Objective       To evaluate the incidence

clinical characteristics and risk factors of the development of paradoxical response (PR) in patients with pleural tuberculosis (TB).       Methods      A retrospective cohort study including 527 patients with diagnosed pleural TB and received anti-TB treatment was carried out.       Results      PR was present in 80 (15%) of 527 patients after (54±38) d following the initiation of treatment. Fever and dyspnoea were the most common symptoms associated with PR. Twenty-six (33%) patients were misdiagnosed as drug-resistant TB

12 (15%) patients were misdiagnosed as pneumonia

and 7 (9%) patients were misdiagnosed of lung cancer. The risk factors for PR were younger age

low serum albumin level

and low white blood cell (WBC) count

low proportion of lymphocyte and high proportion of polymorphonuclear neutrophil (PMN) in pleural fluid (all P0.05).       Conclusion      PR is common in pleural TB treatment and is frequently misdiagnosed.  Younger age

hypoalbuminemia

low WBC count

low proportion of lymphocyte and high proportion of PMN in pleural fluid are associated with the development of PR.