We conducted a long-term follow-up study in patients with
rheumatic diseases who were candidates for biologics treatment to evaluate the effects of biologic agents on the risk of
tuberculosis infection and the effect of prophylactic treatment on
tuberculosis activation. One hundred one patients with
rheumatic diseases who were candidates for biologics treatment were recruited, and 57 healthy subjects were recruited as controls.
Tuberculin skin test (TST) and the T-SPOT.TB test were performed for all subjects at baseline. Follow-up testing by the T-SPOT.TB assay was performed every 6 months in patients with
rheumatic diseases and at 2 years of recruitment in the healthy controls. In patients with
rheumatic diseases and healthy controls, the TST-positive (induration, ≥10 mm) rates were 37.6% (38/101) and 34.0% (18/53), respectively (P > 0.05), while the T-SPOT.TB-positive rates were 46.5% (47/101) and 21.1 (12/57), respectively (P = 0.0019). Fifty-two patients were followed up at month 6 with a T-SPOT.TB-positive rate of 40.4%, and 49 were followed up for ≥12 months with a T-SPOT.TB-positive rate of 36.7%, with no significant difference in the positive rate at different time points including baseline (P > 0.05). Long-term follow-up revealed that conversion to T-SPOT.TB positivity occurred only in the biologics treatment group, with a positive conversion rate of 11.2% (4/38). Most importantly, no
latent tuberculosis developed into active
tuberculosis during follow-up with T-SPOT.TB screening and preemptive treatment with
isoniazid. Biologics treatment appears to increase the risk of
tuberculosis infection. However,
tuberculosis activation could be prevented by preemptive
isoniazid treatment in patients with
latent tuberculosis infection while receiving biologics
therapy.