Giacomo Oteri

Effects of etanercept, a tumour necrosis factor‐α antagonist, in an experimental model of periodontitis in rats

Etanercept is a tumour necrosis factor antagonist with anti‐inflammatory effects. The aim of our study was to evaluate, for the first time, the therapeutic efficacy of in vivo inhibition of TNF‐α in an experimental model of periodontitis.

Staging of osteonecrosis of the jaw requires computed tomography for accurate definition of the extent of bony disease

Management of osteonecrosis of the jaw associated with antiresorptive agents is challenging, and outcomes are unpredictable. The severity of disease is the main guide to management, and can help to predict prognosis. Most available staging systems for osteonecrosis, including the widely-used American Association of Oral and Maxillofacial Surgeons (AAOMS) system, classify severity on the basis of clinical and radiographic findings. However, clinical inspection and radiography are limited in their ability to identify the extent of necrotic bone disease compared with computed tomography (CT). We have organised a large multicentre retrospective study (known as MISSION) to investigate the agreement between the AAOMS staging system and the extent of osteonecrosis of the jaw (focal compared with diffuse involvement of bone) as detected on CT. We studied 799 patients with detailed clinical phenotyping who had CT images taken. Features of diffuse bone disease were identified on CT within all AAOMS stages (20%, 8%, 48%, and 24% of patients in stages 0, 1, 2, and 3, respectively). Of the patients classified as stage 0, 110/192 (57%) had diffuse disease on CT, and about 1 in 3 with CT evidence of diffuse bone disease was misclassified by the AAOMS system as having stages 0 and 1 osteonecrosis. In addition, more than a third of patients with AAOMS stage 2 (142/405, 35%) had focal bone disease on CT. We conclude that the AAOMS staging system does not correctly identify the extent of bony disease in patients with osteonecrosis of the jaw.

Bisphosphonate-Associated Osteonecrosis of the Jaw in Patients with Multiple Myeloma and Breast Cancer

Osteonecrosis of the jaw is an unremitting adverse outcome associated with bisphosphonate therapy in patients with multiple myeloma or bone metastases from solid tumors. Twelve patients who presented with exposed bone associated with bisphosphonates were reviewed to determine the type, dosage and duration of their bisphosphonate therapy, presenting findings, comorbidities and the event that incited the bone exposure. The discontinuation of bisphosphonate therapy has not helped reverse the presence of osteonecrosis, and the surgical manipulation of the involved site appears to worsen the underlying bone pathology. Hyperbaric oxygen, which has proven efficacious in other forms of osteonecrosis by establishing an oxygen gradient, is of no definitive benefit to patients with bisphosphonate-induced exposed bone. Antibiotic therapy is useful in controlling pain and swelling but ineffective in preventing the progression of the exposed bone. To date, prevention is the only currently possible therapeutic approach to the management of this complication.

Up to a quarter of patients with osteonecrosis of the jaw associated with antiresorptive agents remain undiagnosed.

Recent data suggest that the traditional definition of bisphosphonate-associated osteonecrosis of the jaw (ONJ) may exclude patients who present with the non-exposed variant of the condition. To test the hypothesis that a proportion of patients with ONJ remain undiagnosed because their symptoms do not conform to the traditional case definition, we did a secondary analysis of data from MISSION (Multicentre study on phenotype, definition and classification of osteonecrosis of the jaws associated with bisphosphonates), a cross-sectional study of a large population of patients with bisphosphonate-associated ONJ who were recruited in 13 European centres. Patients with exposed and non-exposed ONJ were included. The main aim was to quantify the proportion of those who, according to the traditional case definition, would not be diagnosed with ONJ because they had no exposed necrotic bone. Data analysis included descriptive statistics, median regression, and Fishers exact test. A total of 886 consecutive patients were recruited and 799 were studied after data cleaning (removal or correction of inaccurate data). Of these, 607 (76%) were diagnosed according to the traditional definition. Diagnosis in the remaining 192 (24%) could not be adjudicated, as they had several abnormal features relating to the jaws but no visible necrotic bone. The groups were similar for most of the phenotypic variables tested. To our knowledge this is the first study in a large population that shows that use of the traditional definition may result in one quarter of patients remaining undiagnosed. Those not considered to have ONJ had the non-exposed variant. These findings show the importance of adding this description to the traditional case definition.

Bisphosphonates Induce Apoptosis of Circulating Endothelial Cells in Multiple Myeloma Patients and in Subjects with Bisphosphonate-Induced Osteonecrosis of the Jaws

Bisphosphonates (BPs) are the current standard of care for bone lesions in patients with multiple myeloma (MM) but they are associated with a number of side effects such as osteonecrosis of the jaw. The exact mechanisms of osteonecrosis are not elucidated, and its physiopathology is based on several hypotheses such as a decrease in bone remodeling or an inhibitory effect on angiogenesis. The aim of our study was to investigate the mechanism involved in the pathogenesis of osteonecrosis. We examined the apoptosis of circulating endothelial progenitor cells in MM subjects before and after BP treatment and in osteonecrosis patients using a flow-cytometric analysis. Our data showed an increase in endothelial cell apoptosis in MM patients after BP administration and in osteonecrosis subjects. Our study seems in agreement with the hypothesis that BPs can inhibit angiogenesis interfering with endothelial cell proliferation and survival, leading to loss of blood vessels and avascular necrosis.

Effects of Hypericum Perforatum, in a rodent model of periodontitis

BackgroundHypericum perforatum is a medicinal plant species containing many polyphenolic compounds, namely flavonoids and phenolic acids. In this study we evaluate the effect of Hypericum perforatum in animal model of periodontitis.MethodsPeriodontitis was induced in adult male Sprague-Dawley rats by placing a nylon thread ligature around the lower 1st molars. Hypericum perforatum was administered at the dose of 2 mg/kg os, daily for eight days. At day 8, the gingivomucosal tissue encircling the mandibular first molar was removed.ResultsPeriodontitis in rats resulted in an inflammatory process characterized by edema, neutrophil infiltration and cytokine production that was followed by the recruitment of other inflammatory cells, production of a range of inflammatory mediators such as NF-κB and iNOS expression, the nitration of tyrosine residues and activation of the nuclear enzyme poly (ADP-ribose) polymerase; apoptosis and the degree of gingivomucosal tissues injury. We report here that Hypericum perforatum exerts potent anti-inflammatory effects significantly reducing all of the parameters of inflammation as described above.ConclusionsTaken together, our results clearly demonstrate that treatment with Hypericum reduces the development of inflammation and tissue injury, events associated with periodontitis.

Effects of verbascoside, biotechnologically purified by Syringa vulgaris plant cell cultures, in a rodent model of periodontitis.

Objectives  Verbascoside has previously been characterized as an effective scavenger of active free radicals and an inhibitor of lipid peroxidation. In the present study, we have investigated the effects of verbascoside from Syringa vulgaris in a rat model of ligature‐induced periodontitis.

Patients with bisphosphonate-associated osteonecrosis of the jaw have unmodified levels of soluble vascular endothelial growth factor receptor 1.

In an article recently published in Leukemia and Lymphoma, Pozzi et al. reported 35 cases of bisphosphonate-associated osteonecrosis of the jaw (ONJ) in multiple myeloma patients [1]. In fact, sinc...

Emerging role of PPAR-β/δ in inflammatory process associated to experimental periodontitis.

The aim of the present study was to evaluate the contribution of peroxisome proliferator-activated receptor (PPAR-β/δ) in animal model of periodontitis. Male Sprague-Dawley rats were lightly anaesthetized with pentobarbitone (35 mg/kg). Sterile, 2-0 black braided silk thread was placed around the cervix of the lower left first molar and knotted medially. Animals received GW0742 (0.3 mg/kg, 10% DMSO, i.p. after the ligature placement and daily for eight days). At day 8, the gingivomucosal tissue encircling the mandibular first molar was removed. One the eighth day after placement of the ligature, we evaluated (1) NF-κB expression, (2) cytokines expression, (3) iNOS expression, (5) the nitration of tyrosine, (6) apoptosis, and (8) the degree of gingivomucosal tissues injury. Administration of GW0742 significantly decreased all of the parameters of inflammation as described above. Taken together, these results demonstrate that GW0742 exerts an anti-inflammatory role during experimental periodontitis and is able to ameliorate the tissue damage.

Association of osteonecrosis of the jaws and POEMS syndrome in a patient assuming rituximab

POEMS syndrome, is a rare condition characterized by polyneuropathy, organomegaly, endocrinopathy, monoclonal proteinaemia, and skin lesions. We report a rare case of a patient affected by Waldenström macroglobulinemia, who developed POEMS syndrome and who presented at the time of diagnosis with oral manifestations of the lymphoma and an osteonecrosis of the jaw (ONJ) after rituximab treatment. Although the etiology of ONJ is not known, it is likely that several factors are at play, including endothelial cell damage, decreased angiogenesis, and microvascular compromise. Our patient was treated with rituximab for a long period, and recent studies have demonstrated the possibility that rituximab, a monoclonal antibody directed against the CD20 can exert part of its anti-tumor action, through its action on angiogenesis. Although our report does not allow identification of rituximab as a new risk factor for the onset of the ONJ, further studies seem necessary to exclude a role of the antibody in the alterations of angiogenesis that could lead to the development of the syndrome after rituximab treatment.