Identification of Putative Bacterial Pathogens for Orofacial Granulomatosis Based on 16S rRNA Metagenomic Analysis

Orofacial granulomatosis (OFG) is a chronic inflammatory disease characterized by nontender swelling of the orofacial tissues, the underlying cause of which remains unknown. Our previous study demonstrated that tooth apical periodontitis (AP) is involved in the development of OFG. To characterize the AP bacterial signatures of OFG patients and identify possible pathogenic bacteria that cause OFG, the compositions of the AP microbiotas in OFG patients and controls were compared using 16S rRNA gene sequencing. Pure cultures of putative bacterial pathogens were established by growing bacteria as colonies followed by purification, identification, and enrichment and then were injected into animal models to determine the causative bacteria contributing to OFG. A specific AP microbiota signature in the OFG patients was shown, characterized by the predominance of phyla Firmicutes and Proteobacteria, notably members of the genera Streptococcus, Lactobacillus, and Neisseria, were found. Streptococcus spp., Lactobacillus casei, Neisseria subflava, Veillonella parvula, and Actinomyces spp. from OFG patients were isolated and successfully cultured in vitro and then injected into mice. Ultimately, footpad injection with N. subflava elicited granulomatous inflammation. IMPORTANCE Infectious agents have long been considered to play a role in the initiation of OFG; however, a direct causal relationship between microbes and OFG has not yet been established. In this study, a unique AP microbiota signature was identified in OFG patients. Moreover, we successfully isolated candidate bacteria from AP lesions of OFG patients and assessed their pathogenicity in laboratory mice. Findings from this study may help provide in-depth insights into the role of microbes in OFG development, providing the basis for targeted therapeutic approaches for OFG.

Non-infectious Granulomatous Lesions of the Orofacial Region

Granulomatous lesions of the orofacial region are a heterogeneous group of disorders characterized by a granulomatous reaction to a variety of stimuli. Infectious agents, foreign material, systemic inflammation and metabolic disorders can all be associated with granulomatous inflammation. In the orofacial region primary causes of granulomatosis include foreign body reaction, delayed hypersensitivity to topical agents and idiopathic orofacial granulomatosis. Secondary causes of granulomas include infectious agents, sarcoid, and Crohn disease. For this review, infectious causes of orofacial granulomatosis (OFG) including bacteria, parasites and fungi will not be discussed.

[A 74-year old woman with orofacial granulomatosis]

INTRODUCTION

Orofacial granulomatosis represents a group of pathologies characterized by a granulomatous inflammation of the face and the oral mucosa. Its etiology is unknown. Since the macrocheilitis resulting from an inflammation could be associated to different pathologies, an accurate diagnosis has to be established.

OBSERVATION

A 74-year old woman developed a swelling of the inferior lip spreading towards the chin. No lesions was present on the oral mucosa. No other symptoms were reported. The biopsy and further exams concluded to an idiopathic orofacial granulomatosis. Triamcinolone 10 mg/ml was used as treatment and has allowed a lasting improvement of the swelling.

DISCUSSION

This rare observation, especially with an older patient, has allowed to illustrate the importance of an accurate diagnosis when facing a macrocheilitis. Indeed, macrocheilitis can be associated to pathologies such as Crohn disease, sarcoidosis or tuberculosis, requiring an appropriate care.

Orofacial granulomatosis: clinical signs of different pathologies

Orofacial granulomatosis (OFG) is an uncommon disease characterized by persistent or recurrent soft tissue enlargement, oral ulceration and a variety of other orofacial features. It could be an oral manifestation of a systemic disease. For a correct differential diagnosis, local and systemic conditions characterized by granulomatous inflammation should be excluded using appropriate clinical and laboratory investigations. In fact, the diagnosis of OFG may be confirmed only by histopathological identification of noncaseating granulomas. The literature from 1943 to 2014 was reviewed with emphasis on the etiology of OFG and on clinical manifestations of systemic pathologies associated with OFG. The precise cause of OFG is still unknown, although several theories have been suggested, such as infection, hereditary factors and allergy. OFG is a disease that has a wide spectrum of presentation, which may include the oral manifestation of a systemic condition such as Crohn's disease, sarcoidosis, granulomatosis with polyangiitis and Melkersson-Rosenthal syndrome.

Oral Crohn's disease: is it a separable disease from orofacial granulomatosis? A review

Symptomatic oral Crohn's disease is comparatively rare. The relationship between orofacial granulomatosis, (where there is granulomatous inflammation and ulceration of the mouth in the absence of gastrointestinal disease) and true oral Crohn's disease is discussed along with the plethora of clinical oral disease presentations associated with both disorders and the differential diagnosis of oral ulceration in patients presenting to a gastroenterological clinic. Specific oral syndromes are outlined including the association between oral manifestations in Crohn's disease and the pattern of intestinal disease and their relationship to other recorded extraintestinal manifestations. The histological and immunological features of oral biopsies are considered as well as the principles of management of symptomatic oral disease. At present, it is suggested that both orofacial granulomatosis and oral Crohn's disease appear to be distinct clinical disorders.

Orofacial granulomatosis of the lip: a report of 2 cases with histological and immunohistochemical analyses and intralesional corticotherapy

Orofacial granulomatosis is a generic term applied to manifestations of several diseases including sarcoidosis, Crohn's disease, Melkersson-Rosenthal syndrome, cheilitis granulomatosa of Miescher, tuberculosis and foreign-body reactions. What bonds these diseases together is the presence of noncaseating granulomas. A typical clinical manifestation of orofacial granulomatosis is recurrent labial swellings that eventually persist. This article describes 2 cases of OG diagnosed with the aid of immunohistochemical analysis and successfully treated with intralesional steroids.

Orofacial granulomatosis in childhood-a clinical entity that may indicate Crohn's disease as well as food allergy

AIM

Orofacial granulomatosis (OFG) is a rare clinical entity with orofacial swelling in association with oral lesions such as mucosal oedema, ulcerations and mucosal tags. The aim of this prospective study was to evaluate the connection between OFG in childhood and systemic disease.

METHODS

During a 3-year period, eight children (9-16 years old) who had been referred to the clinic of oral medicine were diagnosed solely with OFG. Thus, none of them had any known systemic disease or gastrointestinal symptoms at the time of referral. The children were then medically examined and followed up for 6-8 years at the department of paediatrics for systemic disease with specific emphasis on inflammatory disorders elsewhere in the gastrointestinal tract.

RESULTS

During follow-up, four patients were diagnosed with Crohn's disease (CD). Further, one girl was found to have a food allergy-induced OFG, with delayed-type hypersensitivity to oats. One boy developed both diabetes and celiac disease during the follow-up. Only two patients had no diagnosis of systemic disease at the end of the observation period.

CONCLUSION

OFG in childhood seems to be frequently related to systemic disease, and children with OFG should be referred to a paediatrician for examination and follow-up.

Oral lesions leading to the diagnosis of Crohn disease: report on 5 patients

Crohn disease is a chronic granulomatous inflammatory disease of the gastrointestinal tract of unknown etiology. Oral lesions are significant, as they may occasionally precede intestinal and systemic manifestations. In this retrospective study, clinical and histopathologic data were reviewed from the files of 5 patients with Crohn disease diagnosed at the Department of Oral Medicine and Maxillofacial Pathology School of Dentistry, Aristotle University, Thessaloniki, Greece, and Division of Stomatology and Oral Surgery, Faculty of Medicine, University of Geneva, Switzerland. In the 5 patients, clinical signs included erosions, deep ulcers, cobblestoning of the buccal mucosa, mucosal tags, and lip swelling. Histopathologic examination revealed a granulomatous inflammation with noncaseating granulomas and deep fissuring of the oral mucosa. In all 5 patients, oral lesions were the early signs of the disease. The diagnosis of Crohn disease was confirmed by a colonoscopy and a biopsy of colonic lesions. Oral lesions may be significant and/or initial signs of Crohn disease. Recognition of the lesions may provide an early diagnosis.

Expression of protease-activated receptor-1 and -2 in orofacial granulomatosis

OBJECTIVE

Orofacial granulomatosis (OFG) is a rare condition characterized by non-caseating granulomas in the orofacial region. Protease-Activated Receptors (PARs) play a role in inflammatory diseases in diverse human tissues. The aim of the study was to investigate the expression of PAR-1, PAR-2, MMP-2, MMP-9, COX-1, and COX-2 in tissues taken from OFG patients.

METHODS

PAR-1, PAR-2, MMP-2, MMP-9, COX-1, and COX-2 expression was evaluated by immunohistochemistry in biopsies taken from oral Crohn's disease (five cases), Melkersson-Rosenthal syndrome (MRS) (six cases), cheilitis granulomatosa (five cases) and normal oral mucosa (five cases).

RESULTS

PAR-1 was observed in mononuclear inflammatory cells in edematous/lichenoid lesions, whereas a strong PAR-2 immunostaining was detected in epithelioid histiocytes and giant cells in granulomatous lesions, irrespective of the clinical features (Crohn vs MRS). MMPs and COX-2 were expressed in the inflammatory component of edematous/lichenoid lesions and markedly overexpressed in granulomatous lesions. COX-1 was weakly and variably expressed in both edematous/lichenoid and granulomatous lesions.

CONCLUSION

Thus, PAR-1 and PAR-2 expressions were related to the intensity and type of inflammatory response but not to the type of clinical lesion. Simultaneous overexpression of PARs, MMPs and COXs suggests synergism among these proinflammatory receptors and enzymes.

Oral biopsies from patients with orofacial granulomatosis with histology resembling Crohn's disease have a prominent Th1 environment

BACKGROUND

Orofacial granulomatosis (OFG) is an idiopathic inflammatory disorder of children and young adults whose clinical symptoms include swelling of the lips or face, mucosal nodularity (cobblestoning), mucosal tags, hyperplasia of the gingivae, and aphthous oral ulcers. Whether some OFG patients with clinical and histological characteristics resembling Crohn's disease (CD) are a special group (oral CD) or true CD patients with symptoms reaching all the way to the oral mucosa remains to be determined.

METHODS

In this study oral biopsies from 10 patients with OFG were analyzed for the presence of T cells, T-cell subsets, B cells, and macrophages, as well as cytokines (IL-4, IL-10, IFN-gamma, IL-12, and TNF-alpha), chemokines (RANTES and MIP-1alpha), and chemokine receptors (CCR3, CCR5, and CXCR3). For comparison, oral tissues from 7 patients with other granulomatous diseases were included.

RESULTS

Compared with the non-OFG group, the OFG group had raised levels of CD4(+) T cells, IFN-gamma, IL-10, and RANTES but reduced levels of CD68(+) macrophages outside the granulomas, whereas within the granulomas the levels of CD3(+) and CD4(+) T cells and of IFN-gamma were raised, but the levels of IL-4 were decreased. These data are indicative of a Th1 environment within the oral OFG tissues, which resembles that already observed in gut CD tissues.

CONCLUSIONS

Therefore, it can be concluded that some OFG patients have both histopathological and immunopathological features that resemble those observed in CD patients.

Lip impressions: a new method for monitoring morphological changes in orofacial granulomatosis

AIM

To develop and evaluate an objective method for assessing lip size and treatment-related morphological changes in orofacial granulomatosis (OFG) patients.

MATERIALS AND METHODS

Patients with swollen lips because of OFG (n=21) were enrolled. A light-body polyvinylsiloxane material was used to take lip impressions before and after treatment (n=10), or during treatment (n=11). Plaster models were cast from the impressions and the lips were measured using callipers. The intra-examiner and inter-examiner reproducibility of the technique were assessed.

RESULTS

OFG patients had significantly larger lips than controls (P<0.0001). The coefficient of variation on repeated measurements of the same impression was 1.6% and for duplicate impressions was 2.6%. Significant reduction in lip size was shown in all 10 patients after diet restriction (P<0.002). Seven of 11 patients whose impressions were taken at least 3 months after the initiation of cinnamon- and benzoate-free diet also showed reduction in lip size during follow up (P<0.002).

CONCLUSIONS

Serial lip impressions appear to be reliable for routine quantification of morphological changes of the lips in OFG patients. We present a new reproducible and sensitive method for assessing changes in lip size in response to treatment in OFG.

Granulomatous cutaneous centrofacial and meningocerebral amebiasis

A 7-year-old, otherwise healthy Peruvian boy presented with a 3-month history of an indurated centrofacial plaque. Histologic examination revealed a granuloma containing free-living amebae tentatively identified as Balamuthia mandrillaris. The patient failed to respond to tentative treatment. He was admitted to the intensive care unit 7 months later with neurologic manifestations of granulomatous amebic encephalitis, which proved fatal. The difficulty in diagnosing this rare presentation of cutaneous amebiasis, the challenge of treating the condition, and the morbidity and high mortality associated with cerebral involvement are discussed.

Case of childhood granulomatous periorificial dermatitis in a Korean boy treated by oral erythromycin

Childhood granulomatous periorificial dermatitis (CGPD) is a disease presenting most commonly in prepubertal children as yellow-brown papules limited to the perioral, perinasal and periocular regions. The condition is benign, self-limiting and is not associated with systemic involvement. We herein report a case of an 11-year-old Korean boy with multiple, asymptomatic, monomorphic, red-to-yellow-colored papular eruptions on the perioral areas of 7-month duration. Histopathological examination revealed upper dermal and perifollicular granulomatous infiltrate. After using oral erythromycin 500 mg daily for 1 year, the condition resolved completely without leaving a scar.

Improvement in orofacial granulomatosis on a cinnamon- and benzoate-free diet

BACKGROUND

Orofacial granulomatosis (OFG) is a chronic inflammatory disorder presenting characteristically with lip swelling but also affecting gingivae, buccal mucosa, floor of mouth, and a number of other sites in the oral cavity. Although the cause remains unknown, there is evidence for involvement of a dietary allergen. Patch testing has related responses to cinnamon and benzoate to the symptoms of OFG, with improvement obtained through exclusion diets. However, an objective assessment of the effect of a cinnamon- and benzoate-free diet (CB-free diet) as primary treatment for OFG has not previously been performed. Thus, this study was undertaken to investigate the benefits of a CB-free diet as first-line treatment of patients with OFG.

MATERIALS AND METHODS

Thirty-two patients with a confirmed diagnosis of OFG were identified from a combined oral medicine/gastroenterology clinic. All had received a CB-free diet as primary treatment for a period of 8 weeks. Each patient underwent a standardized assessment of the oral cavity to characterize the number of sites affected and the type of inflammation involved before and after diet.

RESULTS

There was a significant improvement in oral inflammation in patients on the diet after 8 weeks. Both global oral and lip inflammatory scores improved (P<0.001), and there was significant improvement in both lip and oral site and activity involvement. However, improvement in lip activity was less marked than oral activity. Response to a CB-free diet did not appear to be site specific. A history of OFG-associated gut involvement did not predict a response to the diet.

CONCLUSIONS

The impact of dietary manipulation in patients with OFG can be significant, particularly with regard to oral inflammation. With the disease most prevalent in the younger population, a CB-free diet can be recommended as primary treatment. Subsequent topical or systemic immunomodulatory therapy may then be avoided or used as second line.

Orofacial granulomatosis: 2 case reports and literature review

Orofacial granulomatosis comprises a group of diseases characterized by noncaseating granulomatous inflammation affecting the soft tissues of the oral and maxillofacial region. The most common clinical presentation is persistent swelling of one or both lips. It is important to establish the diagnosis accurately because this condition is sometimes a manifestation of Crohn's disease or sarcoidosis. This article describes 2 cases of orofacial granulomatosis, in one of which the condition was a manifestation of Crohn"s disease. The diagnostic approach to and the treatment of orofacial granulomatosis are reviewed.

Oro-facial granulomatosis: Crohn's disease or a new inflammatory bowel disease?

BACKGROUND

Oro-facial granulomatosis (OFG) is a rare chronic inflammatory disorder presenting characteristically with lip swelling but also affecting gingivae, buccal mucosa, floor of mouth, and a number of other sites in the oral cavity. Histologically, OFG resembles Crohn's disease (CD), and a number of patients with CD have oral involvement identical to OFG. However, the exact relationship between OFG and CD remains unknown.

METHODS

Thirty-five patients with OFG and no gut symptoms were identified from a combined oral medicine/gastroenterology clinic. All underwent a standardized assessment of the oral cavity and oral mucosal biopsy to characterize the number of sites affected and the type of inflammation involved. Hematological and biochemical parameters were also recorded. All 35 patients underwent ileocolonoscopy and biopsy to assess the presence of coexistent intestinal inflammation.

RESULTS

Ileal or colonic abnormalities were detected in 19/35 (54%) cases. From gut biopsies, granulomas were present in 13/19 cases (64%). An intestinal abnormality was significantly more likely if the age of OFG onset was less than 30 years (P=0.01). Those with more severe oral inflammation were also more likely to have intestinal inflammation (P=0.025), and there was also a correlation between the histologic severity of oral inflammation and the histologic severity of gut inflammation (P=0.047). No relationship was found between any blood parameter and intestinal involvement.

CONCLUSIONS

Endoscopic and histologic intestinal abnormalities are common in patients with OFG with no gastrointestinal symptoms. Younger patients with OFG are more likely to have concomitant intestinal involvement. In these patients, granulomas are more frequent in endoscopic biopsies than reported in patients with documented CD. OFG with associated intestinal inflammation may represent a separate entity in which granulomatous inflammation occurs throughout the gastrointestinal tract in response to an unknown antigen or antigens.