Management of IGRA-Positive Patient with Pemphigus Vulgaris Planned for Rituximab

Immediate Next Steps

• The American College of Rheumatology recommends initiating treatment for latent tuberculosis infection (LTBI) and delaying rituximab for at least 1 month after starting anti-tubercular therapy in patients with pemphigus vulgaris 1
• A chest radiograph should be obtained immediately to evaluate for active tuberculosis or past TB exposure, and if the chest X-ray shows abnormalities suggestive of TB, a sputum examination should be performed to exclude active disease 1
• The British Association of Dermatologists suggests considering referral to an infectious disease specialist or pulmonologist for TB management 1

LTBI Treatment and Rituximab

• The American Thoracic Society recommends starting anti-tubercular prophylaxis immediately upon confirming LTBI, with standard LTBI regimens including isoniazid for 9 months, and waiting a minimum of 1 month after initiating LTBI treatment before administering the first dose of rituximab 1
• The British Association of Dermatologists suggests that standard LTBI regimens include isoniazid for 9 months, and a 3-month isoniazid-rifapentine regimen as an alternative 3, 4

Special Considerations for Rituximab and TB Risk

• Rituximab is classified as a high-risk immunosuppressive agent for HBV reactivation, with a 16.9% reactivation rate in exposed patients, and TB reactivation follows similar high-risk patterns, causing profound and durable B-cell depletion lasting 6-12 months 2

Treatment Algorithm for Patient

• If the chest X-ray is negative, the patient should start LTBI treatment immediately, continue current pemphigus management, and schedule rituximab for 4-6 weeks from now, with continued LTBI prophylaxis throughout rituximab treatment and for several months after completion 1, 4, 3
• If the chest X-ray is positive or active TB is suspected, the patient should complete a full treatment course for active TB before any rituximab, delay rituximab until TB treatment is completed, and optimize pemphigus control with alternative agents during this period 1, 4, 3

Monitoring During and After Rituximab

• Extended monitoring is essential because rituximab causes prolonged immunosuppression, with monthly monitoring for TB symptoms during rituximab treatment and for at least 12 months after completion, and clinical signs to monitor including fever, night sweats, weight loss, persistent cough, and hemoptysis 2, 1

Pemphigus Management During TB Treatment Period

• The patient still needs effective pemphigus control during the 1-month delay, with continued or optimized systemic corticosteroids, and addition of conventional immunosuppressants if not already on them, such as mycophenolate mofetil or azathioprine 4, 3