CYP3A4 genetic polymorphisms predict cyclosporine-related clinical events in Chinese renal transplant recipients.

BACKGROUND: Cyclosporin A (CsA) is a substrate of both cytochrome P450 3A (CYP3A) and P-glycoprotein (P-gp), some of the single nucleotide polymorphisms (SNPs) in these genes are associated with interindividual variations in CsA pharmacokinetics. We studied the influence of these SNPs on the incidence of rejection and CsA nephrotoxicity, as well as pneumonia within one year after renal transplant and post-transplantation diabetes mellitus (PTDM), in order to find whether genetic evaluation may help to identify patients at risk and to modulate CsA therapy to optimize graft and patient outcomes. METHODS: A total of 208 renal transplant recipients receiving CsA were genotyped for ABCB1 (C1236T, G2677T/A, and C3435T), CYP3A4 1G, and CYP3A5 3 by direct sequencing method. Retrospective case control study was utilized to identify the association between CYP3A4 1G, CYP3A5 3, ABCB1 genetic polymorphisms and CsA-related outcomes. RESULTS: The patients with a CYP3A4 1G/ 1G genotype were found to have a higher incidence of acute rejection compared with those with CYP3A4 1/1. CONCLUSION: CYP3A4 1G/1G genotype predict increased risk of acute rejection, so genetic evaluation may partly help to identify patients at risk and to modulate CsA therapy to optimize graft and patient outcomes.

Serum major-histocompatibility-complex class I-related chain A antibody detection for the evaluation of graft dysfunction in renal allograft recipients.

BACKGROUND: In addition to the well-known antibodies against human leukocyte antigens (HLA)-induced kidney-graft rejection, polymorphic major-histocompatibility-complex (MHC) class I-related chain A (MICA) antigens can elicit antibodies and have been suggested to play a role in the antibody-mediated allograft rejection (AMR). We carried out a prospective study of MICA antibodies in post-renal transplant patients to determine the association between MICA antibodies, C4d staining, histological features, and graft outcome. METHODS: We tested 52 patients who had biopsy results due to graft dysfunction. The MICA antibodies in concurrent sera were determined by Luminex. All patients were followed up for one year after renal biopsy. The influence of antibody production on the function of graft was analyzed. RESULTS: Antibodies against MICA were positive in 15 out of the 52 patients (28.9%). The presence of MICA antibodies was associated with renal-allograft deterioration. During one-year follow-up, the estimated glomerular filtration rate (eGFR) decreased (24.0 ± 3.4)% among recipients with anti-MICA antibodies. However, among recipients without anti-MICA antibodies, the eGFR has declined only (8.4 ± 3.0)% (P = 0.017). The association between C4d staining, histological features and MICA antibody production was found no significant difference. CONCLUSION: Besides anti-HLA antibodies, the presence of post-transplant MICA antibody is associated with poor graft outcome and increases the risk of graft failure.

Tacrolimus combined with corticosteroids in treatment of nephrotic idiopathic membranous nephropathy: a multicenter randomized controlled trial.

BACKGROUND: Idiopathic membranous nephropathy (IMN), a common cause of nephrotic syndrome in adults, is usually treated with corticosteroids in combination with cyclophosphamide or cyclosporine. A recent placebo-controlled study suggested that tacrolimus monotherapy was effective in IMN. However, the effectiveness of tacrolimus versus classic regimen and its potential nephrotoxicity remain inconclusive. This study evaluated the efficacy and safety of tacrolimus plus prednisone in patients with nephrotic IMN. METHODS: Seventy-three patients with nephrotic IMN were recruited in this multicenter randomized controlled trial, 39 receiving tacrolimus and prednisone, while 34 receiving cyclophosphamide and prednisone. Tacrolimus was given at 0.1 mg/kg/d initially and adjusted to a blood trough level at 5 to 10 ng/mL for 6 months and then reduced to 2 to 5 ng/mL in the subsequent 3 months. RESULTS: Intention-to-treat analysis suggested that the remission rate at the end of the sixth month was significantly higher in tacrolimus group than that in cyclophosphamide group (85% versus 65%, P < 0.05). The decrease of proteinuria was significantly greater in tacrolimus group. At the end of the 12th month, the remission rates were comparable between these 2 groups. Patients treated with tacrolimus were more likely to develop glucose intolerance (or diabetes mellitus), infection, and hypertension. No obvious nephrotoxicity of calcineurin inhibitor was found in repeat renal biopsy. CONCLUSIONS: Tacrolimus plus corticosteroids is an alternative therapeutic regimen for nephrotic IMN. The short-term efficacy might be better than cyclophosphamide plus prednisone.

Real-time assay of immobilized tannase with a stopped-flow conductometric device.

A stopped-flow manifold was developed to assay and characterize immobilized tannase (EC 3.1.1.20). The immobilized enzyme reactor was inserted within the tube-type electrode pair (cell constant=103.2 cm(-1)) for a real-time conductometric measurement. Tris buffer (2 mM, pH=7.0) was used as the carrier for sensitivity improvement. The activities and kinetic parameters (Km values) for propyl gallate, methyl gallate and tannic acid were investigated.

[Treatment of proliferative lupus nephritis with leflunomide and steroid: a prospective multi-center controlled clinical trial].

OBJECTIVE: Leflunomide (LEF) is a selective inhibitor of de novo pyrimidine synthesis, currently used in the treatment of rheumatoid arthritis. To evaluate the efficacy and safety of LEF in the treatment of proliferative lupus nephritis, a prospective multi-center controlled clinical trial was conducted. METHODS: Patients with biopsy-confirmed proliferative lupus nephritis were recruited. Patients of recent onset who had not used any immunosuppressive drug were given either oral LEF (group A) or IV cyclophosphamide (group B); relapsed patients who had received immunosuppressive therapy 3 months before were given LEF (group C). Efficacy and safety were evaluated at 6 months after treatment. RESULTS: Total 51 patients were enrolled, 4 patients withdrew due to adverse events. For those initial treated patients, total response rate were 80% in group A and 75% in group B, complete remission rate were 40% and 25% respectively, not statistically different. Renal parameters (proteinuria, serum albumin and serum creatinine) and systemic lupus erythematosus disease activity index (SLEDAI) improved similarly in both groups. For 14 relapsed patients, total response rate was 60% and complete remission rate was 6.7%. Major adverse events reported in LEF treated patients were infection and alopecia. Herpes zoster was the most often type among infectious events, and one case of severe lung infection was reported. CONCLUSION: LEF combined with steroid was effective in the induction therapy of proliferative lupus nephritis. LEF was generally well-tolerated, its efficacy in maintenance therapy and long-term safety remains to be clarified.

Use of ascorbate-rich dialysate to attenuate oxidative stress in maintenance hemodialysis patients.

BACKGROUND: Oxidative stress exists in uremic milieu, particularly in maintenance hemodialysis (MHD) patients, and accounts for certain long-term complications. Yet little is known about whether supplementation of ascorbic acid (vitamin C, or vitC) via extracorporeal circuit has substantial effects on minifying oxidative impairment. SUBJECTS AND METHODS: The entire experiment consisted of three sections: 1) Practicing ascorbate dialysate among 8 MHD patients in a single dialysis session, compared with a conventional hemodialysis session and another one with intravenous injection of vitC. In each session, oxidative stress markers--namely, plasma total ascorbic acid (TAA), ratio of dehydroascorbic acid (DHAA) to TAA (DHAA/TAA), vitamin E (vitE), and malondialdehyde (MDA)--in both plasma and erythrocytes were measured. 2) A relatively long-term application of ascorbate dialysate in 12 of 23 MHD patients, who were randomly allocated to experimental group (n = 12), and control group (n = 11). Oxidative stress markers and main hematological and biochemical indices were determined at the beginning and end of the period. 3) Application of ascorbate dialysate in 10 MHD patients with intravenous iron treatment, performed in similar procedures as section 1. In addition to determining the aforementioned oxidative stress markers, area under the curve (AUC0-180 min) of ratio of plasma MDA to cholesterol (MDA:Cho) was calculated to evaluate the extent of lipoperoxidation. RESULTS: 1) Plasma TAA gradually decreased during dialysis, whereas a mild increase appeared in MDA. A protruding TAA concentration peak, as well as an extreme DHAA/TAA reduction, followed the injection of vitC, but soon a precipitous fall in DHAA/TAA ensued. Stable plasma TAA and slightly raised vitE were observed when applying ascorbate dialysate. 2) Plasma TAA augmented (27.4 +/- 13.3 vs. 16.8 +/- 9.5 mg/dL, P < .05) and plasma low-density lipoprotein (oxLDL) became two-thirds of baseline data (32.6 +/- 25.2 vs. 83.8 +/- 56.5 micromol/L, P < .05) in the experimental group, whereas oxLDL in the control group reduced quantitatively but not significantly in statistics. (3) As iron sucrose was infused, the decline of TAA and ascending of MDA would be abated not only by intravenous drop of vitC, but also by ascorbate dialysate; however, TAA or MDA curve manifested totally distinguished in the two modalities. AUC0-180 min in ascorbate dialysate group was significantly less than that in control group (400.25 +/- 28.54 vs. 487.25 +/- 109.82). CONCLUSION: Plasma ascorbic acid diminished a great deal during hemodialysis, and at the same time oxidative stress formed and intensified, which will be exacerbated by a remedy of frequent intravenous iron. Ascorbate supplementation, by means of either infusion or extracorporeal circuit, can lessen the loss and therefore attenuate oxidative stress. The latter pattern takes the advantage of retaining the approximate internal balance instead of exquisite change in vivo due to administration of intravenous vitC.