Mechanisms of Post-Exertional Malaise (PEM)

Prof Christian Puta addressed the mechanisms underlying Post-exertional Malaise (PEM), and began by clarifying that there is no single, universally valid explanation for the occurence of PEM, but rather various factors that act individually or in concert. There are changes in the small blood vessels that lead to a lack of oxygen supply to muscle tissue. Mitochondrial dysfunction also leads to an anaerobic metabolism. The associated lactate excess and adrenergic stress ultimately affect the immune system. The resulting dysregulation of the immune system in turn leads to a chronic inflammatory response and an overproduction of regulatory T cells. Another current hypothesis also points to a connection between PEM and Epstein-Barr virus (EBV) reactivation after herpesvirus infection.