Cyclosporine-Induced renal dysfunction

Platelets in Renal Disease

Kidney disease is a major global health concern, affecting millions of people. Nephrologists have shown interest in platelets because of coagulation disorders caused by renal diseases. With a better understanding of platelets, it has been found that these anucleate and abundant blood cells not only play a role in hemostasis, but also have important functions in inflammation and immunity. Platelets are not only affected by kidney disease, but may also contribute to kidney disease progression by mediating inflammation and immune effects. This review summarizes the current evidence regarding platelet abnormalities in renal disease, and the multiple effects of platelets on kidney disease progression. The relationship between platelets and kidney disease is still being explored, and further research can provide mechanistic insights into the relationship between thrombosis, bleeding, and inflammation related to kidney disease, and elucidate targeted therapies for patients with kidney disease.

Association Between Readmission After Liver Transplant and Adverse Immunosuppressant Reactions: A Prospective Cohort With a 1-Year Follow-up

OBJECTIVE

To measure the association between readmission after liver transplantation and corresponding adverse drug reactions.

METHODS

A total of 48 patients undergoing liver transplantation were prospectively followed for 1 year. Of these, 23 were readmitted and evaluated by a pharmacist for causes of adverse drug reaction. The detection of adverse drug reactions was based on a combination of clinical interviews and physical and laboratory exams. Adverse reactions were defined in accordance with the Naranjo algorithm.

RESULTS

A total of 67.6% of all readmissions were related to adverse drug reactions, with tacrolimus accounting for 80% of the drug reactions. The most common cause of readmission was infection (48.6%), followed by procedure-related reasons (29.7%). Of all patients requiring admission, 39.1% had Model for End-stage Liver Disease (MELD) scores below 21 at the time of transplantation, 17.4% had MELD scores between 21 and 29, and 43.5% had MELD scores above 29. Most (66.7%) of those readmitted more than twice had MELD scores above 29.

CONCLUSION

Adverse drug reactions related to immunosuppressants frequently lead to readmission among liver transplant patients, and in our series tacrolimus was the most frequently associated drug.

Celecoxib offsets the negative renal influences of cyclosporine via modulation of the TGF-β1/IL-2/COX-2/endothelin ET(B) receptor cascade

Endothelin (ET) signaling provokes nephrotoxicity induced by the immunosuppressant drug cyclosporine A (CSA). We tested the hypotheses that (i): celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, counterbalances renal derangements caused by CSA in rats and (ii) the COX-2/endothelin ET(B) receptor signaling mediates the CSA-celecoxib interaction. Ten-day treatment with CSA (20 mg/kg/day) significantly increased biochemical indices of renal function (serum urea, creatinine), inflammation (interleukin-2, IL-2) and fibrosis (transforming growth factor-β₁, TGF-β₁). Histologically, CSA caused renal tubular atrophy along with interstitial fibrosis. These detrimental renal effects of CSA were largely reduced in rats treated concurrently with celecoxib (10 mg/kg/day). We also report that cortical glomerular and medullary tubular protein expressions of COX-2 and ET(B) receptors were reduced by CSA and restored to near-control values in rats treated simultaneously with celecoxib. The importance of ET(B) receptors in renal control and in the CSA-celecoxib interaction was further verified by the findings (i) most of the adverse biochemical, inflammatory, and histopathological profiles of CSA were replicated in rats treated with the endothelin ETB receptor antagonist BQ788 (0.1 mg/kg/day, 10 days), and (ii) the BQ788 effects, like those of CSA, were alleviated in rats treated concurrently with celecoxib. Together, the data suggest that the facilitation of the interplay between the TGF-β1/IL-2/COX-2 pathway and the endothelin ET(B) receptors constitutes the cellular mechanism by which celecoxib ameliorates the nephrotoxic manifestations of CSA in rats.

Urinary excretion of oxidative damage markers in a rat model of vascularized composite allotransplantation

BACKGROUND

Vascularized composite allotransplantation is an emerging field of transplantation that provides a potential treatment for complex tissue defects after traumatic loss or tumor resection and for the repair of congenital abnormalities. However, vascularized composite allotransplantation recipients have suffered from acute and chronic graft rejection that is associated with oxidative stress. This study investigated the oxidative damage in a rat vascularized composite allotransplantation model by measuring three urinary biomarkers, 8-oxo-7,8-dihydroguanine (8-oxoGua), 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), and malondialdehyde.

METHODS

Rats received two different immunosuppressants, including cyclosporine A and mycophenolate mofetil after transplantation, with one group also receiving mesenchymal stem cells before transplantation. Urine was collected and analyzed for 8-oxo-7,8-dihydroguanine, 8-oxo-7,8-dihydro-2'-deoxyguanosine, and malondialdehyde by liquid chromatography coupled to tandem mass spectometry methods.

RESULTS

Rats undergoing vascularized composite allotransplantation had higher urinary levels of 8-oxo-7,8-dihydroguanine, 8-oxo-7,8-dihydro-2'-deoxyguanosine, and malondialdehyde compared with rats undergoing syngeneic transplantation. Cyclosporine A/mycophenolate mofetil following treatment prolonged the allograft survival in a dose-dependent manner. Compared with rats undergoing vascularized composite allotransplantation with cyclosporine A/mycophenolate mofetil treatment alone, rats undergoing mesenchymal stem cell combined treatment showed the longest allograft survival, and had approximately 50 percent lower urinary levels of malondialdehyde together with approximately 2.7-times higher levels of 8-oxo-7,8-dihydroguanine.

CONCLUSIONS

Mesenchymal stem cell combined treatment efficiently managed oxidative stress in rats undergoing vascularized composite allotransplantation, and urinary 8-oxo-7,8-dihydroguanine and malondialdehyde could be regarded as good responders to the mesenchymal stem cell therapy.

Safety and tolerability of cyclosporin a in severe traumatic brain injury patients: results from a prospective randomized trial

Cyclosporin A (CsA) has recently been proposed for use in the early phase after traumatic brain injury (TBI), for its ability to preserve mitochondrial integrity in experimental brain injury models, and thereby provide improved behavioral outcomes as well as significant histological protection. The aim of this prospective, randomized, double-blind, dual-center, placebo-controlled trial was to evaluate the safety, tolerability, and pharmacokinetics of a single intravenous infusion of CsA in patients with severe TBI. Fifty adult severe TBI patients were enrolled over a 22-month period. Within 12 h of the injury patients received 5 mg/kg of CsA infused over 24 h, or placebo. Blood urea nitrogen (BUN), creatinine, hemoglobin, platelets, white blood cell count (WBC), and a hepatic panel were monitored on admission, and at 12, 24, 36, and 48 h, and on days 4 and 7. Potential adverse events (AEs) were also recorded. Neurological outcome was recorded at 3 and 6 months after injury. This study revealed only transient differences in BUN levels at 24 and 48 h and for WBC counts at 24 h between the CsA and placebo patients. These modest differences were not clinically significant in that they did not negatively impact on patient course. Both BUN and creatinine values, markers of renal function, remained within their normal limits over the entire monitoring period. There were no significant differences in other mean laboratory values, or in the incidence of AEs at any other measured time point. Also, no significant difference was demonstrated for neurological outcome. Based on these results, we report a good safety profile of CsA infusion when given at the chosen dose of 5 mg/kg, infused over 24 h, during the early phase after severe head injury in humans, with the aim of neuroprotection.

Long-term treatment of sirolimus but not cyclosporine ameliorates diabetic nephropathy in the rat

BACKGROUND

Not just de novo induction of diabetes mellitus, but also the progression of diabetic nephropathy may be enhanced under immunosuppressive therapy after organ transplantation. We evaluated whether sirolimus (SRL) or cyclosporine A (CsA) therapy would be a superior immunosuppressant in streptozotocin-induced diabetic nephropathy.

METHODS

Diabetes was induced by intravenous injection of streptozotozin (60 mg/kg body weight) in 26 male Sprague-Dawley rats. Eight days after diabetes induction, animals were divided into three groups, which were treated with placebo (n=8), SRL (n=9), or CsA (n=9). Six nondiabetic placebo-treated rats were included as controls.

RESULTS

After 19 weeks of diabetes, SRL significantly decreased fibrosis as assessed by periodic acid Schiff staining and by specific extracellular matrix proteins such as fibronectin and laminin at messenger RNA and protein level compared with the diabetic placebo group. SRL ameliorated renal inflammation, glomerular hypertrophy, and podocyte loss as indicated by morphometric and immunohistological analysis. SRL lowered expression and activity of glomerular transforming growth factor-beta1/2 and vascular endothelial growth factor, all of which are considered central cytokines in the pathogenesis of diabetic nephropathy. In contrast, calcineurin phosphatase inhibition through CsA did not ameliorate any of the features of diabetic nephropathy compared with placebo treatment but slightly aggravated glomerular fibrosis without affecting transforming growth factor-beta1/2 or vascular endothelial growth factor.

CONCLUSION

Compared with CsA, SRL by anti-inflammatory, antifibrotic, and podocyte-protective effects clearly seems to be the superior treatment of prevention or amelioration of diabetic nephropathy in the rat.

Variation in Leukocyte Subset Concentrations Affects Calcineurin Activity Measurement: Implications for Pharmacodynamic Monitoring Strategies

Background: In renal transplantation patients, therapeutic drug monitoring of the calcineurin (CN) inhibitor cyclosporin A (CsA) is mandatory because of the drug’s narrow therapeutic index. Pharmacodynamic monitoring of CN inhibition therapy could provide a tool to define and maintain the therapeutic efficacy of CsA therapy. We investigated the effect of variation in cell counts of leukocyte subsets on leukocyte CN activity measurement in renal transplant recipients.

Methods: We measured leukocyte CN activity, whole blood CsA concentrations, and leukocyte subset cell counts in 25 renal transplant recipients. Blood was collected before graft implantation and CsA therapy, 1 day before transplantation when CsA therapy was already started, and 5 days after transplantation. Monocyte, granulocyte, CD4+ T-cell, CD8+ T-cell, B-cell, and natural killer–cell CN activities and CsA inhibition sensitivities were determined in vitro by a spectrophotometric CN assay.

Results: Leukocyte CN activity was inhibited after drug intake. Inter- and intrapatient variation in leukocyte subset cell counts resulted in variation of sample composition. The mean (SD) CN activity varied among leukocyte cell subsets, ranging from 650 (230) to 166 (26) pmol/min/106 cells for monocytes and CD4+ T cells, respectively. CsA half maximal inhibitory concentration (IC50) values ranged from 15 to 78 μg/L for monocytes and B cells, respectively.

Conclusion: Inter- and intraindividual leukocyte subset cell count variation can affect measured CN activity independent of CsA concentration. Cell-specific activity and drug sensitivity should be considered for sample validation to optimize method specificity when pharmacodynamic monitoring strategies are applied in a clinical setting.

Therapeutic efficacy of dl-α-lipoic acid on cyclosporine A induced renal alterations

The present study was designed to evaluate the possible beneficial effect of lipoic acid in preventing the renal damage induced by cyclosporine A in rats. Male albino rats of Wistar strain were divided into four groups and treated as follows. Two groups received cyclosporine A by oral gavage (25 mg/kg/body weight) for 21 days to induce nephrotoxicity, one of which simultaneously received lipoic acid treatment (20 mg/kg body weight) for 21 days. A vehicle (olive oil) and a lipoic acid drug control were also included. Cyclosporine A induced renal damage was evident from the decreased activities of tissue marker enzymes (alkaline phosphatase, acid phosphatase, lactate dehydrogenase, aspartate transaminase and alanine transaminase) and decreased activities of ATPases (Na+, K+-ATPase, Ca2+-ATPase and Mg2+ ATPase). An apparent increase in the levels of serum constituents (urea, uric acid and creatinine) and urinary marker enzymes (N-acetyl-beta-D-glucosaminidase, beta-glucosidase, beta-galactosidase, cathepsin-D and gamma-glutamyl transpeptidase) along with significant decline in creatinine clearance were seen in the cyclosporine treated rats, which was reversed upon treatment with lipoic acid. Ultrastructural observations were also in agreement with the above abnormal changes. Lipoic acid effectively reverted these abnormal biochemical changes and minimized the morphological lesions in renal tissue. Hence, this study clearly exemplifies that lipoic acid might be an ideal choice against cyclosporine A induced cellular abnormalities.

Conversion From Cyclosporine to Tacrolimus for Chronic Allograft Nephropathy

We investigate the effect of conversion from a cyclosporine (CsA) based-regimen to a tacrolimus (FK506)-based regimen with respect to graft renal function induced by chronic allograft nephropathy (CAN). Thirty-one patients with a histological diagnosis of CAN were included after other causes of chronic graft dysfunction had been excluded. Conversion to FK506 was undertaken at an initial dose of 0.15 mg/kg/d, which was subsequently adjusted to maintain FK506 whole blood trough levels between 5 and 10 mug/L. The rate of decline of renal function before and after the FK506 conversion was represented by regression lines (slope) of the reciprocal of serum creatinine versus time. To evaluate the effect of conversion on allograft function, we gathered data on serum lipids, blood glucose, proteinuria, and hypertension. When postconversion slopes were compared to preconversion slopes for each patient, 20 patients (64.5%) showed positive regression lines and four patients (12.9%), less negative. Seven patients (22.6%) displayed an increased rate of decline in renal function with regression lines becoming more negative. FK506 was associated with a significant decrease in lipid levels, proteinuria, and hypertension. No patient returned to dialysis at the end of the 36-month follow-up. Conversion from a CsA-based regimen to a tacrolimus-based regimen was an effective alterative for salvage of patients with abnormal graft renal function induced by CAN.

Spectrophotometric assay for calcineurin activity in leukocytes isolated from human blood

The calcineurin inhibitors, cyclosporine and tacrolimus, still constitute the cornerstone of immunosuppressive regimen after organ transplantation. An efficient and feasible way to measure calcineurin activity and inhibition by these drugs may improve therapeutic monitoring of these drugs in transplant recipients. Calcineurin activity was measured in leukocyte lysates isolated from human blood using spectrophotometric phosphate quantification. The dephosphorylation of a 19-amino acid peptide substrate of calcineurin was determined using the Malachite green phosphate reagent in the presence of okadaic acid and with and without the calcium chelator EGTA. Sample storage and lysis buffer components were among the variables optimized, and the inhibitory effect of calcineurin inhibitors was investigated. Observed loss of calcineurin activity during sample storage was eliminated by adding ascorbic acid to lysis buffer. The final inter- and intraassay variation coefficients were 10 and 4.5%, respectively, and the detection limit was 15 pmol min(-1)x10(6) WBC(-1), where WBC is white blood cells (leukocytes). In vitro IC50 values were 212 and 34 microg/L for cyclosporine and tacrolimus, respectively. In vivo calcineurin inhibition was observed when calcineurin activity was measured in transplant recipients on maintenance therapy with cyclosporine and tacrolimus.

TAURINE ATTENUATES HYPERTENSION AND RENAL DYSFUNCTION INDUCED BY CYCLOSPORINE A IN RATS

Cyclosporine A (CsA) is the first-line immunosuppressant used for the management of solid organ transplantation and autoimmune diseases. Nephrotoxicity is the major limitation of CsA use. Recent evidence suggests that reactive oxygen species (ROS) play an important role in mediating CsA-induced hypertension and nephrotoxicity. Taurine, the major intracellular free beta-amino acid, is known to be an endogenous anti-oxidant and membrane-stabilizing agent. The present study was designed to investigate the effects of taurine on CsA-induced oxidative stress, hypertension and renal dysfunction. 2. Animals were assigned into four groups of seven rats each as follows: (i) control group, receiving vehicle (olive oil; 1 mL/kg, s.c.); (ii) CsA group, given CsA (25 mg/kg per day, s.c.) for 21 days; (iii) taurine group, supplemented with taurine (1% in the drinking water); and (iv) taurine + CsA group, treated with taurine 3 days before and concurrently during CsA injections for 21 days. 3. Cyclosporine A administration elevated blood pressure, reduced serum nitric oxide (NO) levels and deteriorated renal function, as assessed by increased serum creatinine levels and proteinuria and reduced urine flow rate and creatinine clearance compared with vehicle-treated rats. Cyclosporine A induced oxidative stress, as indicated by increased renal tissue concentrations of thiobarbituric acid-reactive substances and reduced concentrations of renal glutathione, glutathione peroxidase and superoxide dismutase. Conversely, no change was noted in renal catalase activity. Moreover, the kidneys of CsA-treated rats showed interstitial inflammation and renal tubular atrophy. 4. Taurine markedly reduced elevated blood pressure, attenuated renal dysfunction and the reduction in serum NO levels and counteracted the deleterious effects of CsA on oxidative stress markers. Furthermore, taurine ameliorated CsA-induced morphological changes. 5. These data clearly indicate the protective potential of taurine against CsA-induced hypertension and nephrotoxicity and suggest a significant contribution of its anti-oxidant property to this beneficial effect.