CXCL8 and chronic obstructive pulmonary disease: Our findings suggest that IL-8 is a target to explore further as a biomarker in predicting 28 days mortality, in patients with AHRF (Acute Hypercapnic Respiratory Failure) and AECOPD (Acute Exacerbation of COPD) who receive treatment with NPPV (Noninvasive Positive Pressure Ventilation).