CRP and chronic obstructive pulmonary disease: Neutrophil-to-Lymphocyte Ratio (NLR), Platelet-to-Lymphocyte Ratio (PLR), and Monocyte-to-Lymphocyte Ratio (MLR) serve as reliable indicators of systemic inflammatory response and exhibit significant elevation in AECOPD patients compared to stable COPD patients, positively correlating with C-reactive protein (CRP) levels and disease severity (6, 7).