IL-1 beta and PGE2 levels are increased in the saliva of children with Langerhans cell histiocytosis

A narrative review of exploring potential salivary biomarkers in respiratory diseases: still on its way

Saliva is abundant with proteins, metabolites, DNA, and a diverse range of bacterial species. During the past two decades, saliva has emerged as a novel diagnostic and evaluation medium for several diseases. Collection of saliva samples is simple, minimally invasive, and convenient even in infants, children, and patients with anxious. Furthermore, with the development of hypersensitive techniques [e.g., microsensor arrays, enzyme-labeled immunosensors, nanoparticle-labeled immunosensors, capacitive or impedimetric immunosensors, magneto immunosensors, field effect transistor immunosensors, and surface enhanced Raman spectroscopy (SERS)], the sensitivity and accuracy of saliva diagnostic procedures have been improved. Nowadays, saliva has been used as a potential medium for several disease diagnosis and assessment, such as periodontitis, caries, cancers, diabetes mellitus, and cardiovascular diseases. Saliva has been used widely for studying microbiomics, genomics, transcriptomics, proteomics, and metabolomics of respiratory diseases, however, the use of salivary biomarkers for the diagnosis, prognosis, and monitoring of respiratory disease is still in its infancy. Herein, we review the progress of research on salivary biomarkers related to several respiratory diseases, including bronchial asthma, chronic obstructive pulmonary disease (COPD), obstructive sleep apnea (OSA), pneumonia, tuberculosis (TB), Langerhans cell histiocytosis (LCH) and cystic fibrosis (CF). Furthermore, several limitations of saliva test such as the lack of standard protocol for saliva collection and reasonable reference values for saliva test are also mentioned in this review.

Langerhans cell histiocytosis: Current concepts in dentistry and case report

Langerhans cell histiocytosis (LCH), which is a rare granulomatous pediatric disease of unknown etiology, is characterized by the idiopathic proliferation and accumulation of abnormal and clonal Langerhans cells or their marrow precursors, resulting in localized, solitary or multiple destructive lesions. These lesions are most commonly eosinophilic granuloma, which are found in craniofacial bone structures such as the skull and mandible, skin and other organs. In children, the disease has a variable initial presentation, and the clinical course, prognosis and survival are unpredictable. The aims of this report were to present an LCH case in a girl aged 2 years, 8 months and her clinicopathological features, to describe the bucodental management provided, and to discuss special dental considerations of this disease.

Key words:Children, dental management, histiocytosis, Langerhans cells.

Solitary Langerhans cell histiocytosis in an adult: case report and literature review

Background

Langerhans cell histiocytosis (LCH) is a disease that often affects children, but can also occur in adults and smokers. Oral manifestations are unusual and are characterized by bone pain, tooth mobility, necrotic ulcers and local edema. The aim of this paper is to describe a clinical case of LCH in an oral cavity that mimicked oral squamous cell carcinoma.

Case presentation

A male, 63 years old, complaining about a “wound in the mouth” for 6 months, without any pain or spontaneous bleeding. His medical history was free of disease. The patient was a smoker for 33 years. Intraoral examination revealed a destructive ulcerative lesion around the upper left first and second molars that resembled an oral squamous cell carcinoma. Biopsy of the ulcerative lesion was performed and the microscopic features showed an inflammatory infiltrate rich in plasma cells. Based on this microscopical finding, the final diagnosis was periodontal disease associated with a proliferative non-neoplastic lesion. The patient was referred to a specialized dental surgeon and underwent periodontal therapy including surgical procedures. After that, according to follow-up with the patient, there were no signs of disease remission. The lesion increased in size, although the patient did not complain of any symptoms. A second biopsy was performed and the microscopic features again showed a rich inflammatory infiltrate with mononuclear cells and histiocytic cells, characterized by pale histiocytes with lobed nuclei, resembling a bean. A varying number of eosinophils also were observed, without any evidence of atypical cells present in this infiltrate. An immunohistochemical staining panel was done to determine the nature of this inflammatory infiltrate by using antibodies S-100, CD1a, CD-68 and CD45RO that were positive. These immunohistochemical findings were fundamental for the final diagnosis of LCH. The treatment included surgical extraction of all superior teeth, radiation and systemic corticoid therapies. After 8 years of treatment, the patient is free of disease.

Conclusion

Although LCH is an unusual lesion in an oral cavity, it can be present. Biopsy and a histological exam are essential to establish the diagnosis. Immunohistochemicals were fundamental to exclude malignant lesion and to confirm the diagnosis of LCH.

Interleukin-1 loop model for pathogenesis of Langerhans cell histiocytosis

We propose Langerhans cell histiocytosis (LCH) is an inflammatory process that is prolonged by mutations. We hypothesize that Merkel cell polyomavirus (MCPyV) infection triggers an interleukin-1 (IL-1) activation loop that underlies the pathogenesis of LCH. Langerhans cells (LCs) are antigen presenting cells in the skin. When LCs encounter exogenous antigens, they migrate from the epidermis into draining lymphoid tissues to initiate T-cell activity. It has been proposed that LC migration-related factors, including E-cadherin, matrix metalloproteinase, and Notch ligand induce LCH activity. We found that the tyrosine phosphatase SHP-1, which binds IL-1 receptor-associated kinase 1, is expressed at a significantly higher level in LCH affecting multiple organ systems (MS-LCH) than in LCH affecting a single organ system (SS-LCH). IL-1 stimulates T helper 17 cells and their signature cytokine IL-17 had been a matter of controversy. We detected higher levels of IL-17A receptor expression in MS-LCH than in SS-LCH and proposed an IL-17 endocrine model that could settle the controversy. IL-1 is the first cytokine secreted in response to sensitizers and promotes LC migration from sentinel tissues. Myeloid differentiation primary response 88 (MyD88), downstream of the IL-1 receptor, has functions in both RAS signaling and inflammation, leading to human cell transformation. In 2010, an activating mutation in the B-rapidly accelerated fibrosarcoma gene (BRAF) V600E was found in LCH. This BRAF mutation induces phosphorylation of the extracellular signal-regulated kinase (ERK) that may play an important role with MyD88 in LCH pathogenesis. However, phosphorylated ERK (pERK) is rapidly dephosphorylated by dual specificity phosphatase 6 (DUSP6), and limited proliferation is predicted in BRAF mutant cells. MyD88 binds pERK via its D-domain, thereby preventing pERK–DUSP6 interaction and maintaining ERK in an active, phosphorylated state. We detected MCPyV-DNA in the peripheral blood cells of two out of three patients with LCH in high-risk organs but not in those of patients with LCH in non–high-risk organs (0/12; P = .029). MCPyV infection can trigger precursor LCH cells with BRAF mutation to produce IL-1; the IL-1 loop is amplified in all LCH subclasses. Our model indicates both BRAF mutation and IL-1 loop regulation as potential therapeutic targets.

Rare case of unifocal Langerhans cell histiocytosis in four-month-old child

Langerhans cell histiocytosis (LCH) comprises a group of disorders, the common feature of which is Langerhans cell proliferation. The clinical presentation is highly varied. The severity and prognosis of the disease are dependent on the type and extent of organ involvement. This paper reports a rare case of a four-month-old white male with unifocal LCH limited exclusively to the mandible, discussing the diagnosis, radiographic and immunohistochemical aspects, treatment and monitoring multidisciplinary of the case.