatal myocardial infarction (MI) and stroke. The effects of serum creatinine at baseline on these endpoints were evaluated. Elevated serum creatinine in RTR was a strong and independent risk factor for MACE, cardiac, non-cardiovascular, and all-cause mortality, but not for stroke or non-fatal MI alone. Serum creatinine was associated with increased mortality and MACE, independent of established CVD risk factors. Graft loss resulted in increased incidences of non-cardiovascular death, all-cause mortality, MACE and non-fatal MI. In conclusion, elevated serum creatinine is a strong risk factor for all-cause, non-cardiovascular and cardiac mortality, and MACE, independent of traditional risk factors, but not for stroke or non-fatal MI alone.

Immunosuppressive Drugs After Simultaneous Pancreas-Kidney Transplantation

INTRODUCTION

We report the early and late secondary effects of tacrolimus or cyclosporine-microemulsion (ME), in combination with mycophenolate mofetil (MMF), and rATG.

PATIENTS AND METHODS

One hundred three patients were randomly assigned to tacrolimus (initial oral dose 0.2 mg/kg) and 102 to cyclosporine-ME (initial daily oral dose 7 mg/kg). All patients received 4 days of concomitant rATG induction therapy [ATG-Fresenius Biotech GmbH (ATG-F) daily dose of 4 mg/kg or Thymoglobulin-Genzyme/Sangstat (Thymo-S) 1.25 mg/kg], MMF (2 to 3 g per day), and short-term corticosteroids.

RESULTS

Thymo-S was associated with a transiently lower white cell count in the first 3 months compared with ATG-F, while ATG-F caused a lower albeit transient early nadir in platelet count. Both polyclonal preparations were well tolerated; they did not differ with respect to clinically relevant side effects such as infections and malignancies. Higher cyclosporine-ME trough levels were associated with pancreas graft thrombosis. Study withdrawal was more frequent among patients on cyclosporine-ME therapy, because of toxicities, graft loss, and lack of efficacy, the last being the cause of subsequent switch to tacrolimus. Tacrolimus-treated patients were mainly withdrawn from the study due to MMF discontinuation.

CONCLUSION

Short-term induction therapy in combined kidney-pancreas transplantation is effective and well tolerated. Tacrolimus causes fewer pancreas graft losses and fewer drug discontinuations due to side effects. When MMF is combined with tacrolimus, dose reductions and discontinuations are common.

Efficacy, Tolerability, and Safety of Lanthanum Carbonate in Hyperphosphatemia: A 6-Month, Randomized, Comparative Trial versus Calcium Carbonate

BACKGROUND/AIMS

Hyperphosphatemia is an important clinical consequence of renal failure, and its multiple adverse systemic effects are associated with significantly increased risks of morbidity and mortality in dialysis patients. Existing oral phosphate binders have not permitted control of serum phosphate within currently accepted guidelines. This study compares lanthanum carbonate with calcium carbonate for control of serum phosphate in hemodialysis patients.

METHODS

In this European multicentre study, 800 patients were randomised to receive either lanthanum or calcium carbonate and the dose titrated over 5 weeks to achieve control of serum phosphate. Serum levels of phosphate, calcium and parathryoid hormone were followed over the following 20 weeks.

RESULTS

Around 65% of patients in each group achieved phosphate control, but in the calcium carbonate group this was at the expense of significant hypercalcemia (20.2% of patients vs. 0.4%). Consequently, calcium x phosphate product tended to be better controlled in the lanthanum group.

CONCLUSION

This 6-month study demonstrates that serum phosphate control with lanthanum carbonate (750-3,000 mg/day) is similar to that seen with calcium carbonate (1,500-9,000 mg/day), but with a significantly reduced incidence of hypercalcemia. Lanthanum carbonate is well tolerated and may be more effective in reducing calcium x phosphate product than calcium carbonate.

The podocyte: from bench to bedside

The understanding of the molecular structure of the podocyte has increased considerabely in recent 5 years by genetic research in inherited glomerulopathies. Injury to the podocyte often leads to a reorganisation of the slit diaphragm and to foot process effacement, which can be noted in all forms of the nephrotic syndrome. Since the recent progress in our understanding of the molecular biology of the podocyte, it has become obvious that the podocyte is crucial in the pathogenesis of not only genetic but also of many acquired glomerulopathies such as focal segmental glomerulosclerosis, membranous glomerulopathy and diabetic nephropathy. In this review we provide a summary of the recent physiological and molecular insights into the podocyte and of its significance in different glomerulopathies.

Lipid and apoprotein changes during atorvastatin up-titration in hemodialysis patients with hypercholesterolemia: a placebo-controlled study

BACKGROUND

Patients with end-stage renal disease commonly present with an atherogenic lipid profile characterized by the accumulation of triglyceride-rich, apoprotein B-containing "remnant" lipoproteins, small dense low-density lipoprotein, and low levels of high-density lipoprotein. They are at increased cardiovascular risk and may benefit from drastic lipid-lowering treatment with atorvastatin, a potent, broadacting lipid regulator. This study aims to assess the effects of atorvastatin on the lipid profile in hemodialysis patients, to determine wether atorvastatin is also effective at lowering lipid levels in this particular high-risk subgroup.

METHODS

In this randomized, placebo-controlled, double-blind study in hemodialysis patients with hypercholesterolemia (n = 42, mean total cholesterol 243 +/- 33 mg/dl (6.3 +/- 0.8 mmol/l)), the efficacy of 4-weekly increasing doses of atorvastatin (10 - 40 mg daily) was investigated. Lipids and apoproteins were measured in plasma and isolated lipoprotein fractions.

RESULTS

Mean total cholesterol and low-density lipoprotein cholesterol progressively decreased with increasing doses of atorvastatin (total cholesterol -33%, low-density lipoprotein cholesterol -43% after 12 weeks), while high-density lipoprotein cholesterol remained unchanged. Plasma levels of apoprotein B and apoprotein E were also significantly reduced by atorvastatin 10 mg, while up-titration to 20 and 40 mg daily provided additional benefits by lowering triglycerides and apoprotein C-III. At week 12, the fraction of small dense low-density lipoprotein was significantly reduced from 23% - 18%, and apoprotein B-containing intermediate-density lipoproteins were no longer detectable.

CONCLUSION

In conclusion, atorvastatin not only treated hypercholesterolemia but also favorably affected the uremic lipid profile in patients on hemodialysis. Atorvastatin 4-weekly dose escalation up to 40 mg daily was well-tolerated. Further prospective studies are needed to evaluate the impact of this improved lipid profile on morbidity and mortality.

THE RATE OF GASTRIC EMPTYING DETERMINES THE TIMING BUT NOT THE EXTENT OF ORAL TACROLIMUS ABSORPTION: SIMULTANEOUS MEASUREMENT OF DRUG EXPOSURE AND GASTRIC EMPTYING BY CARBON-14-OCTANOIC ACID BREATH TEST IN STABLE RENAL ALLOGRAFT RECIPIENTS

Tacrolimus is characterized by a highly variable oral bioavailability and narrow therapeutic window. Tacrolimus absorption from the gastrointestinal tract is to a large extent determined by the genotypic, phenotypic, and functional expression of P-glycoprotein and CYP3A in the gut wall and liver. It is disputed whether the gastric emptying rate per se is important for determining oral bioavailability of tacrolimus and whether delayed gastric emptying is clinically relevant for therapeutic drug dosing. We conducted a pharmacokinetic study in 50 renal recipients, measuring simultaneously the rate of gastric emptying using a carbon-14-octanoic acid breath test and quantifying drug exposure by area under the concentration-time curve sampling. Gastric half emptying time (t1/2) significantly correlated with time to reach maximum blood tacrolimus (tmax) concentration (r2 = 0.30; p < 0.0001), whereas the gastric emptying coefficient, reflecting the overall gastric emptying rate, showed a weak inverse correlation with tmax (r2 = 0.14; p = 0.007). The time-dependent rate of gastric emptying strongly correlated with the simultaneously measured blood tacrolimus concentration over the first 4 h after oral drug administration (r2 = 0.96; p < 0.0001). Comparison between patients with and without delayed gastric emptying confirmed that maximum blood tacrolimus concentration was reached significantly more slowly in the former group (tmax, 2 +/- 1 h versus 1.48 +/- 0.68 h; p = 0.04), whereas the extent of tacrolimus absorption was not different. Despite a strong association between gastric emptying rate and the timing of tacrolimus absorption from the gut in stable recipients, gastric emptying rate does not affect the total extent of drug absorption and is not responsible for significant alterations in drug exposure, even in situations of delayed gastric emptying.

Parenting, family contexts, and personality characteristics in youngsters with VCFS

Parenting, family contexts, and personality characteristics in youngsters with VCFS: The personality profiles for 48 youths with Velo-Cardio-Facial syndrome (VCFS) were described using the California Child Q-Set (CCQ). Associations between personality characteristics and parenting (i.e., Control and Warmth vs. Anger) and family contexts (i.e., Experienced Family Stress, Marital Conflict and Parental Consistency) were investigated. Personality characteristics were found to be related to parenting (in particular, Parental Warmth vs. Anger) but not to family contexts. Parents who reported more Parental Warmth (and less Anger) in interactions had children with higher Agreeableness, Conscientiousness and Emotional Stability and with lower Irritability and Dependency. Parental Control was positively related to children's Dependency and negatively to children's Conscientiousness. Compared to fathers, mothers exerted more Control. Differences in parenting and family contexts were related to the mode of inheritance but not to IQ, age, gender, and cardiac defects. Families in which a familial deletion occurred reported higher levels of Marital Conflict and lower Warmth in the parent-child interactions.

Caregiving burden of families looking after persons with intellectual disability and behavioural or psychiatric problems

BACKGROUND

During the last decade, there has been a growing interest in outpatient support services for persons with intellectual disability (ID) and psychiatric and/or behavioural problems and their families. In this study, we explore the family burden that is associated with children or adults with ID and behavioural or psychiatric problems living at home.

METHOD

The research group consisted of 66 clients of In Casa, a project of outpatient treatment. Their average age is 18.97 years and their average IQ 55.37. The Reiss Screen for Maladaptive Behaviour (adults) or Reiss Scales for Children's Dual Diagnosis (children) and the Nijmegen Family Situation Questionnaire have been administered.

RESULTS

About 62% of the children and 86% of the adults living at home and referred to In Casa have severe psychiatric or behavioural problems as measured by the Reiss scales. The dual diagnosis has a more negative impact on the family situation than the condition of ID only.

CONCLUSION

Parents consider the psychiatric or behavioural problems of their child to be an extra burden and feel it more difficult to raise and manage such a child. This impels them to change the situation and to call on the help of external services. Some methodological questions and the implications of the findings in terms of support needs are discussed.

Long-term pharmacokinetic study of the novel combination of tacrolimus and sirolimus in de novo renal allograft recipients

It was recently shown in two randomized studies that combining sirolimus (rapamycin) and tacrolimus is very efficient in renal transplantation. However, little is known about the long-term pharmacokinetics of this combination. We performed simultaneous AUC measurements (area under the concentration curves) of sirolimus and tacrolimus at 1, 3, and 12 months posttransplantation in nine de novo recipients treated with this drug combination to characterize the evolution of the pharmacokinetics of both drugs and to investigate possible interactions between the two compounds. Patients were treated with a standard-dose tacrolimus or with a reduced-dose tacrolimus in combination with sirolimus and corticosteroids. This long-term pharmacokinetic study has shown that when sirolimus is combined with tacrolimus, dose changes of sirolimus are reflected by pharmacokinetic exposure parameters. Patients taking a low dose of sirolimus in combination with a standard dose tacrolimus might require sirolimus dose increments over time to maintain constant exposure to sirolimus. Further prospective dose-controlled studies are necessary to investigate a possible effect of a standard-dose tacrolimus on long-term sirolimus bioavailability and/or metabolism. Dose reductions of tacrolimus in both study groups were reflected by concordant decreasing pharmacokinetic exposure parameters, which illustrates the common clinical practice of reducing the dose of calcineurin inhibitor as time elapses after transplantation.

Long-term changes in mycophenolic acid exposure in combination with tacrolimus and corticosteroids are dose dependent and not reflected by trough plasma concentration: a prospective study in 100 de novo renal allograft recipients

Tacrolimus and cyclosporine A have different effects on exposure to concomitantly administered mycophenolate mofetil (MMF), measured as the mycophenolic acid (MPA) dose interval area under the plasma concentration versus time curve (AUC0-12 h) or the plasma MPA predose concentration (C0). This has led to recommendations in using a 50% lower dose of MMF in combination with tacrolimus compared to cyclosporin A. At present, no long-term data are available regarding the pharmacokinetics (PK) of different dosages of MMF in combination with tacrolimus and the clinical variables that influence the dose-exposure relationship of MPA. A prospective 12-month pharmacokinetic study was performed in 100 de novo renal transplant recipients treated with two different MMF dosages (1 g/day vs. 2 g/day) in combination with tacrolimus and corticosteroids. MPA AUC data were collected 7 days, 6 weeks, and 3 and 12 months posttransplantation, and model-independent PK parameters were calculated. Clinical variables that could possibly influence MPA PK were evaluated. The MPA AUC0-12 h significantly increased toward 6 weeks (p < 0.05) but only in the 2-g MMF dosing group. The MPA AUC0-12 h in the 1-g MMF group reached its nadir at 3 months, while in the 2-g MMF group, it remained elevated until 3 months, returning to baseline values by 12 months. This differential evolution in exposure was not only inadequately reflected by the corresponding MPA C0 concentrations, but the MPA C0 concentrations also were not significantly different between the two dosing groups at early postgrafting (day 7) and at 12 months. Using multiple stepwise regression analysis, C0 (r = 0.51, p < 0.0001) and end-of-dose interval MPA plasma concentration (C12: r2 = 0.61, p < 0.0001) were found to poorly predict MPA AUC0-12 h, while MPA plasma concentrations at 4 hours (C4: r2 = 0.85, p < 0.0001) and 6 hours postdosing (C6: r2 = 0.83, p < 0.0001) were superior but hampered by a large prediction bias and imprecision. An abbreviated 2-hour AUC measurement (r2 = 0.78), using three sampling points (C0, C40 [MPA plasma concentration 40 min postdosing], C2), provided the best compromise between a monitoring tool that is theoretically ideal and practically feasible. MPA pharmacokinetics were not influenced by recipient age, gender, and body weight or by serum albumin concentrations, allograft function, or corticosteroid or tacrolimus dose. Mild hepatic dysfunction early after grafting did result in significantly reduced MPA exposure (MPA AUC0-12 h, p = 0.01 and C0, p = 0.03). In this study, it was demonstrated for the first time that the dynamics of long-term MPA pharmacokinetics in combination with tacrolimus differ according to the daily MMF dose and that this effect is not adequately reflected by MPA trough concentrations. Using the latter as a routine measure for therapeutic drug monitoring might mislead clinicians into drawing wrong conclusions in terms of relating questions of efficacy or toxicity to MPA exposure.