Dyslipidemia following kidney transplantation: diagnosis and treatment

High-Density Lipoprotein Particles and Torque Teno Virus in Stable Outpatient Kidney Transplant Recipients

Torque teno virus (TTV) is emerging as a potential marker for monitoring immune status. In transplant recipients who are immunosuppressed, higher TTV DNA loads are observed than in healthy individuals. TTV load measurement may aid in optimizing immunosuppressive medication dosing in solid organ transplant recipients. Additionally, there is a growing interest in the role of HDL particles in immune function; therefore, assessment of both HDL concentrations and TTV load may be of interest in transplant recipients. The objective of this study was to analyze TTV loads and HDL parameters in serum samples collected at least one year post-transplantation from 656 stable outpatient kidney transplant recipients (KTRs), enrolled in the TransplantLines Food and Nutrition Cohort (Groningen, the Netherlands). Plasma HDL particles and subfractions were measured using nuclear magnetic resonance spectroscopy. Serum TTV load was measured using a quantitative real-time polymerase chain reaction. Associations between HDL parameters and TTV load were examined using univariable and multivariable linear regression. The median age was 54.6 [IQR: 44.6 to 63.1] years, 43.3% were female, the mean eGFR was 52.5 (±20.6) mL/min/1.73 m2 and the median allograft vintage was 5.4 [IQR: 2.0 to 12.0] years. A total of 539 participants (82.2%) had a detectable TTV load with a mean TTV load of 3.04 (±1.53) log10 copies/mL, the mean total HDL particle concentration was 19.7 (±3.4) μmol/L, and the mean HDL size was 9.1 (±0.5) nm. The univariable linear regression revealed a negative association between total HDL particle concentration and TTV load (st.β = -0.17, 95% CI st.β: -0.26 to -0.09, p < 0.001). An effect modification of smoking behavior influencing the association between HDL particle concentration and TTV load was observed (Pinteraction = 0.024). After adjustment for age, sex, alcohol intake, hemoglobin, eGFR, donor age, allograft vintage and the use of calcineurin inhibitors, the negative association between HDL particle concentration and TTV load remained statistically significant in the non-smoking population (st.β = -0.14, 95% CI st.β: -0.23 to -0.04, p = 0.006). Furthermore, an association between small HDL particle concentration and TTV load was found (st.β = -0.12, 95% CI st.β: -0.22 to -0.02, p = 0.017). Higher HDL particle concentrations were associated with a lower TTV load in kidney transplant recipients, potentially indicative of a higher immune function. Interventional studies are needed to provide causal evidence on the effects of HDL on the immune system.

Haematological Drugs Affecting Lipid Metabolism and Vascular Health

Many drugs affect lipid metabolism and have side effects which promote atherosclerosis. The prevalence of cancer-therapy-related cardiovascular (CV) disease is increasing due to development of new drugs and improved survival of patients: cardio-oncology is a new field of interest and research. Moreover, drugs used in transplanted patients frequently have metabolic implications. Increasingly, internists, lipidologists, and angiologists are being consulted by haematologists for side effects on metabolism (especially lipid metabolism) and arterial circulation caused by drugs used in haematology. The purpose of this article is to review the main drugs used in haematology with side effects on lipid metabolism and atherosclerosis, detailing their mechanisms of action and suggesting the most effective therapies.

Dyslipidemia in Renal Transplant Recipients

Dyslipidemia is a frequent complication after kidney transplantation (KT) and is an important risk factor for cardiovascular disease (CVD). Renal transplant recipients (RTRs) are considered at high, or very high, risk of CVD, which is a leading cause of death in this patient group. Despite many factors of post-transplant dyslipidemia, the immunosuppressive treatment has the biggest influence on a lipid profile. There are no strict dyslipidemia treatment guidelines for RTRs, but the ones proposing an individual approach regarding CVD risk seem most suitable. Proper diet and physical activity are the main general measures to manage dyslipidemia and should be introduced initially in every patient after KT. In the case of an insufficient correction of lipemia, statins are the basis for hypolipidemic treatment. Statins should be introduced with caution to avoid serious side-effects (e.g., myopathy) or drug-drug interactions, especially with immunosuppressants. To lower the incidence of adverse effects, and improve medication adherence, ezetimibe in combination with statins is recommended. Fibrates and bile sequestrants are not recommended due to their side-effects and variable efficacy. However, several new lipid-lowering drugs like Proprotein convertase subtilisin/Kexin type9 (PCSK9) inhibitors may have promising effects in RTRs, but further research assessing efficacy and safety is yet to be carried out.

An overview of the efficacy and safety of everolimus in adult solid organ transplant recipients

As the risk of graft loss due to acute rejection has declined, the goal of post-transplant management has switched to long-term preservation of organ function. Minimizing calcineurin inhibitor (CNI)-related nephrotoxicity is a key component of this objective. Everolimus is a mammalian target of rapamycin inhibitor/proliferation-signal inhibitor with potent immunosuppressive and anti-proliferative effects. It has been widely investigated in large randomized clinical studies that have shown it to have similar anti-rejection efficacy compared with standard-of-care regimens across organ transplant indications. With demonstrated potential to facilitate the reduction of CNI therapy and preserve renal function, everolimus is an alternative to the current standard-of-care CNI-based regimens used in de novo and maintenance solid organ transplantation recipients. Here, we provide an overview of the evidence from the everolimus clinical study program across kidney, liver, heart, and lung transplants, as well as other key data associated with its use in CNI reduction strategies in adult transplant recipients.

Evaluation of Changes Over Time in the Drug Burden and Medication Regimen Complexity in ESRD Patients Before and After Renal Transplantation

BACKGROUND

Medication regimen complexity (MRC) has not been characterized in detail in patients with end-stage renal disease (ESRD). The objective of the present study was to quantify changes over time in the prescription drug burden and MRC in patients with ESRD (before transplantation, on discharge after kidney transplantation [M0], and 4 months [M4] and 12 months [M12] afterward).

METHODS

We retrospectively studied adult patients having undergone kidney transplantation. The number and types of drug prescribed, the pill burden, and the MRC index (MRCI) at 4 different time points (before transplantation, M0, M4, and M12) were extracted from the patients' medical records. MRCI was calculated by adding each drug score (calculated according to its formulation, dosing frequency, and additional instructions concerning administration). Hence, the MRCI took account of all prescription drugs. A logistic regression model was used to identify factors associated with an elevated MRCI at M12.

RESULTS

The median (interquartile range) age of the 354 study participants was 52 years (42-62). Respectively 21%, 42%, 53%, and 38% of the patients were taking 10 or more drugs before transplantation and at M0, M4, and M12. At M12, the 3 most frequently prescribed drug classes were immunosuppressants, cardiovascular system drugs, and drugs acting on the alimentary tract and metabolism. The pill burden and MRCI before transplantation were significantly lower (P < 0.001) than at each time point after transplantation. Diabetes and dyslipidemia were independently associated with an elevated MRCI at M12.

CONCLUSION

In kidney transplant recipients, the drug burden and MRCI were greater at all time points after transplantation than before transplantation. The impact of the drug burden and MRC on medication adherence and clinical outcomes in these patients requires further evaluation.

HLA-G14bp ins/del polymorphism and post-transplant weight gain in kidney transplantation: potential implications beyond tolerance

Background

Human leukocyte antigen (HLA)-G is a non-classical HLA molecule with immunomodulant and immunosuppressive functions, involved in transplantation tolerance. HLA-G14bp ins/del polymorphism in exon 8 has been associated with allograft rejection and kidney transplant outcome, with controversial results. We investigated associations of HLA-G14bp ins/del polymorphism on onset of some of the main post-transplant risk factors, like excess body weight, lipid abnormalities, increased fasting plasma glucose. Polymorphisms of cytokines with both immunosuppressive and metabolic effects were also assessed for comparisons and associated analysis.

Methods

The present study involved kidney transplant recipients (n = 173) in which body mass index, cholesterol, triglycerides, fasting plasma glucose were registered in the first years after transplantation and analyzed in association with genotypes. Presence of hypertension and smoking habits, demographic, transplant-related and therapeutic data of patients were also recorded. Polymerase chain reaction, sequence-specific primer amplification and Taqman allelic discrimination techniques were used for genotyping of HLA-G14bp ins/del, interleukin (IL)-10(−1082G > A,-819 T > C,–592A > C), transforming growth factor-β(+ 869 T > C,+915C > G), IL-6(−174G > C), tumor necrosis factor-α(−308G > A) and IL-18(−137G > C,-607C > A). Effects of genotypes on clinical markers at each time point (pre-transplant and 1 to 5 years after transplant) were analyzed using a repeated-measures general linear model analysis; adjustment for potential confounders was performed.

Results

Results showed that HLA-G14bp ins/ins was significantly associated with obesity, in particular after transplantation (3 years, p = 0.002, OR = 4.48, 95% CI:1.76–11.41). Post-transplant body mass index was significantly increased in HLA-G14bp ins/ins carriers (3 and 4 years, p = 0.033 and p = 0.044); effects of HLA-G14bp genotypes on post-transplant BMI were confirmed by using repeated-measures analysis and after controlling for confounding variables. Cytokine genotypes did not associate with the examined factors.

Conclusions

The study of transplanted patients allowed to evidence a potential relationship between post-transplant weight gain and HLA-G14bp ins/del polymorphism, previously involved in rejection for its immunosuppressive/tolerogenic activity. This novel association could widen the knowledge of the role and functions of HLA-G molecules in diseases and transplantation.

The Many Faces of Calcineurin Inhibitor Toxicity-What the FK?

Calcineurin inhibitors (CNIs) are both the savior and Achilles' heel of kidney transplantation. Although CNIs have significantly reduced rates of acute rejection, their numerous toxicities can plague kidney transplant recipients. By 10 years, virtually all allografts will have evidence of CNI nephrotoxicity. CNIs have been strongly associated with hypertension, dyslipidemia, and new onset of diabetes after transplantation-significantly contributing to cardiovascular risk in the kidney transplant recipient. Multiple electrolyte derangements including hyperkalemia, hypomagnesemia, hypercalciuria, metabolic acidosis, and hyperuricemia may be challenging to manage for the clinician. Finally, CNI-associated tremor, gingival hyperplasia, and defects in hair growth can have a significant impact on the transplant recipient's quality of life. In this review, the authors briefly discuss the pharmacokinetics of CNI and discuss the numerous clinically relevant toxicities of commonly used CNIs, cyclosporine and tacrolimus.

Cholesterol Disturbances and the Role of Proper Nutrition in CKD Patients

Chronic kidney disease (CKD) is a widespread disease with increasing prevalence in the modern society. Lipid disturbances are common in this group of patients. In most patients with CKD atherogenic dyslipidemia is observed. Dyslipidemia in patients with renal diseases increases the risk of cardiovascular diseases and it accelerates the progression of chronic kidney disease to its end stage. The amelioration of dyslipidemia and the lowering of oxidative stress, inflammatory processes, insulin sensitivity and remnant lipoproteins levels may lead to the reduction in cardiovascular burden. Nutritional interventions can strengthen the beneficial effect of treatment and they play an important role in the preservation of overall well-being of the patients with CKD since the aim of appropriate diet is to reduce the risk of cardiovascular events, prevent malnutrition, and hamper the progression of kidney disease. The management of dyslipidemia, regardless of the presence of chronic kidney disease, should be initiated by the introduction of therapeutic lifestyle changes. The introduction of diet change was shown to exert beneficial effect on the lipid level lowering that reaches beyond pharmacological therapy. Currently available evidence give the impression that data on dietary interventions in CKD patients is not sufficient to make any clinical practice guidelines and is of low quality.

Ratio of triglyceride to high-density lipoprotein cholesterol and risk of major cardiovascular events in kidney transplant recipients

BACKGROUND

Dyslipidemia is common in kidney transplant (KT) recipients. We analyzed the ratio of triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) in KT recipients to identify risk factors for major cardiovascular events (MACE).

METHODS

We retrospectively included KT recipients with a lipid profile performed 1 year after transplantation. We classified patients according to the TG/HDL-C divided into quintiles. Subsequently, we analyzed the association between TG/HDL-C and MACE, defined as heart failure, coronary artery disease, and cerebrovascular disease confirmed by imaging studies.

RESULTS

A total of 1301 KT recipients were enrolled. The median follow-up duration was 7.4 years (interquartile range 4.4-11.1 years). During the follow-up period, 80 (6.2%) patients developed MACE, which included 38 of unstable anginas, 9 of MIs, 19 of heart failures, 18 of cerebral infarcts, and 4 of cerebral hemorrhages. The fourth and fifth quintiles of TG/HDL-C showed a significantly increased risk of MACE [fourth quintile: adjusted hazard ratio (aHR), 3.38; 95% confidence interval (CI) 1.44-7.95; p = 0.005, fifth quintile: aHR, 2.67; 95% CI 1.13-6.30; p = 0.02]) compared to the second quintile of TG/HDL-C. This association is particularly evident in subgroups of non-DM, HTN, no history of CVD, and statin users.

CONCLUSIONS

Higher TG/HDL-C levels may be associated with MACE risk in KT recipients.

Statin therapy for preventing cardiovascular diseases in patients treated with tacrolimus after kidney transplantation

Background

Lipid abnormalities are prevalent in tacrolimus-treated patients. The aim of the study was to evaluate the preventive effects of statin therapy on major adverse cardiovascular events (MACE) in patients treated with tacrolimus-based immunosuppression after kidney transplantation (KT), and to identify the risk factors.

Methods

This observational cohort study included adult patients who underwent KT and were treated with tacrolimus. Patients who received any lipid-lowering agents except statins, or had a history of immunosuppressant use before transplantation were excluded. The primary outcome was the adjusted risk of the first occurrence of MACE. The secondary outcomes included the risk of individual cardiovascular disease (CVD) and changes in cholesterol level. Subgroup analyses were performed in the statin-user group according to the dosage and/or type of statin.

Results

Compared with the control group (n=73), the statin-users (n=92) had a significantly reduced risk of MACE (adjusted HR, 0.31; 95% CI, 0.13–0.74). In the Cox regression analysis, old age, history of CVD, and comorbid hypertension were identified as independent factors associated with increased MACE. The total cholesterol levels were not significantly different between the two groups. Subjects with higher cumulative defined daily dose of statins had significantly lower risks of MACE.

Conclusion

Statin therapy in patients treated with tacrolimus after KT significantly lowered the risk of MACE. Long-term statin therapy is clearly indicated in older kidney transplant recipients for secondary prevention.

[Correlation of blood concentration of tacrolimus with serum cystatin C in renal transplant recipients and effect of tacrolimus on glucose and lipid metabolism]

OBJECTIVE

To investigate the correlation between blood concentrations of tacrolimus (FK506) and cystatin C (Cys C) and the effect of FK506 on glycolipid metabolism in renal transplant recipients.

METHODS

A total of 325 patients receiving renal transplantation between August, 2014 and September, 2015 in Nanfang Hospital were divided into 4 groups according to the postoperative time (1 month group, 1-3 months group, 4-6 months group, and 7-12 months group). FK506 blood trough concentration was measured at the time of postoperative follow-up, and creatinine (Scr) and Cys C levels were also detected. Results Plasma FK506 concentration decreased with age in the recipients and showed a positive correlation with Cys C (r=0.985, P=0.015) but no obvious correlation with Scr (r=0.259, P=0.741). FK506 had no effect on blood glucose (5.53-5.59 mmol<L) or blood lipids (TG 1.47-1.55 mmol<L, TC 5.04-5.17 mmol<L, LDL-C 3.00-3.07 mmol<L, and VLDL 0.73-0.76 mmol<L) in patients 1-6 months after renal transplantation.

CONCLUSION

FK506 does not affect the level of glycolipid metabolism in patients after renal transplantation. Cys C is positively related to blood concentration of FK506 in the renal transplantation recipients. The rational use of FK506 can improve the effectiveness and safety of the treatment in the recipients.

Adipose tissue mTORC2 regulates ChREBP-driven de novo lipogenesis and hepatic glucose metabolism

Adipose tissue de novo lipogenesis (DNL) positively influences insulin sensitivity, is reduced in obesity, and predicts insulin resistance. Therefore, elucidating mechanisms controlling adipose tissue DNL could lead to therapies for type 2 diabetes. Here, we report that mechanistic target of rapamycin complex 2 (mTORC2) functions in white adipose tissue (WAT) to control expression of the lipogenic transcription factor ChREBPβ. Conditionally deleting the essential mTORC2 subunit Rictor in mature adipocytes decreases ChREBPβ expression, which reduces DNL in WAT, and impairs hepatic insulin sensitivity. Mechanistically, Rictor/mTORC2 promotes ChREBPβ expression in part by controlling glucose uptake, but without impairing pan-AKT signalling. High-fat diet also rapidly decreases adipose tissue ChREBPβ expression and insulin sensitivity in wild-type mice, and does not further exacerbate insulin resistance in adipose tissue Rictor knockout mice, implicating adipose tissue DNL as an early target in diet-induced insulin resistance. These data suggest mTORC2 functions in WAT as part of an extra-hepatic nutrient-sensing mechanism to control glucose homeostasis.

The kinase mTOR controls anabolic metabolism. Here, the authors create fat-specific mTORC2 knockout mice using the Adiponectin-Cre driver and show mTORC2 signalling is important for systemic metabolic homeostasis by controlling adipocyte de novo lipogenesis and glucose uptake.

High-density lipoprotein: structural and functional changes under uremic conditions and the therapeutic consequences

High-density lipoprotein (HDL) has attracted interest as a therapeutic target in cardiovascular diseases in recent years. Although many functional mechanisms of the vascular protective effects of HDL have been identified, increasing the HDL plasma level has not been successful in all patient cohorts with increased cardiovascular risk. The composition of the HDL particle is very complex and includes diverse lipids and proteins that can be modified in disease conditions. In patients with chronic kidney disease (CKD), the accumulation of uremic toxins, high oxidative stress, and chronic micro-inflammatory conditions contribute to changes in the HDL composition and may also account for protein/lipid modifications. These conditions are associated with a decreased protective function of HDL. Therefore, the HDL quantity and the functional quality of the particle must be considered. This review summarizes the current knowledge of dyslipidemia in CKD patients, the effects of lipid-modulating therapy, and the structural modifications of HDL that are associated with dysfunction.

Long-term risk of mesenteric ischemia in patients with inflammatory bowel disease: a 13-year nationwide cohort study in an Asian population

BACKGROUND

It is unclear whether patients with inflammatory bowel disease (IBD) have higher risks of developing mesenteric ischemia.

METHODS

We enrolled 9,363 patients who had been hospitalized because of IBD between January 1998 and December 2010, along with 37,452 control patients who were matched at a 1:4 proportion for age, sex, and index year. We accounted the cumulative incidences and hazard ratios (HRs) of developing mesenteric ischemia during the 13-year study period.

RESULTS

Patients with IBD had a considerably higher incidence rate of subsequent mesenteric ischemia compared with the controls (22.7 vs 3.09 per 10,000 person-years), with adjusted HR of 6.33 (95% confidence interval: 4.75 to 8.43). A multivariate stratified analysis showed that the mesenteric ischemia risk after adjustment for comorbidities is significantly higher in patients of all age groups, particularly in patients younger than 44 years (adjusted HR: 48.0; 95% confidence interval: 11.3 to 203.9). Moreover, patients with IBD were at highest risk of developing mesenteric ischemia within the first year of follow-up.

CONCLUSIONS

Careful follow-up and effective therapy are necessary to reduce the excessive risk in these patients.

Short and long term in vivo effects of Cyclosporine A and Sirolimus on genes and proteins involved in lipid metabolism in Wistar rats

OBJECTIVE

Cyclosporine A (CsA) and sirolimus (SRL) are immunosuppressive agents (IA) associated with new onset diabetes after transplantation and dyslipidemia. We aim to evaluate the molecular effects of CsA (5mg/kg/day) and SRL (1mg/kg/day) treatment for 3 and 9weeks on lipid metabolism, in Wistar rats.

MATERIALS/METHODS

Lipolysis was evaluated in isolated adipocytes, while triglycerides (TG) and non-esterified fatty acid (NEFA) were measured in serum. Gene and protein expression involved in lipid metabolism was assessed in adipose tissue and liver.

RESULTS

CsA and SRL treatments of rats for 3 and 9weeks increased isoproterenol-stimulated lipolysis by 5-9 fold and 4-6 fold in isolated adipocytes, respectively. While CsA increased adipocyte weight and diameter, as well as NEFA and TG levels in circulation after 9weeks, SRL treatment caused ectopic deposition of TG in the liver after 3weeks. Moreover, ACC1 and FAS protein expression was increased after 3weeks (>100%, p<0.01), while HSL was increased after 9weeks of CsA treatment. On the other hand, SRL decreased the expression of lipogenic genes, including ACC1 (50%, p<0.05), lipin1 (25%, p<0.05), PPAR-γ (42%, p<0.05) and SCD1 (80%, p<0.001) in adipose tissue, after 3weeks of treatment.

CONCLUSION

The effects of both IAs on expression of lipolytic and lipogenic genes suggest that these agents influence lipid metabolism, thus contributing to the dyslipidemia observed during immunosuppressive therapy.

Effects of cyclosporine and sirolimus on insulin-stimulated glucose transport and glucose tolerance in a rat model

Cyclosporine (CsA) and sirolimus (SRL) have been associated with undesirable side effects, including posttransplantation diabetes and hyperlipidemia, but the molecular mechanisms underlying these effects remain to be elucidated. Animal studies focusing on clinically relevant doses are advised. This study sought to compare the metabolic effects on isolated rat adipocytes treated with either CsA or SRL ex vivo and after long-term in vivo treatment in Wistar rats. We assessed the ex vivo effects of CsA (0.5-30 μmol/L) and SRL (1-250 μmol/L) on insulin-stimulated (14)C-glucose uptake in epididymal adipocytes (n = 6-9). In parallel, rats (n = 12) were treated with either vehicle, CsA (5 mg/kg/d) or SRL (1 mg/kg/d) for either 3 or 9 weeks. At the end of the treatment, glucose tolerance test (GTT) and insulin-stimulated (14)C-glucose uptake as well as biochemical parameters were analyzed. A significant reduction in the insulin-stimulated glucose uptake over basal was observed among isolated adipocytes, whether exposed ex vivo or in vivo to CsA or SRL treatment. Furthermore, the SRL group showed significantly lighter fat pads and smaller adipocytes at 3 weeks with a smaller gain in body weight throughout the study compared with either the vehicle or CsA cohorts. Glucose intolerance was observed after a GTT, at the end of the treatment with either drug. Additionally, at 9 weeks serum triglycerides were increased by CsA compared with vehicle or SRL treatment. Interestingly, although SRL-treated animals presented higher fed and fasted insulin levels compared with either group, suggesting insulin resistance, the CsA group presented lower fed and fasted insulin values, suggesting a defect in insulin secretion at 9 weeks. These results suggested that either ex vivo treatment of fat cells or in vivo treatment of rats with CsA or SRL impaired insulin-stimulated glucose uptake by adipocytes. Both drugs caused glucose intolerance, which altogether could be responsible for the development of posttransplantation diabetes.

Acute effects of fructose consumption on uric acid and plasma lipids in patients with impaired renal function

OBJECTIVE

Metabolic disturbances are common in patients with renal function impairment and are related to high rates of cardiovascular incidents and mortality. Kidney transplantation leads to improved survival but may lead to additional metabolic alterations caused by immunosuppressive drugs and improved nutrition.

MATERIALS AND METHODS

The short-term effect of oral fructose load on serum uric acid (UA), plasma lipids, and blood pressure (BP) was studied in 85 patients with chronic kidney disease (CKD) and impairment of renal function (glomerular filtration rate 50-65 ml/min per 1.73 m(2)), comprising 55 renal transplant recipients (RTR) treated with standard triple immunosuppressive therapy including a calcineurin inhibitor (CNI) cyclosporine A (CsA) or tacrolimus (Tac) and 30 non-transplanted patients with CKD. Both non-transplanted CKD patients and RTR had stable renal function and a comparable degree of kidney dysfunction. All subjects received orally 70 g of fructose dissolved in 200 ml of water. Serum UA, lipids, and blood pressure were measured at baseline and 60, 120, 180, and 240 minutes after fructose administration.

RESULTS

There was a significant increase of serum UA concentration (p<0.001) in both CKD patients and RTR--CsA- or Tac-treated patients comparable in the latter. Total cholesterol (TC), LDL, and HDL cholesterol significantly decreased and serum triglycerides (TG) markedly increased in RTR, whereas in CKD patients all serum lipid fractions increased. Blood pressure was unaffected by fructose intake.

CONCLUSION

Both non-transplanted and transplanted patients with mild renal function impairment show similar acute purine metabolic disturbances following oral administration of fructose but in the latter dietary fructose may induce a smaller hyperlipidemic response.

Dyslipidemia after kidney transplantation and correlation with cyclosporine level

Background

Dyslipidemia after kidney transplantation is a frequent finding and is multifactorial. Immunosuppressive agents such as cyclosporine (CsA) can cause hypercholesterolemia.

Objectives

As there were few reports with conflicting evidence on whether CsA related dyslipidemia is dose related and that CsA monitoring assays (trough level, C0, or two hour post dose level, C2) is a better predictor for dyslipidemia development; hence, the current study, in a large sample size, was designed to answer these questions.

3. Patients and Methods

In the current retrospective cross sectional study, 1391 kidney transplant recipients were enrolled. All patients received CsA plus mycophenolatemofetile or azathioprine and prednisolone. Serum creatinine, CsA blood levels and lipid profile were measured after 12-14 h fasting. Mann-Whitney and Kruskal-Wallis, Pearson`s test and logistic regression were used for data analyses.

Results

Mean age of 1391studied population was 38.7 ± 15 years old. Hypercholesterolemia and hypertriglyceridemia were observed in 58.9% and 86.6%, respectively and they were more significantly detected in cadaveric kidney transplantation. Dyslipidemia had weak correlation with age of recipient, serum creatinine, C0 and C2 levels of CsA. At logistic regression, serum creatinine was the only risk factor for hypercholesterolemia development after kidney transplantation (OR = 1.6, CI 95%: 1.4 -1.8).

Conclusions

Dyslipidemia is a common finding after kidney transplantation and has no correlation with CsA level. According to conflicting data on the precise effect of different factors in inducing dyslipidemia, prospective large sample size studies should consider better control of dyslipidemia.

Lipid parameters, doses and blood levels of calcineurin inhibitors in renal transplant patients

The calcineurin inhibitors (CNIs) [cyclosporin A (CsA) and tacrolimus (Tac)] are currently the most widely prescribed drugs for maintenance of immunosuppression after renal transplantation. These immunosuppressants are associated with side effects such as hyperlipidemia. We evaluated the differential effects of different CNIs on serum lipid parameters in renal transplant patients. Moreover, the aim of this study is to investigate the relationships between doses and blood levels of CNIs, and blood levels of CNIs and lipid parameters retrospectively. Two groups of 98 non-diabetic renal transplant patients, each treated with different CNIs, were studied: group A (n = 50, mean age: 31 ± 10 years), CsA, mycophenolate mofetil/azathioprin, steroid; group B (I = 48, mean age: 34 ± 12 years), Tac, mycophenolate mofetil/azathioprin, steroid. In renal transplant patients, CNIs blood levels and doses were examined at 1, 3, 6, 9, and 12 months after transplantation. Biochemical laboratory parameters including plasma lipids [total-cholesterol (CHOL), low-density lipoprotein (LDL)-CHOL, high-density lipoprotein (HDL)-CHOL, and triglycerides (TG)], CNI levels and doses were examined at 1, 3, 6, 9, and 12 months after transplantation. None of the patients received anti-lipidemic drugs during the study period. Blood levels of CNIs were detectable in all whole-blood samples by Cloned- Enzyme-Donor Immunoassay (CEDIA). The relationship between CNIs blood levels and CHOL, (LDL)-CHOL, HDL-CHOL, TG were evaluated. The mean serum CHOL levels and LDL-CHOL levels of patients in group A were found significantly higher than the patients in group B during the 12 month of follow up (p < 0.05). There was no significant difference in TG and HDL-CHOL plasma levels between group A and group B (p > 0.005). In group A the daily dose of CsA was significantly correlated with the mean blood levels of CsA at the 1st and 3rd months (r = 0.387, p = 0.005; r = 0.386, p = 0.006), respectively. In group A, the daily dose of CsA was significantly correlated with the mean serum TG levels during the 12 month of follow up (r = 0.420, p = 0.003). In group B, the daily dose of Tac was significantly correlated with the mean blood level of Tac (r = 0.335, p = 0.020) at the 1st month. No correlation was found between mean Tac blood levels and lipid parameters during the 12-month of follow up (p > 0.05). Significant positive correlation was observed between the CsA blood levels and LDL-CHOL levels (r = 0.338, p = 0.027) at the 3rd month. In the renal transplant patients with well functioning grafts, CsA therapy is associated with increased CHOL and LDL-CHOL ratio which represents an increased atherogenic risk tended to be associated with CsA. Serum LDL-CHOL levels may be effected by blood CsA levels.

Lipid profile changes during the first year after kidney transplantation: risk factors and influence of the immunosuppressive drug regimen

AIM

This study analyzed the incidence, time course, and risk factors associated with dyslipidemia during the first year after kidney transplantation among patients receiving various immunosuppressive regimens.

METHODS

The analysis included 474 kidney transplant recipients receiving cyclosporine (CSA) combined with sirolimus (SRL; n=137) or mycophenolate (MMF, n=58) or everolimus (EVR, n=47); or SRL combined with MMF (n=32); or tacrolimus (TAC) combined with SRL (n=86) or MMF (n=114). All patients received prednisone. We evaluated the influence of demographic features, clinical outcomes, and statin use on lipid profiles during the first year after transplantation. total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (hdl-C), low-density lipoprotein cholesterol (ldl-C), non-HDL-C, TC:HDL-C, LDL-C:HDL-C, TG:HDL-C.

RESULTS

Lipid profiles were within the recommended ranges in 28% of patients pretransplantation and in 10% at 1 year; 27% of them received statins. At 1 year, LDL-C<100 mg/dL was observed in 31.8% of patients but more than 35% of these patients still showed other lipid fractions or ratios outside recommended target concentrations. Among all patients with LDL-C>100 mg/dL, almost 70% to 80% had other lipid fractions or ratios within target ranges. A logistic regression analysis showed age, gender, time on dialysis, diabetes, type of calcineurin inhibitor (CSA vs TAC), adjunctive therapy (SRL/EVR vs MMF) and prednisone dose to be associated with dyslipidemia.

CONCLUSION

Dyslipidemia is frequent at 1 year after transplantation. The lack of agreement among changes observed in lipid fractions and ratios suggests that more studies are necessary to guide therapy besides targeting LDL-C concentrations as recommended by current guidelines.

In vitro influence of fatty acids and bilirubin on binding of mycophenolic acid to human serum albumin

Mycophenolic acid (MPA) is 98-99% bound to albumin. Because MPA is restrictively cleared and has a low extraction coefficient, increase in its free fraction related to decreased albumin binding results in lower total concentrations but unchanged unbound concentrations. Multiple factors, including hypoalbuminemia, impaired renal function, and accumulated mycophenolic acid glucuronide are known to reduce MPA protein binding. Little is known about the influence of fatty acids and bilirubin on this issue. By using quenching fluorescence method, the aims of this study were to investigate in vitro the binding properties of MPA, then the influence of myristic acid and bilirubin on MPA binding to albumin. The estimate of dissociation constant (Kd) of MPA was 13.2 [CI 95 12.7-13.8] μM. In the presence of myristic acid (concentration range 4-100 μM), apparent Kd (Kd(app)) of MPA was approximately 1.5-10-fold greater. For myristic acid/albumin molar ratio reachable in clinical settings (2:1 and 5:1), Kd(app) of MPA rose about a factor 1.5 and 2.2, respectively. In the presence of bilirubin (concentration range 0.5-5 μM), Kd(app) of MPA was approximately 1.5-5-fold greater than MPA Kd. For bilirubin/albumin molar ratio reachable in clinical settings (1:4 and 1:2), Kd(app) of MPA rose about a factor 1.5 and 1.9, respectively. These data suggest that hypertriglyceridemia or cholestasis may significantly increase MPA free fraction in clinical settings, thereby lowering MPA total concentration in plasma while the free concentration remains unchanged. These results may help to optimize the therapeutic drug monitoring of MPA.