BACKGROUND: Ocular tuberculosis (TB) affects 1-2% of patients with TB, with TB uveitis being the most common. This series aims to look at different manifestations of tuberculosis associated uveitis and the different tests used to make a presumptive or definitive diagnosis.
METHODS: Patients diagnosed with TB related uveitis in Hong Kong SAR between 2017 and 2020 were reviewed. Demographics, clinical features, investigations and treatments of patients were collected.
RESULTS: Fifteen eyes in 10 patients with a mean age 57.30 ± 10.17 years were included. The ocular manifestations on presentation included anterior uveitis (50%), posterior uveitis (40%) and panuveitis (10%), where 70% of them were unilateral and 30% were bilaterally infected; on subsequent visits the manifestations further developed into posterior uveitis (40%), panuveitis (40%) and anterior uveitis (20%), where 50% of them were unilateral and 50% bilateral infected. Tuberculosis tests were positive in 5 out of 7 Mantoux tests, 4 out of 4 T-SPOT TB tests, 3 out of 4 QuantiFERON-TB gold tests, 1 out of 1 lymph node biopsy, 0 out of 9 chest x-rays, and no aqueous fluid polymerase chain reaction (PCR) was tested. Vision impairing complications were seen in 6 patients where retinal vasculitis was most commonly seen. With anti-TB treatment prescribed in 9 patients, side effects occurred in 5 patients, including ocular hypertension, disc swelling, and hepatitis.
CONCLUSIONS: Ocular TB infections may manifest in various forms, and can involve different parts of the eye. Bilateral involvement of TB is commonly presented, and both eyes should be evaluated at every follow up. When TB is suspected in a patient, diagnostic confirmation requires multimodal investigations where a negative chest x-ray is not useful in ruling out ocular TB infections, especially in an endemic region like Hong Kong. In these patients, it is crucial to have a high index of suspicion for TB, even when they do not demonstrate classical respiratory signs and symptoms of TB.

OBJECTIVE: To investigate the possibility of combining tuberculosis (TB)-interferon (IFN)-γ release assays (IGRAs) with lymphocyte enumeration for diagnosis of Mycobacterium tuberculosis infection.
METHODS: We performed a retrospective study of 166 TB patients [68 patients with pulmonary tuberculosis TB (PTB) and 98 patients with extra-pulmonary TB (EPTB)] diagnosed in our hospital between January 2016 and May 2018 along with 377 non-TB patients. The diagnostic performance of the TB-IGRA was evaluated using receiver operating characteristic (ROC) curves. Youden\'s index was used to determine the optimal cut-off threshold.
RESULTS: IFN-γ release in patients with PTB and EPTB were dramatically higher compared with non-TB patients (203.58±18.00 pg/mL, 201.83±14.56 pg/mL and 32.12±4.36 pg/mL, respectively). IFN-γ release was positively correlated with lymphocyte counts and percentages in patients with PTB (r = 0.252 and r = 0.278, respectively) and EPTB (r = 0.229 and r = 0.298, respectively). No correlation was observed in non-TB patients. The area under the ROC curve for TB-IGRA was 0.884. When the optimal cut-off value for IFN-γ (14 pg/mL, Youden\'s index 0.661) was applied, the sensitivity was 88.6% and the specificity was 77.5%.
CONCLUSIONS: Combining TB-IGRA with lymphocyte enumeration was effective for diagnosis of early-stage Mycobacterium tuberculosis infection.

BACKGROUND: Quick diagnosis of smear-negative pulmonary tuberculosis (TB) and extra-pulmonary TB are urgently needed in clinical diagnosis. Our research aims to investigate the usefulness of the interferon-γ release assay (IGRA) for the diagnosis of smear-negative pulmonary and extra-pulmonary TB.
METHODS: We performed TB antibody and TB-IGRA tests on 389 pulmonary TB patients (including 120 smear-positive pulmonary TB patients and 269 smear-negative pulmonary TB patients), 113 extra-pulmonary TB patients, 81 patients with other pulmonary diseases and 100 healthy controls. Blood samples for the TB-Ab test and the TB-IGRA were collected, processed, and interpreted according to the manufacturer\'s protocol.
RESULTS: The detection ratio of smear-positive pulmonary TB patients and smear-negative pulmonary TB patients were 90.8% (109 of 120) and 89.6% (241 of 269), respectively. There was no statistically significant difference of its performance between these two sample sets (P > 0.05). The detection ratio of positive TB patients and extra-pulmonary TB patients were 90.0% (350 of 389) and 87.6% (99 of 113), respectively, which was not significantly different (P > 0.05).
CONCLUSIONS: In this work, the total detection ratio using TB-IGRA was 89.4%, therefore TB-IGRA has diagnostic values in smear-negative pulmonary TB and extra-pulmonary TB diagnosis.

OBJECTIVE: To investigate the risk factors for false-negative T-SPOT.TB results in patients with pulmonary TB (PTB) and extra-pulmonary TB (EPTB).
METHODS: Patients with suspected TB who underwent valid T-SPOT.TB tests were prospectively enrolled at Beijing Chest Hospital between November 2012 and November 2013. Basic characters and clinical laboratory findings were compared between true-positive and false-negative T-SPOT.TB groups.
RESULTS: Of 1928 suspected TB patients, 774 (530 PTB and 244 EPTB) microbiologically/histopathogenically-confirmed patients (636 culture-confirmed) were analyzed. Forty-six PTB patients (8.7%) and 32 EPTB patients (13.1%) had negative T-SPOT.TB results. Multivariate analysis showed that increased age [odds radio (OR) 2.26, 95% confidence interval (CI) 1.11-4.58], over-weight (BMI ≥ 25 kg/m(2), OR 2.43, 95% CI 1.05-5.63), and a longer period of illness before hospitalization (>6 months, OR 2.46, 95% CI 1.24-4.92) were independent risk factors for false-negative T-SPOT.TB results in PTB patients. In EPTB patients, increased age (OR 2.42, 95% CI 1.09-5.35) also showed an independent association with false-negative T-SPOT.TB results.
CONCLUSIONS: Careful interpretation of negative T-SPOT.TB results is necessary in older patients with suspected PTB or EPTB, and in PTB patients who are over-weight or have had longer periods of illness before hospitalization.