Non-invasive measurement of transcutaneous carboxyhemoglobin (SpCO) by CO-oximetry has been shown to reflect disease activity in asthma, allergic rhinitis, Staphylococcal pneumonia/sepsis and to correlate positively with lung function in cystic fibrosis. Given published studies of heme oxygenase activity in these diseases as a reflection of oxidant or inflammatory activity, does measurement of SpCO reflect endogenous... more »