Can a bacterial respiratory tract infection be excluded only based on procalcitonin levels? Is it necessary to measure C-reactive protein (CRP) levels?
Jadwiga Wedzicha, MD: The use of procalcitonin is interesting. I will deal with that first. I think it is useful in pneumonia, it has been useful potentially in intensive care. We started [measuring] procalcitonin in COPD because there had been some studies. And we actually found the change is very small.
The problem is that in chronic obstructive pulmonary disease (COPD) you have underlying airway bacterial colonization. The changes in procalcitonin may be relatively small. CRP goes up. The higher the CRP, the more likely you are to have a bacterial infection. But as we know, CRP is not that specific. That is the problem.