A longitudinal study of TGF-beta1 protein levels in renal allograft recipients converted from CsA to MMF or AZA.

Cyclosporine (CsA) is thought to enhance transforming growth factor (TGF)-beta1 production in vitro and in vivo and this may have a negative effect on long-term graft survival. Therefore, we studied TGF-beta1, plasma levels in 30 patients before kidney transplantation, after transplantation during CsA treatment and after conversion from CsA to azathioprine (AZA) or mycophenolate mofetil (MMF). We questioned whether TGF-beta1 plasma levels would decrease after the discontinuation of CsA and whether the TGF-beta1 plasma levels did correlate with CsA trough levels and kidney function, measured by serum creatinine levels. TGF-beta1 plasma levels measured 1 yr after transplantation were lower compared to levels measured before transplantation, however not significantly (p = 0.08). After conversion from CsA to MMF or AZA, a slight increase was observed in some patients, but in the total group TGF-beta1 levels remained unaffected. No correlation was found between the TGF-beta1 levels and CsA trough levels nor with creatinine levels. In conclusion, we did not observe higher TGF-beta1 plasma levels in plasma levels of patients receiving CsA treatment compared to blood from the same patients while on AZA or MMF.