Latest medical literature on sandimmune

Our library of drug research abstracts drawn from the medical literature is updated on a regular schedule, and you can be assured that new sandimmune research articles will be listed here shortly after becoming available to us.

Medical research on sandimmune

Human Leukocyte Antigen (HLA) B-27 and older age are associated with augmented cyclosporine blood bioavailability in renal allograft recipients: An attempt toward individualization of immunosuppression.

Ann Transplant. 2008; 13(2): 32-6
Nemati E, Taheri S, Pourfarziani V, Einollahi B
Background: Therapeutic drug monitoring of cyclosporine (CsA) blood values in renal transplant recipients is of extreme importance; hence, finding contributing factors in this issue is relevant. In this study, we aimed to evaluate potential associations of some characteristics of the recipients including their human leukocyte antigen haplotypes with their drug bioavailability. Material/Methods: 616 patients who had a valid HLA typing result concomitant with other demographic data in our local data registry were consecutively selected. We extracted their HLA typing, age, gender, weight, cause of renal failure, first measured CsA trough level (C0) and concomitantly measured creatinine, CsA administered dosage, time duration from transplantation, routine laboratory test results, panel reactive antibodies percentage, and immunosuppression type. Bivariate and multivariate linear regressions were employed to evaluate associations of these factors with blood C0 values. Results: 64.5% of patients were male. Mean age at transplantation was 40.7+/-15.8. Mean first measured C0 was 271+/-178 ng/ml. Analysis showed that the only factors which had independent association with C0 were age at transplantation, dose/weight ratio and HLA-B27. Conclusions: genetic factors as well as age of patients are two founded factors in this study which are recommended to be considered in monitoring drug administration in organ transplant recipients.

EXACERBATION BY NICOTINE OF THE CYCLOSPORINE A-INDUCED IMPAIRMENT OF beta-ADRENOCEPTOR-MEDIATED RENAL VASODILATION IN RATS.

Clin Exp Pharmacol Physiol. 2008 Jun 18;
El-Gowilly SM, Ghazal AR, Gohar EY, El-Mas MM
1. Nicotine is implicated in smoking-related renovascular impairment and worsening of existing nephropathies. In the present study, we investigated whether nicotine aggravates the deleterious effect of the immunosuppressant drug cyclosporine A (CsA) on renal vasodilation induced by the beta-adrenoceptor agonist isoprenaline. 2. Bolus isoprenaline (0.03-8.0 micromol) elicited dose-dependent vasodilation of phenylephrine-preconstricted perfused kidneys that was attenuated by infusion at 5 mL/min of nicotine (5 x 10(-4) mol/L) or CsA (2 micromol/L). Further, chronic administration of nicotine (0.4 mg/kg per day) or CsA (20 mg/kg per day) for 3 weeks reduced isoprenaline-induced vasodilation and elevated plasma urea and creatinine concentrations, effects that were magnified when both nicotine and CsA were administered concurrently. 3. The role of endothelial and smooth muscle signalling in the acute nicotine/CsA renovascular interaction was investigated. Vasodilation caused by 0.25 micromol isoprenaline was attenuated by 6 micromol/L propranolol and 10 mmol/L tetraethylammonium (TEA), potentiated by 100 micromol/L hexamethonium and 7 micromol/L diclophenac, and virtually abolished in 80 mmol/L KCl-preconstricted tissues. N(G)-Nitro-l-arginine (l-NNA; 200 micromol/L), methylene blue (10 micromol/L), 3-[(3-cholamidopropyl)-dimethyl-ammonio]-1-propane-sulphonate (CHAPS; 0.2% for 30 s), nifedipine (750 nmol/L), atropine (1 micromol/L) and SQ22536 (an adenylyl cyclase inhibitor; 3 x 10(-5) mol/L) had no effect on isoprenaline responses. 4. Nicotine (5 x 10(-4) mol/L) reduced isoprenaline-induced vasodilation and this effect was potentiated by concurrent CsA (2 micromol/L) infusion. Nicotine-induced impairment of the vasodilator response to isoprenaline was reduced by hexamethonium and potentiated by l-NNA, methylene blue, CHAPS and nifedipine. Alternatively, CsA exacerbation of the nicotine-isoprenaline interaction was abolished by propranolol, l-NNA, methylene blue, CHAPS, l-arginine, TEA and nifedipine. 5. In summary, nicotine and CsA produce additive impairment of kidney function and beta-adrenoceptor-mediated renovascular control, nitric oxide (NO)-cGMP signalling tonically restrains nicotine-induced impairment of isoprenaline vasodilation and the endothelial NO-K(+) pathway modulates the aggravating effect of CsA on nicotine-isoprenaline interactions.

CD25, CD28 and CD38 expression in peripheral blood lymphocytes as a tool to predict acute rejection after liver transplantation.

Clin Transplant. 2008 Jun 18;
Boleslawski E, Benothman S, Grabar S, Correia L, Podevin P, Chouzenoux S, Soubrane O, Calmus Y, Conti F
Background/Aim: The aim of this study was to determine whether the expression of CD25, CD28 and CD38 (which reflects the degree of T-cell activation) by peripheral blood mononuclear cells constitutes a useful means of measuring the immune status of liver transplant recipients. Methods: Fifty-two patients enrolled in a prospective randomized study comparing cyclosporine and tacrolimus as the principal immunosuppressive drugs were monitored prospectively. The expression of CD25, CD28 and CD38 was analyzed on CD3-, CD4- and CD8-positive cells from whole blood using flow cytometry. The prognostic value of baseline and day 14 measurements regarding acute rejection was examined using Kaplan-Meier estimates for univariate analyses and the Cox model for multivariate analyses. Results: The mean frequencies of CD28 and CD38-expressing T cells were significantly higher in patients with acute rejection (p = 0.01 and p = 0.001, respectively), whereas the frequency CD25-expressing T cells did not differ significantly. Under univariate analysis, baseline CD25 levels, the type of calcineurin inhibitor, as well as the CD28 and CD38 frequencies obtained at day 14 were associated with the subsequent development of acute rejection. Under multivariate analysis, only CD28 and CD38 frequencies obtained at day 14 were independently associated with acute rejection. Conclusions: The evaluation of CD28 and CD38 expression in peripheral blood lymphocytes is a simple marker that could be used routinely in clinical practice to assess the level of immunosuppression.

Epstein-Barr virus load in whole blood is associated with immunosuppression, but not with post-transplant lymphoproliferative disease in stable adult heart transplant patients.

Transpl Int. 2008 Jun 18;
Doesch AO, Konstandin M, Celik S, Kristen A, Frankenstein L, Sack FU, Schnabel P, Schnitzler P, Katus HA, Dengler TJ
Development of Epstein-Barr virus (EBV)-associated post-transplant lymphoproliferative disease (PTLD) is a serious complication following heart transplantation (HTX). This study investigates EBV DNA load in adult heart transplant recipients, its association with immunosuppression, and its potential as a marker for development of PTLD. EBV DNA load was measured prospectively by quantitative real-time polymerase chain reaction (PCR) in 172 stable HTX patients. Sixty-seven patients (39.0% of total) had a positive EBV PCR at initial examination [median 4.9 (range 1.1-16.9) years post-HTX]. In follow-up testing of 67 positive patients 6 months later, 36 patients continued to have a positive EBV PCR. Overall incidence of EBV DNA was significantly associated with calcineurin inihibitors, azathioprine medication, and with the absence of mycophenolate mofetil (MMF) treatment. In patients with positive EBV DNA levels at initial examination and negative levels at retesting, cyclosporine A levels were found to be significantly higher at initial examination (148.4 +/- 70.2 vs. 119.6 +/- 53.5 ng/ml, P < 0.05). Three patients (1.7%, 3/172) were diagnosed with PTLD during the course of the study (mean follow up 4.0 years). EBV DNA viral load determination does not appear to be useful for risk prediction or early diagnosis of PTLD in adults after HTX, but an association of EBV DNA load with qualitative and quantitative immunosuppression is demonstrated.

Molecular Determinants of Magnesium Homeostasis: Insights from Human Disease.

J Am Soc Nephrol. 2008 Jun 18;
Alexander RT, Hoenderop JG, Bindels RJ
The past decade has witnessed multiple advances in our understanding of magnesium (Mg(2+)) homeostasis. The discovery that mutations in claudin-16/paracellin-1 or claudin-19 are responsible for familial hypomagnesemia with hypercalciuria and nephrocalcinosis provided insight into the molecular mechanisms governing paracellular transport of Mg(2+). Our understanding of the transcellular movement of Mg(2+) was similarly enhanced by the realization that defects in transient receptor potential melastatin 6 (TRPM6) cause hypomagnesemia with secondary hypocalcemia. This channel regulates the apical entry of Mg(2+) into epithelia. In so doing, TRPM6 alters whole-body Mg(2+) homeostasis by controlling urinary excretion. Consequently, investigation into the regulation of TRPM6 has increased. Acid-base status, 17beta estradiol, and the immunosuppressive agents FK506 and cyclosporine affect plasma Mg(2+) levels by altering TRPM6 expression. A mutation in epithelial growth factor is responsible for isolated autosomal recessive hypomagnesemia, and epithelial growth factor activates TRPM6. A defect in the gamma-subunit of the Na,K-ATPase causes isolated dominant hypomagnesemia by altering TRPM6 activity through a decrease in the driving force for apical Mg(2+) influx. We anticipate that the next decade will provide further detail into the control of the gatekeeper TRPM6 and, therefore, overall whole-body Mg(2+) balance.

Short-Term Cyclosporine Therapy and Cotransplantation of Donor Splenocytes: Effects on Graft Rejection and Survival Rates in Pigs Subjected to Renal Transplantation.

J Surg Res. 2008 Feb 29;
Maestri M, Rademacher J, Gaspari A, Lenti LM, Crespi S, Cansolino L, Novelli G, Agoglitta D, Maffeis F, Ferrario di Tor Vajana A, Oldani G, Dionigi P
BACKGROUND: Donor-specific allogeneic loading can prolong the survival of solid organ transplants by inducing a state known as acceptance. Several populations of cells are known to be involved in this process, but their exact roles have yet to be defined. The aim of this study was to assess the effects of portal-vein transfusion of donor-specific splenocytes (DST) after short-term cyclosporine A (CyA) therapy in pigs subjected to renal transplantation. METHODS: Four groups of unrelated swine underwent renal transplantation with removal of the native kidneys. Antirejection protocols consisted in portal-vein DST (3 x 10(8) cells/kg) (Group 2, n = 7); intravenous CyA (9 mg/kg/d) on postoperative days 1-12 (Group 3, n = 14); and DST + CyA (as described above) (Group 4, n = 13). Results (through postoperative day 90) were compared with those obtained in untreated control recipients (Group 1, n = 7). RESULTS: Compared with animals of Groups 1, 2, and 3, Group 4 recipients presented significantly longer survival (mean: 90 days, P < 0.01 in Kaplan-Meier analysis) and better renal function (P < 0.05). Graft histology revealed preserved parenchyma. CONCLUSION: The role of spleen cells in the immune response has probably been underestimated. Cotransplantation of donor splenocytes seems to induce a certain degree of acceptance toward the renal allograft. The route of administration (portal-vein infusion in this study) may be crucial for developing favorable mechanisms of recognition.

An Interleukin-6-Neutralizing Antibody Prevents Cyclosporine-Induced Nephrotoxicity in Mice.

J Surg Res. 2008 Jan 29;
Laspina M, Tripathi S, Gatto LA, Bruch D, Maier KG, Kittur DS
INTRODUCTION: Chronic use of cyclosporine A (CyA) induces nephrotoxicity primarily due to endothelial dysfunction. In our previous studies, potential mechanisms were identified in vitro and implicated nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and interleukin-6 (IL-6) as key components in causing endothelial dysfunction. In this study, we tested the hypothesis that NADPH oxidase activity and IL-6 are key components in renal damage in an in vivo model. METHODS: Male mice C57B/6 mice from Jackson Laboratory (Bar Harbor, ME) at 6-8 wks were subjected to a low-salt diet throughout the trial. After 1 week on a low-salt diet, the mice were injected daily with treatments in 50 muL vehicle composed of 75% cremaphor (Sigma, St. Louis, MO) and ethanol for 5 wks. A vehicle-alone group was also set aside. Mice were weighed and 25 mg/kg/day cyclosporine (Novartis Pharma, St. Louis, MO) was injected daily. Apocynin (Calbiochem, Gibbstown, NJ) 20 mg/kg were injected either alone or concomitantly with CyA. Another group of mice were administered IL-6 antibody (Cat no. MAB406; R&D Systems, Minneapolis, MN) at 2 mug/day along with CyA. The kidneys were removed en bloc immediately and submitted in formalin for paraffin sections. Trichrome stains were performed. Slides were blinded and 10 photographs of cortical areas per treatment group were taken, which covered an estimate of 10% surface area in random fashion. Areas of renal damage, which were determined by tubular necrosis, were identified and quantified by amount of necrosis per photograph. Each photograph was divided into 10 blocks, and the number of blocks that contained necrotic tubules per photo was recorded. RESULTS: The two control mice (low salt only) had no damage. The four vehicle mice had trace amounts of tubular necrosis. CyA treatment group demonstrated the highest amount of damage (29/70; 41%). CyA with apocynin, a specific NADPH oxidase inhibitor, was found to have 36% (22/60) damage, whereas the CyA with IL-6 antibody only was observed to have 15% (6/40) damage. Comparing imaging analysis, there was no difference between mice treated with CyA alone and with CyA with apocynin. However, the amount of damage in mice treated with CyA and IL-6 antibody was found to be significantly lower than both CyA and CyA with apocynin. CONCLUSIONS: CyA action as a calcineurin inhibitor has allowed prolongation of kidney transplants, but its chronic use has led to devastating consequences such as allograft nephropathy. Previously, we have identified potential mechanisms of CyA-induced endothelial dysfunction in vitro. The current study identifies increased IL-6 expression as a mechanism by which CyA induces renal damage and that the use of an IL-6-neutralizing antibody may be useful in reducing CyA-induced renal damage.

Knockdown of cytosolic glutaredoxin 1 leads to loss of mitochondrial membrane potential: implication in neurodegenerative diseases.

PLoS ONE. 2008; 3(6): e2459
Saeed U, Durgadoss L, Valli RK, Joshi DC, Joshi PG, Ravindranath V
Mitochondrial dysfunction including that caused by oxidative stress has been implicated in the pathogenesis of neurodegenerative diseases. Glutaredoxin 1 (Grx1), a cytosolic thiol disulfide oxido-reductase, reduces glutathionylated proteins to protein thiols and helps maintain redox status of proteins during oxidative stress. Grx1 downregulation aggravates mitochondrial dysfunction in animal models of neurodegenerative diseases, such as Parkinson's and motor neuron disease. We examined the mechanism underlying the regulation of mitochondrial function by Grx1. Downregulation of Grx1 by shRNA results in loss of mitochondrial membrane potential (MMP), which is prevented by the thiol antioxidant, alpha-lipoic acid, or by cyclosporine A, an inhibitor of mitochondrial permeability transition. The thiol groups of voltage dependent anion channel (VDAC), an outer membrane protein in mitochondria but not adenosine nucleotide translocase (ANT), an inner membrane protein, are oxidized when Grx1 is downregulated. We then examined the effect of beta-N-oxalyl amino-L-alanine (L-BOAA), an excitatory amino acid implicated in neurolathyrism (a type of motor neuron disease), that causes mitochondrial dysfunction. Exposure of cells to L-BOAA resulted in loss of MMP, which was prevented by overexpression of Grx1. Grx1 expression is regulated by estrogen in the CNS and treatment of SH-SY5Y cells with estrogen upregulated Grx1 and protected from L-BOAA mediated MMP loss. Our studies demonstrate that Grx1, a cytosolic oxido-reductase, helps maintain mitochondrial integrity and prevents MMP loss caused by oxidative insult. Further, downregulation of Grx1 leads to mitochondrial dysfunction through oxidative modification of the outer membrane protein, VDAC, providing support for the critical role of Grx1 in maintenance of MMP.

Chronic Aspiration of Gastric Fluid Induces the Development of Obliterative Bronchiolitis in Rat Lung Transplants.

Am J Transplant. 2008 Jun 12;
Li B, Hartwig MG, Appel JZ, Bush EL, Balsara KR, Holzknecht ZE, Collins BH, Howell DN, Parker W, Lin SS, Davis RD
Long-term survival of a pulmonary allograft is currently hampered by obliterative bronchiolitis (OB), a form of chronic rejection that is unique to lung transplantation. While tracheobronchial aspiration from gastroesophageal reflux disease (GERD) has clinically been associated with OB, no experimental model exists to investigate this problem. Using a WKY-to-F344 rat orthotopic left lung transplant model, the effects of chronic aspiration on pulmonary allograft were evaluated. Recipients received cyclosporine with or without 8 weekly aspirations of gastric fluid into the allograft. Six (66.7%) of 9 allografts with aspiration demonstrated bronchioles with surrounding monocytic infiltrates, fibrosis and loss of normal lumen anatomy, consistent with the development of OB. In contrast, none of the allografts without aspiration (n = 10) demonstrated these findings (p = 0.002). Of the grafts examined grossly, 83% of the allografts with chronic aspiration but only 20% without aspiration appeared consolidated (p = 0.013). Aspiration was associated with increased levels of IL-1alpha, IL-1beta, IL-6, IL-10, TNF-alpha and TGF-beta in BAL and of IL-1alpha, IL-4 and GM-CSF in serum. This study provides experimental evidence linking chronic aspiration to the development of OB and suggests that strategies aimed at preventing aspiration-related injuries might improve outcomes in clinical lung transplantation.

The Chemokine Receptor Cxcr3 Is Not Essential for Acute Cardiac Allograft Rejection in Mice and Rats.

Am J Transplant. 2008 Jun 12;
Zerwes HG, Li J, Kovarik J, Streiff M, Hofmann M, Roth L, Luyten M, Pally C, Loewe RP, Wieczorek G, Bänteli R, Thoma G, Luckow B
Chemokine receptors have gained attention as potential targets for novel therapeutic strategies. We investigated the mechanisms of allograft rejection in chemokine receptor Cxcr3-deficient mice using a model of acute heart allograft rejection in the strain combination BALB/c to C57BL/6. Allograft survival was minimally prolonged in Cxcr3-deficient mice compared to wild-type (wt) animals (8 vs. 7 days) and treatment with a subtherapeutic dose of cyclosporine A (CsA) led to similar survival in Cxcr3-deficient and wt recipients (13 vs. 12 days). At rejection grafts were histologically indistinguishable. Microarray analysis revealed that besides Cxcr3 only few genes were differentially expressed in grafts or in spleens from transplanted or untransplanted animals. Transcript analysis by quantitative RT-PCR of selected cytokines, chemokines, or chemokine receptors or serum levels of selected cytokines and chemokines showed similar levels between the two groups. Furthermore, in a rat heart allograft transplantation model treatment with a small molecule CXCR3 antagonist did not prolong survival despite full blockade of Cxcr3 in vivo. In summary, Cxcr3 deficiency or pharmacologic blockade does not diminish graft infiltration, tempo and severity of rejection. Thus, Cxcr3 does not appear to play a pivotal role in the allograft rejection models described here.