Despite generally good adherence to her ICS regimen, for the past 2 years Joanne has exhibited a pattern of relatively stable dyspnea (difficult breathing) that deteriorates during airway infections.

Results of examination:
• FEV1 is 25% of expected, with 33% reversibility.
• FENO is 12 ppb.

Questions:
• Is Joanne’s COPD becoming more severe?
• Is her COPD responsive to ICS therapy?

Interpretation:
As noted in Frank’s case, many patients with COPD may have been prescribed ICS based on unknown criteria, possibly raising questions about the appropriateness of continuing with such a regimen. In such cases, measurement of FENO levels may help identify patients with severe, unstable COPD, as well as those who are likely to respond to ICS treatment.

Action:
Joanne’s doctor tells her to stop taking her inhaled beclomethasone.

Results:
Within 2 weeks of discontinuing ICS therapy, Joanne’s FENO value rapidly rises to 60 ppb – a pattern reminiscent of asthma.
The ICS regimen is reinstated, whereupon Joanne’s FENO gradually decreases to baseline levels over the next 5 weeks.

Conclusion:
Joanne has a case of COPD-eosinophilic related inflammation that appears to respond to ICS therapy.