Oral epithelial dysplasia with lymphocytic immune response: clinicopathological characterisation of 44 cases.

AIMS: Oral epithelial dysplasia (OED) often exhibits a lymphocytic/lichenoid immune response (LIR), imparting histological resemblance to lichenoid mucositis and rendering diagnosis challenging. The clinical appearances of OED and lichenoid inflammatory processes are generally divergent, presenting as well-demarcated hyperkeratotic plaques and diffuse white and/or red mucosal change with variably prominent Wickham striae, respectively. To date, clinicopathological characterisation of OED with LIR, including clinical/gross appearance, has not been depicted. METHODS AND RESULTS: Cases of solitary OED with LIR for which a clinical photograph was available were identified in the authors' institutional files. Clinical and histological features were documented. In 44 identified cases, dysplasia was mild (19 of 44, 43.2%), moderate (19 of 44, 43.2%) and severe (six of 44, 13.6%). Clinically/grossly, all 44 cases (100.0%), presented as well-demarcated hyperkeratotic plaques lacking diffuse white-and-red mucosal change or Wickham striae. Histologically, OED with LIR exhibited numerous 'lichenoid' features beyond the lymphocytic band in the superficial lamina propria, including: leucocyte transmigration (38 of 44, 86.4%), spongiosis (37 of 44, 84.1%), Civatte/colloid bodies (36 of 44, 81.8%), basal cell degeneration (29 of 45, 65.9%), sawtooth rete ridges (11 of 44, 25.0%) and subepithelial clefting (7 of 44, 15.9%). CONCLUSIONS: Virtually any lichenoid histological feature may be seen in OED with LIR, representing a significant diagnostic pitfall. The typical clinical appearance of OED with LIR is of a well-demarcated hyperkeratotic plaque, characteristic of keratinising dysplasia and devoid of lichenoid features. This suggests that pathologist access to clinical photographs during diagnostic interpretation of biopsied white lesions, which represents opportunity to perform gross examination of the disease process, may reduce interobserver variability and improve diagnostic accuracy in this challenging differential diagnosis.

Total RNA sequencing reveals gene expression and microbial alterations shared by oral pre-malignant lesions and cancer.

Head and neck cancers are a complex malignancy comprising multiple anatomical sites, with cancer of the oral cavity ranking among the deadliest and the most disfiguring cancers globally. Oral cancer (OC) constitutes a subset of head and neck cancer cases, presenting primarily as tobacco- and alcohol-associated oral squamous cell carcinoma (OSCC), with a 5-year survival rate of ~ 65%, partly due to the lack of early detection and effective treatments. OSCC arises from premalignant lesions (PMLs) in the oral cavity through a multi-step series of clinical and histopathological stages, including varying degrees of epithelial dysplasia. To gain insights into the molecular mechanisms associated with the progression of PMLs to OSCC, we profiled the whole transcriptome of 66 human PMLs comprising leukoplakia with dysplasia and hyperkeratosis non-reactive (HkNR) pathologies, alongside healthy controls and OSCC. Our data revealed that PMLs were enriched in gene signatures associated with cellular plasticity, such as partial EMT (p-EMT) phenotypes, and with immune response. Integrated analyses of the host transcriptome and microbiome further highlighted a significant association between differential microbial abundance and PML pathway activity, suggesting a contribution of the oral microbiome toward PML evolution to OSCC. Collectively, this study reveals molecular processes associated with PML progression that may help early diagnosis and disease interception at an early stage.

Characterization of orofacial features in sclerodermatous chronic graft-versus-host disease.

BACKGROUND: Chronic graft-versus-host disease (cGVHD) is a leading cause of morbidity and mortality following allogeneic hematopoietic cell transplantation (alloHCT). The sclerodermatous form of cGVHD can be particularly debilitating; however, orofacial sclerodermatous involvement remains poorly described. OBJECTIVE: To characterize orofacial features of sclerodermatous cGVHD in a single center cohort of patients who underwent alloHCT. STUDY DESIGN: Retrospective data were collected from electronic medical records and analyzed descriptively. RESULTS: There were 39 patients who received alloHCT between 1993 and 2017 and developed orofacial sclerodermatous cGVHD. Concomitant cutaneous sclerodermatous cGVHD was common (n = 20, 51%). Orofacial sclerodermatous cGVHD features included fibrous bands of the buccal mucosa (n = 23, 59%), limited mouth opening (n = 19, 54%), perioral fibrosis (n = 8, 21%), and focal gingival recession (n = 4, 10%). Oral mucosal fibrosis was observed at the site of active or resolved chronic lichenoid inflammation in 30 patients, with all but two also presenting with a history of ulcerations. Management included jaw stretching exercises (n = 10; 6 stable/improved), surgery (n = 3; 2 improved), and intralesional corticosteroid injections (n = 2; 2 improved). CONCLUSIONS: Orofacial involvement with sclerodermatous cGVHD can present with multiple manifestations including fibrous banding, limited mouth opening, perioral fibrosis, and focal gingival recession. Surgical and non-surgical management strategies may improve clinical function and reduce morbidity.

Dynamic real-time optical microscopy of oral mucosal lesions using confocal laser endomicroscopy.

OBJECTIVES: Confocal laser endomicroscopy (CLE) is a novel non-invasive point-of-care optical biopsy technology that enables real-time in vivo microscopic visualisation of cellular and tissue architecture. In this study, we assessed the diagnostic accuracy of a hand-held fluorescence single-fibre distal-scanning CLE (fsdCLE) platform for diagnosing oral epithelial dysplasia (OED) and oral squamous cell carcinoma (OSCC). MATERIALS AND METHODS: Forty-seven patients presenting with 63 distinct oral mucosal lesions were subjected to optical biopsy using a miniaturised fsdCLE system (ViewnVivo®, Optiscan Imaging Ltd) and topical exogenous acriflavine hydrochloride contrast agent before undergoing tissue biopsy and histopathological consensus review by four pathologists. CLE images were captured in vivo in real-time during clinical examination and assessed on-the-fly for the presence of cellular and architectural features of OED/OSCC offering an instantaneous diagnosis. Predicted optical diagnoses were compared to definitive consensus tissue histopathology. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy were calculated for the presence/absence of dysplasia/malignancy on optical biopsy. Percentage agreement, Fleiss' kappa, and intraclass correlation coefficient (ICC) were calculated for each assessment stage during the consensus histopathology process. RESULTS: Diagnostic accuracy was extremely high at 88.9%. Other metrics were sensitivity 86.8%, specificity 92%, PPV 94.3% and NPV 82.1%. One hundred percent of carcinoma cases were detected accurately using CLE in the clinic. CONCLUSION: fsdCLE is a highly accurate, easy-to-use, rapid and slide-free point-of-care in vivo optical technology for diagnosing OED/OSCC and discriminating between dysplastic and non-dysplastic pathology. It demonstrates near-perfect agreement with traditional consensus histopathology without the need for physical tissue biopsy.

World Workshop on Oral Medicine VII: Oral adverse effects to biologic agents in patients with inflammatory disorders. A scoping review.

BACKGROUND: Biologic agents are rapidly emerging as an effective therapy to treat autoimmune and other chronic diseases. The use of these agents is poorly characterized, resulting in a lack of guidance for dental practitioners. Case reports of oral adverse events have begun to emerge. However, their scope and frequency have not been summarized and analysed to date. The objective of this review was to characterize the literature on oral adverse effects associated with biological therapy when used for autoimmune and inflammatory disorders. METHODS: This review was developed in accordance with scoping review recommendations. Search strategies were developed and employed for six databases. Studies were selected using a systematic search process but with broad inclusion of study types given the paucity of information available. Reports of oral adverse events were analysed descriptively according to agent, mechanism of action, underlying disease, and oral adverse effect observed. RESULTS: Our search returned 2080 articles and 51 met our inclusion criteria, of which most were case reports. The most frequent adverse effects included angioedema, oral lichenoid lesions, osteonecrosis of the jaw, and oral infections. There were also cases of oral malignancies associated with use of biologic agents. Less common effects such as pigmentation were also described. CONCLUSIONS: Oral adverse events have been reported in patients on biologic therapy, albeit in small numbers to date. This limits the generalizability of these results, which should not be used to generate a clinical guideline as they are based primarily on case reports. However, this study presents the first review characterizing the adverse effects observed. Large multi-center studies will be necessary to further define the oral and dental complications caused by biologic agents.

Characterization of initial/early histologic features of proliferative leukoplakia and correlation with malignant transformation: a multicenter study.

The aim of this multicenter retrospective study is to characterize the histopathologic features of initial/early biopsies of proliferative leukoplakia (PL; also known as proliferative verrucous leukoplakia), and to analyze the correlation between histopathologic features and malignant transformation (MT). Patients with a clinical diagnosis of PL who have at least one biopsy and one follow-up visit were included in this study. Initial/early biopsy specimens were reviewed. The biopsies were evaluated for the presence of squamous cell carcinoma (SCCa), oral epithelial dysplasia (OED), and atypical verrucous hyperplasia (AVH). Cases that lacked unequivocal features of dysplasia were termed "hyperkeratosis/parakeratosis not reactive (HkNR)". Pearson chi-square test and Wilcoxon test were used for statistical analysis. There were 86 early/initial biopsies from 59 patients; 74.6% were females. Most of the cases had a smooth/homogenous (34.8%) or fissured appearance (32.6%), and only 13.0% had a verrucous appearance. The most common biopsy site was the gingiva/alveolar mucosa (40.8%) and buccal mucosa (25.0%). The most common histologic diagnosis was OED (53.5%) followed by HkNR (31.4%). Of note, two-thirds of HkNR cases showed only hyperkeratosis and epithelial atrophy. A lymphocytic band was seen in 34.8% of OED cases and 29.6% of HkNR cases, mostly associated with epithelial atrophy. Twenty-eight patients (47.5%) developed carcinoma and 28.9% of early/initial biopsy sites underwent MT. The mortality rate was 11.9%. Our findings show that one-third of cases of PL do not show OED with most exhibiting hyperkeratosis and epithelial atrophy, but MT nevertheless occurred at such sites in 3.7% of cases.

Oral manifestations of immune-related adverse events in cancer patients treated with immune checkpoint inhibitors.

Immunotherapy with immune checkpoint inhibitors (ICIs) has transformed cancer treatment over the past decade, improving survival rates in numerous advanced cancers. Immune-related adverse events (irAEs) are common and can affect any organ system, with many of these toxicities being well-characterized with clear grading criteria and management approaches. There has been less emphasis on oral manifestations of irAEs. This review provides an overview of oral manifestations of irAEs, including mucosal and salivary gland toxicities, and proposes a grading system and management guidelines. irAEs are common treatment-related toxicities in patients treated with ICIs. Oral irAEs can range from asymptomatic white reticulations to life-threatening mucocutaneous reactions requiring aggressive management with corticosteroids and/or permanent discontinuation of ICIs. Oral healthcare providers should be prepared to identify and manage oral irAEs in collaboration with oncologists and other specialists.

Direct immunofluorescence is of limited utility in patients with low clinical suspicion for an oral autoimmune bullous disorder.

OBJECTIVES: Oral autoimmune bullous disorders show clinical overlap with diseases such as lichen planus and others that may cause desquamative gingivitis. As direct immunofluorescence is expensive, we sought to determine if routine histology alone would be sufficient to distinguish between oral autoimmune bullous disorders and mimics. METHODS: We searched the records for patients with a suspected oral autoimmune bullous disorder who underwent biopsies for concurrent routine histologic evaluation and direct immunofluorescence and who had at least one follow-up visit. Cases were separated into high and low suspicion subgroups based on clinical findings. RESULTS: Within 148 cases, the sensitivity of routine histology alone was 0.810, with a negative predictive value of 0.889. However, the specificity was 0.989 with a positive predictive value of 0.979. Of the high suspicion cases, 57 (47.1%) were found to be consistent with an oral autoimmune bullous disorder, with a total of 11 histologic false negatives. 8 cases, all in the high suspicion subgroup, showed indeterminate direct immunofluorescence results. There were no histologic false negatives or inconclusive direct immunofluorescence results in the low suspicion subgroup. CONCLUSIONS: In patients with a low clinical suspicion for an oral autoimmune bullous disorder, it is reasonable and more cost-effective to evaluate the lesion with routine histology alone.

Oral immune-related adverse events associated with PD-1 inhibitor therapy: A case series.

OBJECTIVE: The aim of this study was to characterize clinical and histopathological features, and management outcomes of patients with oral immune-related adverse events (irAEs) secondary to programmed cell death-1 (PD-1) inhibitors. METHODS: This was a case series of cancer patients receiving PD-1 inhibitor therapy who were referred to oral medicine for the development of oral irAEs. Demographic, clinical, and histopathological data were collected from electronic medical records. RESULTS: There were 13 patients (7 males) with a median age of 68 years (range: 39-82) who were treated with nivolumab (n = 7) or pembrolizumab (n = 6). Oral irAEs included lichenoid lesions (n = 10), erythema multiforme (EM) (n = 2), and acute graft-versus-host disease reactivation (n = 1), with or without ulcerations (n = 8). Four patients (31%) presented with only oral irAEs. Oral biopsies showed lichenoid mucositis (n = 4). Management with topical and systemic steroids led to complete symptomatic response in most patients (n = 12). PD-1 inhibitor therapy was temporarily discontinued (n = 3) and discontinued indefinitely (n = 2) due to severe oral irAEs. CONCLUSION: Patients receiving PD-1 inhibitors may develop oral irAEs characterized by lichenoid lesions, ulcers, or EM. Topical and systemic steroids appear to be effective in managing oral lesions although the severity of irAEs may necessitate PD-1 inhibitor therapy dose modification.

Evaluation of a community-based dental screening program prior to radiotherapy for head and neck cancer: a single-center experience.

PURPOSE: Oral toxicities following radiation therapy (RT) for head and neck (HN) cancer can be profound and are associated with poor health outcomes. The Division of Oral Medicine and Dentistry at Brigham and Women's Hospital and Dana-Farber Cancer Institute therefore implemented a dental evaluation program designed for community-based (CB) dentists to evaluate and treat patients scheduled for HN RT. The aim of this retrospective single-center cohort study was to assess the compliance of CB dentists with this pre-RT dental evaluation program. METHODS: A retrospective analysis of dental evaluations completed by CB dentists from December 2013 to December 2015 was performed. Descriptive statistics were used to determine compliance. RESULTS: A total of 186 dental evaluations were received. Compliance with completion of dental treatment was as follows: scaling and prophylaxis: 94.5% (172/182); dental restorations: 78.7% (48/61); endodontic therapy: 76.9% (10/13); and dental extractions: 76.9% (30/39). Compliance of CB dentists with all requested components of the pre-RT evaluation and treatment was 77.4% (144/186). The median distance traveled by patients to the CB dentist and to the hospital was 5.2 miles (range 0.03-66.0) and 46.5 miles (range 0.8-1457; p < 0.01), respectively. CONCLUSION: In this study, the majority of patients completed their necessary dental treatment in a timely manner by their CB dentist in collaboration with an oral medicine specialist. Given the high compliance of CB dentists, this program could serve as a model for other cancer centers to optimize oral and dental health prior to RT.

Oral keratosis of unknown significance shares genomic overlap with oral dysplasia.

OBJECTIVES: To identify molecular characteristics of keratosis of unknown significance and to nominate pathways of molecular progression to oral cancer. Our work could provide a rationale for monitoring and treating these lesions definitively. METHODS: Patients with oral leukoplakia were eligible for our prospective observational study. We correlated alterations in cancer-associated genes with clinical and histopathologic variables (keratosis of unknown significance vs. moderate-to-severe dysplasia) and compared these alterations to a previously molecularly characterized oral cancer population. RESULTS: Of 20 enrolled patients, 13 (65%) had evidence of keratosis of unknown significance, while seven (35%) had dysplasia. Nine patients (45%) developed oral cancer (4/13 with keratosis of unknown significance, 5/7 with dysplasia). At a median follow-up of 67 (range 22-144) months, median overall survival was significantly shorter for patients with dysplasia (hazard ratio 0.11, p = .02). KMT2C and TP53 alterations were most frequent (75% and 35%, respectively). There were molecular similarities between keratosis of unknown significance and dysplasia patients, with no significant differences in mutational frequency among genes with ≥15% rate of alteration. CONCLUSIONS: Among patients with leukoplakia, both patients with keratosis of unknown significance and patients with dysplasia developed oral cancer. Molecular alterations between these two groups were similar at this sample size.

World Workshop on Oral Medicine VII: Immunobiologics for salivary gland disease in Sjögren's syndrome: A systematic review.

OBJECTIVE: This systematic review evaluated the efficacy of immunobiologics for the management of oral disease in Sjögren's syndrome (SS). MATERIALS AND METHODS: MEDLINE® , Embase, Scopus, and the Cochrane Library were searched for evidence on the use of immunobiologics for management of glandular disease in SS. Primary outcomes were xerostomia and salivary gland dysfunction, assessed via visual analogue scales, disease-specific scales for SS, measurement of salivary flow, ultrasound data, and quality of life measures. RESULTS: Seventeen studies (11 randomized controlled trials and 6 observational studies) met inclusion criteria. Rituximab showed efficacy in improving salivary gland function but not xerostomia. Abatacept showed promise in improving both xerostomia and salivary flow. Belimumab exhibited long-term improvement of salivary flow and subjective measures. The novel agent CFZ533 improved both disease activity and patient-reported indexes. CONCLUSIONS: There is strong evidence pointing to the efficacy of rituximab in the management of oral disease in SS. Future controlled trials may elucidate the efficacy of belimumab and abatacept. The new drug CFZ533 is a promising alternative for the management of SS and its salivary gland involvement. In considering these agents, the promise of efficacy must be balanced against the harmful effects associated with biologic agents.

World Workshop of Oral Medicine VII: A systematic review of immunobiologic therapy for oral manifestations of pemphigoid and pemphigus.

OBJECTIVE: To assess the evidence for treatment of oral involvement of pemphigus and pemphigoid with biologics. STUDY DESIGN: This systematic review used a comprehensive search strategy to identify literature describing oral involvement of pemphigus or pemphigoid treated with a biologic agent. The primary outcome measures were efficacy and safety of biologic therapy. RESULTS: Inclusion criteria were met by 154 studies including over 1200 patients. Treatment of pemphigus with a total of 11 unique biologic agents and 3 unique combinations of agents is reported. Five randomized controlled trials (RCT) were included in the final analysis that investigated infliximab, IVIg, rituximab, and autologous platelet-rich plasma therapy for pemphigus vulgaris. Three non-RCT studies reported on successful rituximab or IVIg therapy for mucous membrane pemphigoid. Studies demonstrated considerable heterogeneity in agent, methods, and quality. CONCLUSIONS: Evidence clearly describing oral tissue response to biologic therapy is sparse. Two RCTs support use of rituximab, one supports use of IVIg, and one pilot study suggests intralesional injection of autologous platelet-rich plasma aids healing of oral PV lesions. As oral lesions of pemphigus and pemphigoid can be refractory to systemic therapy, drug trials including biologic therapies should document details regarding response of the oral lesions to therapy.

Primordial odontogenic tumour: report of two cases.

AIMS: Primordial odontogenic tumour (POT) is a rare mixed odontogenic neoplasm that is composed of primitive ectomesenchyme resembling dental papilla, surfaced by odontogenic epithelium resembling inner enamel epithelium, without hard tissue formation. Most reported cases have presented in the posterior mandible as a well-demarcated radiolucency associated with an unerupted tooth in the first two decades of life. The aim of this report is to describe the clinicopathological features of two more cases of POT. METHODS AND RESULTS: Each presented as an asymptomatic well-delineated radiolucency in the mandible in a 15-year-old female and an 18-year-old male, respectively. Both tumours were composed of a proliferation of plump spindle and stellate cells in delicately collagenous and myxoid stroma, surfaced by columnar-squamous epithelial cells with reverse nuclear polarisation at the tumour periphery. In one case, the formation of abortive tooth germ-like structures was noted. This has not been reported previously and supports the hypothesis of the primordial nature of this tumour. Both patients showed no recurrence at 3- and 20-month follow-up, respectively. CONCLUSION: This report describes two additional cases of POT for a total of 11 cases reported in the English language literature.

The Use of Hyperbaric Oxygen for the Prevention and Management of Osteoradionecrosis of the Jaw: A Dana-Farber/Brigham and Women's Cancer Center Multidisciplinary Guideline.

BACKGROUND: Osteoradionecrosis of the jaw (ORN) is an infrequent yet potentially devastating complication of radiation therapy to the head and neck region. Treatment options include antimicrobial therapy, local sequestrectomy, resection, and the use of hyperbaric oxygen (HBO). Published data on ORN are difficult to compare because of the lack of a universally accepted classification and staging system, and the literature on the use of HBO to either prevent or successfully manage ORN is controversial and inconclusive. Therefore, we aimed to establish a standard approach for using HBO at our institution. MATERIALS AND METHODS: A literature search was conducted of articles published in the English language between January 1980 and January 2016. Retrieved articles were evaluated by two independent reviewers. Isolated case reports, abstracts, case series, review articles, and cohort studies without a control group were excluded; summary data were extracted from the remaining studies. A panel of experts from Head and Neck Oncology and Oral Medicine from the Dana-Farber Cancer Institute and Brigham and Women's Hospital reviewed the summary data and established multidisciplinary guidelines on the use of HBO for the prevention and management of ORN. RESULTS: Seven studies were evaluated and reviewed by the multidisciplinary panel. There was no consistent evidence in support of HBO for either the prevention or management of ORN. CONCLUSION: Based on the available evidence and expert opinion, routine use of HBO for the prevention or management of ORN is not recommended and is rarely used at our institution. The Oncologist 2017;22:343-350 IMPLICATIONS FOR PRACTICE: The Division of Head and Neck Oncology of Dana-Farber/Brigham and Women's Cancer Center does not recommend the routine use of HBO for the prevention or management of ORN. Adjunctive HBO may be considered for use on a case-by-case basis in patients considered to be at exceptionally high risk who have failed conservative therapy and subsequent surgical resection.

HPV-16 in a distinct subset of oral epithelial dysplasia.

Human papillomavirus (HPV) 16 is the most common high-risk HPV type identified in oropharyngeal and cervical neoplasia. Recently, HPV-associated oral epithelial dysplasia with specific histopathologic features and demographics similar to HPV-oropharyngeal carcinoma has been identified. The objective of this study was to evaluate histopathologically all cases of HPV-oral epithelial dysplasia seen in one center and identify HPV types in a subset of cases. Cases with specific histopathology for HPV-oral epithelial dysplasia that were positive both by immunohistochemical studies for p16 and by in situ hybridization for high-risk types of HPV were further analyzed using QIAamp DNA Tissue Kits (Qiagen, Hilden, Germany). DNA was extracted, amplified, and digested with restriction enzymes and run on a polyacrylamide gel. Digestion patterns were visually compared with a database of known HPV digestion patterns for identification. There were 53 specimens included in the analysis. There were 47 males and six females (7.8:1), with a median age of 55 years (range 41-81). The most common site of involvement was the tongue/floor of mouth (77% of cases). Of the 53 cases, 94% exhibited parakeratosis and/or hyperkeratosis. All the cases featured karyorrhexis, apoptosis, and characteristics of conventional carcinoma in situ. The quantity of DNA extracted was sufficient for analysis in 22 cases. HPV-16 was identified in 20/22 (91%) cases. One case was associated with HPV-33 and one with HPV-58 (5% each). Eight of the 53 cases (15%) were associated with invasive squamous cell carcinomas.

Leukoplakia-A Diagnostic and Management Algorithm.

Oral white lesions are frequently encountered in daily practice. Most white lesions are benign (eg, reactive keratoses or keratoses from inflammatory conditions) and the diagnosis is usually evident from the clinical presentation and histopathology. Leukoplakia is a common condition characterized by an increased risk for malignant transformation. Histopathology of leukoplakia can disclose hyperkeratosis with dysplasia or carcinoma or hyperkeratosis or parakeratosis without dysplasia. Treatment depends on demographic, social, clinical, and histopathologic factors. This review focuses on the diagnosis and management of oral leukoplakia.

Hematopoietic Cell Transplantation in Patients with Medication-Related Osteonecrosis of the Jaws.

Patients with medication-related osteonecrosis of the jaw (MRONJ) are at risk for developing infections and often require long-term antimicrobial therapy for management. It is unclear whether patients with multiple myeloma (MM) who develop MRONJ experience increased morbidity when they undergo hematopoietic cell transplantation (HCT). The aim of this study was to characterize the course of HCT in MM patients with MRONJ. A retrospective chart review was conducted for patients with MM and MRONJ who underwent HCT between December 2005 and December 2014. Data collected included bisphosphonate use, MRONJ stage, positive blood cultures, number of febrile days, and length of hospital stay. Eleven patients (median age, 61; range, 46 to 71) fulfilled the criteria. Patients received zoledronic acid (72.7%), pamidronate (18.1%), or a combination of both (9%). At the time of HCT, 10 patients were in stage 1 MRONJ with 1 in stage 0. All patients had only mandibular involvement. No patient developed pain/infection at the MRONJ site during hospitalization. Bacteremia with positive blood cultures for Staphylococcus aureus occurred in 3 patients (27.2%), and 4 patients (36.3%) developed fever lasting between 4 to 6 days (of who 1 had positive blood cultures). The median length of hospital stay was 17 days (range, 7 to 22 days). These data suggests that patients with MM and MRONJ who undergo HCT are not at increased risk of developing symptoms associated with the MRONJ site or HCT-related infectious complications, and their MRONJ is not worsened by HCT.

Possible pathogenic engagement of soluble Semaphorin 4D produced by γδT cells in medication-related osteonecrosis of the jaw (MRONJ).

Prior consensus held that medication-related osteonecrosis of the jaw (MRONJ) lesion was composed of necrotic bone; however, more recent studies have identified inflammatory infiltrates in the lesion. Herein, we report that remarkably elevated infiltrating γδT cells (90% of lymphocytes) express Semaphorin 4D (Sema4D) in human patient with MRONJ lesion, whereas γδT cells only account for 2-5% of lymphocytes in blood. Importantly, Sema4D is implicated in the pathogenesis of T cell-mediated inflammatory diseases, such as rheumatoid arthritis and multiple sclerosis. Indeed, in a mouse model of MRONJ, an elevated number of γδT, but not αßT, cells infiltrating in the MRONJ-like lesion was observed. Both elevated soluble Sema4D (sSema4D) production accompanied by pro-inflammatory cytokines, including TNF-α IFN-γ and IL-1ß, and Sema4D-expressing γδT cells were detected in mouse MRONJ-like lesion. Activated γδT cells produced sSema4D in vitro, which could promote TNF-α production from macrophages. Meanwhile, γδT cell-KO mice were resistant to the induction of MRONJ and, hence, showed no elevation of local productions of Sema4D and TNF-α. Finally, systemic administration of anti-Sema4D neutralizing mAb suppressed the onset of MRONJ in wild-type mice in conjunction with diminished level of TNF-α. These results suggested a critical pathogenic engagement of Sema4D produced by γδT cells in the development of MRONJ.