MRC1 and chronic obstructive pulmonary disease: Other studies show that the numbers and percentages of CD163+, CD204+ or CD206+ alveolar macrophages in patients with COPD at GOLD stages III and IV are significantly higher than in those at GOLD stages I and II and those in smokers and nonsmokers with a significant negative correlation between the number of CD163+, CD204+ or CD206+ alveolar macrophages and the predicted FEV1 [70].