A 52-year-old man with a 10-year history of rheumatoid arthritis presents with progressive joint destruction and systemic manifestations. Regarding the cellular and molecular features of chronic inflammation in this condition, all of the following are characteristic EXCEPT:

Explanation

## Chronic Inflammation: Key Cellular and Molecular Features **Key Point:** Chronic inflammation is characterized by a prolonged course (weeks to years) with simultaneous tissue destruction and attempted repair, NOT rapid resolution. ### Characteristic Features of Chronic Inflammation | Feature | Description | Mechanism | |---------|-------------|----------| | **Cell type** | Lymphocytes, macrophages, plasma cells, fibroblasts | Persistent antigen/irritant stimulation | | **Tissue response** | Fibrosis, angiogenesis, granulation tissue | Repair attempt alongside ongoing injury | | **Duration** | Weeks to months to years | Unresolved causative stimulus | | **Outcome** | Tissue destruction + scarring | Chronic cycle of injury and repair | | **Acute inflammation** | Rapid onset, neutrophil-dominant, resolves in days | Opposite of chronic | ### Why Option 3 is Incorrect **High-Yield:** Chronic inflammation does NOT resolve rapidly. By definition, it persists for weeks to years. The hallmark is **simultaneous tissue destruction and repair**, not complete restoration. Acute inflammation resolves in 2–3 weeks; chronic inflammation does not. ### Why the Other Options Are Correct 1. **Lymphocytes and macrophages** — The classic chronic inflammatory infiltrate, replacing the neutrophil-dominant acute phase. 2. **Fibroblast proliferation and collagen deposition** — Central to chronic inflammation; leads to fibrosis and scarring (e.g., pulmonary fibrosis in TB, hepatic cirrhosis). 4. **Angiogenesis and granulation tissue** — Part of the reparative phase; new blood vessels and connective tissue form as the body attempts healing. **Clinical Pearl:** In rheumatoid arthritis, chronic inflammation drives pannus formation (fibroblast-rich tissue) that erodes cartilage and bone — a hallmark of chronic joint disease. **Mnemonic:** **CLAM** = **C**hronic, **L**ymphocytes, **A**ngiogenesis, **M**acrophages — the four pillars of chronic inflammation.