Intrathoracic Administration of OK-432 Elevates the Serum Procalcitonin Levels

OBJECTIVE: The intrathoracic administration of OK-432, a lyophilized preparation of the heat- and penicillin-treated Su-strain of type 3, group A Streptococcus pyogenes, is performed in Japan for pleurodesis of malignant pleural effusion or pneumothorax. Persistent fever is often observed after pleurodesis. To elucidate whether procalcitonin (PCT) is useful for distinguishing between the side effects of OK-432 and infection, we measured the serum PCT levels before and after pleurodesis. METHODS: We performed a prospective study of 12 patients with refractory pleural effusion or pneumothorax who required pleurodesis using OK-432 between August 2011 and February 2012. The serum PCT and C-reactive protein (CRP) levels were measured on days 1 and 3. RESULTS: Of the 12 patients, five had pneumothorax and seven had uncontrolled pleural effusion with carcinomatous pleurisy. The median serum levels of PCT and CRP increased from 0.055 to 1.59 ng/mL (p=0.0022) and from 1.52 to 16.82 mg/dL (p=0.0022), respectively. The fevers subsided without antibiotic administration. CONCLUSION: The serum PCT level may not be useful for distinguishing fever caused by side effects of OK-432 from that caused by bacterial infection. The intrathoracic administration of OK-432 increased the serum levels of both PCT and CRP in the absence of any bacterial infection.