Onset of Pneumothorax Carries Poor Prognosis for Patients With CTD-ILD

Historically, few studies have focused on what implications spontaneous pneumothorax has on patients with connective tissue disease-associated interstitial disease (CTD-ILD). A new study is now putting a spotlight on these implications, finding that the complication does not bode well for disease prognosis.

According to the study, published in PLoS ONE, the onset of spontaneous pneumothorax is strongly indicative of a poor outcome for patients. In fact, these patients were more than 20 times more likely to have a poor prognosis compared with patients who did not develop pneumothorax (HR 22.0; 95% CI 10.3—46.9; P <.001).

“The study highlights the clinical importance of pneumothorax as a serious complication associated with poor outcomes in patients with CTD-ILD, of which clinicians should be aware in the clinical course of CTD-ILD,” stressed the researchers.

According to the researchers, this complication was common among the 140 patients who received a CTD-ILD diagnosis between January 2000 and December 2014. Over the course of the study, 18 had developed pneumothorax. The cumulative incidence was 6.5% at 1 year, 8.7% at 3 years, and 11.3% at 5 years following diagnosis. Fifty percent of patients who developed pneumothorax had developed the complication within 1 year of their CTD-ILD diagnosis.

Throughout the study, 33 patients died, with the mortality rate falling significantly higher among patients who developed pneumothorax than those who did not (66.7% vs 17.2%, respectively). Consequently, patients with pneumothorax also had worse 10-year survival rates. Patients with the complication had a 10-year survival rate of just under 30% (29.6%) compared to a rate of 81.3% among patients without the complication.

“It was important to elucidate the predictive factors for the onset of pneumothorax as our findings demonstrated that pneumothorax was significantly associated with poorer outcomes in patients with CTD-ILD,” noted the researchers. “In the present study, we found that a lower BMI was associated with the onset of pneumothorax in patients with CTD-ILD, which is consistent with previous reports regarding primary spontaneous pneumothorax and secondary pneumothorax in patients with [idiopathic pulmonary fibrosis].”

Aside from BMI, greater extent of reticular abnormalities (>Grade 2) and the administration of methylprednisolone pulse therapy were heavily associated with the onset of pneumothorax. Among all patients, 37.1% received intravenous methylprednisolone pulse therapy. Patients receiving the treatment were more than 3 times more likely to develop the complication.

Other therapies used in the study included prednisolone alone and prednisolone in combination with immunosuppressive agents.

Reference

Nishimoto K, Fujisawa T, Yoshimura K, et al. Pneumothorax in connective tissue disease-associated interstitial lung disease. PLoS ONE. Published online July 7, 2020. doi: 10.1371/ journal.pone.0235624