Inflammation and Immune Pathology USMLE Step 1 Practice Question
A 45-year-old woman with systemic sclerosis presents with progressive skin thickening and dyspnea. Vital signs show BP 138/82, HR 98, RR 22, SpO2 92% on room air. Chest X-ray reveals bilateral interstitial infiltrates. Skin biopsy demonstrates excessive collagen deposition with prominent fibroblast and myofibroblast proliferation. Notably, inflammatory cell infiltration is minimal. Which cytokine is most responsible for the fibrotic pathology in this patient?
Answer choices
- ATumor necrosis factor-alpha (TNF-α) inducing endothelial cell apoptosis
- BTransforming growth factor-beta (TGF-β) promoting fibroblast differentiation and collagen synthesisCorrect answer
- CInterleukin-10 (IL-10) suppressing macrophage activation and inflammation
- DInterleukin-4 (IL-4) promoting Th2 differentiation and antibody production
- EInterleukin-2 (IL-2) driving Th1 cell proliferation and IFN-γ production
- FInterleukin-6 (IL-6) activating B cell differentiation and immunoglobulin production
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