Population pharmacokinetics of voriconazole and CYP2C19 polymorphisms for optimizing dosing regimens in renal transplant recipients.

AIMS: The aims of the present study were to characterize the pharmacokinetics of voriconazole in renal transplant recipients and to identify factors significantly affecting pharmacokinetic parameters. We also aimed to explore the optimal dosing regimens for patients who developed invasive fungal infections. METHODS: A total of 105 patients (342 concentrations) were included prospectively in a population pharmacokinetic analysis. Nonlinear mixed-effects models were developed using Phoenix NLME software. Dosing simulations were performed based on the final model. RESULTS: A one-compartment model with first-order absorption and elimination was used to characterize voriconazole pharmacokinetics. Population estimates of clearance, volume of distribution and oral bioavailability were 2.88 l·h-1 , 169.3 l and 58%, respectively. The allele frequencies of cytochrome P450 gene (CYP) 2C19*2, *3 and *17 variants were 29.2%, 5.2% and 0.5%, respectively. CYP2C19 genotype had a significant effect on the clearance. Voriconazole trough concentrations in poor metabolizers were significantly higher than in intermediate metabolizers and extensive metabolizers alike. The volume of distribution increased with increased body weight. The oral bioavailability was substantially lower within 1 month after transplantation but increased with postoperative time. Dosing simulations indicated that during the early postoperative period, poor metabolizers could be treated with 150 mg intravenously or 250 mg orally twice daily; intermediate metabolizers with 200 mg intravenously or 350 mg orally twice daily; and extensive metabolizers with 300 mg intravenously twice daily. CONCLUSIONS: Using a combination of CYP2C19 genotype and postoperative time to determine the initial voriconazole dosing regimens followed by therapeutic drug monitoring could help to advance individualized treatment in renal transplantation patients with invasive fungal infections.

The Effect of Voriconazole on Tacrolimus in Kidney Transplantation Recipients: A Real-World Study.

Tacrolimus is an immunosuppressant with a narrow therapeutic window. Tacrolimus exposure increased significantly during voriconazole co-therapy. The magnitude of this interaction is highly variable, but it is hard to predict quantitatively. We conducted a study on 91 kidney transplantation recipients with voriconazole co-therapy. Furthermore, 1701 tacrolimus concentration data were collected. Standard concentration adjusted by tacrolimus daily dose (C/D) and weight-adjusted standard concentration (CDW) increased to 6 times higher during voriconazole co-therapy. C/D and CDW increased with voriconazole concentration. Patients with the genotype of CYP3A5 *3/*3 and CYP2C19 *2/*2 or *2/*3 were more variable at the same voriconazole concentration level. The final prediction model could explain 54.27% of the variation in C/D and 51.11% of the variation in CDW. In conclusion, voriconazole was the main factor causing C/D and CDW variation, and the effect intensity should be quantitative by its concentration. Kidney transplant recipients with CYP3A5 genotype of *3/*3 and CYP2C19 genotype of *2/*2 and *2/*3 should be given more attention during voriconazole co-therapy. The prediction model established in this study may help to reduce the occurrence of rejection.

Predictors of Adverse Events and Determinants of the Voriconazole Trough Concentration in Kidney Transplantation Recipients.

Voriconazole is the mainstay for the treatment of invasive fungal infections in patients who underwent a kidney transplant. Variant CYP2C19 alleles, hepatic function, and concomitant medications are directly involved in the metabolism of voriconazole. However, the drug is also associated with numerous adverse events. The purpose of this study was to identify predictors of adverse events using binary logistic regression and to measure its trough concentration using multiple linear modeling. We conducted a prospective analysis of 93 kidney recipients cotreated with voriconazole and recorded 213 trough concentrations of it. Predictors of the adverse events were voriconazole trough concentration with the odds ratios (OR) of 2.614 (P = 0.016), cytochrome P450 2C19 (CYP2C19), and hemoglobin (OR 0.181, P = 0.005). The predictive power of these three factors was 91.30%. We also found that CYP2C19 phenotypes, hemoglobin, platelet count, and concomitant use of ilaprazole had quantitative relationships with voriconazole trough concentration. The fit coefficient of this regression equation was R2  = 0.336, demonstrating that the model explained 33.60% of interindividual variability in the disposition of voriconazole. In conclusion, predictors of adverse events are CYP2C19 phenotypes, hemoglobin, and voriconazole trough concentration. Determinants of the voriconazole trough concentration were CYP2C19 phenotypes, platelet count, hemoglobin, concomitant use of ilaprazole. If we consider these factors during voriconazole use, we are likely to maximize the treatment effect and minimize adverse events.

Plasma Exosomes Derived From Patients With End-Stage Renal Disease and Renal Transplant Recipients Have Different Effects on Vascular Calcification.

End-stage renal disease (ESRD) patients usually develop extensive and progressive vascular calcification, and lots of calcification inhibitors as well as procalcifying factors are involved in the process. However, the mechanisms of vascular calcification in ESRD patients are still ill-defined. In the present study, we found that the plasma exosomes derived from ESRD patients (ESRD-Ex) promoted calcification of vascular smooth muscle cells (VSMCs) significantly, while plasma exosomes from renal transplant recipients (RTR-Ex) could partially attenuate VSMCs calcification. Moreover, the protein concentration of ESRD-Ex was significantly higher than plasma exosomes from the normal health control group (Nor-Ex) and RTR-Ex, and the content of both matrix gla protein (MGP) and Fetuin-A, the calcification inhibitors, were prominently lower in ESRD-Ex than those in Nor-Ex. The content of Annexin-A2, one of the calcification promoters, was significantly higher in ESRD-Ex and RTR-Ex than that in Nor-Ex. However, bone morphogenetic protein (BMP-2) and receptor activator for nuclear factor-κB ligand (Rankl) had no significant difference among the three groups. In addition, the content of Fetuin-A in RTR-Ex was higher than that in ESRD-Ex, although it was still lower than that in Nor-Ex. Furthermore, the levels of both Fetuin-A and MGP in plasma exosomes were negatively while the levels of Annexin-A2 in plasma exosomes was positively correlated to coronary artery calcification scores (CACS). These results indicated that ESRD-Ex significantly promoted VSMCs calcification, while renal transplantation could partially attenuate the procalcification effect of exosomes. Fetuin-A and MGP were decreased, but Annexin-A2 was increased in ESRD-Ex, and renal transplantation could increase the level of Fetuin-A rather than MGP.

Aberration methylation of miR-34b was involved in regulating vascular calcification by targeting Notch1.

Vascular calcification is one of the most important factors for cardiovascular and all-cause mortality in patients with end-stage renal diseases (ESRD). The current study was aimed to investigate the function and mechanisms of miR-34b on the calcification of vascular smooth muscle cells (VSMCs) both in vitro and in vivo. We found that the expression of miR-34b was significantly suppressed in VSMCs with high inorganic phosphate (Pi) treatment, as well as mouse arteries derived from 5/6 nephrectomy with a high-phosphate diet (0.9% Pi, 5/6 NTP) and human renal arteries from uraemia patients. Overexpression of miR-34b alleviated calcification of VSMCs, while VSMCs calcification was enhanced by inhibiting the expression of miR-34b. Bisulphite sequencing PCR (BSP) uncovered that CpG sites upstream of miR-34b DNA were hypermethylated in calcified VSMCs and calcified arteries due to 5/6 NTP, as well as calcified renal arterial tissues from uraemia patients. Meantime, increased DNA methyltransferase 3a (DNMT3a) resulted in the hypermethylation of miR-34b in VSMCs, while 5-aza-2'-deoxycytidine (5-aza) reduced the methylation rate of miR-34b and restored the expression of miR-34b in VSMCs. When DNMT3a was knocked down using DNMT3a siRNA, the effect of 3.5 mM of Pi on calcification of VSMCs was abrogated. In addition, Notch1 was validated as the functional target of miR-34b and involved in the process of calcification of VSMCs. Taken together, our data showed a specific role for miR-34b in regulating calcification of VSMCs both in vitro and in vivo, which was regulated by upstream DNA methylation of miR-34b and modulated by the downstream target gene expression, Notch1. These results suggested that modulation of miR-34b may offer new insight into a novel therapeutic approach for vascular calcification.

[Association of gene polymorphisms of cytokine and cytokine receptor with type III prostatitis].

OBJECTIVE: To explore the role of the gene polymorphism of cytokine and cytokine receptors in the pathogenesis of type III prostatitis. METHODS: We genotyped 24 outpatients diagnosed with type III prostatitis and 51 healthy volunteer controls for the single nucleotide polymorphisms of 13 cytokines and cytokine receptors at 22 sites by Sequence Specific Primer -PCR (SSP-PCR). RESULTS: The patients exhibited significantly higher frequencies of the genotypes of IL-10-819 T/T (62.5%) and IL-10-592 A/A (62.5%), the haplotype of IL-10 (-1082/-819/-592) ATA (75.0%) and the diploid genotype of IL-10 (-1082/-819/-592) ATA/ATA (62.5%), than with the healthy controls (31.3% , 31.3%, 25.0% and 31.2%) (P < 0. 05). CONCLUSION: Our data suggested that anti-inflammation cytokine IL-10 gene polymorphisms were associated with the pathogenesis of type III prostatitis.

Cancer risks in recipients of renal transplants: a meta-analysis of cohort studies.

Renal transplantation is associated with an increased risk of cancers at multiple sites; however, the relationships between increased cancer risk and participant characteristics remain unclear. We searched PubMed, Embase, and the Cochrane Library to identify prospective observational studies performed up to July 2017. Totally 11 prospective studies reported data on 79,988 renal transplant recipients were included. Renal transplant recipients were found to display a higher risk of all cancers (standard incidence ratio [SIR]: 2.89; 95% CI: 2.13-3.91; P < 0.001), gastric cancer (SIR: 1.93; 95% CI: 1.60-2.34; P < 0.001), colon cancer (SIR: 1.85; 95% CI: 1.53-2.23; P < 0.001), pancreatic cancer (SIR: 1.53; 95% CI: 1.23-1.91; P < 0.001), hepatocellular carcinoma (SIR: 2.45; 95% CI: 1.63-3.66; P < 0.001), lung cancer (SIR: 1.68; 95% CI: 1.29-2.19; P < 0.001), thyroid cancer (SIR: 5.04; 95% CI: 3.79-6.71; P < 0.001), urinary bladder cancer (SIR: 3.52; 95% CI: 1.48-8.37; P = 0.004), renal cell cancer (SIR: 10.77; 95% CI: 6.40-18.12; P < 0.001), non-melanoma skin cancer (SIR: 12.14; 95% CI: 6.37-23.13; P < 0.001), melanoma (SIR: 2.48; 95% CI: 1.08-5.67; P = 0.032), Hodgkin's lymphoma (SIR: 4.90; 95% CI: 3.09-7.78; P < 0.001), non-Hodgkin lymphoma (SIR: 10.66; 95% CI: 8.54-13.31; P < 0.001), lip cancer (SIR: 29.45; 95% CI: 17.85-48.59; P < 0.001), breast cancer (SIR: 1.11; 95% CI: 1.00-1.24; P = 0.046), and ovarian cancer (SIR: 1.60; 95% CI: 1.23-2.07; P < 0.001). However, renal transplantation did not significantly influence the risks of uterine cancer (P = 0.171), and prostate cancers (P = 0.188). Our findings suggest that patients who receive renal transplantation have an increased risk of cancer at most sites, apart from uterine and prostate cancers patients.

Arterial Calcification Is Regulated Via an miR-204/DNMT3a Regulatory Circuit Both In Vitro and in Female Mice.

Arterial calcification is a common cardiovascular disease that initiates from a process of osteoblastic differentiation of vascular smooth muscle cells (VSMCs). Accumulating evidence has demonstrated that microRNAs play an important role in regulating arterial calcification. miR-204 was significantly downregulated in calcified human renal arteries from patients with uremia; calcified arteries of mice, due to 5/6 nephrectomy with a high-phosphate diet (5/6 NTP); and in VSMCs induced by high phosphate concentration. The overexpression of miR-204 alleviated the osteoblastic differentiation of VSMCs. Bisulphite sequencing PCR revealed that CpG sites upstream of miR-204 DNA were hypermethylated in calcified VSMCs; in calcified arteries of mice, due to 5/6 NTP; and in calcified renal artery tissues from patients with uremia. Moreover, increased DNMT3a resulted in the hypermethylation of miR-204 in high phosphate concentration-induced VSMCs, whereas 5-aza-2'-deoxycytidine could restore the expression of miR-204 in high phosphate concentration-induced VSMCs. Moreover, we found that DNMT3a was the target of miR-204, and the methylation ratio of miR-204 was decreased significantly, meaning that the expression of miR-204 was restored when DNMT3a was knocked down by using DNMT3a small interfering RNA, resulting in abrogation of the effect of high phosphate concentration on VSMC calcification. The progress of arterial calcification is regulated by the miR-204/DNMT3a regulatory circuit.

[Evaluation of 126 radical cystectomy with orthotopic ileal or sigmoidocolic neobladder].

OBJECTIVE: To evaluate the long-term clinical effects of orthotopic ileal or sigmoidocolic neobladder. METHODS: One hundred and twenty six patients with bladder cancer who underwent radical cystectomy and orthotopic ileal or sigmoidocolic neobladder from 1989 to 2001 were followed up, the clinical data was collected and analysed. Hautmann orthotopic ileal neobladder was performed on 84 cases and orthotopic sigmoidocolic neobladder was performed on 42 cases; Lymph node clearing during surgery was performed on 62 cases, chemotherapy and radiotherapy was performed on 64 cases after surgery. The continence and complications were compared between sigmoidocolic group and ileal group, the tumor recurrent rate and the 5-year survival rate were compared between lymphnode clearing group and chemoradical therapy group. RESULTS: Complete follow up was performed in 122 cases. Ureter broaden and urine backflow rate were higher in sigmoidocolic group than in ileal group (P < 0.05), nocturnal continence rate in sigmoidocolic group was higher than in ileal group (P < 0.05); Post-surgical tumor recurrent rate in lymphnode clearing group was lower than in chemoradical therapy group (P < 0.05), the 5-year survival rate in lymphnode clearing group was higher than in chemoradical therapy group (P < 0.05). The overall short-term complication rate was 15.9% (20/126), the overall long-term complication rate was 9.8% (12/122). CONCLUSION: The effects of orthotopic ileal or sigmoidocolic neobladder were satisfactory with low complication rate, lymphnode clearing during the surgery can increase the 5-year survival rate when compared with the chemoradical group.

[Slowing progression of chronic allograft nephropathy by conversion from cyclosporin A to tacrolimus].

OBJECTIVE: To investigate the feasibility and safety of substituting tacrolimus(FK506) for cyclosporin A(CsA) on delaying the pace of renal dysfunction in patients with biopsy-proven chronic allograft nephropathy(CAN). METHODS: Seventy-three renal transplantation patients with CAN proved by allograft biopsy were collected in this study. Patients were randomly divided into 2 groups. Patients were either converted to FK506(FK506 group, n=43) or remained on their initial CsA-based immunosuppression(CsA group, n=30). The clinical data at study entry and after 12 months including blood urea nitrogen(BUN), serum creatinine(SCr), glomerular filtration rate(GFR), 24-hour urine protein excretion, serum total cholesterol(TC), triglyceride(TG), low density lipoprotein(LDL) and the side effects of calcineurin inhibitors were monitored during a follow-up of over 12 months. RESULTS: Twelve months later, the level of SCr was statistically reduced and GFR levels were obviously elevated in the FK506 group as compared with CsA group [(194.8+/-42.5)micromol/L vs. (245.4+/-52.8)micromol/L and (50.14+/-3.92)mL/(min.1.73 m(2)) vs. (40.58+/-2.49)mL/(min.1.73 m2), P<0.01]. Quantity of 24-hour urine protein excretion in the FK506 group was (2.0+/-0.5)g which is significantly lower than (3.9+/-0.7)g in the CsA group(P<0.01). TC, TG, and LDL levels remained unchanged in the CsA group, while those were statistically reduced in the FK506 group respectively [(5.19+/-0.73)mmol/L vs. (6.94+/-1.37)mmol/L, (1.86+/-0.84)mmol/L vs. (3.14+/-1.38)mmol/L, (3.03+/-0.71)mmol/L vs. (3.82+/-0.89)mmol/L, P<0.01]. Tremor obviously increased (P<0.01) and hypertension obviously decreased (P<0.05) in the FK506 group compared with the CsA group. CONCLUSION: FK506 treatment can greatly improve the proteinuria and hyperlipidemia. Conversion from CsA to FK506 is an effective and safe alternative therapy for delaying the progression of renal dysfunction induced by CAN.

Current Status of Research on Osteoporosis after Solid Organ Transplantation: Pathogenesis and Management.

Improved survival following organ transplantation has brought to the forefront some long-term complications, among which osteoporosis and associated fractures are the major ones that adversely affect the quality of life in recipients. The pathogenesis of osteoporosis in transplant recipients is complex and multifactorial which may be related to increased bone resorption, decreased bone formation, or both. Studies have shown that the preexisting underlying metabolic bone disorders and the use of immunosuppressive agents are the major risk factors for osteoporosis and fractures after organ transplantation. And rapid bone loss usually occurs in the first 6-12 months with a significant increase in fracture risk. This paper will provide an updated review on the possible pathogenesis of posttransplant osteoporosis and fractures, the natural history, and the current prevention and treatment strategies concerning different types of organ transplantation.

Mechanism and Treatment Strategy of Osteoporosis after Transplantation.

Osteoporosis (OP) has emerged as a frequent and devastating complication of organ solid transplantation process. Bone loss after organ transplant is related to adverse effects of immunosuppressants on bone remodeling and bone quality. Many factors contribute to the pathogenesis of OP in transplanted patients. Many mechanisms of OP have been deeply approached. Drugs for OP can be generally divided into "bone resorption inhibitors" and "bone formation accelerators," the former hindering bone resorption by osteoclasts and the latter increasing bone formation by osteoblasts. Currently, bisphosphonates, which are bone resorption inhibitors drugs, are more commonly used clinically than others. Using the signaling pathway or implantation bone marrow stem cell provides a novel direction for the treatment of OP, especially OP after transplantation. This review addresses the mechanism of OP and its correlation with organ transplantation, lists prevention and management of bone loss in the transplant recipient, and discusses the recipients of different age and gender.

[Role of interleukin-17 and Th17 cells in acute renal allograft rejection in mice].

OBJECTIVE: To investigate the role of Thl7 cells and the cytokine interleukin-17 (IL-17) in acute allograft rejection in mice. METHODS: Mouse models of kidney transplantation were randomly divided into rejection group and isograft group. On the post-operative day (POD) 3 and 7, we tested the serum IL-17 level using enzyme-linked immunosorbent assay and measured the number of Th17 cells in the renal grafts by flow cytometry. The grafts were harvested and fixed in 10% formalin to prepare paraffin sections for routine pathological inspection. RESULTS: Compared to isograft group, the allograft group showed a significantly higher level of serum IL-17 on POD3 and POD7 (P<0.05), and the level of IL-17 is significantly higher on POD7 than on POD3 (P<0.05). The allograft group showed more infiltrating Th17 cells in the grafts on POD3 and POD7 (P<0.05), and the cell number was significantly greater on POD7 (P<0.05). Pathological examination also showed an increased severity of graft rejection with the post-transplantation time. CONCLUSION: Thl7 cells may play an important role in the development of renal graft rejection. IL-17 may serve as a potential specific indicator for predicting allograft rejection.

[Surgical strategy for ectopic kidneys: analysis of 35 cases].

OBJECTIVE: To explore the surgical strategy for ectopic kidney and evaluate the clinical outcomes. METHODS: From January 2000 to October 2009, 35 cases of ectopic kidney were treated surgically in our hospital. Definite diagnoses were established in all the cases by ultrasound, intravenous urography (IVU), cystoscope, CT, magnetic resonance urography (MRU) and radionuclide imaging before the surgery. In these patients, 26 had ipsilateral ectopic ureteral orifice (including 5 with bilateral duplicated kidneys and ureter), 9 had moderate or severe hydronephrosis (including 3 with ectopic kidney calculi), and 24 had dysplastic kidney (24/35). All the patients underwent operations, including 26 with ectopic nephrectomy, 7 with ectopic ureterovesical reimplantation, and 3 with ectopic renal pelvis incision. RESULTS: The clinical effect was satisfactory in all the cases during the follow up of 7 to 29 months. CONCLUSION: Appropriate surgical approaches according to the concurrent deformities and complications can achieve good clinical results in patients with ectopic kidneys.