A longitudinal study of TGF-beta(1) protein levels in renal allograft recipients converted from CsA to MMF or AZA

Cyclosporine (CsA) is thought to enhance transforming growth factor (TGF)-b eta(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 level s in 30 patients before kidney transplantation, after transplantation durin g CsA treatment and after conversion from CsA to azathioprine (AZA) or myco phenolate mofetil (MMF). We questioned whether TGF-beta(1) plasma levels wo uld decrease after the discontinuation of CsA and whether the TGF-beta(1) p lasma levels did correlate with CsA trough levels and kidney function, meas ured by serum creatinine levels, TGF-beta(1) plasma levels measured 1 yr af ter transplantation were lower compared to levels measured before transplan tation, 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 tot al group TGF-beta(1) levels remained unaffected. No correlation was found b etween the TGF-beta(1) levels and CsA trough levels nor with creatinine lev els. In conclusion, we did not observe higher TGF-beta(1) plasma levels in plasma levels of patients receiving CsA treatment compared to blood from th e same patients while on AZA or MMF.