Table 5. Characteristics of patients with PTB stratified by MTB-cfDNA positivity and analysis of factors associated with MTB-cfDNA positivity.
| Variable | MTB-cfDNA positive | P value | Multivariate analysis | P value | |
|---|---|---|---|---|---|
| Yes (n = 13) | No (n = 11) | Adjusted OR (95% CI) | |||
| Age, years | 66.4±19.9 | 57.0±22.1 | 0.284 | 1.073 (0.990–1.163) | 0.085 |
| Male sex | 9 (69) | 8 (73) | 1.000 | 0.690 (0.060–7.959) | 0.766 |
| BMI (kg/m2) | 21.9±3.9 | 20.0±2.4 | 0.173 | ||
| Ever smoker | 8 (62) | 7 (64) | 1.000 | ||
| Diabetes | 5 (38) | 1 (9) | 0.166 | ||
| Malignancy | 2 (15) | 2 (18) | 1.000 | ||
| CKD | 1 (8) | 0 | 1.000 | ||
| Fever | 2 (15) | 0 | 0.482 | ||
| BCG scar | 9 (69) | 9 (90) | 0.339 | ||
| Smear positive | 7 (54) | 4 (36) | 0.444 | ||
| Multi-lobar or cavitary lesion | 9 (69) | 5 (45) | 0.408 | ||
| IGRA positive | 13 (100) | 9 (82) | 0.199 | ||
| IFN-γ (IU/mL) | |||||
| MTB-Ag—nil | 7.25±2.71 | 2.99±3.52 | 0.003 | 1.772 (1.117–2.809) | 0.015 |
| MLR >0.42 | 10 (77) | 6 (55) | 0.390 | ||
Abbreviations: BCG, Bacillus Calmette–Guérin vaccine; BMI, body mass index; cfDNA, cell-free DNA; CKD, chronic kidney disease; IFN-γ, interferon-gamma; IGRA, interferon-gamma release assay; MLR, monocyte to lymphocyte ratio; MTB-Ag, Mycobacterium tuberculosis (MTB)-specific antigen stimulation.