Skin prick test with self-saliva in patients with oral aphthoses: a diagnostic pathergy for Behcet's disease and recurrent aphthosis

Streptococcal infection and autoimmune diseases

Excessive activation of immune cells by environmental factors, such as infection or individual genetic risk, causes various autoimmune diseases. Streptococcus species are gram-positive bacteria that colonize the nasopharynx, respiratory tract, gastrointestinal tract, genitourinary tract, and skin. Group A Streptococcus (GAS) species cause various symptoms, ranging from mild infections, such as tonsillitis and pharyngitis, to serious infections, such as necrotizing fasciitis and streptococcal toxic shock syndrome. The contribution of GAS infections to several autoimmune diseases, including acute rheumatic fever, vasculitis, and neuropsychiatric disorders, has been studied. In this review, we focus on the association between streptococcal infections and autoimmune diseases, and discuss current research on the mechanisms underlying the initiation and progression of autoimmune diseases.

Infectious agents and pathogenesis of Behçet's disease: An extensive review

Behçet's disease (BD) is a multisystemic chronic vasculitis. Sustained and enhanced immune responses were reportedly associated with active BD. Although genetic polymorphisms increase development risk, genetic factors alone cannot account for BD development, suggesting the involvement of exogenous factors. Also, how various infectious agents promote BD in high-risk populations is not fully understood. In this review, we summarized the current findings on the associations of infectious agents with BD pathogenesis. The review also highlights the potential microbial risk factors and their pathogenic role in BD progression. Interactions between genetic and infectious risk factors was also discussed. Furthermore, evidence implied that after the eradication of infectious agents, BD symptoms and recurrence decreased, thus highlighting that combined use of antibiotics may be an effective therapy for BD. Finally, we summarized the main limitation of the current related studies, providing valuable insights and a basis for future studies on BD pathogenic factors.

The diagnostic role of pathergy test in patients with Behçet's disease from the Western Europe

The aim of the study is to evaluate the frequency and features of positive pathergy test (PPT) in Italy, its role in the diagnosis of Behçet's disease (BD), and any association with other BD-related manifestations. 52 BD patients, 52 patients with axial spondyloarthritis (ax-SpA), and 26 healthy controls (HCs) underwent intradermal injection of normal saline and intradermal needle soaked with fresh self-saliva. The results of pathergy tests were statistically analysed in the light of demographic, clinical, and therapeutic features of subjects enrolled. Pathergy test performed with saline resulted always negative in all groups. Skin prick test using self-saliva resulted in the occurrence of a papule in 3 (5.8%) BD patients and in 1 (1.9%) patient with ax-SpA. A ≥ 15 mm erythematous area surrounding the needle prick site was observed in 22 (42.3%) BD patients, 5 (9.6%) patients with ax-SpA, and 2 (7.7%) HCs (p = 0.00002). The frequency of skin erythema was significantly more frequent in patients with BD than those with ax-SpA (p < 0.0001) and HCs (p = 0.003). No statistically significant differences were observed between ax-SpA patients and HCs (p = 1.000). The occurrence of skin erythema at pathergy test was not associated with any BD-related clinical manifestation. Erythema at self-saliva prick test presented a sensitivity of 42.31% (CI 28.73-56.80%) and a specificity of 91.03% (CI 82.38-96.32%). The development of a ≥ 15 mm erythematous area at self-saliva prick test could be sufficient to unveil the hyper-reactivity of the innate immune system in BD patients from Western Europe, where the development of skin erythema shows good sensitivity and specificity toward the diagnosis of BD.

Pathergy test with a 23G needle with and without self-saliva in patients with Behçet's disease, recurrent aphthous stomatitis and control group compared to the 20G test

Objectives

The pathergy test (PT) is part of the diagnostic criteria of Behçet’s disease (BD). Factors like needle character and number of punctures can affect the sensitivity of PT. We tried to compare its positivity using a thinner needle with and without self-saliva in active and inactive BD, recurrent aphthous stomatitis (RAS), and healthy people.

Material and methods

Twenty patients with active and 13 with inactive BD, 20 with RAS, and 34 healthy controls underwent 3 types of PT: 1 – the most recommended 20G dry needle PT, 2 – 23G dry needle PT, and 3 – 23G PT with self-saliva. The positivity and diagnostic accuracy of the tests between groups were compared.

Results

All tests were negative in the normal healthy group. In active BD, the positivity of PT with self-saliva (70%) was higher than the 20G PT (20%) (p-value = 0.004), being more correlated to disease activity (p-value = 0.046). In the RAS group, there was no difference in the positivity of all tests (p-value = 0.068). All tests had high diagnostic accuracy in discriminating between patients with active BD and the controls (p < 0.05). The pathergy test with self-saliva showed significant diagnostic accuracy in discriminating BD from non-BD participants (p < 0.001). The results of dry 23G PT were the same as those of 20G PT.

Conclusions

The self-saliva PT test was more positive in patients with active BD, correlated with disease activity, was more sensitive, had equal specificity in detecting BD from the control group, and was more sensitive but less specific in detecting BD, compared to the RAS group. The positivity and accuracy of dry 23G needle PT were the same as the 20G PT.

Pathergy test with self-saliva using a thin (23G) needle is more sensitive has equal specificity in detecting patients with BD compared to the control group and is more sensitive but less specific in detecting the patients with BD compared to the RAS group. The positivity and accuracy of dry 23G needle PT is the same as the most recommended 20G dry PT. Pathergy test by wet 23G needle (with self-saliva) is more positive in patients with active BD compared to PT by dry 20G needle.

Behçet's Disease: An Overview of Etiopathogenesis

Behçet's disease (BD) is a systemic inflammatory disease with a chronic, relapsing-remitting course of unknown etiology hallmarked predominantly by mucocutaneous lesions and ocular involvement. BD shares some common features with autoimmune and autoinflammatory diseases and spondyloarthropathies (MHC-I-opathies). It is related to more than one pathogenic pathway triggered by environmental factors such as infectious agents in genetically predisposed subjects. The interplay between genetic background and immune system is linked to the BD presentation. Genetic factors have been investigated extensively, and several recent genome-wide association studies have confirmed HLA-B ^* 51 to be the strongest genetic susceptibility factor. However, new non-HLA susceptibility genes have been identified. Genetic variations in the genes encoding the cytokines could affect their function and be associated with disease susceptibility. Infectious agents such as Streptococcus sanguinis or the differences in salivary or gut microbiome composition can be considered to trigger the innate-derived inflammation, which is, subsequently, sustained by adaptive immune responses. Altered trimming of microbial and/or endogenous peptides by endoplasmic reticulum aminopeptidase 1 (ERAP1), presented by HLA-B ^* 51, may play a key role in BD pathogenesis causing an alteration in T cell balance with downregulation of Tregs and expansion of Th1 and Th17. The activity of neutrophils is increased and there is an intense neutrophil infiltration in the early stage of inflammation in organs affected by the disease. Association with HLA-B ^* 51 and increased IL-17 response seems to have an important role in neutrophil activity. In this paper, we provide an overview of the most recent advances on BD etiopathogenesis.

Salivary changes in oral mucosal diseases

Saliva is a unique biological fluid that can be easily collected and analyzed with low cost and low morbidity. Therefore, there is a growing attention for using salivary biomarkers in the diagnosis and monitoring of disease progress and response to treatment. Salivary changes have been described in relation to oral mucosal diseases. This article discusses the causes and consequences of salivary hypofunction and presents a review of the literature related to changes in salivary parameters in various oral mucosal diseases and in systemic diseases with possible oral mucosal involvement.

Mucosal Lesions in an Allergy Practice

The diagnosis and treatment of mucosal disease with an allergic pathogenesis are challenging. Oral allergy is often a hypersensitivity reaction with variable symptoms and physical exam findings. Clinical diagnosis requires a history of prior allergen exposure, a delay from exposure to clinical findings, and improvement following allergen removal. The past decades have seen great contributions to the field of oral allergy. The aim of this review is to provide an approach to the diagnosis and treatment of oral dermatologic disease with a focus on diseases with an investigated allergic pathogenesis.

Behçet's syndrome pathophysiology and potential therapeutic targets

Behçet syndrome is a systemic inflammatory disorder characterized by multiorgan involvement such as oral and genital ulcers, uveitis, skin lesions as well as by less frequent, but often more severe, central nervous system and vascular manifestations. The pathogenetic mechanisms are still incompletely known; however the interaction between a specific genetic background and environmental or infectious factors certainly contributes to the immune dysregulation that characterizes this disease. The discovery of new immunological pathways in Behçet syndrome pathogenesis may help us to set up new treatments. In this review, we will focus our attention on the possible mechanisms underlying Behçet syndrome pathogenesis and their potential role as novel therapeutic targets.

A New Diagnostic Way for Behcet's Disease: Skin Prick with Self-Saliva

Behcet's disease (BD) is a mysterious multisystemic disorder characterized by recurrent involvement of mucocutaneous (including recurrent aphthous stomatitis; RAS), ocular, intestinal, vascular, and/or nervous system organs. Previously, the positivity of "pathergy test", which is one of the diagnostic examinations, was reported to be related to the possession of HLA-B51 gene in BD patients, even though the positivity is low and different from the countries. Here, instead of the ordinal pathergy test, we would like to propose the prick with self-saliva as a new diagnostic way for patients with RAS of BD based on the genetic intrinsic factors including HLA-B51 and extrinsic triggering factors. BD patients are considered to acquire the hypersensitivity against oral streptococci through the innate immune mechanism in the oral cavity. Bes-1 gene and 65 kD of heat shock protein (HSP-65) derived from oral S. sanguinis are supposed to play important roles as extrinsic factors in BD pathogenesis. Although the prick positivity was not related to the possession of HLA-B51 gene, the method is suggested to be a significant way for BD diagnosis. The results also suggest that BD symptoms are due to the vascular immune responses by monocytes expressed oral streptococcal agents of the patients.