What is the initial stage of the cycle of fibrosis?

• A. Acute neutrophil influx
• B. Edema
• C. Osteogenesis
• D. Chronic, low-grade inflammation

Answer: (D)

Fibrosis starts to develop when injury prompts ongoing inflammatory signaling that keeps fibroblasts activated and driving scar tissue formation. The initial stage is chronic, low-grade inflammation, not a sudden burst of immune activity. This persistent inflammatory environment releases profibrotic cytokines like TGF-β and PDGF, which push resident fibroblasts or sentinel cells into myofibroblasts that synthesize collagen and other extracellular matrix components. While acute neutrophil influx and edema are characteristic of immediate tissue injury, they are part of the short-term response and don’t establish the lasting fibrotic cycle. Osteogenesis has no direct role in initiating fibrosis.