TGF-β1 is the most important cytokine in wound healing scar formation and fibrosis. In keloid scars, TGF-β1 signaling is characteristically altered. Which cell type is primarily responsible for excessive collagen deposition in keloids?

• A Mast cells
• B Keratinocytes
• C Myofibroblasts derived from fibroblasts ✓
• D Endothelial cells

Explanation

Keloid scars are characterized by persistent, excessive fibroproliferation beyond wound boundaries. Myofibroblasts — fibroblasts that have differentiated under the influence of TGF-β1 and mechanical stress — are the principal effector cells responsible for excess collagen (especially type I and III) production, crosslinking, and matrix remodeling in keloids. Keloid myofibroblasts show resistance to apoptosis, perpetuating fibrosis. Mast cells contribute to inflammatory signaling but are not the primary collagen-producing cells.

Reference: Bailey & Love's Short Practice of Surgery, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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