Platelet-derived growth factor (PDGF) isoform and PDGF receptor expression in drug-induced gingival overgrowth and hereditary gingival fibrosis

Drug-Induced Gingival Overgrowth-Molecular Aspects of Drug Actions

Drug-induced gingival overgrowth (DIGO) is one of the side effects produced by therapeutic agents, most commonly phenytoin, nifedipine and cyclosporin A. However, the precise mechanism of DIGO is not entirely understood. A literature search of the MEDLINE/PubMed databases was conducted to identify the mechanisms involved in DIGO. The available information suggests that the pathogenesis of DIGO is multifactorial, but common pathogenic sequelae of events emerge, i.e., sodium and calcium channel antagonism or disturbed intracellular handling of calcium, which finally lead to reductions in intracellular folic acid levels. Disturbed cellular functions, mainly in keratinocytes and fibroblasts, result in increased collagen and glycosaminoglycans accumulation in the extracellular matrix. Dysregulation of collagenase activity, as well as integrins and membrane receptors, are key mechanisms of reduced degradation or excessive synthesis of connective tissue components. This manuscript describes the cellular and molecular factors involved in the epithelial-mesenchymal transition and extracellular matrix remodeling triggered by agents producing DIGO.

Systemic disease or periodontal disease? Distinguishing causes of gingival inflammation: a guide for dental practitioners. Part 1: immune-mediated, autoinflammatory, and hereditary lesions

Periodontitis and gingivitis remain two of the most common diseases that affect the oral cavity. As they are caused by plaque, effective oral hygiene, elimination of plaque-retentive factors and successful periodontal treatment will result in resolution of gingival and periodontal inflammation. Certain systemic diseases can have a clinical appearance similar to periodontal diseases or exacerbate existing periodontitis/gingivitis and vice versa. This paper aims to provide the dental practitioner with an understanding of the manifestations of systemic diseases to the periodontium and highlights elements in the clinical assessment, which will aid in establishing a correct diagnosis. Additional anamnestic and clinical clues are important for distinguishing between plaque-induced and non-plaque-induced lesions. The first part of this compendium covers immune-mediated and hereditary conditions as causes of gingival lesions, which can resemble those caused by dental plaque. The different conditions are presented concisely and exemplified by clinical photographs. Dental practitioners should be aware of the various manifestations of systemic diseases to the periodontium in order to offer appropriate diagnosis and treatment, which can reduce both patient morbidity and mortality.

In vivo association of immunophenotyped macrophages expressing CD163 with PDGF-B in gingival overgrowth-induced by three different categories of medications

AIMS

This study was carried out to identify and outline the degree of relationship between immunophenotyped macrophages expressing CD163 and PDGF-B in cyclosporine-A, phenytoin, and nifedipine-induced gingival overgrowth.

METHODS

Eighty adult male albino rats were selected and divided into four equal groups. Group I received no treatment. Rats of groups II, III, and IV were administered cyclosporine-A, phenytoin, and nifedipine, respectively. Routine tissue processing was carried out for staining with CD163 and PDGF-B. The results of this study were analyzed statistically.

RESULTS

Group I exhibited score 0 gingival overgrowth while group II yielded score 3 with blunt and bulbous gingival crests. Rats of group III showed score 2 with knife edge and group IV revealed less pronounced gingival overgrowth and mostly the gingival crest was knife edge. Group II had the highest mean value for CD163 while group I showed the lowest value. In addition, group II had the highest mean value for PDGF-B while group I showed the lowest value. Statistically, there was an overall significant difference between the studied groups as well as between each two groups.

CONCLUSION

Strong association exists between immunophenotyped macrophages expressing CD163 and PDGF-B in GO induced by these medications. In addition, CD163 and PDGF-B upregulated in cyclosporine-A-induced GO compared to phenytoin and nifedipine medications.

Interleukin-10 gene promoter polymorphisms are associated with cyclosporin A-induced gingival overgrowth in renal transplant patients

OBJECTIVE

Interleukin-10 (IL-10) is an anti-inflammatory cytokine whose genetic polymorphisms are associated with the production of IL-10 and the susceptibility to periodontal diseases. The aim of this study was to investigate the possible association of IL-10 single nucleotide polymorphisms (SNPs) and cyclosporin A (CsA)-induced gingival overgrowth (GO) in renal transplant patients in a Chinese population, taking into account subgingival microbiota as additional variables.

MATERIAL AND METHODS

A total of 202 patients were dichotomized into two groups: 122 with GO and 80 without GO. The IL-10-1082 SNP, -819 SNP and -592 SNP were measured using an allele-specific PCR method. The levels of subgingival bacteria were measured by real-time PCR. Genotype and allele frequencies were analyzed using the Chi-square test and logistic regression analysis.

RESULTS

The frequency of IL-10-819TT (-592AA) genotype was statistically higher in patients with GO than that in patients without GO (P<0.05). Multiple logistic regression analysis demonstrated that the prevalence of GO is not dependent on age, gender, and pharmacological variables, being significantly associated with the carriers of ATA haplotype (OR=2.425, 95%CI=1.214-4.845, P=0.012). Moreover, ATA positive carriers in the GO group presented significantly higher levels of Porphyromonas gingivalis and Treponema denticola than those negative carriers.

CONCLUSIONS

Our results show that IL-10-819TT (-592AA) genotype and ATA halpotype are associated with susceptibility to CsA-induced GO. Meanwhile, ATA haplotype is associated with a higher detection of P. gingivalis and T. denticola in GO patients, and may increase the risk of developing GO.

Relationship between IL-1A polymorphisms and gingival overgrowth in renal transplant recipients receiving Cyclosporin A

AIM

Levels of interleukin-1alpha (IL-1alpha) are elevated in periodontal inflammation. IL-1A gene polymorphisms are associated with inflammatory diseases. This study aimed to investigate IL-1A gene polymorphism in Cyclosporin A (CsA)-treated renal transplant patients and investigate the association between this polymorphism and gingival crevicular fluid (GCF) levels of several cytokines.

MATERIALS AND METHODS

Fifty-one renal transplant patients on CsA treatment (25 with and 26 without gingival overgrowth) and 29 healthy controls were recruited for the study. Demographic, pharmacological and periodontal parameters were recorded and gingival overgrowth was assessed.

RESULTS

Multiple regression analysis showed that genotype was significantly associated with gingival overgrowth (p=0.02). Carriage of the IL-1A (-889) T allele was strongly protective [95% confidence interval (CI): 0.046-0.77], although not significantly associated with IL-1alpha protein levels in GCF. IL-1alpha, IL-1beta and IL-8, but not IL-6, were detected in GCF of CsA-treated patients, but none of them was significantly associated with gingival overgrowth.

CONCLUSIONS

This study is the first to associate a gene polymorphism as a risk factor for CsA-induced gingival overgrowth in renal transplant patients, demonstrating that IL-1A polymorphism might alter individual susceptibility to CsA. However, there was no association between GCF cytokine levels and the presence of gingival overgrowth or patient IL-1A genotype.