Variáveis de risco associadas ao crescimento gengival em indivíduos transplantados renais sob os regimes imunossupressores deciclosporina, tacrolimus e sirolimus

Abstract

Studies regarding gingival overgrowth (GO) and its associated risk factors in renal transplant recipients under cyclosporine A (CsA) and tacrolimus (Tcr) imunosuppressive regimens have shown conflicting findings and there is no available data regarding sirolimus (Sir). Therefore, the present study wich is displayed as a review of literature and 3 scientific papers aimed to evaluate: 1) prevalence, severity and risk variables associated with GO in subjects under Sir-based regimens; 2) interleukin-6 (IL-6) gene polymorphism in subjects medicated with CsA, Tcr, and Sir and its association with GO; and 3) bacterial frequency and risk variables associated with GO in subjects under CsA, Tcr, and Sir-based immunosuppressive regimens. An eligible sample was selected from two public hospitals in Belo Horizonte city, Brasil. Participants were all renal transplant recipients, from both gender and multiethinic group, were 18 years old or more and had a minimum of six of the twelve most anterior teeth in the upper or lower dental arches. Periodontal assessment included visual inspection of GO, plaque index, and papillary bleeding index. Oral mucosa swabs were taken once from all subjects and IL-6 (174 G/C) polymorphism evaluated through PCR-RFLP (Polymerase Chain Reaction - Restriction Fragment Length Polymorfism). Non-stimulated saliva samples were colected and the presence of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Parvimonas micra, Treponema denticola e Tannerella forsythia was assessed through PCR (Polymerase Chain Reaction). A descriptive analysis and comparisons between GO+ and GO- subjects were performed in relation to demographic, pharmacological, and periodontal variables, as well as IL-6 genotypes and alleles, and bacterial frequencies, through appropriate testes. The first study (n = 144) regarding Sir-based regimens demonstrated a GO prevalence of 20.8% associated with time since transplant, papillary bleeding index, and calcineurin inhibitors previous use. However, GO was determined not to be clinically significant. The second study (n = 135, that is CsA n = 45, Tcr n = 45, Sir n = 45) showed no significant differences in the distribution of IL-6 GG, GC, and CC genotypes, as well as G and C alleles between GO+ and GO- subjects in any of the immunosuppressive regimens under investigation. The third study (n = 135, that is CsA n = 45, Tcr n = 45, Sir n = 45) showed a significant difference between GO+ and GO- subjects in relation to the frequency of periodontal pathogens, specially in regards to Tannerella forsythia in Tcr-based immunosuppressive regimens. In general, pharmacological variables, represented by CsA previous use and concomitant use of clacium channel blockers, and periodontal variables, represented by papillary bleeding, were associated with GO. Findings from the present study point towards the importance of periodontal variables (bleeding/inflammation) and pharmacological variables (drug synergism) in the occurrence of GO. Cooperation betweem medical and dental health care personnel in the maintenance therapies of renal transplant recipients prove to be necessary. Managing periodontal conditions in post-transplant subjects under immunosuppressive maintenance regimens may improve gingival status and quality of life.