Abstract
BACKGROUND: The increasing number of patients with miliary tuberculosis (MTB) is a concern in an aging society because of its high mortality rate. Several prognostic biomarkers for MTB have been identified; however, the predictive ability of monocytes as biomarkers remains unknown. This study demonstrates the usefulness of monocytes as prognostic biomarkers for MTB. MATERIALS AND METHODS: We retrospectively compared the clinical findings of 52 patients with MTB hospitalized between April 2013 and October 2021. The predictive ability of biomarkers for 3-month prognosis and their cutoff values were calculated. Survival times and longitudinal changes in monocytes after initiating treatment were compared. RESULTS: A smaller number of monocytes (#M), higher lymphocyte-monocyte ratio (LMR), higher neutrophil-monocyte ratio, and poorer performance status were associated with death within 3 months. #M was an independent prognostic factor. #M and LMR exhibited the highest predictive performance compared to others using receiver operating characteristic curve analysis (area under the curve = 0.86 and 0.85, respectively). Survival time was shorter in patients with #M ≤ 200 cells/μL and LMR > 2.5. Rapidly increasing #M after treatment was related to better prognosis in patients with #M ≤ 200 cells/μL at diagnosis. CONCLUSIONS: #M at diagnosis and longitudinal changes in monocytes are related to MTB prognosis.