Some effects of non-surgical therapy on gingival inflammatory cell subsets in patients with adult and early-onset periodontitis

Differences between inflammatory and catabolic mediators of peri-implantitis and periodontitis lesions following initial mechanical therapy: An exploratory study

BACKGROUND AND OBJECTIVE

The aim of this study was to analyze the differences in inflammatory and catabolic mediators expressed in peri-implantitis compared to periodontitis lesions after non-surgical therapy. Peri-implantitis is associated with a faster rate of bone loss when compared with periodontitis, and peri-implant non-surgical therapy is ineffective to cure peri-implantitis. This may be due to persistent inflammation in peri-implantitis tissues after initial mechanical treatment.

MATERIAL AND METHODS

Eleven patients with peri-implantitis and 10 with severe chronic periodontitis received non-surgical therapy. They were included at re-evaluation (8 weeks) if they presented pocket depth ≥6 mm with bleeding on probing, and the indication for open flap debridement surgery. Connective tissues were harvested during surgery from diseased sites. Healthy gingiva were harvested during third molar extraction in a third group of healthy patients (n=10). Explants were incubated for 24 hours in media culture and the release of cytokines, chemokines, growth factors, osteoprotegerin, receptor activator of nuclear factor kappa-B ligand (RANKL), matrix metalloproteinase and tissue inhibitors of matrix metalloproteinase (TIMP) in the conditioned media was analyzed by an exploratory multiplex immunoassay. When difference was found in the conditioned media, an immunohistochemistry was performed to compare expression in the tissues.

RESULTS

Connective tissues from non-stabilized peri-implantitis exhibited a distinct cytokine profile compared to periodontitis lesions that did not respond to initial therapy. Indeed, TIMP-2 was significantly increased in media from peri-implantitis (P≤.05). In addition, the in situ expression of TIMP-2, interleukin-10 and RANKL was also significantly increased in peri-implantitis tissues (P≤.05). However, the ratio of RANKL/osteoprotegerin-positive cells did not vary (P≥.05).

CONCLUSION

This study suggests that peri-implantitis and periodontitis connective tissues exhibit differences in response to non-surgical treatment, which may contribute to a different pattern of disease evolution.

The B Cell-Stimulatory Cytokines BLyS and APRIL Are Elevated in Human Periodontitis and Are Required for B Cell-Dependent Bone Loss in Experimental Murine Periodontitis

B-lineage cells (B lymphocytes and plasma cells) predominate in the inflammatory infiltrate of human chronic periodontitis. However, their role in disease pathogenesis and the factors responsible for their persistence in chronic lesions are poorly understood. In this regard, two cytokines of the TNF ligand superfamily, a proliferation-inducing ligand (APRIL) and B-lymphocyte stimulator (BLyS), are important for the survival, proliferation, and maturation of B cells. Thus, we hypothesized that APRIL and/or BLyS are upregulated in periodontitis and contribute to induction of periodontal bone loss. This hypothesis was addressed in both human and mouse experimental systems. We show that, relative to healthy controls, the expression of APRIL and BLyS mRNA and protein was upregulated in natural and experimental periodontitis in humans and mice, respectively. The elevated expression of these cytokines correlated with increased numbers of B cells/plasma cells in both species. Moreover, APRIL and BLyS partially colocalized with κ L chain-expressing B-lineage cells at the epithelial-connective tissue interface. Ligature-induced periodontitis resulted in significantly less bone loss in B cell-deficient mice compared with wild-type controls. Ab-mediated neutralization of APRIL or BLyS diminished the number of B cells in the gingival tissue and inhibited bone loss in wild-type, but not in B cell-deficient, mice. In conclusion, B cells and specific cytokines involved in their growth and differentiation contribute to periodontal bone loss. Moreover, APRIL and BLyS have been identified as potential therapeutic targets in periodontitis.

Generalized Aggressive Periodontitis Associated With a Plasma Cell Gingivitis Lesion: A Case Report and Non-Surgical Treatment

INTRODUCTION

Plasma cell gingivitis (PCG) is an unusual inflammatory condition characterized by dense, band-like polyclonal plasmacytic infiltration of the lamina propria. Clinically, it appears as gingival enlargement with erythema and swelling of the attached and free gingiva and is not associated with any loss of attachment. The aim of this report is to present a rare case of severe generalized aggressive periodontitis (GAgP) associated with a PCG lesion that was successfully treated and maintained non-surgically.

CASE PRESENTATION

A 32-year-old white male with a non-contributory medical history presented with gingival enlargement with diffuse erythema and edematous swelling, predominantly around teeth #5 through #8. Clinical and radiographic examination revealed generalized severe periodontal breakdown. A complete blood count and biochemical tests were within normal limits. Histologic and immunohistochemical examination were consistent with PCG. A diagnosis of severe GAgP associated with a PCG lesion was assigned. Treatment included elimination of possible allergens and non-surgical periodontal treatment in combination with azithromycin. Clinical examination at reevaluation revealed complete resolution of gingival enlargement, erythema, and edema and localized residual probing depths of 5 mm. One year after treatment, the clinical condition was stable. Radiographs indicated improved bone levels and formation of crestal lamina dura.

CONCLUSION

This case report highlights the unusual coexistence of GAgP and PCG, in which non-surgical treatment with elimination of all possible causes in combination with antimicrobials resulted in elimination of the gingival enlargement and significant improvement of periodontal parameters.

Gene expression in periodontal tissues following treatment

BACKGROUND

In periodontitis, treatment aimed at controlling the periodontal biofilm infection results in a resolution of the clinical and histological signs of inflammation. Although the cell types found in periodontal tissues following treatment have been well described, information on gene expression is limited to few candidate genes. Therefore, the aim of the study was to determine the expression profiles of immune and inflammatory genes in periodontal tissues from sites with severe chronic periodontitis following periodontal therapy in order to identify genes involved in tissue homeostasis.Gingival biopsies from 12 patients with severe chronic periodontitis were taken six to eight weeks following non-surgical periodontal therapy, and from 11 healthy controls. As internal standard, RNA of an immortalized human keratinocyte line (HaCaT) was used. Total RNA was subjected to gene expression profiling using a commercially available microarray system focusing on inflammation-related genes. Post-hoc confirmation of selected genes was done by Realtime-PCR.

RESULTS

Out of the 136 genes analyzed, the 5% most strongly expressed genes compared to healthy controls were Interleukin-12A (IL-12A), Versican (CSPG-2), Matrixmetalloproteinase-1 (MMP-1), Down syndrome critical region protein-1 (DSCR-1), Macrophage inflammatory protein-2beta (Cxcl-3), Inhibitor of apoptosis protein-1 (BIRC-1), Cluster of differentiation antigen 38 (CD38), Regulator of G-protein signalling-1 (RGS-1), and Finkel-Biskis-Jinkins murine osteosarcoma virus oncogene (C-FOS); the 5% least strongly expressed genes were Receptor-interacting Serine/Threonine Kinase-2 (RIP-2), Complement component 3 (C3), Prostaglandin-endoperoxide synthase-2 (COX-2), Interleukin-8 (IL-8), Endothelin-1 (EDN-1), Plasminogen activator inhibitor type-2 (PAI-2), Matrix-metalloproteinase-14 (MMP-14), and Interferon regulating factor-7 (IRF-7).

CONCLUSION

Gene expression profiles found in periodontal tissues following therapy indicate activation of pathways that regulate tissue damage and repair.

Immunohistochemical evaluation of the inflammatory response in periodontal disease

In order to contribute to the knowledge of the pathogenesis of periodontal disease, an immunohistochemical analysis of the density of inflammatory mononucleated cells and the number of dendritic cells was performed using anti-CD4, anti-CD20, anti-CD25, anti-CD68 and anti-protein S-100 antibodies in 17 cases of chronic gingivitis (CG) and 25 of chronic periodontitis (CP). The CD4+ and CD68+ cells exhibited a diffuse distribution in the connective tissue. CD20+ cell distribution was predominantly in groups and the CD25+ cells exhibited a diffuse or focal distribution. The S-100+ cells were identified in the epithelium and the lamina propria, exhibiting distinct morphology and number. The statistical analysis showed no significant differences (p>0.05) between CG and CP regarding the density of the CD4+ and CD20+ cells and the number of S-100+ cells. However, significant differences (p<0.05) were found between the groups in the density of CD25+ and CD68+ cells . The density of macrophages was greater in CG and the level of cellular activation of the lymphocyte infiltrate was greater in CP. No differences were detected between the aforementioned conditions regarding the density of the T and B lymphocytes and to the number of the dendritic cells.

Increased release of IL-12p70 by monocytes after periodontal therapy

OBJECTIVES

It has been suggested that periodontal inflammation may result in an altered immune response. The peripheral immune capacity in periodontitis patients can be investigated using lipopolysaccharide (LPS)-stimulated whole blood cell cultures (WBCC), known to reflect the behavior of monocytes in particular. A previous study in our laboratory revealed that monocytes in the stimulated cultures from periodontitis patients behaved functionally different compared with controls. The present study investigated whether this different response of periodontitis patients' monocytes is intrinsic or acquired.

MATERIAL AND METHODS

The release of inflammatory mediators was measured in Escherichia coli LPS-stimulated WBCC from 12 periodontitis patients before and after periodontal therapy. In addition, the total leukocyte and leukocyte differentiation counts were also determined in the patients before and after therapy.

RESULTS

The levels of interleukin (IL)-12p70 in cell culture supernatants increased two times and those of prostaglandin E2 showed a trend towards reduction after therapy, whereas the levels of IL-1beta, IL-6, IL-8, IL-10, IL-12p40 and tumor necrosis factor-alpha did not change. The total number of white blood cells was decreased after periodontal therapy.

CONCLUSIONS

After periodontal therapy, the functional phenotype of the peripheral blood monocytes from patients was reconstituted, resembling that of subjects without periodontitis.

Prevalence of Human Herpesviruses in Patients with Aggressive Periodontitis

BACKGROUND

Recent studies have demonstrated that various human viruses, especially cytomegalovirus (HCMV) and Epstein-Barr virus type-1 (EBV-1), seem to play a part in the pathogenesis of human periodontitis. The aim of this investigation was to evaluate the subgingival presence of HCMV and EBV in patients with aggressive periodontitis (AgP) and healthy subjects and to examine the effect of treatment on the incidence of these viruses 3 months following surgery.

METHODS

A polymerase chain reaction (PCR) method determined the presence of HCMV and EBV-1. Subgingival plaque samples from 17 consecutive AgP patients and 16 healthy controls were collected. The following indices were measured: plaque index (PI), gingival index (GI), probing depths (PD), and clinical attachment loss (CAL). Clinical parameters were assessed pretherapy and at 3 months following surgical and antimicrobial therapy.

RESULTS

HCMV was detected in 64.7% of AgP patients but not detected in healthy subjects (P < 0.001) and EBV-1 in 70.6% of AgP patients and 6.3% of the healthy controls (P < 0.001). HCMV and EBV-1 coinfection was detected in 41.7% of AgP patients. A statistically significant decrease was found in all clinical parameters 3 months after treatment. There was a statistically significant decrease in HCMV and EBV-1 following therapy (P < 0.001; no HCMV; 1 patient with EBV-1).

CONCLUSIONS

These findings indicate that subgingival presence of EBV-1 HCMV is strongly associated with aggressive periodontitis, and coinfection with HCMV and EBV-1 appears to be particularly deleterious to periodontal health.

Some effects of non-surgical therapy on gingival inflammatory cell subsets in patients with early-onset periodontitis associated with Actinobacillus actinomycetemcomitans

BACKGROUND

Limited information is available as to whether local cellular immunity in early-onset periodontitis (EOP) subjects harboring Actinobacillus actinomycetemcomitans (Aa) differs from that in patients without Aa. In addition, the effect of scaling and root planing on various lymphocyte subsets is described rather sparsely.

METHODS

In 10 subjects with early-onset periodontitis harboring Aa (EOP-Aa) and in 10 subjects without Aa (EOP-nonAa), clinical measurements were recorded and gingival biopsies were performed before and after scaling and root planing. The specimens were cut into serial sections; using the alkaline phosphatase-antialkaline phosphatase technique, monoclonal antibodies to CD20 (B cells), CD30 (plasma cells), and CD45RO (T-memory cells) were applied as well as polyclonal antibodies to alpha, gamma, and mu chains (Ig A, G, and M). Cells were counted from an area of 0.25 mm2 in areas showing the largest infiltration.

RESULTS

Before therapy, mean counts of all cell phenotypes were found to be markedly enhanced in the EOP-Aa group compared to EOP-nonAa subjects. Following scaling and root planing, the numbers of all phenotypes decreased in both groups. However, comparing the data before and after therapy in the EOP-Aa group, the P value was <0.05 only for CD30-positive cells. In the EOP-nonAa group, the differences before and after therapy reached statistical significance (P<0.05) for all cell counts, except for IgM-positive cells. Furthermore, reduction of probing depth and gain of clinical attachment reached the 0.05 level of statistical significance only in EOP-nonAa subjects.

CONCLUSIONS

In EOP subjects harboring Aa, inflammatory cell subsets were detected in 2- to 3-fold higher numbers compared to patients without Aa. Scaling and root planing resulted in a decrease of all cell phenotypes studied in individuals without Aa, whereas in subjects with Aa, the only significant decrease that was seen occurred in plasma cells.