Role of MDR1 gene polymorphisms in gingival overgrowth induced by cyclosporine in transplant patients.
OBJECTIVE
The aim of the present study was to determine the association between genotypes of the MDR1 gene, encoding P-glycoprotein, and gingival overgrowth in transplant patients treated with cyclosporine, and to evaluate the effect of periodontal treatment in these patients.


METHODS
Fifty transplant patients receiving therapy with cyclosporine and suffering from gingival overgrowth were subjected to nonsurgical periodontal treatment and received oral hygiene instructions. Hyperplastic index, periodontal probing depths, bleeding and plaque scores were recorded at baseline and after 3 and 6 mo. Patients were dichotomized into two groups: those with a hyperplastic index of < 30% (minimal gingival overgrowth) and those with a hyperplastic index of > or = 30% (clinically significant gingival overgrowth). MDR1 C3435T and G2677T polymorphisms were evaluated in all patients and in 100 controls.


RESULTS
At baseline, 32 patients (64%) had minimal gingival overgrowth and 18 patients (36%) had clinically significant gingival overgrowth. The mutated C3435T genotype was significantly more frequent in the second group (p < 0.019). The significant association between gingival overgrowth and the 3435TT genotype was confirmed by logistic regression analysis (p < 0.031). The differences in hyperplastic index, observed at baseline between patients with the TT genotype and those with the CC/CT genotype disappeared in the second and third evaluation. The mean monthly change of the square root of the gingival overgrowth scores for all patients, assessed using linear models, was significantly different from baseline (-0.17 points per month, p < 0.00001); and this was particularly evident in subjects with renal transplant (-1.62, p < 0.01).


CONCLUSIONS
Aetiological periodontal and self-performed maintenance therapy is effective in reducing gingival overgrowth, particularly in subjects with the 3435TT genotype and in patients with renal transplant.
De Iudicibus
S
S
Department of Biomedical Sciences, University of Trieste, Trieste, Italy.
Castronovo
G
G
Gigante
A
A
Stocco
G
G
Decorti
G
G
Di Lenarda
R
R
Bartoli
F
F
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000096:biosynthesis / Q000235:genetics*; D000658:Amoxicillin / Q000627:therapeutic use; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D016022:Case-Control Studies; D017291:Clarithromycin / Q000627:therapeutic use; D016572:Cyclosporine / Q000009:adverse effects*; D012534:Dental Scaling; D005260:Female; D019214:Gingival Overgrowth / Q000139:chemically induced* / Q000235:genetics* / Q000628:therapy; D016027:Heart Transplantation; D006801:Humans; D007166:Immunosuppressive Agents / Q000009:adverse effects*; D016030:Kidney Transplantation; D016031:Liver Transplantation; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D020125:Mutation, Missense; D009910:Oral Hygiene; D012150:Polymorphism, Restriction Fragment Length; D020641:Polymorphism, Single Nucleotide; D011446:Prospective Studies
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000900:Anti-Bacterial Agents; D007166:Immunosuppressive Agents; D000658:Amoxicillin; D016572:Cyclosporine; D017291:Clarithromycin