Table 1. Characteristics of patients with PTB and controls with LTBI (n = 81).
| Variable | PTB cases (n = 24) | LTBI controls (n = 57) | P value |
|---|---|---|---|
| Age, years | 62.1±21.0 | 63.7±17.4 | 0.727 |
| Male sex | 17 (71) | 30 (43) | 0.028 |
| BMI (kg/m2) | 21.0±3.4 | 23.4±3.2 | 0.003 |
| Ever smoker | 15 (63) | 16 (23) | 0.003 |
| Diabetes | 6 (25) | 12 (17) | 0.680 |
| Malignancy | 4 (17) | 4 (6) | 0.187 |
| CKD | 1 (4) | 2 (3) | 1.000 |
| BCG scar | 18 (78) | 53 (79) | 1.000 |
| IFN-γ (IU/mL) | |||
| MTB-Ag–nil | 5.30±3.73 | 2.78±2.91 | 0.005 |
| Mitogen–nil | 7.63±3.04 | 9.35±1.37 | 0.005 |
| Differential counts a | |||
| Lymphocyte (k/mm3) | 1.37±0.42 | 1.85±0.53 | <0.001 |
| Monocyte (k/mm3) | 0.68±0.36 | 0.51±0.21 | 0.006 |
| MLR | 0.52±0.22 | 0.28±0.10 | <0.001 |
| qPCR Ct value | 38.06 [35.73–45] | 45.0 [45.0–45.0] | <0.001 |
aFor two patients with LTBI, no data on blood differential count or MLR were available.
Abbreviations: BCG, Bacillus Calmette–Guérin vaccine; BMI, body mass index; CKD, chronic kidney disease; IFN-γ, interferon-gamma; MLR, monocyte to lymphocyte ratio; MTB-Ag, Mycobacterium tuberculosis–specific antigen stimulation; qPCR Ct value, quantitative polymerase chain reaction–derived cycle threshold value.