Clinical features in secondary and cryptogenic organising pneumonia.

SETTING

The clinical differences between cryptogenic organising pneumonia (COP) and secondary organising pneumonia (OP) have not been studied well.

OBJECTIVE

To compare clinical features in COP and secondary OP.

DESIGN

Causes, clinical features, treatment, radiographic studies and pathology were studied.

RESULTS

After re-evaluation, 104 patients fulfilled the diagnostic criteria, 58 for COP and 46 for secondary OP. The mean age was 68 years. Most of the patients were smokers (79/104). Infections were the most common causes of secondary OP (21/46). Cough was the most common symptom and crackles the most common sign. Crackles were more common in patients with secondary OP (P = 0.02). Transbronchial biopsy was the diagnostic test in 81/104 cases. Most patients had lowered partial oxygen pressure (PO(2)) and mildly restrictive spirometry, with no differences between the two groups. Radiographic features were similar. Corticosteroids were the treatment in 70% of the patients, but 27% received no pharmacological treatment. The average initial dose of steroids was 42 mg prednisolone, and was similar for both groups. Relapses were seen in 20% of cases, with no difference between the two groups.

CONCLUSION

There were no major differences in clinical features of COP and secondary OP, except that crackles were more common in secondary OP.