Clinical demographics of included study subjects
| Clinical features, n (%) | Symptomatic TB suspects | Asymptomatic individuals | |||||
|---|---|---|---|---|---|---|---|
| Total active TB (n=84) | Pulmonary TB (n=35) | Pleural TB (n=23) | Lymph node TB (n=26) | Other diseases* (n=12) | Latent TB (n=45) | Non-TB controls (n=40) | |
| Median age in years (range) | 27 (18–72) | 27 (18–54) | 28 (18–72) | 26 (18–57) | 39 (20–55) | 29 (18–60) | 28 (18–68) |
| Men/women | 45/39 | 20/15 | 11/12 | 14/12 | 5/7 | 29/16 | 13/27 |
| Abnormal chest x-ray† | 58 (69%) | 35 (100%) | 23 (100%) | 0 (0%) | 7 (58%) | 0 (0%) | 0 (0%) |
| Positive Mtb culture‡ | 24 (29%) | 24 (69%) | ND | ND | 0 (0%) | ND | ND |
| Positive Mtb cyto-histopathology | 49 (58%) | ND | 23 (100%) | 26 (100%) | 0 (0%) | ND | ND |
| Positive TST ≥10 mm | 75 (89%) | 30 (86%) | 20 (87%) | 25 (96%) | 3 (25%) | 45 (100%) | 0 (0%) |
| Positive QFTG (cut-off 0.35)§ | 66 (79%) | 25 (71%) | 17 (74%) | 24 (92%) | 3 (25%) | 45 (100%) | 0 (0%) |
| HIV infection | 27 (32%) | 12 (34%) | 7 (30%) | 8 (31%) | 4 (33%) | 10 (22%) | 22 (55%) |
| Parasite infections¶ | 9 (11%) | 4 (11%) | 1 (4.3%) | 4 (15%) | 0 (0%) | ND | ND |
| BCG vaccination | 17 (20%) | 10 (29%) | 5 (22%) | 2 (7.7%) | 3 (25%) | 12 (27%) | 10 (25%) |
| Disease outcome (cured)** | 62 (74%) | 24 (69%) | 20 (87%) | 18 (69%) | ND | ND | ND |
↵* Diseases other than TB included patients with confirmed pneumonia (n=3), malignancies (n=4) or non-specific reactive lymphadenitis (n=5).
↵† Abnormal radiological chest x-ray findings included pulmonary infiltrates, pleural effusions and dense lesions.
↵‡ Mtb culture was performed on bronchoalveolar lavage obtained from patients with pulmonary TB. Mtb culture-negative patients (n=11) all had clinical symptoms of TB, abnormal chest x-ray findings and responded to standard anti-TB treatment.
↵§ Indeterminant QFTG responses were found in: pulmonary TB (n=2), pleural TB (n=2), and lymph node TB (n=1). All indeterminant results were from patients with TB/HIV coinfection.
↵¶ Parasite infections at the time of diagnosis included strongyloides stercoralis, ascaris, trichuris trichiura, amoeba histolytica. n=6/9 patients with TB with parasite infections were HIV positive.
↵** Disease outcome evaluated 8 months after the start of standard anti-TB therapy included response to treatment as determined by clinical recovery and resolution of lesions evident on the chest x-ray. A few patients (n=11) did not fully recover, and some were lost to follow-up (n=11).
ALS, Antibodies in Lymphocyte Supernatant; Mtb, Mycobacterium tuberculosis; ND, not determined; QFTG, QuantiFERON-TB Gold in-Tube; TB, tuberculosis; TST, tuberculin skin test.