Background: Patients who suffer from anorexia nervosa (AN) are characterized by exceedingly lower body weight, micro- and macro-nutrient deficiencies, and hyposalivation as compared to healthy subjects. In addition, AN may predispose to difficulties in oral health maintenance. However, little is known about the relationship between stress-dependent salivary neuro/immunopeptidergic biomarkers such as opiorphin and immunoglobulins (Ig) and AN.The aim of this case-control study was to evaluate salivary opiorphin and immunoglobulins in female children and adolescents diagnosed with AN compared to healthy controls.
Methods: Adolescent patients with clinically-confirmed severe restrictive subtype AN (Body Mass Index BMI < 15 kg/m2, mean age 15.0 ± 1.8, n = 83) were examined in the first week of hospital admission and compared to healthy matched controls (n = 79). Measurements of salivary opiorphin, IgA, IgG, IgM (ELISA technique), and oral hygiene levels (Plaque Control Record index-PCR) were performed.
Results: In the AN group, a significantly higher concentration of opiorphin was evidenced (3.1 ± 4.1 ng/ml) compared to the control group (1.1 ± 1.2 ng/ml), (p < 0.001), contrary to IgM, which was significantly lower (311.0 ± 185.3 ng/ml) than in the control group (421.2 ± 168.1 ng/ml), (p < 0.001). There were no significant differences in the levels of IgA and IgG, despite a higher concentration of IgA in the AN group vs. controls (p = 0.14). Spearman analysis revealed a correlation between opiorphin and age (p < 0.05), but also with all immunoglobulins IgA, IgG, IgM (p = 0.006, p < 0.001, p < 0.001). Similarly a correlation was found between PCR index and immunoglobulins IgG, IgM (respectively p = 0.028, p < 0.001), and between body mass, BMI, IBW% and IgA, IgM (all p < 0.05).
Conclusions: In the acute phase of AN, salivary changes in opiorphin and immunoglobulins related to dental plaque suggest an essential role in oral health balance. Changes related to AN may affect the anti-inflammatory and analgesic components of saliva and suggest their use as neurobiological markers in severe malnutrition.
Keywords: Anorexia nervosa; Immunoglobulins; Opiorphin; Oral hygiene; Saliva.
The orofacial region is affected by various inflammatory and autoimmune conditions, which might translate into general and regional changes. Saliva is one of the biological fluids where biomarkers of the aforementioned conditions, including sensitivity to pain, could be detected. It is also noteworthy that anorexia nervosa (AN) and malnutrition may change the saliva's analgesic or immune content, but this scientific area is still not satisfactorily explored. The present work related to analgesic (opiorphin peptide) and anti-infectious agents (immunoglobulins Ig A, IgG, IgM) in said body fluid among 83 adolescent patients with severe AN compared to 79 healthy controls. In addition, oral hygiene levels were assessed in the oral cavity via the Plaque Control Record index (PCR). In the AN group, the concentration of opiorphin was significantly higher as compared to the control group, in contrast to IgM, which was significantly lower than in the control group. There were no notable differences in the levels of IgA and IgG between groups, despite a slightly higher concentrations of IgA in the AN group. A correlation was found between opiorphin and all immunoglobulins. A similar correlation was found between PCR index and all immunoglobulins.The present work shows how analgesic opiorphin depends on the oral inflammatory status. This might be a direction for further investigating the immune alterations in patients with AN-related malnutrition. Inclusion of AN patients in intensive oral hygiene care may also be considered.
© 2022. The Author(s).