We report a case of tuberculous pleurisy in a 54-year-old man who initially presented with negative interferon-gamma release assay (IGRA) results and elevated pleural fluid adenosine deaminase (ADA) levels. Bacteriological confirmation was obtained only when the pleural fluid culture grew Mycobacterium tuberculosis one month later. The IGRA yielded positive results approximately two months after symptom onset. This case highlights the limitations of IGRAs and ADA as definitive diagnostic tools and underscores the need to consider primary tuberculosis in early IGRA negative cases. Clinicians should be aware of the time-dependent nature of immune sensitization when evaluating patients with suspected tuberculous pleurisy.
Takeda et al. (2026) studied this question.