SPARC gene polymorphism in renal transplant patients with gingival overgrowth

Gingival enlargement frequently occurs in transplant patients receiving immunosuppressive drugs. It was hypothesized that gingival enlargement associated with cyclosporin use results from increases in the number of fibroblasts and the volume of extracellular matrix. SPARC (secreted protein, acidic, and rich in cysteine) regulates cell-matrix interactions, binding to structural matrix proteins, and is induced by cyclosporin A (CsA). The aim of the study was to determine whether there is an association between SPARC genotypes and gingival enlargement in kidney transplant patients given CsA.

Sixty-two unrelated kidney transplant patients with gingival overgrowth and 124 control transplant patients without overgrowth were enrolled into the study. Gingival overgrowth was assessed at 6 months after transplantation. All patients were given CsA as a principal immunosuppressive agent during the post-transplant period. SPARC polymorphism was determined using polymerase chain reaction-restriction fragments length polymorphism assay.

In kidney transplant patients with gingival overgrowth, the mean score of gingival overgrowth was 1.42+/-0.63, whereas in control subjects it was 0. The distribution of SPARC 998C>G alleles among all kidney transplant patients, as well as in the two study subgroups, did not differ significantly from Hardy-Weinberg equilibrium. The frequencies of the 998G allele (24.2% versus 18.5%) and of 998G allele carriers (40.3% versus 33.1%) among individuals with gingival overgrowth was higher compared to the control group, but the differences did not reach the statistical difference. The risk for gingival overgrowth was highest among patients carrying the 998GG genotype (OR 2.25), but it did not differ significantly from the risks associated with the other genotypes.

No association between SPARC gene polymorphism and gingival overgrowth was revealed in kidney transplant patients who were administered CsA.