New immunosuppressive drugs in heart transplantation

Only a few randomized clinical trials have been performed so far in heart transplant recipients, mainly because of the relatively small number of heart transplants performed worldwide each year. The main focus of the few controlled trials that have been completed has been the prevention and treatment of heart allograft rejection. In the area of pharmacologic immunosuppression, both biological agents and drugs have been the subject of investigation. Among the biological agents, chimeric monoclonal antibodies directed against the interleukin (IL)-2 receptor, which have been found to be safe and effective in renal transplant recipients, are now undergoing the test of controlled trials in heart transplant recipients. Immunosuppressive drugs that have been studied in controlled trials include calcineurin inhibitors (such as the microemulsion formulation of cyclosporine and tacrolimus) and inhibitors of purine synthesis, such as mycophenolate mofetil. Non-pharmacologic prophylactic immunosuppression with photopheresis has also been tested in a prospective, multicenter, randomized trial. New immunosuppressive regimens, such as mycophenolate mofetil combined with a monoclonal antibody against the IL-2 receptor, are being tested with the aim to reduce or eliminate calcineurin inhibitors or corticosteroids. Although clinical approaches to the induction of tolerance have undergone preliminary clinical evaluation, the ability to induce tolerance to an allograft in humans remains an elusive goal.     

Use of EQUORAL in de novo renal transplant recipients

This paper presents our experience to date with using a cyclosporine formulation Equoral (IVAX Pharmaceuticals) together with mycophenolate mofetil plus a steroid immunosuppressive regimen in the treatment of de novo renal transplant recipients. Ten cadaveric donor renal transplant recipients of mean age 51.6 years (range 37-66) were followed up over 6 months for the development of rejection attacks and side effects. All patients received prednisolone, mycophenolate mofetil (1 g/day during the first 5 days posttransplant and then 20 mg/kg/day) plus cyclosporine (3 mg/kg/day). Biopsy proven acute rejection episodes were observed in 2 out of 10 patients (20%). Six months patient as well as renal graft survival rate was 100%. The development of graft function was immediate after transplantation. The mean serum creatinine levels were gradually decreased. Over the 6-month posttransplant period, the function of the graft was satisfactory and stable. The majority of observed adverse events were those commonly reported with the use of cyclosporine and they resolved with a reduction in cyclosporine dose. Equoral treatment demonstrated an acceptable safety profile with maintenance of adequate renal function without incidence of malignancy/lymphoproliferative disease or serious infections. In conclusion, Equoral plus mycophenolate mofetil immunosuppression seems effective and safe on terms acute rejection rates, patient and renal graft survival rates and side profiles.     

不同治疗方案治疗重型IgA肾病疗效分析

目的观察吗替麦考酚酯(MMF)方案与环磷酰胺(CTX)方案治疗重症IgA肾病的临床疗效。方法选取我院2014年1月~2016年2月收治的重型IgA肾病患者68例,按照随机数字表法分为MMF组与CTX组,MMF组给予泼尼松联合吗替麦考酚酯治疗,CTX组给予泼尼松联合环磷酰胺治疗,治疗6个月后,比较两组患者临床疗效、肾功能指标情况。结果MMF组的临床总有效率为97.06%,CTX组为73.53%,组间比较差异具有统计学意义(P0.05);MMF组24h尿蛋白、血肌酐(Scr)、尿素氮(BUN)水平明显低于CTX组,肾小球滤过率(GFR)高于CTX组,差异均有统计学意义(均P0.05)。结论激素联合吗替麦考酚酯治疗重型IgA肾病的疗效显著,肾功能改善明显,值得临床推广。     

Bone quality and healing in a swine vascularized bone allotransplantation model using cyclosporine-based immunosuppression therapy

Although vascularized bone and joint allotransplantation is a promising new treatment option for reconstructing large bone defects, the need for immunosuppressive agents to prevent rejection in these procedures poses a major problem. This problem stems from the fact that several of these agents can cause harmful side effects, such as alterations in bone quality and healing. Therefore, the purpose of this study was to determine what effect the commonly used immunosuppressant regimen cyclosporine A-based combination therapy has on bone quality and healing. In 10 pigs, vascularized bone allografts with skin and muscle components (osteomyocutaneous free flaps) were transplanted from size-matched donor animals. Recipient animals received oral cyclosporine A/mycophenolate mofetil/prednisone therapy for 90 days. Bone quality was studied before and after transplantation by measuring the bone's acoustic velocity and density and calculating the bone's elastic coefficient. Bone healing was assessed using radiographic analysis. Four animals were lost as a result of graft rejection or immunosuppression-related complications before the 90-day endpoint of the study. Although bone specimens taken from the six animals that completed the 90-day protocol had histological signs of rejection, they all seemed to have normal bone healing. Posttransplant bone density values were significantly decreased (p < 0.05) (1544.7 +/- 47.5 kg/m3) as compared with pretransplant values (1722.7 +/- 44.1 kg/m3). Results of the acoustic velocity and elastic coefficients measurements showed a significant decrease (p < 0.05) in posttransplant values (from 3503.0 +/- 165.1 meters/sec to 2963.0 +/- 54.6 meters/sec and from 21.6 +/- 2.2 GPa to 13.6 +/- 0.5 GPa, respectively), indicating diminished bone quality. The findings indicate that cyclosporine A/mycophenolate mofetil/prednisone combination therapy is ineffective in preventing bone rejection, that it decreases bone quality, and that it is associated with systemic toxicity, suggesting that this immunosuppressive regimen at the doses used in this study is not ideal for vascularized bone allotransplantation procedures.     

Intracellular IFN-γ and IL-2 expression monitoring as surrogate markers of the risk of acute rejection and personal drug response in de novo liver transplant recipients

Biomarker monitoring is needed in transplantation to reflect individual response to immunosuppressive drugs and graft outcome. We evaluated intracellular expression and soluble production of interferon-(IFN)-γ and interleukin-(IL)-2 as predictive biomarkers of acute rejection (AR) and personal drug response. Pharmacokinetic–pharmacodynamic profiles were determined in 47 de novo liver recipients treated with tacrolimus, mycophenolate mofetil and prednisone. Of the 47 patients, AR occurred in nine. There were no differences in drug concentrations between rejectors and non-rejectors. A pre-transplantation cut-off value of 55.80% for %CD8⁺–IFN-γ⁺ identified patients at high risk of AR with a sensitivity of 75% and a specificity of 82%. In the first week post-transplantation, patients with a % inhibition for soluble IFN-γ, %CD8⁺–IFN-γ⁺ and %CD8⁺–IL2⁺ lower than 40% developed AR, showing low susceptibility to immunosuppressive drugs. Therefore, effector-T-cell response monitoring may help physicians to identify personal response to treatment and patients at high risk of AR.     

Potential Role of Mycophenolate Mofetil in the Management of Neuroblastoma Patients

In human neuroblastoma cell lines (LAN5, SHEP and IMR32), mycophenolic acid (MPA) at concentrations (10^? 7–10^? 6 M) readily attainable during immunosuppressive therapy with mycophenolate mofetil (Cellcept), induces guanine nucleotide depletion leading to cell cycle arrest and apoptosis through a p53 mediated pathway (up‐regulation of p53, p21 and bax and down‐regulation of bcl‐2 and survivin). MPA‐induced apoptosis is also associated to a marked decrease of p27 protein. In the same cell lines MPA, at lower concentrations (50 nM), corresponding to the plasma levels of the active free drug during Cellcept therapy, induces differentiation toward the neuronal phenotype by causing a partial chronic guanine nucleotide depletion. MPA‐induced differentiation is not associated to p27 accumulation as occurs using retinoic acid. At a fixed concentration of MPA a higher percentage of apoptotic or differentiated cells is obtained when non dialysed serum substitutes for the dialysed one, due to the higher hypoxanthine concentration in the former (about 10 µM) leading to competition on HPRT‐mediated salvage of guanine. At hypoxanthine or oxypurinol concentrations higher than 1 µM (up to 100 µM) no further enhancement of MPA effects was obtained, in agreement with the recently described safety of the allopurinol‐mycophenolate mofetil combination in the treatment of hyperuricemia of kidney transplant recipients. The apoptotic effects of MPA do not appear to be significantly increased by the UDP‐glucuronosyltransferase inhibitor niflumic acid.     

Immunosuppressive Drugs Modulate the Replication of Hepatitis B Virus (HBV) in a Hydrodynamic Injection Mouse Model

Hepatitis B virus (HBV) reactivation and recurrence are common in patients under immunosuppression and can be controlled by hepatitis B immunoglobulin, antivirals, and hepatitis B vaccine. However, the detailed analysis of HBV infection under immunosuppression is essential for the prophylaxis and therapy for HBV reactivation and recurrence. In this study, HBV replication and T cell responses were analyzed in a HBV-transfected mouse model under immunosuppressive therapy. During the treatment, HBV replication was at a high level in mice treated with dexamethasone, cyclosporine, and cyclophosphamide, whereas was terminated in mice treated with mycophenolate mofetil. After the withdrawal, HBV replication was at low or high levels in the dexamethasone-treated mice or in both cyclosporine- and cyclophosphamide-treated mice. The early withdrawal of cyclosporine allowed the recovery of suppressed T cell responses and led to subsequent HBV clearance, while the adoptive immune transfer to the mice with HBV persistence led to HBV suppression. Taken together, long-term HBV persistence under immunosuppression depends on the immunosuppressive drugs used and on the treatment duration and is mediated by the suppressed intrahepatic CD8 T cell response. These data may be helpful for individualized immunosuppressive therapy in patients with high risk of HBV reactivation and recurrence, and the mouse system is suitable for studying HBV reactivation and recurrence under immunosuppression.     

Fungi as Eukaryotes: Understanding the Antifungal Effects of Immunosuppressive Drugs

The immunosuppressive agents cyclosporine, tacrolimus, and sirolimus are naturally occurring products of environmental fungi or bacteria, so the fact that they possess intrinsic antifungal activity is not surprising. Both calcineurin and the target of rapamycin (TOR) are conserved across eukaryotes and share a common function, regulating the organism’s ability to react to environmental changes and response to stress. In the medically important fungi Candida, Cryptococcus, and Aspergillus, mutations in the calcineurin gene affect in vitro patterns of growth and serum sensitivity, and attenuate virulence in animal models. Notably, cyclosporine, tacrolimus, and sirolimus exhibit strong synergy with many classes of antifungal drugs including azoles, amphotericin B, and the echinocandins, with potentiation of fungicidal effects even against drug-resistant strains. Hopefully, future studies will realize the promise of exploiting the antifungal properties of the immunosuppressive drugs to help decrease the burden of these clinically important infections on patient survival.     

The actin cytoskeleton of kidney podocytes is a direct target of the antiproteinuric effect of cyclosporine A

The immunosuppressive action of the calcineurin inhibitor cyclosporine A (CsA) stems from the inhibition of nuclear factor of activated T cells (NFAT) signaling in T cells. CsA is also used for the treatment of proteinuric kidney diseases. As it stands, the antiproteinuric effect of CsA is attributed to its immunosuppressive action. Here we show that the beneficial effect of CsA on proteinuria is not dependent on NFAT inhibition in T cells, but rather results from the stabilization of the actin cytoskeleton in kidney podocytes. CsA blocks the calcineurin-mediated dephosphorylation of synaptopodin, a regulator of Rho GTPases in podocytes, thereby preserving the phosphorylation-dependent synaptopodin-14-3-3 beta interaction. Preservation of this interaction, in turn, protects synaptopodin from cathepsin L-mediated degradation. These results represent a new view of calcineurin signaling and shed further light on the treatment of proteinuric kidney diseases. Novel calcineurin substrates such as synaptopodin may provide promising starting points for antiproteinuric drugs that avoid the serious side effects of long-term CsA treatment.     

Activation of renal profibrotic TGFβ controlled signaling cascades by calcineurin and mTOR inhibitors

The calcineurin inhibitors (CNI) cyclosporine A (CsA) and tacrolimus represent potent immunosuppressive agents frequently used for solid organ transplantation and treatment of autoimmune disorders. Despite of their immense therapeutic benefits, residual fibrosis mainly in the kidney represents a common side effect of long-term therapy with CNI. Regardless of the immunosuppressive action, an increasing body of evidence implicates that a drug-induced increase in TGFβ and subsequent activation of TGFβ-initiated signaling pathways is closely associated with the development and progression of CNI-induced nephropathy. Mechanistically, an increase in reactive oxygen species (ROS) generation due to drug-induced changes in the intracellular redox homeostasis functions as an important trigger of the profibrotic signaling cascades activated under therapy with CNI. Although, inhibitors of the mechanistic target of rapamycin (mTOR) kinase have firmly been established as alternative compounds with a lower nephrotoxic potential, an activation of fibrogenic signaling cascades has been reported for these drugs as well. This review will comprehensively summarize recent advances in the understanding of profibrotic signaling events modulated by these widely used compounds with a specific focus put on mechanisms occurring independent of their respective immunosuppressive action. Herein, the impact of redox modulation, the activation of canonical TGFβ and non-Smad pathways and modulation of autophagy by both classes of immunosuppressive drugs will be highlighted and discussed in a broader perspective. The comprehensive knowledge of profibrotic signaling events specifically accompanying the immunomodulatory activity of these widely used drugs is needed for a reliable benefit-risk assessment under therapeutic regimens.     

Efficacy and Safety of an Everolimus- vs. a Mycophenolate Mofetil-Based Regimen in Pediatric Renal Transplant Recipients

Introduction

Data on the efficacy and safety of everolimus in pediatric renal transplantation compared to other immunosuppressive regimens are scarce.

Patients/Methods

We therefore performed a multicenter, observational, matched cohort study over 4 years post-transplant in 35 patients on everolimus plus low-dose cyclosporine, who were matched (1:2) with a control group of 70 children receiving a standard-dose calcineurin-inhibitor- and mycophenolate mofetil-based regimen.

Results

Corticosteroids were withdrawn in 83% in the everolimus vs. 39% in the control group (p<0.001). Patient and graft survival were comparable. The rate of biopsy-proven acute rejection episodes Banff score ≥ IA during the first year post-transplant was 6% in the everolimus vs. 13% in the control group (p = 0.23). The rate of de novo donor-specific HLA antibodies (11% in everolimus, 18% in controls) was comparable (p = 0.55). At 4 years post-transplant, mean eGFR in the everolimus group was 56±33 ml/min per 1.73 m² vs. 63±22 ml/min per 1.73 m² in the control group (p = 0.14). Everolimus therapy was associated with less BK polyomavirus replication (3% vs. 17% in controls; p = 0.04), but with a higher percentage of arterial hypertension and more hyperlipidemia (p<0.001).

Conclusion

In pediatric renal transplantation, an everolimus-based regimen with low-dose cyclosporine yields comparable four year results as a standard regimen, but with a different side effect profile.     

Protein—drug complexes important for immunoregulation and organ transplantation

Recently, two structures of the Ser/Thr phosphorylase calcineurin in complex with FK506 and its cognate immunophilin, FKBP12, have been reported, both solved by small pharmaceutical companies focused on structure-based drug design. A realization, however, that the toxicities associated with calcineurin-mediated immunosuppressants might be mechanism based has driven the current interest in alternative approaches to autoimmunity prophylaxis and preventing transplant rejection. Regulatory approval in 1995 of the immunosuppressant prodrug mycophenolate mofetil, whose active metabolite, mycophenolic acid, inhibits inosine monophosphate dehydrogenase, has focused attention on the potential significance of the de novo purine-biosynthesis pathway as a target for immunosuppressive drugs, leading ultimately to the solution of enzyme structure as a drug design target. As this and other clinically relevant targets are discovered, elaborated and refined via the activity of their cognate agents (as was the case for the phosphatase calcineurin via the activity of cyclosporin), a critical opportunity should ensue for structural biology to exert a profound effect on the future development of these therapies.     

Effect of immunosuppressive and other drugs on the cortisol-cortisone shuttle in human kidney and liver.

BACKGROUND: Impaired 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) has been suggested in patients with hypertension or renal disease, where it may contribute to sodium retention and hypertension. 11beta-HSD1, which is expressed predominantly in liver and adipose tissue, influences glucose homeostasis and fat distribution by altering intracellular cortisol (F) concentrations. We tested immunosuppressive drugs that cause hypertension, and substances that interfere with steroidogenesis or influence glucose homeostasis for their ability to influence the inhibition of 11beta-HSD isozymes. METHODS: For inhibition experiments, we used microsomes prepared from unaffected parts of human liver segments and resected human kidney cortex because of hepatocarcinoma or renal cell cancer. The inhibitory potency of several compounds was evaluated in concentrations from 10(-9)-10(-5) mol/l. RESULTS: Only sirolimus, but not cyclosporine A, tacrolimus, mycophenolate mofetil, or azathioprine showed a slight inhibition of 11beta-HSD2 activity. None of the drugs that inhibit steroidogenesis (suramine, mitotane, etomidate, and aminogluthethimide) or steroid metabolism (rifampicine) influenced 11beta-HSDs, nor did ginsenoides Re, Rc, and Rb1. Among sulfonylureas, only gliclazide decreased significantly 11beta-HSD1 activity. CONCLUSIONS: Increased blood pressure due to immunosuppressive drugs is probably not caused by direct inhibition of 11beta-HSD2. An additional glucose lowering effect of sulfonylurea gliclazide may be due to its ability to inhibit 11beta-HSD1.     

Cyclosporine blocks the induction of class I and class II MHC products in mouse kidney by graft-vs-host disease

The ability of cyclosporine to prevent the increase in Ia and H-2K expression that occurs in mice with graft-vs-host disease (GVHD) was examined by means of absorption, indirect immunofluorescent staining (IIF), and indirect immunoperoxidase staining (IIP). Acute GVHD was induced in irradiated C3H/HeJ mice (H-2k) by injections of bone marrow and spleen cells from C57BL/6J mice (H-2b). Ten days after induction of acute GVHD, the spleens of mice not receiving cyclosporine expressed only donor Ia, reflecting their reconstitution by donor cells. The kidneys of such mice had a 10-fold increase in host Ia and H-2K expression, as previously reported. Treatment with cyclosporine reduced the amount of donor Ia and H-2K in spleens, and prevented the enhanced expression of recipient Ia and H-2K in kidneys in a dose-dependent manner. IIF or IIP staining showed that the principal change was in kidney tubules, where the induction of Ia and H-2K expression was greatly diminished. Cyclosporine administered to normal mice did not alter Ia expression except at high doses, at which it decreased Ia expression in kidneys and in spleens. The results suggest that prevention of enhanced MHC product expression could be part of the immunosuppressive actions of cyclosporine.     

The influence of immunosuppressive drugs on neural stem/progenitor cell fate in vitro

In allogenic and xenogenic transplantation, adequate immunosuppression plays a major role in graft survival, especially over the long term. The effect of immunosuppressive drugs on neural stem/progenitor cell fate has not been sufficiently explored. The focus of this study is to systematically investigate the effects of the following four different immunotherapeutic strategies on human neural progenitor cell survival/death, proliferation, metabolic activity, differentiation and migration in vitro: (1) cyclosporine A (CsA), a calcineurin inhibitor; (2) everolimus (RAD001), an mTOR-inhibitor; (3) mycophenolic acid (MPA, mycophenolate), an inhibitor of inosine monophosphate dehydrogenase and (4) prednisolone, a steroid. At the minimum effective concentration (MEC), we found a prominent decrease in hNPCs' proliferative capacity (BrdU incorporation), especially for CsA and MPA, and an alteration of the NAD(P)H-dependent metabolic activity. Cell death rate, neurogenesis, gliogenesis and cell migration remained mostly unaffected under these conditions for all four immunosuppressants, except for apoptotic cell death, which was significantly increased by MPA treatment.     

NDUFV1 attenuates renal ischemia–reperfusion injury by improving mitochondrial homeostasis

Impaired mitochondrial function and dysregulated energy metabolism have been shown to be involved in the pathological progression of kidney diseases such as acute kidney injury (AKI) and diabetic nephropathy. Hence, improving mitochondrial function is a promising strategy for treating renal dysfunction. NADH: ubiquinone oxidoreductase core subunit V1 (NDUFV1) is an important subunit of mitochondrial complex I. In the present study, we found that NDUFV1 was reduced in kidneys of renal ischemia/reperfusion (I/R) mice. Meanwhile, renal I/R induced kidney dysfunction as evidenced by increases in BUN and serum creatinine, severe injury of proximal renal tubules, oxidative stress, and cell apoptosis. All these detrimental outcomes were attenuated by increased expression of NDUFV1 in kidneys. Moreover, knockdown of Ndufv1 aggravated cell insults induced by H₂O₂ in TCMK-1 cells, which further confirmed the renoprotective roles of NDUFV1. Mechanistically, NDUFV1 improved the integrity and function of mitochondria, leading to reduced oxidative stress and cell apoptosis. Overall, our data indicate that NDUFV1 has an ability to maintain mitochondrial homeostasis in AKI, suggesting therapies by targeting mitochondria are useful approaches for dealing with mitochondrial dysfunction associated renal diseases such as AKI.     

Comparison of long-term immunosuppression for limb transplantation using cyclosporine, tacrolimus, and mycophenolate mofetil: implications for clinical composite tissue transplantation

This study compared the efficacy of long-term intermittent immunosuppression in preventing the rejection of a limb transplant across the strongest histocompatibility barrier in ACI --> Lewis rats using the conventional immunosuppressive agent cyclosporine-A and the newer immunosuppressive agents FK-506 (tacrolimus) and RS-61443 (mycophenolate mofetil). The recipient animals were immunosuppressed daily for 14 days postoperatively, followed by long-term intermittent, twice-weekly immunosuppression using cyclosporine 25 mg/kg, RS-61443 30 mg/kg, or FK-506 2 mg/kg. All three immunosuppressive agents were able to prolong the rejection of the skin component of a limb transplant compared with nonimmunosuppressed controls. Eight of nine animals receiving cyclosporine immunosuppression showed signs of rejection of the skin component of the limb transplant while continuing to receive long-term immunosuppression and had a mean rejection time of 61.6 days. Seven of 10 animals immunosuppressed with RS-61443 also showed signs of rejection while still receiving immunosuppression, with a mean rejection time of 43.6 days. Nine of 10 animals receiving FK-506 immunosuppression showed no signs of skin rejection, but died of bacterial pneumonia between 273 and 334 days after transplantation, with a mean rejection time of 296.1 days. There was no statistically significant difference between intermittent immunosuppression with cyclosporine and RS-61443, but FK-506 was significantly superior to both cyclosporine and RS-61443. The implication of this study is that FK-506, but not cyclosporine or RS-61443, is probably the only single immunosuppressive agent capable of preventing rejection of the skin component of a composite tissue transplant. Combination immunosuppression with FK-506 and RS-61443, therefore, may be required to allow composite tissue transplantation to become a predictable clinical reality in the future.     

Negative Regulation of TGFβ Signaling by Stem Cell Antigen-1 Protects against Ischemic Acute Kidney Injury

Acute kidney injury, often caused by an ischemic insult, is associated with significant short-term morbidity and mortality, and increased risk of chronic kidney disease. The factors affecting the renal response to injury following ischemia and reperfusion remain to be clarified. We found that the Stem cell antigen-1 (Sca-1), commonly used as a stem cell marker, is heavily expressed in renal tubules of the adult mouse kidney. We evaluated its potential role in the kidney using Sca-1 knockout mice submitted to acute ischemia reperfusion injury (IRI), as well as cultured renal proximal tubular cells in which Sca-1 was stably silenced with shRNA. IRI induced more severe injury in Sca-1 null kidneys, as assessed by increased expression of Kim-1 and Ngal, rise in serum creatinine, abnormal pathology, and increased apoptosis of tubular epithelium, and persistent significant renal injury at day 7 post IRI, when recovery of renal function in control animals was nearly complete. Serum creatinine, Kim-1 and Ngal were slightly but significantly elevated even in uninjured Sca-1-/- kidneys. Sca-1 constitutively bound both TGFβ receptors I and II in cultured normal proximal tubular epithelial cells. Its genetic loss or silencing lead to constitutive TGFβ receptor—mediated activation of canonical Smad signaling even in the absence of ligand and to KIM-1 expression in the silenced cells. These studies demonstrate that by normally repressing TGFβ-mediated canonical Smad signaling, Sca-1 plays an important in renal epithelial cell homeostasis and in recovery of renal function following ischemic acute kidney injury.     

Long‐term mTOR inhibitors administration evokes altered calcium homeostasis and platelet dysfunction in kidney transplant patients

The use of the mammal target of rapamycin (mTOR) inhibitors has been consolidated as the therapy of election for preventing graft rejection in kidney transplant patients, despite their immunosuppressive activity is less strong than anti‐calcineurin agents like tacrolimus and cyclosporine A. Furthermore, as mTOR is widely expressed, rapamycin (a macrolide antibiotic produced by Streptomyces hygroscopicus) is recommended in patients presenting neoplasia due to its antiproliferative actions. Hence, we have investigated whether rapamycin presents side effects in the physiology of other cell types different from leucocytes, such as platelets. Blood samples were drawn from healthy volunteers and kidney transplant patients long‐term medicated with rapamycin: sirolimus and everolimus. Platelets were either loaded with fura‐2 or directly stimulated, and immunoassayed or fixed with Laemmli's buffer to perform the subsequent analysis of platelet physiology. Our results indicate that rapamycin evokes a biphasic time‐dependent alteration in calcium homeostasis and function in platelets from kidney transplant patients under rapamycin regime, as demonstrated by the reduction in granule secretion observed and subsequent impairment of platelet aggregation in these patients compared with healthy volunteers. Platelet count was also reduced in these patients, thus 41% of patients presented thrombocytopenia. All together our results show that long‐term administration of rapamycin to kidney transplant patients evokes alteration in platelet function.     

Cyclosporine in transplantation - a history of converging timelines

Discovery and pharmacological development of cyclosporine was conducted by Jean Borel and colleagues in the 1970s. Cyclosporine is the first compound to inhibit the lymphocytes specifically and reversibly, and represents the prototype of a new generation of immunosuppressive drugs: the calcineurine inhibitors. Historical chronology of successes in clinical application of cyclosporine and development of solid-organ transplantation are retraced here, underscoring the converging timelines of this drug and these interventions. In 1978-79 the first successful results of the use of cyclosporine in kidney were reported. Cyclosporine was the first single drug able to control rejection. In 1982-83 first trials demonstrated the benefit from treatment with cyclosporine in kidney recipients compared to azathioprine and steroids. In the 1980s solid-organ transplantation entered the cyclosporine era with unhoped-for results in heart transplantation. The present review focuses also on cyclosporine-based regimen of immunosuppression, adverse side effects and safety in pregnancy in subjects under treatment with cyclosporine.