PLoS ONE (Jan 2020)

Human T-cell leukemia virus type 1 may invalidate T-SPOT.TB assay results in rheumatoid arthritis patients: A retrospective case-control observational study.

  • Kunihiko Umekita,
  • Yayoi Hashiba,
  • Kosho Iwao,
  • Chihiro Iwao,
  • Masatoshi Kimura,
  • Yumi Kariya,
  • Kazuyoshi Kubo,
  • Shunichi Miyauchi,
  • Risa Kudou,
  • Yuki Rikitake,
  • Katoko Takajo,
  • Takeshi Kawaguchi,
  • Motohiro Matsuda,
  • Ichiro Takajo,
  • Eisuke Inoue,
  • Toshihiko Hidaka,
  • Akihiko Okayama

DOI
https://doi.org/10.1371/journal.pone.0233159
Journal volume & issue
Vol. 15, no. 5
p. e0233159

Abstract

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BACKGROUND:CD4-positive T cells are the main target of human T-cell leukemia virus type 1 (HTLV-1). Interferon-γ release assays rely on the fact that T-lymphocytes release this cytokine when exposed to tuberculosis-specific antigens and are useful in testing for latent tuberculosis infection before initiating biologic therapy, such as anti-tumor necrosis factor agents. However, the reliability of interferon-γ release assays in detecting tuberculosis infection among HTLV-1-positive patients with rheumatoid arthritis (RA) remains unclear. The present study aimed to evaluate the use of the T-SPOT.TB assay in HTLV-1-positive RA patients. METHODS:Overall, 29 HTLV-1-positive RA patients and 87 age- and sex-matched HTLV-1-negative RA patients (controls) were included from the HTLV-1 RA Miyazaki Cohort Study. Results of the T-SPOT.TB assay for latent tuberculosis infection screening were collected from medical records of patients. RESULTS:Approximately 55% of the HTLV-1-positive RA patients showed invalid T-SPOT.TB assay results (odds ratio: 108, 95% confidence interval: 13.1-890, p 10 in the negative controls. HTLV-1 proviral load values were significantly higher in patients with invalid results compared with those without invalid results (p = 0.003). CONCLUSION:HTLV-1 infection affects T-SPOT.TB assay results in RA patients. Assay results in HTLV-1 endemic regions should be interpreted with caution when screening for latent tuberculosis infection before initiation of biologic therapy.