High-Dose Intravenous Iron with Either Ferric Carboxymaltose or Ferric Derisomaltose: A Benefit-Risk Assessment.

The intravenous iron formulations ferric carboxymaltose (FCM) and ferric derisomaltose (FDI) offer the possibility of administering a large amount of iron in one infusion. This results in faster correction of anemia and the formulations being better tolerated than oral iron formulations. This triad of logistic advantages, improved patient convenience, and fast correction of anemia explains the fact that intravenous iron formulations nowadays are frequently prescribed worldwide in the treatment of iron deficiency anemia. However, these formulations may result in hypophosphatemia by inducing a strong increase in active fibroblast growth factor-23 (FGF-23), a hormone that stimulates renal phosphate excretion. This effect is much more pronounced with FCM than with FDI, and therefore the risk of developing hypophosphatemia is remarkably higher with FCM than with FDI. Repeated use of FCM may result in severe osteomalacia, which is characterized by bone pain, Looser zones (pseudofractures), and low-trauma fractures. Intravenous iron preparations are also associated with other adverse effects, of which hypersensitivity reactions are the most important and are usually the result of a non-allergic complement activation on nanoparticles of free labile iron-Complement Activation-Related Pseudo-Allergy (CARPA). The risk on these hypersensitivity reactions can be reduced by choosing a slow infusion rate. Severe hypersensitivity reactions were reported in < 1% of prospective trials and the incidence seems comparable between the two formulations. A practical guideline has been developed based on baseline serum phosphate concentrations and predisposing risk factors, derived from published cases and risk factor analyses from trials, in order to establish the safe use of these formulations.

Hepatitis E-associated encephalopathy in a renal transplant recipient.

Hepatitis E virus genotype 3 is not rare in developed countries, and may cause chronic hepatitis in immunocompromised patients. This may not only lead to abnormalities in liver test and malaise, but to severe neurological symptoms as well. In this case, chronic hepatitis E infection caused encephalopathy, an atactic gait, Lhermitte's sign, incomplete bladder emptying and peripheral sensory neuropathy in a renal transplant recipient. The diagnosis was not performed until years after the onset of first symptoms and several months after the onset of neurological symptoms. If treated adequately, viral load can be reduced in over two-thirds of patients and neurological symptoms are often resolved. More widespread knowledge about this virus and its extrahepatic manifestations may lead to a quicker diagnosis, and may limit pathology. Serological screening should be added to standard pretransplant virological screening, so that, in the future, patients without antibodies could be vaccinated.

Effect of immunosuppressive agents on long-term survival of renal transplant recipients: focus on the cardiovascular risk.

In the control of acute rejection, attention is being focused more and more on the long-term adverse effects of the immunosuppressive agents used. Since cardiovascular disease is the main cause of death in renal transplant recipients, optimal control of cardiovascular risk factors is essential in the long-term management of these patients. Unfortunately, several commonly used immunosuppressive drugs interfere with the cardiovascular system. In this review, the cardiovascular adverse effects of the immunosuppressive agents currently used for maintenance immunosuppression are thoroughly discussed. Optimising immunosuppression means finding a balance between efficacy and safety. Corticosteroids induce endothelial dysfunction, hypertension, hyperlipidaemia and diabetes mellitus, and impair fibrinolysis. The use of corticosteroids in transplant recipients is undesirable, not only because of their cardiovascular effects, but also because they induce such adverse effects as osteoporosis, obesity, and atrophy of the skin and vessel wall. Calcineurin inhibitors are the most powerful agents for maintenance immunosuppression. The calcineurin inhibitor ciclosporin (cyclosporine) not only induces these same adverse effects as corticosteroids but is also nephrotoxic. Tacrolimus has a more favourable cardiovascular risk profile than ciclosporin and is also less nephrotoxic. It has little or no effect on blood pressure and serum lipids; however, its diabetogenic effect is more prominent in the period immediately following transplantation, although at maintenance dosages, the diabetogenic effect appears to be comparable to that of ciclosporin. The diabetogenic effect of tacrolimus can be managed by reducing the dose of tacrolimus and early corticosteroid withdrawal. The effect of tacrolimus on endothelial function has not been completely elucidated. The proliferation inhibitors azathioprine and mycophenolate mofetil (MMF) have little effect on the cardiovascular system. Yet, indirectly, by inducing anaemia, they may lead to left ventricular hypertrophy. MMF is an attractive alternative to azathioprine because of its higher potency and possibly lower risk of malignancies. Sirolimus also induces anaemia, but may be promising because of its antiproliferative features. Whether the hyperlipidaemia induced by sirolimus counteracts its beneficial effects is, as yet, unknown. It may be combined with MMF, however, initial attempts resulted in severe mouth ulcers.

Conversion from cyclosporine to tacrolimus improves quality-of-life indices, renal graft function and cardiovascular risk profile.

Long-term use of cyclosporine after renal transplantation results in nephrotoxicity and an increased cardiovascular risk profile. Tacrolimus may be more favorable in this respect. In this randomized controlled study in 124 renal transplant patients, the effects of conversion from cyclosporine to tacrolimus on renal function, cardiovascular risk factors, and perceived side-effects were investigated after a follow-up of 2 years. After conversion from cyclosporine to tacrolimus renal function remained stable, whereas continuation of cyclosporine was accompanied by a rise in serum creatinine from 142 +/- 48 micromol/L to 157 +/- 62 micromol/L (p < 0.05 comparing both groups). Conversion to tacrolimus resulted in a sustained reduction in systolic and diastolic blood pressure, and a sustained improvement in the serum lipid profile, leading to a reduction in the Framingham risk score from 5.7 +/- 4.3 to 4.8 +/- 5.3 (p < 0.05). Finally, conversion to tacrolimus resulted in decreased scores for occurrence of and distress due to side-effects. In conclusion, conversion from cyclosporine to tacrolimus in stable renal transplant patients is beneficial with respect to renal function, cardiovascular risk profile, and side-effects. Therefore, for most renal transplant patients tacrolimus will be the drug of choice when long-term treatment with a calcineurin inhibitor is indicated.

Improved cardiovascular risk profile and renal function in renal transplant patients after randomized conversion from cyclosporine to tacrolimus.

Cyclosporine is considered to contribute to the high cardiovascular morbidity and mortality in patients after renal transplantation. Tacrolimus may be more favorable in this respect, but controlled data are scarce. In this prospective randomized study in 124 stable renal transplant patients, the effects of conversion from cyclosporine to tacrolimus on cardiovascular risk factors and renal function were investigated. Follow-up was 6 mo. Statistical analysis was performed by ANOVA for repeated measurements. The serum creatinine level decreased from 137 +/- 30 micromol/L to 131 +/- 29 micromol/L (P < 0.01). Three months after conversion from cyclosporine to tacrolimus, mean BP significantly decreased from 104 +/- 13 to 99 +/- 12 mmHg (P < 0.001). Serum LDL cholesterol decreased from 3.48 +/- 0.80 to 3.11 +/- 0.74 mmol/L (P < 0.001,) and serum apolipoprotein B decreased from 1018 +/- 189 to 935 +/- 174 mg/L (P < 0.001). Serum triglycerides decreased from 2.11 +/- 1.12 to 1.72 +/- 0.94 mmol/L (P < 0.001). In addition, both rate and extent of LDL oxidation were reduced. The fibrinogen level decreased from 3638 +/- 857 to 3417 +/- 751 mg/L (P < 0.05). Plasma homocysteine concentration did not change. Three months after conversion, plasma fasting glucose level temporarily increased from 5.4 +/- 1.3 mmol/L to 5.8 +/- 1.9 mmol/L (P < 0.05). Conversion to tacrolimus resulted in a significant reduction of the Framingham risk score. In conclusion, conversion from cyclosporine to tacrolimus in stable renal transplant patients has a beneficial effect on renal function, BP, serum concentration and atherogenic properties of serum lipids, and fibrinogen.

Increase in tacrolimus trough levels after steroid withdrawal.

Although there are experimental reports of cytochrome P450 3A4 iso-enzyme (CYP3A4) induction by glucocorticoids, there are no clinical reports about an interaction between tacrolimus and steroids. Therefore, tacrolimus trough level and dose were compared after dose-normalization before and after withdrawal of prednisolone. After withdrawal of 5 mg prednisolone, the median tacrolimus dose-normalized level increased by 14% in the retrospective ( n=54), and by 11% in the prospective ( n=8) part of the study. After withdrawal of 10 mg, this increase was 33% ( n=30) and 36% ( n=14), respectively. An additional pharmacokinetic part of the study ( n=8) revealed an 18% increase in AUC ( P=0.05) after withdrawal of 5 mg prednisolone, which is compatible with a reduced metabolism after steroid withdrawal. The significant increase in tacrolimus exposure after steroid withdrawal may on the one hand counteract the reduction in immunosuppression intended by steroid withdrawal, and, on the other hand, may result in an increase of serum creatinine which could be misinterpreted as rejection.

Early steroid withdrawal in renal transplantation with tacrolimus dual therapy: a pilot study.

BACKGROUND: With tacrolimus-based immunosuppression, it appears safe to withdraw steroids 3 to 6 months after renal transplantation. We hypothesized whether steroids could also be safely withdrawn early after transplantation. METHODS: Sixty-two patients (first or second transplant, with no previous immunological failure, and current panel reactive human leucocyte antigen [HLA] antibodies [PRA]<50%), treated with tacrolimus, were prospectively randomized to stop steroids (10 mg prednisolone) after day 7 posttransplantation (stop group [STOP], n=28) or to gradually wean off steroids in 3 to 6 months (tapering group [TAP], n=34). Analyses were performed on an intention-to-treat basis. RESULTS: After a median follow-up of 2.7 years, patient and graft survival were 97 and 90% and comparable between both groups (P =0.11 and P=0.13, respectively). The incidence of acute rejection was 29 (STOP) versus 33% (TAP) ( P=0.30). The time to the first rejection was a median of 35 days (STOP) versus 11 days (TAP) ( =0.19). The severity of the rejections (1997 Banff classification) was comparable (P =0.57). Creatinine clearance and proteinuria were similar (P >0.70). The incidence of infections was comparable ( P>0.10). The incidence of new-onset diabetes mellitus, defined as the use of antidiabetic medication, was 8.0 (STOP) versus 30.3% (TAP) (P =0.04). All cases occurred in the STOP group after 1 year, while all cases occurred in TAP in the first 4 months ( P<0.001). CONCLUSIONS: Compared with tapering in 3 to 6 months, stopping steroids 1 week posttransplantation results in comparable patient and graft survival and in a similar incidence of acute rejections. The incidence of new-onset diabetes may be reduced. The immunosuppressive benefit of adding 10 mg prednisolone to tacrolimus seems to be limited.

A late episode of post-transplant diabetes mellitus during active hepatitis C infection in a renal allograft recipient using tacrolimus.

BACKGROUND: An association between hepatitis C virus and (post-transplant) diabetes mellitus has been reported. METHODS: We report a patient on tacrolimus-based immunosuppression who developed an episode of post-transplant diabetes mellitus (PTDM) 2 years after renal transplantation, after contracting a hepatitis C infection. Her glucose metabolism was evaluated regularly by intravenous glucose tolerance tests before and after the PTDM episode. RESULTS: Before contracting hepatitis C, the patient's insulin resistance and insulin secretion were normal. After contracting hepatitis C, tacrolimus exposure increased, insulin resistance increased, and insulin secretion decreased markedly. Despite low tacrolimus exposure in the last 4 years, glucose metabolism did not recover completely. Although PTDM resolved and insulin resistance normalized, pancreatic beta cell secretion remained impaired by approximately 50% compared with the period before hepatitis C infection. CONCLUSION: After an initial increase in insulin resistance, insulin secretion decreased markedly in a patient who contracted hepatitis C 12 to 22 months after renal transplantation. This change resulted in an episode of PTDM. Increased tacrolimus exposure secondary to reduced cytochrome P-450 metabolism as a result of impaired hepatocellular function at the time of the development of PTDM seems a likely explanation for the marked decrease in insulin secretion. Viral toxicity to the beta cell might be an additional explanation. The latter might be suspected from several reports about an association between diabetes mellitus and hepatitis C in patients who do not use drugs that interfere with glucose metabolism.

Glucose metabolism in the first 3 years after renal transplantation in patients receiving tacrolimus versus cyclosporine-based immunosuppression.

The long-term effects of tacrolimus and cyclosporine on pancreatic islet cell function in renal transplant recipients are unclear. Therefore, a prospective, randomized, longitudinal study was performed that compared glucose metabolism in adult kidney allograft recipients on tacrolimus versus cyclosporine-based immunosuppression. Twenty-three white renal allograft recipients, randomized for either therapy with cyclosporine or tacrolimus, underwent intravenous glucose tolerance tests 6 times during the first 3 yr after transplantation. Concomitant therapy (low-dose steroids and azathioprine) was the same in both groups. Insulin sensitivity index (kG), insulin resistance (insulin/glucose ratio and homeostasis model assessment), and C-peptide and insulin secretion were calculated. Trough levels of tacrolimus and cyclosporine were measured. The occurrence of posttransplantation diabetes mellitus was prospectively monitored. Statistical analysis was performed by ANOVA for repeated measures, and parametric and nonparametric tests were also performed. Although only one patient treated with cyclosporine developed posttransplantation diabetes mellitus, kG levels were below normal in up to one-third of both patients who received tacrolimus and cyclosporine. The only significant difference between patients who received tacrolimus and those who received cyclosporine was in pancreatic secretion capacity at week 3 after transplantation, when the increment of C-peptide secretion was 57% lower and the increment of insulin secretion was 48% lower for patients receiving tacrolimus. In both groups, from week 3 to month 6, there was a tendency toward an increase in kG, despite a significant increase in fasting glucose and insulin resistance calculated by homeostasis model assessment. After month 6, there were no significant changes in any of the parameters of glucose metabolism, indicating that long-term use of either tacrolimus or cyclosporine does not cause chronic, cumulative pancreatic toxicity.

Glucose metabolism in renal transplant recipients on tacrolimus: the effect of steroid withdrawal and tacrolimus trough level reduction.

The relative role of steroids and tacrolimus in the development of glucose metabolic disorders and hyperlipidemia after renal transplantation has not yet been clearly established. Therefore, glucose metabolism was prospectively evaluated by intravenous glucose tolerance test, as was lipid profile, in fifteen white nondiabetic renal transplant recipients three times: before and after steroid withdrawal and after tacrolimus trough level reduction. After withdrawal of 10 mg of prednisolone, insulin resistance decreased (fasting C-peptide, 0.99 to 0.77 nmol/L [P < 0.0009]; fasting insulin, 9.5 to 8.1 mU/L [P = 0.09]; insulin/glucose ratio, 1.85 to 1.45 mU/mmol [P = 0.10]) and lipid levels decreased (total cholesterol, 5.1 to 4.2 mmol/L [P = 0.006]); HDL cholesterol, 1.4 to 1.1 mmol/L [P = 0.01]; LDL cholesterol, 3.0 to 2.5 mmol/L [P = 0.15]; triglycerides, 1.52 to 0.91 mmol/L [P = 0.02]). After tacrolimus trough level reduction from 9.5 to 6.4 ng/ml, pancreatic beta-cell secretion capacity improved (C-peptide secretion increased from 49.0 to 66.6 nmol x min/L [P = 0.04] and insulin secretion increased from 1134 to 1403 mU x min/L [P = 0.06]). HbA1c improved also, from 5.9 to 5.3% (P = 0.002). Lipids did not change. In conclusion, steroid withdrawal resulted in a decrease in insulin resistance and a reduction in lipids, and tacrolimus trough level reduction resulted in an improved pancreatic beta-cell secretion capacity. Therefore, these therapeutic measurements may contribute to the reduction of the cardiovascular morbidity and mortality in renal transplant recipients.

Influence of tacrolimus on glucose metabolism before and after renal transplantation: a prospective study.

Most studies concerning the influence of tacrolimus on glucose metabolism have been performed either in animals or after organ transplantation. These clinical studies have largely been transversal with patients who were using steroids. Therefore, this prospective, longitudinal study investigated the influence of tacrolimus on glucose metabolism before and after transplantation. Eighteen Caucasian dialysis patients underwent an intravenous glucose tolerance test before and 5 d after the start of tacrolimus. Insulin sensitivity index (k(G)), insulin resistance (insulin/glucose ratio and homeostasis model assessment), and C-peptide and insulin secretion were calculated. Trough levels of tacrolimus were measured. After transplantation, the occurrence of posttransplantation diabetes mellitus (PTDM) was prospectively monitored. Statistical analysis was performed using the Wilcoxon signed ranks test and Spearman's rho for correlation. Before tacrolimus, k(G) was indeterminate in three patients. During tacrolimus, k(G) decreased in 16 of 18 patients, from a median of 1.74 mmol/L per min to 1.08 mmol/L per min (P<0.0001). The correlation between C-peptide and insulin data was excellent. Insulin secretion decreased from 851.0 mU x min/L to 558.0 mU x min/L (P = 0.014), whereas insulin resistance did not change. Insulin sensitivity correlated negatively with tacrolimus trough level. After transplantation, three patients developed PTDM; before tacrolimus, two had an indeterminate and one a low normal k(G). During tacrolimus administration, k(G) decreased in almost all patients as a result of a diminished insulin secretion response to a glucose load, whereas insulin resistance did not change. Patients with an abnormal or indeterminate k(G) seem to be at risk of developing PTDM while on tacrolimus.