Impaired Microcirculation in Children After Kidney Transplantation: Everolimus Versus Mycophenolate Based Immunosuppression Regimen.

Background/aims: Whether the immunosuppressive regimen is associated with micro- and macro-vascular status in pediatric kidney transplant recipients (KTx) is unknown.

Methods: We performed a cross-sectional, case-control study in 44 pediatric KTx patients on either everolimus (EVR) plus calcineurin inhibitor or standard treatment, i.e. mycophenolate mofetil plus calcineurin inhibitor. Measurement of carotid intima-media thickness (cIMT) via ultrasound, central pulse wave velocity (PWV) by a cuff-based oscillometric technique, and skin microvascular blood flow during local heating via laser-Doppler-fluximetry (LDF) served as marker of subclinical vascular disease. Serum concentrations of angiopoietin-1 and -2, fibroblast-growth factor 23 (FGF23) and soluble klotho were measured.

Results: EVR-treated patients exhibited a similar degree of hypertension, increased cIMT, elevated pro-inflammatory angiopoietin-2, and diminished endothelial survival factor angiopoietin-1 compared to healthy children but presented with a twofold more reduced skin micro-vascular function compared to standard treatment (each p< 0.001). By contrast, PWV and soluble klotho levels were normal in both groups.

Conclusion: Endothelial dysfunction seems more frequent in KTx patients on EVR-based immunosuppressive regimen compared to standard immunosuppression.