Transforming growth factor-beta1 gene expression and cyclosporine A-induced gingival overgrowth: a pilot study

Aims: The relationship between gingival overgrowth (GO) induced by cyclosporine A (CsA) and transforming growth factor‐β1 (TGF‐β1) remains unclear. The aims of the present study were to evaluate TGF‐β1 gene expression under different immunosuppressive treatments and its association with TGF‐β1 gene functional polymorphism and GO in renal transplant recipients. Material and Methods: The study included 98 CsA‐treated renal transplant recipients (with and without GO) and 44 tacrolimus‐treated transplant patients (without GO). TGF‐β1 mRNA expression was measured using a real‐time quantitative polymerase chain reaction assay. The levels were correlated with TGF‐β1 gene polymorphisms at codons 10 and 25, with different immunosuppressive treatment and GO. Results: The level of TGF‐β1 gene expression was insignificantly lower in the CsA‐treated group compared with the tacrolimus group, and significantly lower in the group with GO compared with patients without GO. In tacrolimus‐ and CsA‐treated patients, but not in patients with GO, the level of TGF‐β1 gene expression was associated with functional phenotypes of TGF‐β1. The incidence, degree and extent of GO were higher in recipients with lower TGF‐β1 gene expression. Conclusions: Lower level TGF‐β1 gene expression, not functional polymorphism, in patients treated with CsA may be considered to be a risk factor for GO.