The crosstalk of hormones and the immune system in rheumatoid arthritis

In this thesis, you will find the results of research trying to unravel part of the communication between the endocrine, immune and parasympathetic nervous system. Studying rheumatoid arthritis (RA) as one example of these diseases, we detected triglycerides, free fatty acids (FFAs), norepinephrine, and pancreatic polypeptides as factors of the endocrine system to be potentially new biomarkers to further help identify the individuals at risk of developing this disease, while FFAs are potentially involved in the pathogenesis of RA. As a factor of importance reflecting the parasympathetic system, we found a higher resting heart rate in individuals at risk for developing RA and patients with established RA. We suggest that restoration of autonomic nervous system dysfunction by vagus nerve stimulation could be a potential treatment for patients who have established RA and possibly as a potential preventive treatment in people at risk of developing RA. Based on our findings we also suggest to explore the role of VNS as a potentially safe treatment to restore glucose tolerance, important in type 2 diabetes mellitus.
For decades, a role for prolactin (PRL) in RA has been suggested. We detected higher expression of the receptor for prolactin (PRLR) on macrophages in RA and also found increased production of PRL upon stimulation by macrophages. With current knowledge, it might be of interest to evaluate the presence of PRL-PRLR interaction in other inflammatory diseases. Blocking the PRLR using the PRLR antagonists could be an interesting approach to explore in RA.