title: Circulating endothelial cells are a novel marker of cyclosporine-induced endothelial damage.
abstract: Microvascular endothelial cells play a key role in transplant immunology. They are also important targets for calcineurin inhibitors. We recently demonstrated elevated numbers of circulating endothelial cells in renal transplant recipients with and without rejection in comparison with healthy controls. Because these patients received either cyclosporine or tacrolimus, we speculated that endothelial damage from calcineurin inhibitors might be responsible for these findings. In the present study, we tested the hypothesis that treatment with calcineurin inhibitors leads to an increase in circulating endothelial cells. We studied 57 renal transplant recipients: 19 on a calcineurin inhibitor-free immunosuppressive regimen and 38 patients on a standard immunosuppressive regimen, including cyclosporine, and matched them for age and serum creatinine. Endothelial cells were isolated from peripheral blood with anti-CD-146-coated immunomagnetic Dynabeads and were counted by fluorescence microscopy. Patients with cyclosporine therapy had elevated numbers of circulating endothelial cells (median 26, range 12 to 82 cells/mL) compared with healthy controls (median 6, range 0 to 82 cells/mL; P<0.001). Patients without calcineurin inhibitor treatment had significantly lower cell numbers (median 12, range 0 to 32 cells/mL; P<0.003) and were not significantly different from normal, untreated controls. In conclusion, renal transplant recipients who do not receive calcineurin inhibitors have significantly lower numbers of circulating endothelial cells than their age- and creatinine-matched counterparts who receive these drugs. We suggest that elevated numbers of circulating endothelial cells indicate damage from calcineurin inhibitors in renal transplant recipients and that circulating endothelial cells are a novel marker of endothelial damage.
authors.affiliation: Medical School, Hannover, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Woywodt
authors.forename: Maik
authors.initials: M
authors.lastname: Schroeder
authors.forename: Michael
authors.initials: M
authors.lastname: Mengel
authors.forename: Anke
authors.initials: A
authors.lastname: Schwarz
authors.forename: Wilfried
authors.initials: W
authors.lastname: Gwinner
authors.forename: Hermann
authors.initials: H
authors.lastname: Haller
authors.forename: Marion
authors.initials: M
authors.lastname: Haubitz
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers; D001773:Blood Cells / Q000737:chemistry / Q000187:drug effects; D065095:Calcineurin Inhibitors; D016572:Cyclosporine / Q000633:toxicity*; D004730:Endothelium, Vascular / Q000737:chemistry / Q000187:drug effects*; D005260:Female; D006801:Humans; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D037121:Plant Lectins / Q000032:analysis
chemical_list: D015415:Biomarkers; D065095:Calcineurin Inhibitors; D037121:Plant Lectins; C036850:Ulex europaeus lectins; D016572:Cyclosporine