Autoantibodies against M5-muscarinic and beta1-adrenergic receptors in periodontitis patients

Association between periodontitis and heart failure in the general population

AIMS

Data on the association between periodontitis and preclinical cardiac alterations remain scarce. The aim of the current study is to determine if periodontitis is associated with morphological and functional cardiac changes measured by transthoracic echocardiography as well as different heart failure (HF) phenotypes.

METHODS

Participants from the population-based Hamburg City Health Study [ClinicalTrial.gov (NCT03934957)], who underwent transthoracic echocardiography and periodontal screening were included. Periodontitis was classified according to Eke and Page (none/mild, moderate, severe). The 2021 ESC HF guidelines were applied and HF was classified into HF with preserved ejection fraction (HFpEF, ejection fraction ≥50%), HF with mid-range and reduced ejection fraction [HF(m)rEF, ejection fraction <50%], and HF in general [HFpEF and HF(m)rEF]. Due to limited size, all subjects with LVEF <50% and symptoms or signs of HF were classified as HF with reduced and mildly reduced ejection fraction [HF(m)rEF].

RESULTS

Within 6209 participants with full periodontal examination, we identified an overlap of n = 167 participants with periodontitis and HF. Participants with severe periodontitis showed a higher burden of cardiovascular risk factors (men at advanced age, diabetes mellitus, hypertension) when compared with participants with none/mild periodontitis. After adjustment for age, sex, body mass index, smoking, diabetes, hypertension, atrial fibrillation, and coronary artery disease, severe periodontitis was significantly associated with HF(m)rEF (odds ratio: 3.16; 95% CI: 1.21, 8.22; P = 0.019), although no association was found for HFpEF and HF in general.

CONCLUSIONS

The current study demonstrated that severe periodontitis was significantly associated with HF(m)rEF, although no relevant associations were found with HFpEF and HF in general as well as echocardiographic variables. The results implicate a potential target group, who need special attention from cooperating physicians and dentists. Future studies are warranted to verify whether systemic inflammation could be the link between the two diseases.

Compensatory Upregulation of Anti-Beta-Adrenergic Receptor Antibody Levels Might Prevent Heart Failure Presentation in Pediatric Myocarditis

BACKGROUND

Myocarditis can be associated with severe heart failure and is caused by different inflammatory and autoimmune responses. The aim of this study was to describe the immunological response in children with myocarditis by analyzing anti-beta-adrenergic receptor antibodies (anti-β-AR Abs).

METHODS

Sera of children who were hospitalized with biopsy-proven myocarditis were prospectively collected between April 2017 and March 2019. Anti-β1-AR Ab, anti-β2-AR Ab, and anti-β3-AR Ab were quantified by a CE-certified ELISA kit. According to normal values for immunoglobulin G (IgG), three age groups, <1, 1-5, and >5-17 years, were defined. Children without inflammatory cardiac pathology and no heart failure signs were served as a control group.

RESULTS

We compared 22 patients with biopsy-proven myocarditis and 28 controls. The median age (interquartile range) of the myocarditis group (MYC) was 12.1 (2.7-16.4) years, 13 men, left ventricular ejection fraction (LVEF) 51% and for control group, the median age was 5.0 (3.0-6.8) years, nine men, LVEF 64%. Myocarditis patients in the age group >5-17 years showed significantly higher anti-β3-AR Ab levels as compared to controls (p = 0.014). Lower anti-β2-AR Ab and anti-β3-AR Ab levels were significantly correlated with higher left ventricular diameters in myocarditis patients. The event-free survival using a combined endpoint (mechanical circulatory support [MCS], transplantation, and/or death) was significantly lower in myocarditis patients with antibody levels below the median as compared to myocarditis patients with antibody levels ≥ the median.

CONCLUSION

Anti-β-AR Ab levels are increased in children with myocarditis and >5 years of age. These antibodies might be upregulated compensatory to prevent further cardiac deterioration. A worse event-free survival in patients with lower anti-β-AR Ab levels might be a therapeutic target for immunoglobulin substitution.

Cholinergic System and Its Therapeutic Importance in Inflammation and Autoimmunity

Neurological and immunological signals constitute an extensive regulatory network in our body that maintains physiology and homeostasis. The cholinergic system plays a significant role in neuroimmune communication, transmitting information regarding the peripheral immune status to the central nervous system (CNS) and vice versa. The cholinergic system includes the neurotransmitter\ molecule, acetylcholine (ACh), cholinergic receptors (AChRs), choline acetyltransferase (ChAT) enzyme, and acetylcholinesterase (AChE) enzyme. These molecules are involved in regulating immune response and playing a crucial role in maintaining homeostasis. Most innate and adaptive immune cells respond to neuronal inputs by releasing or expressing these molecules on their surfaces. Dysregulation of this neuroimmune communication may lead to several inflammatory and autoimmune diseases. Several agonists, antagonists, and inhibitors have been developed to target the cholinergic system to control inflammation in different tissues. This review discusses how various molecules of the neuronal and non-neuronal cholinergic system (NNCS) interact with the immune cells. What are the agonists and antagonists that alter the cholinergic system, and how are these molecules modulate inflammation and immunity. Understanding the various functions of pharmacological molecules could help in designing better strategies to control inflammation and autoimmunity.