High risk of activation of latent tuberculosis infection in rheumatic disease patients

Abstract

Objective: To evaluate the risk of activation of latent tuberculosis infection (LTBI) in Chinese patients with rheumatic diseases who have received glucocorticoid treatment.

Methods: We conducted a 2-year study, enrolling 1788 patients with rheumatic diseases who were treated with glucocorticoid for at least 4 weeks at the Department of Immunology and Rheumatology, First Affiliated Hospital of Nanchang University. Interferon-release assays (IGRA) were performed with patient blood samples obtained at baseline. Patient data, including age, gender, body mass index (BMI), duration and dosage of glucocorticoid and disease-modifying antirheumatic drug (immunosuppressant) treatment and comorbidities (malignancies, diabetes, chronic renal failure, silicosis) were collected. Patients were followed for 2 years to detect the emergence of active tuberculosis (TB).

Results: 21.8% (349/1600) of the patients tested positive in IGRA, indicating LTBI. 2-year follow-up showed that 18 (5.16%) patients with positive IGRA but only 4 (0.35%) patients with negative IGRA developed active TB (p < .05). SLE patients had the highest activation rate of 2.22 per 100 total recruitment cases/year. Univariate and multivariate analysis showed that low BMI(<18.5), administration of high dose glucocorticoids (>15 mg daily), and comorbidities that included interstitial lung disease and malignant cancers were significantly associated with LTBI activation.

Conclusion: Our results suggest that screening and preventive therapy of LTBI may be advisable for Chinese rheumatic disease and particularly SLE patients undergoing glucocorticoid therapy with dosage above 15 mg prednisone equivalent daily for more than 4 weeks.

Keywords:

• Active tuberculosis
• interferon-release assays
• immunosuppressant
• glucocorticoid therapy
• rheumatic disease

Ethical approval

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

Informed consent

Informed consent was obtained from all individual participants included in the study.

Disclosure statement

No potential conflict of interest was reported by the authors.