A longitudinal study of TGF-β1 protein levels in renal allograft recipients converted from CsA to MMF or AZA

Cyclosporine (CsA) is thought to enhance transforming growth factor (TGF)-beta(1) production in vitro and in vivo and this may have a negative effect on long-term graft survival. Therefore, we studied TGF-beta(1) 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-beta(1) plasma levels would decrease after the discontinuation of CsA and whether the TGF-beta(1) plasma levels did correlate with CsA trough levels and kidney function, measured by serum creatinine levels, TGF-beta(1) 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-beta(1) levels remained unaffected. No correlation was found between the TGF-beta(1) levels and CsA trough levels nor with creatinine levels. In conclusion, we did not observe higher TGF-beta(1) plasma levels in plasma levels of patients receiving CsA treatment compared to blood from the same patients while on AZA or MMF.