Korean J Dermatol.  2022 Jan;60(1):1-6.

The Relationship between Systemic Anti-Psoriatic Treatment and Positive Interferon-Gamma Release Assay Rate in Moderate-Severe Korean Psoriasis Patients

• Yang SY
• Chun EJ
• Kim JK
• Kim SS
• Kim CW

Abstract

Background
The relationship between latent tuberculosis and the use of certain biologics is well known, but the relationship between the test for latent tuberculosis results and psoriasis itself or systemic anti-psoriatic treatment (cyclosporine and methotrexate) has not been elucidated to date.
Objective
To assess the influence of psoriasis and systemic anti-psoriatic treatment on results of the interferon-gamma release assay.
Methods
A retrospective study was conducted on 353 patients who were screened for latent tuberculosis before the use of medicines for moderate to severe psoriasis. The screening was based on results of the interferon-gamma release assay. The control group included 2,025 health care workers who were screened for latent tuberculosis during a general medical examination.
Results
Interferon-gamma release assay was positive in 35.4% of the patients and 11.6% of the subjects from the control group. There was a statistically significant correlation between psoriasis and assay positivity (p＜0.05). Among the patients, no statistically-relevant association regarding previous use of cyclosporine or methotrexate was found (cyclosporine: p=0.284, methotrexate: p=0.231). Furthermore, patients were divided into two groups according to treatment duration, i.e., shorter or longer than 6 months. There were no relevant differences in treatment duration cyclosporine: p=0.243, methotrexate: p=0.743).
Conclusion
This study revealed a higher prevalence of interferon-gamma release assay positivity in patients with psoriasis. However, conventional anti-psoriatic drugs, such as cyclosporine and methotrexate, showed no significant difference regarding the assay positivity.

Keyword

Biologics; Interferon-gamma release assay; Latent tuberculosis; Psoriasis