What is the best next step for a 58-year-old woman with a reactive Tuberculin Gold (TB gold) test, no respiratory symptoms, Lupus, and Rheumatoid Arthritis (RA) on Orencia (abatacept), with a normal Chest X-Ray (CXR)?

Management of Latent Tuberculosis Infection in a Patient with Autoimmune Disease on Biologic Therapy

The best next step for this 58-year-old woman with reactive TB Gold test, normal CXR, lupus, and RA on Orencia is to initiate treatment for latent tuberculosis infection (LTBI) with isoniazid for 9 months or another recommended LTBI regimen. 1

Assessment of Current Status

• The patient has a reactive TB Gold test (IGRA) which indicates latent tuberculosis infection in the absence of active TB 1
• Normal chest X-ray rules out active pulmonary TB but is consistent with latent TB 1
• No respiratory symptoms further supports latent rather than active TB 1
• The patient is immunosuppressed due to:
  • Underlying autoimmune conditions (lupus and RA) 1
  • Treatment with Orencia (abatacept), a biologic agent 1

Management Algorithm

Step 1: Rule out active TB

• Reactive TB Gold with normal CXR and no respiratory symptoms is consistent with latent TB infection 1
• Although sputum examination is not indicated for most persons being considered for LTBI treatment, it may be considered in immunosuppressed patients to definitively rule out active TB 1

Step 2: Initiate LTBI treatment

• Treatment of LTBI is strongly indicated in this patient due to:
  • Positive TB Gold test 1
  • Immunosuppression from both underlying diseases and biologic therapy 1
  • Increased risk of TB reactivation with ongoing immunosuppressive therapy 1

Step 3: Choose appropriate LTBI regimen

• Recommended regimens include:
  • Isoniazid for 9 months (preferred) 1, 2
  • Rifampin for 4 months 1, 2
  • Isoniazid and rifapentine once weekly for 3 months (under direct observation) 2

Special Considerations for This Patient

• Patients on biologics with LTBI should receive treatment before continuing biologic therapy 1
• According to ACR guidelines, treatment with biologics can be initiated or resumed after 1 month of latent TB treatment 1
• While Orencia (abatacept) may have a lower risk of TB reactivation compared to TNF inhibitors 3, LTBI treatment is still indicated in all patients with positive TB screening tests regardless of the specific biologic agent 1
• Annual TB screening should be considered if the patient has ongoing risk factors for TB exposure 1

Important Considerations and Pitfalls

• Patients with autoimmune diseases on immunosuppressive therapy may have false-negative TB screening results; however, this patient already has a positive test 1
• Monitoring for hepatotoxicity is essential during LTBI treatment, especially in older patients 1
• Drug interactions between LTBI medications and the patient's current medications should be evaluated 2
• Patients who test positive for TB Gold at baseline will likely remain positive even after successful treatment of LTBI, so monitoring for clinical symptoms rather than repeat testing is recommended for future surveillance 1
• Although studies suggest abatacept may have less TB reactivation risk than TNF inhibitors 4, 3, LTBI treatment is still required with a positive screening test 1

The evidence strongly supports treating LTBI in this immunocompromised patient with a positive TB Gold test to prevent progression to active TB disease, which would have significant morbidity and mortality implications 1, 2.