Dynamic Foundations of Disease — Paper X Rheumatoid Arthritis as a Dynamical System: Early-Life Immune Imprinting and BAFF–IFN Loop Activation

This conceptual paper proposes a dynamical systems interpretation of rheumatoid arthritis (RA), integrating early-life immune imprinting with BAFF–interferon (IFN) feedback dynamics. It suggests that early-life conditions define the parameter space within which later immune responses evolve, influencing the activation threshold of self-reinforcing immune loops. Within this framework, the BAFF–IFN axis is conceptualized as a core feedback structure capable of generating sustained immune activation. Rheumatoid arthritis is thus interpreted not as a discrete onset of disease, but as a transition into a stable attractor state following a prolonged phase of subclinical instability. This perspective reframes autoimmunity as a trajectory shaped by early conditions and evolving system dynamics, and highlights the importance of detecting early instability patterns and targeting feedback mechanisms to alter disease progression. This paper is part of the Dynamic Foundations of Disease series and extends the RA/Chaos-Theory framework by integrating early-life immune imprinting as a determinant of system dynamics.