Biallelic frameshift variant in the TBC1D2B gene in two siblings with progressive gingival overgrowth, fibrous dysplasia of face, and mental deterioration.

Biallelic loss-of-function variants in the TBC1D2B gene were recently reported as a cause of a neurodevelopmental disorder with seizures and gingival overgrowth. Here, we report two male siblings with the similar clinical characteristics. They started with gingival overgrowth and bilateral growth of soft tissues in the malar region at 3 years of age, which evolved with significant maxillary hypertrophy and compression of the brainstem due to fibrous dysplasia of facial bones. After disease evolution, they presented with mental deterioration, limb tremors, and gait ataxia. One of them also presented with seizures. Whole exome sequencing revealed a novel biallelic frameshift variant [c.595del; p.(Val199Trpfs*22)] in the TBC1D2B gene in both patients, which was confirmed and found in heterozygous state in each of their parents. There are strong similarities in clinical characteristics, age of onset, and evolution between the patients described here and cases reported in the literature, including cherubism-like phenotype with progressive gingival overgrowth and seizures. This is the fourth family in the world in which a biallelic loss-of-function variant in the TBC1D2B gene is associated with this phenotype. These results support that loss of TBC1D2B is the cause of this rare condition.

Biallelic loss-of-function variants in TBC1D2B cause a neurodevelopmental disorder with seizures and gingival overgrowth.

The family of Tre2-Bub2-Cdc16 (TBC)-domain containing GTPase activating proteins (RABGAPs) is not only known as key regulatorof RAB GTPase activity but also has GAP-independent functions. Rab GTPases are implicated in membrane trafficking pathways, such as vesicular trafficking. We report biallelic loss-of-function variants in TBC1D2B, encoding a member of the TBC/RABGAP family with yet unknown function, as the underlying cause of cognitive impairment, seizures, and/or gingival overgrowth in three individuals from unrelated families. TBC1D2B messenger RNA amount was drastically reduced, and the protein was absent in fibroblasts of two patients. In immunofluorescence analysis, ectopically expressed TBC1D2B colocalized with vesicles positive for RAB5, a small GTPase orchestrating early endocytic vesicle trafficking. In two independent TBC1D2B CRISPR/Cas9 knockout HeLa cell lines that serve as cellular model of TBC1D2B deficiency, epidermal growth factor internalization was significantly reduced compared with the parental HeLa cell line suggesting a role of TBC1D2B in early endocytosis. Serum deprivation of TBC1D2B-deficient HeLa cell lines caused a decrease in cell viability and an increase in apoptosis. Our data reveal that loss of TBC1D2B causes a neurodevelopmental disorder with gingival overgrowth, possibly by deficits in vesicle trafficking and/or cell survival.

Elevated Interleukin-17A expression in amlodipine-induced gingival overgrowth.

BACKGROUND AND OBJECTIVES: Amlodipine, a calcium channel blocker derivative, is frequently used by patients with high blood pressure. Studies reported that it can induce gingival overgrowth. However, the underlying mechanism is not fully described yet. Interleukin-17A (IL-17A) is known as a proinflammatory cytokine, but current studies indicate that it has a role in fibrotic disorders and epithelial-mesenchymal transition (EMT). The aim of this study was to figure out the possible role of IL-17A in amlodipine-induced gingival overgrowth. MATERIALS AND METHODS: Twenty-nine (29) individuals participated in the study, and they were assigned into 3 groups based on medical status and clinical periodontal examination; 9 patients with amlodipine-induced gingival overgrowth, 11 patients with inflammatory gingival overgrowth, and 9 healthy individuals as a control group. Clinical periodontal parameters including plaque index (PI), gingival index (GI), and gingival overgrowth index (GOI) were recorded. Blood and gingival crevicular fluid (GCF) samples were obtained. Gingival tissues were taken by appropriate periodontal surgery following initial periodontal therapy. To detect IL-17A on tissue samples, immunohistochemistry (IHC) was performed. Quantitative analysis was done, and the expression level of IL-17A was given as the percent positively stained cells. Enzyme-linked immunosorbent assay (ELISA) kits were used to analyze IL-17A in serum and GCF samples. RESULTS: All recorded clinical parameters were significantly higher in gingival overgrowth groups compared with control. Evaluation of inflammation on tissue sections did not show any significant change within the groups. Immunohistochemistry findings showed that IL-17A expression was increased in amlodipine samples (81.90%) compared with control samples (42.35%) (P < .001). There was an increase in the inflammatory group (66.08%) which is significantly less than the amlodipine group (P < .05). IL-17A levels in serum and GCF samples were not different within the study groups. CONCLUSION: In this study, elevated IL-17A expression regardless of inflammation shows that amlodipine might cause an increase of IL-17A in gingival tissues. This increase might induce fibrotic changes and EMT in gingival overgrowth tissues. The association of IL-17A with fibrosis and EMT in gingival tissues requires further investigation.

Molecular Aspects of Drug-Induced Gingival Overgrowth: An In Vitro Study on Amlodipine and Gingival Fibroblasts.

Gingival overgrowth is a serious side effect that accompanies the use of amlodipine. Several conflicting theories have been proposed to explain the fibroblast's function in gingival overgrowth. To determine whether amlodipine alters the fibrotic response, we investigated its effects on treated gingival fibroblast gene expression as compared with untreated cells. MATERIALS AND METHODS: Fibroblasts from ATCC® Cell Lines were incubated with amlodipine. The gene expression levels of 12 genes belonging to the "Extracellular Matrix and Adhesion Molecules" pathway was investigated in treated fibroblasts cell culture, as compared with untreated cells, by real time PCR. RESULTS: Most of the significant genes were up-regulated. (CTNND2, COL4A1, ITGA2, ITGA7, MMP10, MMP11, MMP12, MMP26) except for COL7A1, LAMB1, MMP8, and MMP16, which were down-regulated. CONCLUSION: These results seem to demonstrate that amlodipine has an effect on the extracellular matrix of gingival fibroblast. In the future, it would be interesting to understand the possible effect of the drug on fibroblasts of patients with amlodipine-induced gingival hyperplasia.

Upregulation of Slug expression by cyclosporine A contributes to the pathogenesis of gingival overgrowth.

BACKGROUND/PURPOSE: Gingival overgrowth occurs as a side effect of systemic medication with immunosuppressant cyclosporine A (CsA). Slug, a master regulator of epithelial-mesenchymal transition, is dramatically upregulated in a variety of fibrotic diseases. The aim of this study is to investigate the role of epithelial-mesenchymal transition marker Slug in the pathogenesis of CsA-induced gingival overgrowth. METHODS: Clinically healthy gingiva and CsA-induced gingival overgrowth specimens were analyzed by immunohistochemistry. The effect of CsA on normal human gingival fibroblasts (HGFs) was used to elucidate whether Slug expression could be affected by CsA by real-time reverse transcription-polymerase chain reaction and western blot. Cell proliferation in CsA-treated HGFs with Slug lentiviral-mediated shRNAi knockdown was evaluated by tetrazolium bromide reduction assay. RESULTS: Slug expression was higher in CsA-induced gingival overgrowth specimens than in clinical healthy gingiva (p < 0.05). Slug expression was significantly higher in CsA-induced gingival overgrowth specimens with higher levels of inflammatory infiltrates (p < 0.05). CsA was found to increase Slug transcript and protein expression in HGFs in a dose-dependent manner (p < 0.05). In addition, knockdown of Slug significantly suppressed CsA-induced cell proliferation in HGFs (p < 0.05). CONCLUSION: Taken together, upregulation of Slug in HGFs stimulated by CsA may play an important role in the pathogenesis of CsA-induced gingival overgrowth.

The role of androgen receptor gene in cyclosporine induced gingival overgrowth.

BACKGROUND AND OBJECTIVE: Gingival overgrowth is a prominent side effect of cyclosporine (CsA) therapy in renal transplant patients. Although the exact mechanism by which this drug induces gingival overgrowth is uncertain, marked variations in individual susceptibility to this drug suggest a genetic predisposition. Studies have shown that genetic variation (polymorphism) in the trinucleotide cytosine-adenine- guanine (CAG) sequence in exon 1 of the androgen receptor (AR) gene is related to altered activity of the AR as a transcription factor. However, the relationship between the length of the CAG repeat and gingival overgrowth has not yet been studied. The present study was carried out to determine whether there is an association between CsA-induced gingival overgrowth and the length of the CAG repeats in the AR gene. MATERIAL AND METHODS: Genomic DNA samples were prepared from the blood of 50 renal transplant patients with CsA-induced gingival overgrowth and from the blood of 100 renal transplant patients on CsA with no gingival overgrowth. RESULTS: The difference in allele distribution among the subjects with gingival overgrowth and control samples was statistically significant (p = 0.001). CONCLUSION: The findings suggest a link between CsA7induced gingival overgrowth and a smaller size of CAG repeat in the AR gene.

Loss of TBC1D2B causes a progressive neurological disorder with gingival overgrowth.

Biallelic loss-of-function variants in TBC1D2B have been reported in five subjects with cognitive impairment and seizures with or without gingival overgrowth. TBC1D2B belongs to the family of Tre2-Bub2-Cdc16 (TBC)-domain containing RAB-specific GTPase activating proteins (TBC/RABGAPs). Here, we report five new subjects with biallelic TBC1D2B variants, including two siblings, and delineate the molecular and clinical features in the ten subjects known to date. One of the newly reported subjects was compound heterozygous for the TBC1D2B variants c.2584C>T; p.(Arg862Cys) and c.2758C>T; p.(Arg920*). In subject-derived fibroblasts, TBC1D2B mRNA level was similar to control cells, while the TBC1D2B protein amount was reduced by about half. In one of two siblings with a novel c.360+1G>T splice site variant, TBC1D2B transcript analysis revealed aberrantly spliced mRNAs and a drastically reduced TBC1D2B mRNA level in leukocytes. The molecular spectrum included 12 different TBC1D2B variants: seven nonsense, three frameshifts, one splice site, and one missense variant. Out of ten subjects, three had fibrous dysplasia of the mandible, two of which were diagnosed as cherubism. Most subjects developed gingival overgrowth. Half of the subjects had developmental delay. Seizures occurred in 80% of the subjects. Six subjects showed a progressive disease with mental deterioration. Brain imaging revealed cerebral and/or cerebellar atrophy with or without lateral ventricle dilatation. The TBC1D2B disorder is a progressive neurological disease with gingival overgrowth and abnormal mandible morphology. As TBC1D2B has been shown to positively regulate autophagy, defects in autophagy and the endolysosomal system could be associated with neuronal dysfunction and the neurodegenerative disease in the affected individuals.

Arthropathy, osteolysis, keloids, relapsing conjunctival pannus and gingival overgrowth: a variant of polyfibromatosis?

Polyfibromatosis is a rare fibrosing condition characterized by fibromatosis in different body areas and by keloid formation, and which can be associated with arthropathy and osteolysis. Familial occurrence has been described, but the cause remains unknown. Here, we describe a patient with characteristics of polyfibromatosis with arthropathy who had in addition severe conjunctival fibrosis, distinctive face, gingival overgrowth, and pigmented keloids. We discuss the resemblances and differences with polyfibromatosis and descriptions of other, similar patients. We conclude that at present it remains uncertain whether the patient has a variant of polyfibromatosis or a separate entity.

Expression of angiotensin II and its receptors in cyclosporine-induced gingival overgrowth.

BACKGROUND AND OBJECTIVES: The renin-angiotensin system (RAS) is considered as a hormonal circulatory system involved in maintaining blood pressure, electrolyte and fluid homeostasis. RAS components can be synthesized in local tissues and are found to play a role in gingival overgrowth. The drug-induced gingival overgrowth (DIGO) is a fibrotic condition, which is associated with multiple factors, including inflammation and adverse drug effects such as cyclosporine A. This study was directed forward to the identification of the angiotensinogen, angiotensin II (Ang II) and its receptors AT1 /AT2 expression in DIGO tissues and cyclosporine-treated human gingival fibroblast cells. MATERIAL AND METHODS: Gingival samples were obtained from patients with cyclosporine-induced gingival overgrowth, chronic periodontitis and normal healthy subjects. The total RNA was isolated and reverse transcription-polymerase chain reaction was performed for angiotensinogen, Ang II and AT1 /AT2 receptor. Ang II protein was estimated from tissue by enzyme immunoassay. The expression of Ang II and its receptors were also examined in gingival fibroblast cells treated with cyclosporine. RESULTS: Ang II mRNA and protein expression was significantly higher in patients with DIGO than in patients with periodontitis and healthy subjects. The AT1 mRNA was expressed more than AT2 in all examined tissues. In gingival fibroblasts, Ang II and AT1 expressions were increased with cyclosporine incorporation compared to controls. CONCLUSION: These results suggest that cyclosporine can modulate local expression of RAS components such as angiotensinogen, Ang II and its receptors in gingival tissues and gingival fibroblast cells.

Tumoral calcinosis: a dental literature review and case report.

UNLABELLED: Tumoral calcinosis (TC) is a rare familial disease characterized by abnormal peri-articular calcification in affected joints, without any associated renal, metabolic or collagen vascular disease. It is characterized by usual hyperphosphataemia with normal serum calcium and alkaline phosphatase values. There are only a few reported cases ofTC patients with dental findings. This article reviews the dental literature and describes progressive gingival, alveolar and mandibular tori enlargement in a 41-year-old female from Zimbabwe with tumoral calcinosis. CLINICAL RELEVANCE: Tumoral calcinosis is a rare disorder of mineral metabolism with oral manifestations.

Cyclosporine-induced gingival overgrowth correlates with NFAT-regulated gene expression: a pilot study.

OBJECTIVE: To determine whether incidence and severity of cyclosporine A (CsA)-induced gingival overgrowth (GO) is related to expression nuclear factor of activated T cells-regulated genes (NFAT-regulated genes). MATERIAL AND METHODS: Expression of NFAT-regulated genes was determined in 36 transplant patients medicated with CsA by real-time PCR before and 2 h after drug intake and residual NFAT activity was estimated as ratio of both measurements. Demographic, periodontal and pharmacologic parameters were recorded and GO assessed from models. Subjects were divided into two groups according to the degree of GO (responders: GO score≥10%). Groups were compared using parametric and non-parametric tests. The association of various CsA-specific and periodontal parameters on incidence and extent of GO were determined using regression analysis. RESULTS: Responders had a more than twofold lower residual NFAT activity than non-responders (7.9% and 18.1%, respectively; p<0.001). Multiple regression analysis revealed gingival inflammation, salivary CsA concentration, and residual NFAT activity to be significant factors influencing the expression of GO. Seventy-seven percent of the variability of GO could be explained by these parameters. CONCLUSIONS: This study showed that pharmacodynamic parameters such as residual NFAT activity may be promising prognostic indicators to identify patients with increased risk for GO.

Transcriptional Analysis Reveals Key Genes in the Pathogenesis of Nifedipine-Induced Gingival Overgrowth.

BACKGROUND: Nifedipine-induced gingival overgrowth (NGO) is a multifactorial pathogenesis with increased extracellular matrix including collagen and glycans, inflammatory cytokines, and phenotype changes of fibroblasts. However, the molecular etiology of NGO is not well understood. The objective of this study is to investigate the key genes in the pathogenesis of NGO. METHODS: In this study, we examined the proliferation and migration abilities of fibroblasts derived from patients with chronic periodontitis, nifedipine nonresponder gingival overgrowth, gingival overgrowth caused by nifedipine, and healthy normal gingiva. We conducted RNA-Seq on these four groups of fibroblasts and analysed the differentially expressed genes (DEGs). RESULTS: Fibroblasts derived from NGO patients had higher proliferation and migration abilities than those of the other groups. Protein-protein interaction network analysis indicated that TGFB2, ITGA8, ITGA11, FGF5, PLA2G4D, PLA2G2F, PTGS1, CSF1, LPAR1, CCL3, and NKX3-1 are involved in the development of NGO. These factors are related to the arachidonic acid metabolism and PI3K/AKT signaling pathways. CONCLUSION: Transcriptional gene expression analysis identified a number of DEGs that might be functionally related to gingival overgrowth induced by nifedipine. Our study provides important information on the molecular mechanism underlying nifedipine-induced gingival overgrowth.

Role of MDR1 gene polymorphisms in gingival overgrowth induced by cyclosporine in transplant patients.

BACKGROUND AND 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. MATERIAL AND 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). CONCLUSION: 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.

Transforming growth factor-beta1 gene expression and cyclosporine A-induced gingival overgrowth: a pilot study.

AIMS: The relationship between gingival overgrowth (GO) induced by cyclosporine A (CsA) and transforming growth factor-beta1 (TGF-beta1) remains unclear. The aims of the present study were to evaluate TGF-beta1 gene expression under different immunosuppressive treatments and its association with TGF-beta1 gene functional polymorphism and GO in renal transplant recipients. MATERIAL AND METHODS: The study included 98 CsA-treated renal transplant recipients (with and without GO) and 44 tacrolimus-treated transplant patients (without GO). TGF-beta1 mRNA expression was measured using a real-time quantitative polymerase chain reaction assay. The levels were correlated with TGF-beta1 gene polymorphisms at codons 10 and 25, with different immunosuppressive treatment and GO. RESULTS: The level of TGF-beta1 gene expression was insignificantly lower in the CsA-treated group compared with the tacrolimus group, and significantly lower in the group with GO compared with patients without GO. In tacrolimus- and CsA-treated patients, but not in patients with GO, the level of TGF-beta1 gene expression was associated with functional phenotypes of TGF-beta1. The incidence, degree and extent of GO were higher in recipients with lower TGF-beta1 gene expression. CONCLUSIONS: Lower level TGF-beta1 gene expression, not functional polymorphism, in patients treated with CsA may be considered to be a risk factor for GO.

SPARC gene polymorphism in renal transplant patients with gingival overgrowth.

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

Systematic review of cyclosporin A-induced gingival overgrowth and genetic predisposition.

OBJECTIVE: This systematic review aimed to investigate the influence of gene polymorphisms on the development of gingival overgrowth in renal transplant patients treated with cyclosporin A. METHOD AND MATERIALS: Electronic and hand literature searches were conducted by two independent reviewers in MEDLINE-Pubmed, Cochrane Library, ISI Web of Science, and SCOPUS Elsevier for prospective (case-control studies, cohort studies), cross-sectional, and retrospective studies published up to June 2016 (first week) in any language. Data were reviewed and extracted in duplicate independently. Methodologic quality assessment of the included studies was performed during the data extraction process. RESULTS: Due to the estimated high risk of bias and the heterogeneity of the included studies in regards to the variety of medications administered to study patients, a systematic review of the literature and not a meta-analysis of the data was performed. Fourteen articles meeting study inclusion criteria were selected for data extraction that examined the association between various genetic polymorphisms and gingival overgrowth in kidney transplant patients receiving cyclosporin A. Interleukin-1A, interleukin-10, transforming growth factor-ß1 and androgen receptor gene polymorphisms may have a significant effect on an individual susceptibility to cyclosporin A-induced gingival overgrowth in renal transplant patients. CONCLUSION: Genetic polymorphisms seem to affect the development of cyclosporin A-induced gingival overgrowth in renal transplant patients. Pharmacogenetics and pharmacogenomics have the potential to determine the clinical outcome of a medication, the drug efficacy, and adverse drug reactions such as gingival overgrowth.

Lack of pathogenic mutations in SOS1 gene in phenytoin-induced gingival overgrowth patients.

OBJECTIVE: Gingival overgrowth is a side effect associated with some distinct classes of drugs, such as anticonvulsants, immunosuppressants, and calcium channel blockers. One of the main drugs associated with gingival overgrowth is the antiepileptic phenytoin, which affects gingival tissues by altering extracellular matrix metabolism. It has been shown that mutation of human SOS1 gene is responsible for a rare hereditary gingival fibromatosis type 1, a benign gingival overgrowth. The aim of the present study is to evaluate the possible contribution of SOS1 mutation to gingival overgrowth-related phenotype. DESIGN: We selected and screened for mutations a group of 24 epileptic patients who experienced significant gingival overgrowth following phenytoin therapy. Mutation scanning was carried out by denaturing high-performance liquid chromatography analysis of the entire coding region of the SOS1 gene. Novel identified variants were analyzed in-silico by using Alamut Visual mutation interpretation software, and comparison with normal control group was done. RESULTS: Mutation scanning of the entire coding sequence of SOS1 gene identified seven intronic variants and one new exonic substitution (c.138G>A). The seven common intronic variants were not considered to be of pathogenic importance. The exonic substitution c.138G>A was found to be absent in 100 ethnically matched normal control chromosomes, but was not expected to have functional significance based on prediction bioinformatics tools. CONCLUSIONS: This study represents the first mutation analysis of the SOS1 gene in phenytoin-induced gingival overgrowth epileptic patients. Present results suggest that obvious pathogenic mutations in the SOS1 gene do not represent a common mechanism underlying phenytoin-induced gingival overgrowth in epileptic patients; other mechanisms are likely to be involved in the pathogenesis of this drug-induced phenotype.

Lack of Association Between TGF-ß1 and MDR1 Genetic Polymorphisms and Cyclosporine-Induced Gingival Overgrowth in Kidney Transplant Recipients: A Meta-analysis.

BACKGROUND: Gingival overgrowth (GO) induced by cyclosporine (CsA), one of the common complications after kidney transplantation, is associated with a genetic component. However, the effect of TGF-ß1 and MDR1 gene polymorphisms on the pathogenesis of CsA-induced GO remains to be determined. This study aimed to determine the association between TGF-ß1 and MDR1 gene polymorphisms and CsA-induced GO in kidney transplant recipients. METHODS: The Pubmed, Embase, Cochrane Library, and Chinese CNKI (China National Knowledge Infrastructure) and Wanfang databases were comprehensively searched. Data were extracted and pooled results estimated from odds ratios (ORs) and 95% confidence intervals (CIs). In addition, quality assessment and publication bias of each eligible study were examined. RESULTS: Three trials focusing on the relationship between TGF-ß1 +869T>C and +915G>C and 3 studies on MDR1 C3435T gene polymorphisms and the onset of CsA-induced GO were included. No association between the +869T>C polymorphism and CsA-induced GO was found in the dominant model (TT+TC vs CC: OR, 0.77; 95% CI, 0.29-2.10; P = .614). In the recessive model, no association was found between the +915G>C polymorphism and CsA-induced GO (CC vs GG+GC: OR, 1.40; 95% CI, 0.81-2.43; P = .225). And in the dominant model, no significance was calculated between MDR1 C3435T gene polymorphisms and CsA-induced GO in kidney transplant recipients (TT vs CC+CT: OR, 1.14; 95% CI, 0.62-2.09; P = .68). CONCLUSIONS: No significant association exists between TGF-ß1 +869T>C, and +915G>C and MDR1 C3435T gene polymorphisms and the pathogenesis of CsA-induced GO in kidney transplant recipients.

Matrix metalloproteinase-1 gene polymorphism in renal transplant patients with and without gingival enlargement.

BACKGROUND: Gingival enlargement frequently occurs in transplant patients receiving immunosuppressive drugs. It was hypothesized that gingival enlargement associated with cyclosporin use results in a disturbance of the homeostatic balance, which is characterized by an increase in the number of fibroblasts and volume of the extracellular matrix. Matrix metalloproteinase (MMP) serves as an initiator of extracellular matrix destruction. The aim of this study was to determine whether there is an association between genotypes of the MMP-1 gene and gingival enlargement in kidney transplant patients. METHODS: Sixty-one unrelated kidney transplant patients with gingival enlargement and 121 control transplant patients without enlargement were enrolled in the study. Six months after transplantation, all patients were given medication, which included cyclosporin A, and gingival enlargement was assessed. MMP-1 polymorphism was determined using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. RESULTS: In kidney transplant patients with gingival enlargement, the mean score of gingival enlargement was 1.42+/-0.63, whereas in control subjects, it was 0.0. There were no significant differences in the frequency of -1607 1G>2G alleles and genotypes between patients with and without gingival enlargement. In all subjects (N=182) and in patients without gingival enlargement, the genotype distribution met Hardy-Weinberg equilibrium criteria, whereas in patients with gingival enlargement, it was markedly different (P<0.06). There was a trend for carriers of at least the 1G allele to have an increased risk of gingival enlargement, but the trend was not statistically significant (odds ratio, 2.32; P<0.073). CONCLUSION: No association between the MMP-1 gene polymorphism and gingival enlargement was revealed in kidney transplant patients who were administered cyclosporin A as a principal immunosuppressive agent.

The relationship of transforming growth factor-beta1 gene polymorphism, its plasma level, and gingival overgrowth in renal transplant recipients receiving different immunosuppressive regimens.

BACKGROUND: Cyclosporin A (CsA) induces gingival overgrowth (GO) in patients who seem to be prone to this disorder. It is still impossible to determine which patients will develop GO. Patients treated with the new immunosuppressive drug tacrolimus seem not to have GO. The aims of this study were to investigate transforming growth factor-beta1 (TGF-beta1) gene polymorphisms in renal transplant recipients treated with CsA or tacrolimus and to establish an association between these polymorphisms and TGF-beta1 plasma concentration and the incidence of GO. METHODS: The examined group consisted of 134 renal transplant recipients. Ninety-two underwent CsA treatment (50 with and 42 without GO), and 42 underwent tacrolimus treatment. Age, gender, time after transplantation, calcineurin inhibitor total dosage, number of teeth, and sulcus bleeding index were analyzed. TGF-beta1 plasma levels were estimated in 60 CsA- and 30 tacrolimus-treated patients. Two biallelic polymorphisms of the TGF-beta1 gene were studied at codon 10 (at position +869) and at codon 25 (at position +915) in patients from the examined group and in 108 healthy volunteers (the control group). RESULTS: The distribution of the high, intermediate, and low TGF-beta1 producer phenotypes was comparable in all the studied groups and in the healthy controls. The high producer phenotype was more frequent in patients with GO. TGF-beta1 levels in the CsA group showed correlation with the phenotypes. The lowest incidence of GO was observed in the 10C/C genotype, whereas the highest was observed in the 10T/C genotype. CONCLUSION: High and intermediate TGF-beta1 producer phenotypes and heterozygous genotype 10T/C might be considered risk factors for GO in patients treated with CsA.