We evaluated the utility of follow-up interferon-gamma release assays (IGRAs) for the diagnosis of reactivation of latent tuberculosis infection (LTBI) or new tuberculosis in ankylosing spondylitis (AS) patients receiving anti-tumor necrosis factor alpha (anti-TNFalpha). The study participants (n=127) had a negative IGRA screening before receiving anti-TNFalpha and were evaluated by follow-up IGRA. We retrospectively examined data of the subjects according to age, gender, tuberculosis prophylaxis, concomitant medications, IGRA conversion and anti-TNFalpha, including type and treatment duration. The median duration of anti-TNFalpha was 21.5 months, and the median age was 35.3 yr. Of the 127 patients, IGRA conversion was found in 10 patients (7.9%). There was no significant variation between IGRA conversion rate and any risk factors except for age. IGRA conversion rate was not significantly different between AS and rheumatoid arthritis (P=0.12). IGRA conversion was observed in AS patients receiving anti-TNFalpha in Korea. A follow-up IGRA test can be helpful for identifying LTBI or new tuberculosis in AS patients receiving anti-TNFalpha.
Adult ; Aged ; Aged, 80 and over ; Antibodies, Monoclonal/*adverse effects/*therapeutic use ; Antirheumatic Agents/adverse effects/therapeutic use ; Female ; Follow-Up Studies ; Humans ; Interferon-gamma/*blood ; Latent Tuberculosis/*blood/*chemically induced/diagnosis ; Longitudinal Studies ; Male ; Middle Aged ; Prognosis ; Reproducibility of Results ; Sensitivity and Specificity ; Spondylitis, Ankylosing/blood/*drug therapy ; Treatment Outcome ; Tumor Necrosis Factor-alpha/antagonists & inhibitors