Management of Immunotherapy in Patients with Interstitial Lung Disease and Influenza

Introduction to Management Principles

The American College of Rheumatology and the American College of Chest Physicians recommend maintaining immunosuppression to prevent ILD progression, a life-threatening complication, and suggest vaccination against influenza as a preventive strategy 1

Discontinuing mycophenolate can lead to disease flare and irreversible pulmonary fibrosis, directly impacting mortality, with a minimum treatment duration of 24 months typically required for long-term maintenance therapy 2
Influenza can be managed with antiviral therapy and supportive care without necessarily stopping immunosuppression, with high-risk patients, including those with ILD on immunosuppression, requiring antiviral treatment if symptoms persist for less than 2 days during a known influenza epidemic 3, 4

Evaluate patients for signs requiring hospitalization, such as tachypnea, tachycardia, hypotension, confusion, and worsening dyspnea, and compare current respiratory status to baseline ILD function 1, 3, 4
Consider rapid influenza testing if within the appropriate timeframe, and initiate antiviral therapy promptly in immunosuppressed populations, with neuraminidase inhibitors as the preferred treatment 3, 4

For mild-moderate influenza, continue the current mycophenolate dose, increase monitoring frequency, and monitor for cytopenias that may require temporary dose reduction 2
For severe influenza requiring hospitalization, consider temporary dose reduction rather than complete discontinuation, with daily monitoring of CBC and metabolic panel, and resume full dose once clinical improvement is documented and infection is resolving 1, 2

Laboratory monitoring should include CBC with differential and CMP more frequently than standard 2-3 week intervals during acute infection, with clinical monitoring involving daily assessment of respiratory status, oxygen requirements, and systemic symptoms 2, 3, 4

Temporary discontinuation of mycophenolate may be warranted in life-threatening infections with septic shock, severe leukopenia or neutropenia, or development of secondary bacterial pneumonia with severe respiratory compromise 2, 3, 4
Avoid reflexively discontinuing immunosuppression for uncomplicated influenza, delaying antiviral therapy, or restarting at full dose after a prolonged hold without gradual re-escalation and laboratory monitoring 1, 2, 3

The American College of Rheumatology and the American College of Chest Physicians explicitly recommend influenza vaccination as a core intervention for patients with SARD-ILD on immunosuppression, along with pneumococcal, COVID-19, and RSV vaccines as appropriate 1

Resume standard monitoring schedule once infection is resolved, perform pulmonary function tests 4-6 weeks post-infection to assess for any ILD progression, and consider high-resolution CT if significant decline in pulmonary function or persistent symptoms are observed 1, 2