2419. Use of a Validated Online Calculator to Determine TB Progression Risk in Patients with Latent Tuberculosis Infection on TNFα Therapy
Session: Poster Abstract Session: Tuberculosis: Epidemiology and Management
Saturday, October 7, 2017
Room: Poster Hall CD
  • Ken Dekitani Poster 3.14.17.pdf (1.2 MB)
  • Background: Patients with latent tuberculosis infection (LTBI) on anti-TNFα therapy (TNFα group) have an increased risk of developing active tuberculosis (TB). Risk of progression can be decreased by completing prophylactic treatment; a 3-month regimen of weekly INH + Rifapentine (RFP) has shown improved treatment completion rates. Increased physician awareness of cumulative risk of TB progression and comorbid risk factors may inform therapeutic choices for this TNFα group

    Methods: In this retrospective study, we systematically quantified the risk of TB progression in 20 LTBI patients in the TNFα group and 74 LTBI immunocompetent controls seen at Saint Louis University hospital from 2010 to 2015 using a validated online calculator, TSTin3D.com. The calculator generates an individual’s cumulative risk of progression to active TB based on demographic information, TST/IGRA results and presence of TB progression risk factors. We then compared risk factor prevalence and treatment completion rates in the two groups.

    Results: A higher proportion (75%) of TNFα group were seen because of recent TST/IGRA conversion from negative to positive, compared to 17.5% in the control group. The TNFα group also had a decreased prevalence of diabetes, smoking, and renal failure. The median cumulative risk of progression to active TB was 17.25% in the TNFα group and 5.87% in the control group. Although the overall LTBI treatment completion rates in our cohort were highest for 3 months INH + RFP (75%) compared to 9 months of INH (56%) or 4 months of Rifampin (54%), only 25% of TNFα group patients were prescribed INH+RFP. However, 70% of patients were able to successfully complete LTBI therapy in the TNFα group.

    Conclusion: TSTin3D.com was able to confirm and quantify the fact that patients with LTBI on TNFα antagonist therapy have a higher median cumulative risk of TB progression compared to immunocompetent controls. Overall, patients were more likely to complete a full course of 3 months of INH+RFP but only 25% of the TNFα group received this treatment. We are currently implementing the use of this calculator in the Infectious Diseases clinic to determine whether quantification of risk will affect prescribing practice among clinicians to increase successful treatment completion rates in patients with LTBI.

    Ken Dekitani, BS1, Michael Scolarici, BS1 and Soumya Chatterjee, MD2, (1)Saint Louis University School of Medicine, St. Louis, MO, (2)Doisy Research Center, Saint Louis University, St Louis, MO


    K. Dekitani, None

    M. Scolarici, None

    S. Chatterjee, None

    Findings in the abstracts are embargoed until 12:01 a.m. PDT, Wednesday Oct. 4th with the exception of research findings presented at the IDWeek press conferences.