In sputum, absolute IL-5 + HPC counts, but not percentages, were elevated in COPD patients with sputum eosinophilia (16.83 ± 14.65 × 102 /gram of sputum vs 0.19 ± 0.07 × 102 /gram of sputum; p < 0.01) (Fig. 6d and e). Here, IL5 is linked to chronic obstructive pulmonary disease.