Ankylosing spondylitis (AS) involves chronic inflammation; why does TNF-alpha blockade eventually lose efficacy in some AS patients?

💡 Explanation

TNF-alpha blockade initially reduces inflammation. However, other cytokines and inflammatory mediators can compensate over time, leading to inflammation via alternative pathways; therefore, TNF-alpha blockade loses efficacy rather than antibody degradation or receptor downregulation fully explaining the effect.

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