Background: Severe gingival hyperplasia (GH) is one of the most frequent side-effects associated with the prescription of Cyclosporine-A (CsA).
Aim: This study statistically modeled the medical and dental risk factors for the development of GH following CsA administration to determine whether renal function post-transplantation was related to the incidence or extent of GH in 236 consecutive renal transplant patients.
Method: All patients were at least 6 months post-transplant and medicated with both traditional oral CsA (n=220 individuals) and the new microemulsion form CsA-Me (n=229 individuals). Patients had either received CsA alone (n=45 individuals) or cyclosporine and nifedipine (n=191 individuals). Gingival overgrowth was assessed and computerized data, available for all patients included; pre- and post-transplant medical history and post-transplant renal function, i.e., serum creatinine levels, documented rejection episodes and glomerular filtration rates (GFR). These data together with CsA serum levels and last-recorded dose of CsA, CsA-Me, nifedipine, azathioprine and prednisolone, were analysed by multivariate regression analysis using SPSS.
Results: The extent and severity of hyperplasia was significantly correlated with the dosage and serum level of CsA at 3, 6 and 12 months post-transplantation; last recorded dosage, however (p<0.0001), was the most accurate predictor of hyperplasia. Gingivitis (p<0.0001) and plaque (p<0.002), were associated with hyperplasia. Duration of renal replacement therapy, age at transplantation, post-transplant interval serum creatinine levels and documented rejection episodes were unrelated with the extent and severity of GH. Of all the renal variables only the correlation of GFR with last recorded doses of CsA and CsA-Me, approached significance; this was then considered for inclusion in the model.
Conclusion: In a multiple regression analysis including GFR, however, only last CsA (and CsA-Me) doses and gingivitis score were selected for inclusion in the final model. These data demonstrate that inter-patient variation in the extent and severity of GH and renal function post-transplantation are unrelated and are mediated independently.