Evaluation of IL‐6 levels and +3954 polymorphism of IL‐1β in burning mouth syndrome: A systematic review and meta‐analysis

Abstract

This study evaluated IL‐6 salivary levels as well as the +3954 polymorphism of IL‐1β in patients with burning mouth syndrome and healthy individuals, through case‐control studies. This systematic review and meta‐analysis followed the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses guidelines. We conducted this research in PubMed/MEDLINE, Cochrane Library and Web of Science databases. The risk of bias was measured based in the Newcastle‐Ottawa Scale. Researches with a group of patients with burning mouth syndrome and a control group in which the presence of the +3954 polymorphism of IL‐1β and/ or IL‐6 salivary levels through non‐stimulated saliva were evaluated to detect if this interleukin concentrations are increased in patients and if the polymorphism is a risk factor for this syndrome. We identified seven studies with total of 440 participants, 229 patients with burning mouth syndrome and 211 healthy controls, ages 24‐84 years old. The female gender was predominant. Patients in the majority of studies did not present increased levels of IL‐6 and the +3954 polymorphism of IL‐1β is not a risk factor for this syndrome. A few studies researched biomarkers in this pathology and more investigations are required not only to identify salivary levels and the polymorphism evaluated, but also other interleukins and polymorphisms in order to clarify the etiopathogenesis of this syndrome as well as for propose new diagnostic methods and treatments.

Salivary biomarkers in burning mouth syndrome: A systematic review and meta‐analysis

“…This resulted in 33 possible references. After reading the full‐text articles, 16 references were discarded for the following reasons: one for not having a CG (Kang et al, 2017), one for not analyzing biomarkers (Castillo‐Felipe et al, 2021), two for being letters to the editor (Boras et al, 2006; López‐Jornet et al, 2009), four for evaluating genetic polymorphisms (Campello et al, 2020; Guimarães et al, 2006; Kim et al, 2017; Vucićević‐Boras et al, 2003), five for not clarifying the diagnostic criteria used for BMS (Hershkovich & Nagler, 2004; Loeb et al, 2008; Simcić et al, 2006; Srinivasan et al, 2008; Suh et al, 2009), and three for not presenting numerical values for biomarker levels (Acharya et al, 2019; Ji et al, 2017; Kho et al, 2013; these values were requested from the authors, and no response was obtained). Finally, 17 studies were included in this systematic review (Figure 1).…”

“…BMS patients suffer bilateral intraoral pain or burning sensation that can vary in intensity without obvious clinical changes. The most frequent location of the pain is the tip of the tongue, but it can also affect palate and lips (Acharya et al, 2019; Campello et al, 2020; Dias Fernandes et al, 2009; Ji et al, 2017; Lopez‐Jornet et al, 2020; Pekiner et al, 2009; Simcić et al, 2006). Pain is often accompanied by xerostomia (without hyposalivation), dysesthesia, and taste alterations (Acharya et al, 2019; Campello et al, 2020; Dias Fernandes et al, 2009; Imura et al, 2016; Ji et al, 2017; Lončar‐Brzak et al, 2020; Pekiner et al, 2009; Simcić et al, 2006).…”

“…. Pain is often accompanied by xerostomia (without hyposalivation), dysesthesia, and taste alterations (Acharya et al, 2019;Campello et al, 2020;Dias Fernandes et al, 2009;Imura et al, 2016;Ji et al, 2017;Lončar-Brzak et al, 2020;Pekiner et al, 2009;Simcić et al, 2006).…”

Efficacy of photobiomodulation in reducing pain and improving the quality of life in patients with idiopathic burning mouth syndrome. A systematic review and meta-analysis

“…For some time, there have been indications that BMS affects people with personalities that are susceptible to anxiety and depression [ 6 , 10 , 11 ] more than those who do not experience such issues. It is a complex disease, and several pathophysiological mechanisms have been described that explain the condition [ 12 , 13 ] of which the following are particularly worth mentioning: (i) alteration in dopaminergic transmission at a central level. In fact, the dopaminergic blink reflex is exaggerated in some patients with BMS [ 14 ].…”

“…Which could explain the thermal and painful sensitivity in the tongue in these patients, as well as an increase in certain taste detection thresholds [ 17 ]. Some recent studies have suggested that, although not clinically visible, inflammation is the cause of the sensation of pain, with this being linked to cytokine actions [ 13 ]. Other studies have indicated that a genetic variation of the dopamine D2 receptor contributes to the sensation of pain [ 18 ]; nonetheless, mounting evidence has indicated the presence of hormonal, psychosocial, genetic and/or neuropathic causative factors [ 4 ], and, to date, final common consensus is yet to be reached.…”