TB Exclusion in AOSD Patients with Previous TB History

Initial Clinical Assessment

The American Thoracic Society recommends verifying documentation of previous TB diagnosis and confirming whether treatment was adequate (duration, regimen completion, treatment response) in AOSD patients with previous TB history 1
Assess current immunosuppression status, as AOSD patients often receive corticosteroids or immunosuppressive therapy that increases TB reactivation risk, according to the Journal for ImmunoTherapy of Cancer 4, 1

Chest radiography is the initial imaging modality, looking for upper lobe infiltrates, cavitation, fibro-cavitary disease, mediastinal/hilar lymphadenopathy, or atypical infiltrates, as recommended by the Praxis Medical Insights 2, 3
Proceed directly to chest CT if the patient is on immunosuppressive therapy, even with normal chest X-ray, as immunocompromised patients frequently have deceptively normal radiographs, according to the Praxis Medical Insights 2, 3

Perform Interferon-Gamma Release Assay (IGRA) rather than tuberculin skin test (TST), as IGRA avoids false-positive results from BCG vaccination common in many countries, as recommended by the Journal for ImmunoTherapy of Cancer and the Praxis Medical Insights 4, 5
Interpret TST ≥5mm as positive if performed in immunocompromised patients, those with recent TB contact, or radiographic evidence of old TB, according to the MMWR Recommendations and Reports and the Praxis Medical Insights 6, 2, 5

Patients with documented adequate previous TB treatment can proceed with AOSD therapy but require clinical monitoring every 3 months for TB reactivation, as recommended by the Thorax journal 1
Exclude active TB through investigations before initiating or continuing immunosuppressive therapy in patients with inadequately treated or undocumented previous TB, according to the Thorax journal 1

Never rely on chest radiography alone in immunocompromised patients—proceed to CT imaging, as recommended by the Praxis Medical Insights 2, 3
Do not interpret negative AFB smears as excluding TB when clinical and radiographic suspicion is high, according to the Praxis Medical Insights 3
TST/IGRA positivity indicates TB infection but does not distinguish active from latent disease; positive results mandate imaging and microbiological workup, as recommended by the Praxis Medical Insights 2, 5
Anergy is common in immunocompromised patients; negative TST/IGRA does not exclude active TB, according to the Journal for ImmunoTherapy of Cancer and the Praxis Medical Insights 4, 2

Distinguish AOSD fever patterns (quotidian spiking) from persistent fever suggesting active TB, as recommended by the Annals of the Rheumatic Diseases 7
Hepatosplenomegaly and lymphadenopathy occur in both AOSD and disseminated TB, requiring careful differentiation, according to the Annals of the Rheumatic Diseases 7