MBL2 and chronic obstructive pulmonary disease: The median serum MBL in COPD II patients was (590 ng/ml, [IQR; 106–2106 ng/ml]), COPD III (659 ng/ml, [IQR; 94–2,363 ng/ml]), and COPD IV (491 ng/ml, [IQR; 85–2,120 ng/ml]).