The Beneficial Effect of 3-Month-Induction Therapy with Corticosteroids and Mycophenolate Mofetil Followed by Maintenance Therapy with Yearly Rituximab Infusions as Sole Maintenance Therapy in Cryptogenic Chronic Hypersensitivity Pneumonitis

Abstract

Background: The available data on cryptogenic chronic hypersensitivity pneumonitis (ccHP) indicate an inherited predisposition to disease with triggering autoimmune phenomena. Hence, we evaluated prospectively the role of a new autoimmune regimen in treatment of its severe and progressive disease. Patients and Methods: A total of 9 patients were included in the study. They had criteria for ccHP viz. 1) clinical features of cryptogenic progressive restrictive lung disease, 2) high-resolution computed tomographic pulmonary abnormalities, and 3) bronchoalveolar lavage lymphocytosis (>30%). The regimen consisted of an initial induction phase of 3-month Solumedrol 1 g IV daily for 3 days followed by 1 month of Prednisone (P) 60 mg/day to tapered down to discontinuation by 3rd month. They also had received Mycophenolate mofetil (MMF) 1 g twice daily for 3 months. This stage was followed by a maintenance phase of yearly Rituximab infusions (1 g followed by 1 g 2 weeks later). Results: compared to their previous 6 months deterioration; all patients showed significant improvement in their forced vital volume, diffusion capacity for carbon monoxide, 6-minutes-walk after the induction phase (at 3 months) which improved further at 15 months with Rituximab therapy. Conclusion: After 3-month induction therapy with P and MMF; yearly R treatment is a safe, practical and effective long-term therapy for ccHP.