Impact of computed tomographic patterns and extent on clinical management and outcomes of patients with organizing pneumonia

Background Organizing pneumonia (OP) has variable clinical and radiographic presentations and unstandardized treatments. Most patients with OP have favourable outcomes, but some develop respiratory insufficiency, experience recurrence, or die. In this study we investigated the impact of computed tomographic (CT) patterns and extent of OP on the diagnostic and therapeutic management that patients received, and that on the therapeutic response and prognosis (particularly the risk of respiratory insufficiency and death).

Methods We retrospectively studied 156 patients with OP followed at our hospital between 2010 and 2021. The diagnosis was confirmed histologically and verified by multidisciplinary specialists. We performed Firth's logistic regression to determine the relationship between CT features and aetiologies, management, and outcomes including the risk of severe disease (defined as the need of supplemental oxygen or mechanical ventilation). We conducted Kaplan-Meier analyses to assess survival differences.

Results Patients exhibiting multi-lobe involvement or mixed patterns, or both, were more likely to have secondary OP and receive immunosuppressants. Higher proportions of these patients experienced recurrence. Compared to patients with single-lobe involvement and single-pattern, they also had an enhanced risk of severe disease (the adjusted odds ratio for patients who simultaneously had multi-lobe involvement and mixed patterns was 27.64; 95% confidence interval, 8.25–127.44). Besides, these patients had decreased survival probabilities.

Conclusion Different CT features of OP impact patients’ management and prognosis. When treating patients with OP exhibiting multi-lobe involvement or mixed patterns, or both, it is important to identify the possible causative aetiology and follow closely for adverse outcomes.