CD33 and idiopathic pulmonary fibrosis: Conversely, CD33+ HLA DR+ absolute counts (OR=0.94, 95% CI [0.88-0.99], P=0.016), CD33+ HLA DR+ CD14dim absolute counts (OR=0.92, 95% CI [0.87-0.98], P=0.006), CD33 on CD33dim HLA DR+ CD11b+ (OR=0.96, 95% CI [0.85-1.08], P=0.037), and CD66b on CD66b++ myeloid cells (OR=0.89, 95% CI [0.82-0.96], P=0.005) were associated with a reduced risk of IPF development.