However, the pfLDH/pfADA ratio outperformed pfLDH alone, with a superior AUC of 24.32, offering high sensitivity (94.6%) and specificity (94.4%).Previous research [29] also highlighted significant differences in the pfLDH/pfADA ratio between TPE and PPE, where MPE or empyema/PPE patients showed notably higher ratios than TPE patients [28].Kim et al. [30] found that the pfADA/serum CRP ratio had higher diagnostic value than the pfADA/pfLDH ratio. The gene discussed is CRP; the disease is empyema.