[Classification of autoinflammatory diseases based on pathophysiological mechanisms]

[Autoinflammation-differences between children and adults]

Autoinflammatory diseases present as multisystemic inflammation and often manifest in early childhood. In contrast, in a few diseases, e.g., the recently described VEXAS (vacuoles, E1 enzyme, X‑linked, autoinflammatory, somatic) syndrome, the first symptoms occur exclusively in adulthood. This article describes how the phenotypic expression and severity of individual autoinflammatory diseases differ depending on age. Furthermore, differences in the development of organ damage in children and adults are pointed out. In addition to the hereditary periodic fever syndromes, the clinical picture of deficiency of adenosine deaminase 2, the interferonopathies, periodic fever, aphthous stomatitis, pharyngitis, and adenitis syndrome as well as VEXAS and Schnitzler syndromes are highlighted.

[Polyarticular juvenile idiopathic arthritis and rheumatoid arthritis : Common features and differences]

The spectrum of polyarthritic diseases in childhood as well as in adulthood is wide. In the differential diagnostics different age-related diseases must be taken into consideration. Although, a clear similarity is obvious in all age groups for the classical diseases of polyarticular juvenile idiopathic arthritis and rheumatoid arthritis with respect to the pathogenesis, clinical manifestation and treatment options, this review points to specific differences. The prognosis of polyarthritis in children mainly depends on the joint manifestation, whereas extra-articular comorbidities play a predominant role in the older adult population.

Role of Proteasomes in Inflammation

The ubiquitin–proteasome system (UPS) is involved in multiple cellular functions including the regulation of protein homeostasis, major histocompatibility (MHC) class I antigen processing, cell cycle proliferation and signaling. In humans, proteasome loss-of-function mutations result in autoinflammation dominated by a prominent type I interferon (IFN) gene signature. These genomic alterations typically cause the development of proteasome-associated autoinflammatory syndromes (PRAAS) by impairing proteasome activity and perturbing protein homeostasis. However, an abnormal increased proteasomal activity can also be found in other human inflammatory diseases. In this review, we cast a light on the different clinical aspects of proteasomal activity in human disease and summarize the currently studied therapeutic approaches.