TY - JOUR T1 - Clinical aspects of pleural disease JF - Thorax JO - Thorax SP - A138 LP - A140 VL - 63 IS - Suppl 7 A2 - , Y1 - 2008/12/01 UR - http://thorax.bmj.com/content/63/Suppl_7/A138.abstract N2 - 1JM Wrightson, 1NM Rahman, 2T Novak, 2JF Huggett, 3RF Miller, 1RJO Davies. 1Oxford Pleural Unit, Oxford Centre for Respiratory Medicine, Churchill Hospital, Oxford Radcliffe Hospitals NHS Trust, Oxford, UK, 2Centre for Infectious Diseases and International Health, Windeyer Institute for Medical Sciences, University College London, London, UK, 3Centre for Sexual Health and HIV Research, Department of Primary Care and Population Sciences, University College London, London, UKIntroduction: Up to 26% of pleural infections have no pathogens identified using standard microbiological and genetic amplification techniques. Possible explanations for this phenomenon include previous use of antibiotics, microbiologically different pleural fluid locules, or difficulty isolating organisms using conventional techniques. Pneumocystis jirovecii (previously carinii) causes pneumonia in immunocompromised hosts. Previous studies have demonstrated an asymptomatic carrier state in immunocompetent individuals—P jirovecii DNA was detected in the bronchoalveolar lavage fluid of 18% of patients with lung disease, 4.4% with bacterial pneumonia (both without HIV) and in the oropharynx of 20% of healthy individuals. We hypothesised that P jirovecii may account for some microbiologically obscure pleural infections and that co-infection with P jirovecii and bacteria may occur in pleural infection. The aim of this study was to assess the prevalence of P jirovecii in pleural infection, using highly sensitive and specific genetic detection techniques.Methods: Pleural fluid was obtained from participants in the MIST1 trial (a double-blind, placebo-controlled trial of intrapleural streptokinase in pleural infection). Criteria for pleural infection were purulence, culture positivity, Gram staining positivity, or pH below 7.2, with clinical evidence of infection. Samples from 100 patients (randomly selected from 454 patients recruited) were analysed using highly sensitive real-time PCR targeting part of the P jirovecii heat shock 70 (HSP70) gene sequence. Potential inhibition of P jirovecii HSP70 PCR was assessed by the use of … ER -