The unknown side of chronic inflammation

Chronic inflammation in the intestine or the joints can often affect the whole body. The international clinical symposium of the Cluster of Excellence PMI brings the often underestimated systemic components to the fore.

People in white robes having a meeting
© Sascha Klahn, Kiel University

The treatment of chronic inflammatory diseases often requires an interdisciplinary approach. Conferences on treatments, like this one at the Comprehensive Center for Inflammation Medicine at Campus Kiel, have meanwhile become training grounds.

Too much cholesterol in the blood promotes deposits in the blood vessels, what is known as atherosclerosis, which can lead to heart attacks and strokes. This is a widely known fact. Less well-known is the fact that chronic inflammatory diseases can also encourage atherosclerosis. "This has been shown with many diseases, whether that is rheumatoid arthritis in the joints, Crohn’s disease in the intestine or psoriasis on the skin. In fact, all patients with chronic inflammatory diseases have an increased risk of developing and also dying from cardiovascular diseases." This is explained by Professor Matthias Laudes, Schleswig-Holstein Excellence-Chair at Kiel University and Director of the newly founded Department of Endocrinology, Diabetology and Clinical Nutritional Medicine at the University Medical Center Schleswig-Holstein (UKSH), Campus Kiel. "We now know that inflammation is just as important as the cholesterol itself in the atherosclerosis plaque," said Laudes. "The reduced life expectancy of patients with these diseases is essentially determined by premature cardiovascular events," stressed Laudes, who is also a member of the Steering Committee of the Cluster of Excellence "Precision Medicine in Chronic Inflammation" (PMI). According to studies, the risk of developing a cardiovascular disease is around twice as high for people with rheumatoid arthritis as it is for the average population.

A second metabolic disease related to inflammation is diabetes mellitus. "It does not occur with all inflammatory diseases. Diabetes and obesity are primarily associated with psoriasis," stressed the diabetologist. In this case, the risk of diabetes depends on the severity of the chronic inflammatory skin disease. The risk of diabetes for patients with severe psoriasis is twice as high as that of the general population, according to one study. It is clear that inflammation and metabolism are very closely interconnected. Laudes said: "There are immune messengers that also trigger metabolic effects per se and conversely there are metabolic hormones that also trigger inflammatory effects."

Often underestimated: systemic inflammation

These secondary and concomitant diseases are the result of systemic inflammation. "Inflammation is ultimately a system-wide problem that has a negative influence on the patient’s whole ageing process. Chronic inflammatory diseases cannot be understood at the level of a single organ." These are the words used by PMI spokesperson Professor Stefan Schreiber to highlight why it is so important to treat patients with inflammatory diseases in an interdisciplinary manner. "We are increasingly moving away from just treating whichever part of the surface of the body is inflamed," explained the Director of the Institute of Clinical Molecular Biology (IKMB) and Director of the Department of Internal Medicine I at the UKSH, Campus Kiel.

This interdisciplinary approach also formed the basis of the international clinical symposium of the Cluster of Excellence PMI. Around 50 renowned national and international experts presented the latest findings from molecular and clinical inflammation research in Kiel University's Audimax in July. What was special about this symposium was that it brought together experts from the four disciplines concerned with chronic inflammation – dermatology (skin), gastroenterology (digestive tract), pneumology (lungs) and rheumatology. After all, said Schreiber, "The problems are often the same, but different disciplines have different solutions. With dialogue and also conflict, we have developed interactive solutions that go beyond the boundaries of the subjects."

Interdisciplinary cooperation is also important because the diseases often overlap. For example, in the case of psoriasis it is often not just the skin that is inflamed but also the joints or the tendons. Up to 40 percent of patients with psoriasis develop this type of psoriasis arthritis. "Often it is the malfunctioning of an organ that brings the patient to the relevant specialist practice. However, systematic studies show that other organs are normally affected too," explained Schreiber. In one study, for example, he tested the lung function of patients with chronic inflammatory bowel diseases. This revealed that during an active flare-up phase of the disease, the lung function was also severely impaired. The patients themselves didn’t even notice this because they were already severely limited by the bowel complaint.

Author: Kerstin Nees