OK-432 pleurodesis for the treatment of pneumothorax in patients with interstitial pneumonia

Background: Pneumothorax occasionally develops in patients with interstitial pneumonia (IP) and is often intractable. As there exists no well-established treatment for pneumothorax with IP, we evaluated the efficacy and safety of pleurodesis with OK-432, a lyophilized preparation of Streptococcus pyogenes Su strain that has been inactivated by benzylpenicillin. Methods: We retrospectively evaluated the efficacy and safety of pleurodesis using OK-432 in 39 patients treated for IP-related pneumothorax between January 2006 and May 2017. Five to 10 Klinische Einheit (KE) of OK-432 was injected through the chest tube of each patient. Pleurodesis was considered successful if 1) the chest tube was removed without air leaks and 2) there was no recurrence of pneumothorax within 4 weeks after tube removal, and no additional treatment was required. Results: OK-432 pleurodesis was performed 46 times in 39 patients. The median number of OK-432 intrapleural injections received was 1 (range, 1-6), and median dose was 10 KE (range, 5-55 KE). The success rate was 63% (29/46) and recurrence rate was 17.4% (8/46). Grade 5 adverse events were observed in eight patients, including two patients who developed acute exacerbation of IP. Patients in whom the first OK-432 pleurodesis was successful had a significantly longer median survival time than patients in whom it was unsuccessful (322 days vs. 70 days, p = 0.036). Conclusions: Our results show that OK-432 pleurodesis is an effective treatment for pneumothorax associated with IP; however, clinicians should be aware of the possibility of adverse events, especially in patients who are critically ill. Copyright (C) 2018 The Japanese Respiratory Society. Published by Elsevier B.V. All rights reserved.