Crevicular fluid levels of TGFbeta1 in drug-induced gingival overgrowth

OBJECTIVE: To determine if local, gingival crevicular fluid (GCF) levels of TGFbeta1 were altered in drug-induced gingival overgrowth. Patients and methods: GCF samples were collected on Periopaper strips from 45 renal transplant recipients who had been medicated with cyclosporin or cyclosporin in combination with other putative overgrowth-inducing drugs for a minimum of 6 months. Twenty-two subjects had gingival overgrowth while the other 23 patients showed no signs of gingival changes and constituted the medicated control group. Non-medicated controls consisted 20 periodontally healthy individuals who had never taken overgrowth-inducing drugs. GCF levels of TGFbeta1 and alkaline phosphatase, a marker of inflammation, were determined by enhanced chemiluminescence ELISA and enzyme activity assays, respectively. RESULTS: TGFbeta1 levels in GCF from overgrowth and non-overgrowth sites in overgrowth sufferers did not differ. However, there were significant differences in median concentration (P = 0.001) and GCF levels of TGFbeta1 per sample (P = 0.05) between study groups with overgrowth patients having higher amounts per sample and lower concentrations than medicated and healthy controls. Median levels of alkaline phosphatase per GCF sample differed between site (P = 0.01) with higher levels present at overgrowth sites. Despite this, the concentration of enzyme in GCF did not differ between site or patient group. CONCLUSIONS: GCF TGFbeta1 detected in overgrowth patients could reflect a higher level of gingival inflammation because of difficulties in plaque control consequent on the development of overgrowth. However, the higher local levels of total TGFbeta1 in overgrowth patients could indicate that it is a risk factor for developing gingival overgrowth.     

Salivary proteins and cytokines in drug-induced gingival overgrowth

Little is known about the involvement of saliva in gingival overgrowth (GO). It was hypothesized that, in this situation, the composition of saliva is altered. Thus, proteins, albumin, cytokines, and growth factors in whole and glandular saliva were investigated. Differences between glandular and gingival contributions to the composition of saliva were explored in patients medicated with cyclosporin who exhibited GO (responders), those without GO (non-responders), and non-medicated subjects (controls). In whole saliva, interleukin-1alpha (IL-1alpha), IL-6, IL-8, epidermal growth factor (EGF), nerve growth factor (NGF), and albumin were detected, but in glandular saliva only EGF and NGF were identified. Albumin and IL-6 differed significantly between responders and controls, although the overall profile of salivary proteins remained unchanged. Thus, inflammatory cytokines and albumin are confined to whole saliva and are associated with GO, whereas its content of EGF and NGF appears unaffected by cyclosporin.     

Expression of fibronectin-binding integrins in gingival epithelium in drug-induced gingival overgrowth

BACKGROUND AND OBJECTIVE: Gingival overgrowth is a side-effect of nifedipine and cyclosporin medications. Integrins are transmembrane glycoproteins that mediate cell adhesion, regulate cell proliferation and participate in the regulation of tissue fibrosis. The aim of this study was to investigate whether expression of epithelial cell integrins is linked to the development of drug-induced gingival overgrowth. MATERIAL AND METHODS: Human gingival biopsies of patients taking nifedipine, cyclosporin, or a combination of both medications, were used. Expression of the alpha5beta1, alphavbeta1 and alphavbeta6 integrins, and of cellular extra domain A of fibronectin, was localized in frozen sections using immunohistochemistry. RESULTS: The activated conformation of the beta1, alpha5beta1 and alphavbeta6 integrins were more frequently expressed in distinct locations in the oral epithelium in the combined drug group. Cellular extra domain A of fibronectin, a ligand for both alpha5beta1 and alphavbeta6 integrins, was expressed within the connective tissue of all groups. It was also expressed around the basal keratinocytes of the control, nifedipine and cyclosporin-induced gingival overgrowth groups, but not in the combined medication group. No relationship between the presence of inflammation and integrin expression was found. CONCLUSION: The results indicate that expression of certain integrins is up-regulated in the epithelium of drug-induced gingival overgrowth where they could participate in controlling the formation of elongated rete ridges and tissue fibrosis.     

TGF-β isoforms and TGF-β receptors in drug-induced and hereditary gingival overgrowth

Drug therapy and hereditary factors are two of the main causes of gingival overgrowth (GO). Both of these forms of GO are associated with increased extracellular matrix production by fibroblasts. Transforming growth factor beta (TGF-beta) is an important mediator of wound healing and tissue regeneration, which stimulates fibroblasts to produce extracellular matrix materials. The aim of this immunohistochemical study was to determine whether there is any altered expression of TGF-beta isoforms or its receptors in tissue from patients with drug-induced GO (DIGO; n=10) and hereditary gingival fibromatosis (n=10) when compared to non-overgrowth tissue (n=10). Compared to control tissues, significantly more fibroblasts expressed TGF-beta1 in both DIGO and hereditary gingival fibromatosis tissues (P<0.03). Cells expressing TGF-beta2 were present at control levels in DIGO but were significantly reduced in hereditary gingival fibromatosis (P<0.02). By contrast, the number of TGF-beta3-positive cells was the same in overgrowth tissues and controls. However, because of differences in total fibroblast densities between groups, there was a proportional increase in TGF-beta3 as well as TGF-beta1 expressing cells within both overgrowth populations (P<0.0001). Furthermore, representation of the TGF-beta2-positive phenotype was reduced in hereditary gingival fibromatosis (P<0.01) but increased in DIGO (P<0.005) compared to controls. Absorbance measurements of the positive cell populations showed that the level of expression was significantly higher for TGF-beta1 in hereditary gingival fibromatosis (P<0.002) and significantly lower for TGF-beta3 in DIGO (P<0.03). No significant differences in the numbers of TGF-betaRI- or RII-positive cells were detected between overgrowth tissues and controls. However, there were increases in the proportion of receptor-positive cells in the total cell population analysed in overgrowth tissues (P<0.0001). These results indicate qualitative and quantitative differences in TGF-beta isoform and receptor expression by fibroblasts in gingival overgrowth that may contribute to disease pathogenesis.     

Connective tissue growth factor in drug-induced gingival overgrowth

BACKGROUND: Drug-induced gingival overgrowth is a known side effect of certain chemotherapeutic agents used for the treatment of systemic disorders. The pathogenesis and mechanisms responsible for this condition are not fully understood. This study assesses for the presence and localization of connective tissue growth factor (CTGF) in drug-induced gingival overgrowth tissues. CTGF immunostaining was compared with sections stained with transforming growth factor (TGF)-beta1 and CD31 antibodies in order to investigate possible pathogenic mechanisms. METHODS: Gingival overgrowth samples were obtained from patients undergoing therapy with phenytoin (n = 9), nifedipine (n = 4), cyclosporin A (n = 5), and control tissues from systemically healthy donors (n = 9). Tissue sections were subjected to peroxidase immunohistochemistry and were stained with CTGF and TGF-beta1 polyclonal primary antibodies. Possible relationships between CTGF staining and angiogenesis were also studied using an anti-CD31 antibody as a marker for endothelial cells. Staining was analyzed by computer-assisted quantitative and semiquantitative methodology at 5 defined sites in all samples based on the location of specific landmarks including epithelium and underlying connective tissues. RESULTS: Cellular and extracellular CTGF content in phenytoin gingival overgrowth tissues was significantly (P<0.05) higher compared to the other gingival overgrowth tissues and the controls. Higher CTGF staining in phenytoin gingival overgrowth tissues was accompanied by an increased abundance of fibroblasts and connective tissue fibers. No strong association of CTGF staining with TGF-beta1 or CD31 staining was found. CONCLUSIONS: The data from the present study show significantly higher CTGF staining in phenytoin-induced gingival overgrowth tissues compared to controls, cyclosporin A-, or nifedipine-induced gingival overgrowth. Moreover, semiquantitative analyses of histologic samples support the concept that the phenytoin overgrowth tissues are fibrotic. These associations suggest a possible role for CTGF in promoting development of fibrotic lesions in phenytoin-induced gingival overgrowth.     

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

OBJECTIVE: To investigate possible associations between platelet-derived growth factor (PDGF), PDGF receptor expression and macrophages in drug-induced and hereditary gingival overgrowth. MATERIALS AND METHODS: Tissues from patients with drug-induced gingival overgrowth (DIGO) (n = 10) and hereditary gingival fibrosis (n = 10) were studied and compared with 'control' gingiva (n = 10). Expression of PDGF and its alpha and beta receptors was investigated immunohistochemically and by RT-PCR. Macrophages were identified by immunostaining for CD68. RESULTS: PDGF isoforms and receptors were detected in most cells within all specimens. There were no differences in the numbers of macrophages, or fibroblasts expressing PDGF or receptors, between groups. The level of PDGF expression by fibroblasts, determined by absorbance measurements, was similar between groups for PDGF A. Significantly lower levels of total PDGF and the receptors were detected in drug-induced overgrowth compared to those in hereditary fibrosis (P < 0.004) and control specimens (P < 0.034). All specimens expressed mRNA for PDGF A, PDGF B and alpha and beta receptors. CONCLUSIONS: These data do not support a pivotal role for macrophage-derived PDGF B in the pathogenesis of DIGO. They suggest that fibroblasts in drug-induced lesions have a lowered capacity to produce, and respond to, PDGF, a property not shared by fibroblasts associated with hereditary fibrosis.     

五种牙周致病菌与药物性牙龈增生的关系

目的 探讨牙周致病菌在药物性牙龈增生发展过程中的作用评价57例服用环孢素的肾移植患者的牙龈增生(gingival overgrowth,GO)指数,将GO指数为1、2、3的患者列为牙龈增生组(A组,28例),将GO指数为0的患者列为牙龈未增生组(B组,29例),采用实时聚合酶链反应(PCR)技术对龈下菌斑内的牙龈卟啉单孢菌(Porphyromonas gingivdis,Pg)、伴放线放线杆菌(Actinobacillus actinomycetemcomitans,Aa)、中间普氏菌(Prevotella intermedia,Pi)、齿垢密螺旋体(Treponema denticola,Td)和福赛氏类杆菌(Tannerella forsythia,Tf)进行定量检测,比较两组患者中细菌检出率的差异,并分析细菌数量和牙龈增生的严重程度之间的相关性.结果 Pg、Td和Tf的检出率在A组分别为96%、82%和89%,均显著高于B组(分别为69%、55%和66%),差异有统计学意义(P<0.05);同时检测出Pg、Td和Tf的概率在A组(79%)明显高于B组(38%),差异有统计学意义(P<0.01);Pg、Td、Tf和Pi的细菌数量随着牙龈增生指数的升高而增加,Aa的细菌数量未发现与牙龈增生相关的变化.结论 Pg、Td和Tf可能在药物性牙龈增生发展过程中起着重要的作用.     

药物性牙龈肥大发病机制的研究进展

药物性牙龈肥大(DIGO)主要由长期服用苯妥英钠、环孢素A、硝苯地平引起,不仅影响牙面的清洁与美观和牙齿正常生理功能,而且可能造成患者心理上的障碍。然而,DIGO发病机制复杂,无法明确,导致治疗较为棘手。许多学者对其进行了多方面的研究,提出许多观点与假设,包括胶原生成与降解失衡机制、炎症等。该文从分子机制与药物具体机制两方面总结了近几年对DIGO发病的研究,并对DIGO未来的研究方向进行探讨,希望能够对DIGO的预防与临床治疗有所帮助。     

Disposition of nifedipine in plasma and gingival crevicular fluid in relation to drug-induced gingival overgrowth

The present study investigates the relationship between the pharmacokinetic variables of nifedipine with the incidence and severity of gingival overgrowth in 9 adult male patients medicated with the drug for at least 6 months. Five of the patients had experienced significant gingival changes and were thus designated "responders". The remaining four patients exhibited no gingival overgrowth, and thus acted as a control. A baseline periodontal examination (plaque scores, bleeding index and gingival overgrowth assessment) was carried out on each patient, and confined to the upper and lower anterior teeth. Serial blood and gingival crevicular fluid samples were collected over an eight-hour investigation period. Samples were analyzed for nifedipine by gas chromatography. No significant difference (p>0.05) was seen between responders and non-responders with regard to drug therapy, periodontal parameters or plasma pharmacokinetics of nifedipine. Nifedipine was detected in the gingival crevicular fluid of seven subjects (all responders, and two non-responders). The peak concentration of nifedipine in crevicular fluid was 15–90 fold greater than levels observed in plasma.     

药物性牙龈增生发病机制的研究进展

药物性牙龈增生是指服用抗癫痫药、钙通道阻滞剂和免疫抑制剂等某些特定药物引起的牙龈增生和体积增大,具有共同的病理组织学特点,其发病机制目前仍无定论。下面就药物性牙龈增生在胶原的合成与降解失衡、上皮细胞的增殖和程序性细胞死亡以及上皮下炎症浸润机制上取得的研究进展作一综述。     

Alpha 2 integrin +807 polymorphism in drug-induced gingival overgrowth

Alpha2 integrin on fibroblasts is reported to play an important role in the induction of drug-induced gingival overgrowth, which is characterized by excessive accumulation of type I collagen in gingival connective tissue. Silent polymorphism 807 T/C within the alpha2 integrin gene is associated with high/low alpha2 integrin expression. The aim of this study was to test the hypothesis that expression of alpha2 integrin 807 T/C polymorphism correlates with drug-induced gingival overgrowth. A case-control study comparing 136 subjects taking calcium channel blockers (72 with vs. 64 without drug-induced gingival overgrowth) demonstrated that the frequency of the +807 C allele was significantly higher in the case group than in the controls (odds ratio, 3.61; 95% confidence interval, 2.14 - 6.10; P < 0.05). The present findings suggest that the alpha2 +807 C allele is one of the genetic risk factors for drug-induced gingival overgrowth.     

Analysis of changes in gingival contour from three-dimensional co-ordinate data in subjects with drug-induced gingival overgrowth

OBJECTIVES: This aim of this study was to develop and assess a technique that could be used to assess accurately the gingival volume changes seen in drug-induced gingival overgrowth by the analysis of data obtained from an entire gingival surface by means of three-dimensional imaging. MATERIAL AND METHODS: Stone dental models of patients before and after gingivectomy procedures were digitized with a laser scanner and then regenerated as computer models constructed from the acquired three-dimensional co-ordinate data. A comparison of superposed "before" and "after" surfaces was undertaken to assess and accurately quantify changes in gingival contour. RESULTS: The mean vertical tissue reduction varied from 1.58 to 2.56 mm in the four study subjects and individual differences are shown. The maximum thickness of removed buccal gingival overgrowth was found to range between 1.20 and 3.40 mm. The volume of tissue removed from each inter-dental papilla ranged from 4.2 to 46.1 mm3 and the mean volume of the papilla removed from each subject+/-SD values was 24.8+/-13.1 mm3. CONCLUSION: This method will measure changes in gingival tissues to within 60 microm in one plane, making it ideal for the assessment of longitudinal changes in gingival contour as seen in the development of gingival overgrowth, its recurrence after surgery or the changes in volume brought about by surgery.     

Antibiotic treatment of incipient drug-induced gingival overgrowth in adult renal transplant patients

BACKGROUND: Drug-induced gingival overgrowth (GO) remains a challenge in periodontics. Partial and total regressions of this GO have been reported after a short course of antibiotics. METHODS: We conducted a double-blinded controlled randomised study to determine the effect of metronidazole (MNZ) or azithromycin (AZM) on the regression of incipient cyclosporin A-induced GO in 40 adult renal transplanted patients. The quantitation of the GO was performed with Image Digital Analysis. RESULTS: None of the patients with GO showed complete remission after 30 days. The pretreatment GO index was 0.895 +/- 0.16 in the metronidazole treatment group (MNZ group, n = 13), 0.932 +/- 0.11 in the azithromycin treatment group (AZM group, n = 14), and 1.073 +/- 0.32 in the controls (placebo group, n = 13). At the end of the study (30 days), the GO index score was lower in 54.4% and 62.3% of the MNZ and AZM groups, respectively, and the mean score differences were statistically significant between the groups (0.897 +/- 0.28, MNZ group vs. 0.909 +/- 0.15, AZM group vs. 1.130 +/- 0.3, placebo group, P < 0.05 ANOVA). CONCLUSIONS: A 7-day course of MNZ or AZM does not induce remission of CsA-induced GO, although it acts on concomitant bacterial over-infection and gingival inflammation.     

药物性牙龈增生与胶原代谢失衡的相关性研究进展

药物性牙龈增生(drug-induced gingival overgrowth,DIGO)是指长期服用某些特定药物而引起的牙龈纤维性增生和体积增大,其发病机制尚不清楚。目前研究表明,胶原的合成和降解失衡与药物性牙龈增生有密切关系。本文就药物性牙龈增生与胶原代谢失衡的相关研究进展作一综述。     

环孢素A诱导牙龈增生动物模型的建立及其病理学表现

目的:建立环孢素A(CyclosporinACsA)诱导的牙龈增生小鼠动物模型,观察其病理学表现,并进行组织测量,确定其可靠性。方法:将CsA溶于橄榄油中,按 30mgCsA/kg体重 /d胃饲远交群ICR雄性小鼠,分别在给药 2、4、6、8周时,随机取实验组小鼠下颌前部标本,体视显微镜下测量其下颌前牙龈体积;制作切片,光镜下观察其牙龈病理表现,并利用图象分析系统测量舌侧牙龈缘上皮厚度。结果:小鼠经胃饲 30mg/kg体重 /d的CsA,①4周后,肉眼见部分下颌前牙舌侧牙龈球形肥大;②体视显微镜下牙龈体积测量显示下颌前牙舌侧牙龈 4周至 8周明显增大(P<0. 01);③此时光镜下开始出现明显的牙龈增生病理表现:上皮增厚,上皮钉突明显且变宽,牙龈结缔组织增厚,基质和成纤维细胞增生,血管扩张等。④龈缘上皮厚度测量 2周时上皮增厚(P<0. 01), 4周增厚更明显(P<0. 001),持续至 8周。结论:胃饲小鼠CsA可诱导牙龈增生,其病理表现与其他动物模型和临床病理一致,该模型有一定可靠性,可用于进一步研究CsA诱导的牙龈增生的发病机理。     

Effects of combined oral treatments with cyclosporine A and nifedipine or diltiazem on drug-induced gingival overgrowth in rats

BACKGROUND: Cyclosporine A (CsA) and calcium channel blockers induce gingival overgrowth in humans and animals. Recently, nifedipine and diltiazem have often been used to control CsA-related hypertension in organ transplant patients. The purpose of this study was to examine the effects of a combined oral treatment of CsA and nifedipine or diltiazem on the severity of gingival overgrowth in rats. METHODS: Fifteen-day-old Fischer rats were treated orally with single or combined applications of CsA, nifedipine, and/or diltiazem for 40 days; and induced gingival overgrowth, rat growth, and blood drug levels were compared among the different experimental groups. The experiment consisted of 6 groups: one control group (group A) and 5 test groups treated with CsA (group B), nifedipine (group C), and diltiazem (group D), as well as those concurrently treated with CsA and nifedipine (group E), and CsA and diltiazem (group F). Gingival overgrowth was determined by measuring the depth of the gingival sulcus. RESULTS: The mandibular buccal gingival sulcus depth of group A was 365 +/- 41.2 microm. Among the test groups, the most remarkable gingival overgrowth was seen in group E (1,020 +/- 63.3 microm), followed by group F (895 +/- 43.8 microm), group B (870 +/- 48.3 microm), group C (525 +/- 116 microm), and then group D (505 +/- 83.2 microm). Rat body weight gain was reduced significantly by oral CsA treatment. Neither nifedipine nor diltiazem suppressed rat growth when used independently; however, rat growth reduced by CsA was further suppressed by a combined use of diltiazem, but not nifedipine. CsA blood levels were reduced by concurrent oral treatment with nifedipine or diltiazem along with the blood levels of those calcium channel blockers when treatment was in combination with CsA. CONCLUSIONS: These results suggest that gingival overgrowth is induced in rats as a side effect of CsA, nifedipine, or diltiazem, and the combined use of these drugs influences rat growth, blood drug levels, and the severity of gingival overgrowth.     

Effectiveness of periodontal therapy in patients with drug-induced gingival overgrowth. Long-term results.

BACKGROUND: Drug-induced gingival overgrowth (DGO) is one of the well-recognized side effects of cyclosporin A (CsA) or nifedipine (Ni). After surgical periodontal therapy, the incidence of DGO recurrence is not known. The aim of this study was to evaluate the results of surgical periodontal therapy in patients receiving CsA or Ni and who exhibit severe long-term DGO. In addition, the relationship between various variables and the recurrence of severe DGO after periodontal surgery was investigated. METHODS: A total of 38 patients, 22 with CsA-induced DGO and 16 with Ni-induced DGO, were included in this study. At baseline, patients received initial periodontal therapy, after which either the upper or lower anterior segment in each patient was surgically treated. Surgical periodontal therapy consisted of the flap technique with a 90 degrees gingivectomy incision. Following surgery, patients were placed on a maintenance therapy recall program and were monitored for 18 months. Patients were seen once a month for the first 3 months and once every 3 months for the following 15 months. Plaque index (PI), papilla bleeding index (PBI) and DGO scores in the treated segments were recorded at each recall appointment. Attendance at recall appointments was also noted for each patient. RESULTS: Recurrence of severe DGO was observed in 13 of the 38 patients (34%) 18 months following periodontal surgery. Multiple regression analysis indicated that age, gingival inflammation, and attendance at recall appointments were significant determinants of the recurrence of severe DGO. CONCLUSIONS: This study suggests that regular re-motivation and professional care at frequent recall appointments after periodontal surgery are of great importance in patients receiving CsA or Ni. By maintaining periodontal health, the life quality of these patients may be raised.