Role of Interferon-Gamma Release Assay for the Diagnosis and Clinical Follow up in Ocular Tuberculosis

ABSTRACT

Purpose

To assess the performance of interferon-gamma release assay (IGRA) associated with tuberculosis skin test (TST) for ocular tuberculosis (OTB) diagnosis and therapeutic decision making.

Method

One hundred and ninety-one patients with ocular inflammation were prospectively followed-up. Patients with clinical signs highly suspected of OTB, TST≥10 mm, and/or IGRA≥0.35 IU/mL received antitubercular therapy (ATT). Sensitivity (Se), specificity (Sp), and area under the curve (AUC) were assessed.

Results

Seventy-two (37.7%) patients received ATT for presumed OTB. Combining TST and IGRA had Se=89.6%, Sp=99.2%, and AUC (0.98) significantly higher compared to TST (0.85, Z=6.3, p<.001) or IGRA (0.95, Z=2.5, p=.01). Prior history of corticosteroids or immunosuppressant with concomitantly oral prednisone and baseline IGRA> 2.0 IU/mL was associated significantly with more recurrences in ATT patients (p=.01)      .

Conclusion

Considering TST and IGRA together was more effective in assessing OTB diagnosis. The real value of the IGRA test to predict recurrences needs further studies.

KEYWORDS:

• Ocular tuberculosis
• interferon gamma release assay
• tuberculosis skin test
• diagnosis
• antitubercular treatment

Acknowledgments

The authors would like to acknowledge the Uveitis/AIDS Sector of the Federal University of São Paulo (UNIFESP) and the Clemente Ferreira Institute for their technical support, and Antonio Díaz Tula for writing the statistical analysis scripts.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was funded the National Council for Scientific and Technological Development (CNPq, Brazil) through Grant 401096/2014 (2015–2018). RPC-M received support as a special visiting researcher under Science Without Frontiers through CNPq Grant 401096/2014-9. YF-Z was granted in part by the “Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES)” under Finance Code 001.