title: Distinct deleterious effects of cyclosporine and tacrolimus and combined tacrolimus-sirolimus on endothelial cells: protective effect of defibrotide.
abstract: Endothelial dysfunction seems to be a key factor in the development of several complications observed early after hematopoietic stem cell transplantation (HSCT). The conditioning regimen and many other factors associated with the procedure are responsible for this endothelial damage. The effects of immunosuppressive agents on endothelial function have not been explored in detail. We evaluated the effects of 3 drugs commonly used in HSCT: 2 calcineurin inhibitors, cyclosporine A (CSA) and tacrolimus (TAC), and an inhibitor of mTOR, sirolimus (SIR). We also evaluated the effect of the combination of TAC and SIR (TAC+SIR), which is used increasingly in clinical practice. Microvascular endothelial cells (HMEC-1) were exposed to these drugs to evaluate changes in (1) intercellular adhesion molecule (ICAM)-1 expression on the cell surface, assessed by immunofluorescence labeling and expressed as the mean gray value (MGV); (2) reactivity of the extracellular matrix (ECM) toward platelets, upon exposure of the ECM to circulating blood; and (3) whole-blood clot formation, assessed by thromboelastometry. Studies were conducted in the absence and presence of defibrotide (DF) to assess its possible protective effect. The exposure of HMEC-1 to CSA and TAC+SIR significantly increased the expression of ICAM-1 (157.5 ± 11.6 and 153.4 ± 9.5 MGV, respectively, versus 105.7 ± 6.5 MGV in controls [both P < .05]). TAC applied alone increased ICAM-1 slightly (120.3 ± 8.2 MGV), and SIR had no effect (108.9 ± 7.4 MGV). ECM reactivity increased significantly only in response to CSA (surface covered by platelets of 41.2% ± 5.4% versus 30.1% ± 2.0%, P < .05). DF attenuated all these changes. No significant changes in the viscoelastic properties of clot formation were observed in any condition with blood samples incubated in vitro. In conclusion, CSA and TAC+SIR had a proinflammatory effect, but only CSA exhibited an additional prothrombotic effect. Interestingly, DF exerted clear protective anti-inflammatory and antithrombotic effects on the endothelium.
authors.affiliation: Hemotherapy-Hemostasis Department, Centre de Diagnòstic Biomèdic, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Hospital Clinic, Universitat de Barcelona, Barcelona, Spain.
authors.forename: Alba
authors.initials: A
authors.lastname: Carmona
authors.forename: Maribel
authors.initials: M
authors.lastname: Díaz-Ricart
authors.forename: Marta
authors.initials: M
authors.lastname: Palomo
authors.forename: Patricia
authors.initials: P
authors.lastname: Molina
authors.forename: Marc
authors.initials: M
authors.lastname: Pino
authors.forename: Montserrat
authors.initials: M
authors.lastname: Rovira
authors.forename: Ginés
authors.initials: G
authors.lastname: Escolar
authors.forename: Enric
authors.initials: E
authors.lastname: Carreras
mesh_terms: D002478:Cells, Cultured; D016572:Cyclosporine / Q000009:adverse effects* / Q000494:pharmacology; D042783:Endothelial Cells / Q000187:drug effects* / Q000276:immunology / Q000473:pathology; D005343:Fibrinolytic Agents / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D006801:Humans; D007166:Immunosuppressive Agents / Q000009:adverse effects* / Q000494:pharmacology; D011089:Polydeoxyribonucleotides / Q000494:pharmacology*; D016559:Tacrolimus / Q000009:adverse effects* / Q000494:pharmacology
chemical_list: D005343:Fibrinolytic Agents; D007166:Immunosuppressive Agents; D011089:Polydeoxyribonucleotides; C036901:defibrotide; D016572:Cyclosporine; D016559:Tacrolimus
keywords: Cyclosporine; Endothelial damage; Immunosuppressive agents; Sirolimus; Tacrolimus; mTOR