Use of Mycophenolate Mofetil or Azathioprine for the Management of Chronic Hypersensitivity Pneumonitis.
The treatment of chronic hypersensitivity pneumonitis (cHP) often includes systemic oral corticosteroids, but the optimal pharmacologic management remains unclear. The morbidity associated with prednisone has motivated the search for alternative therapies. We aimed to determine the effect of treatment with mycophenolate mofetil (MMF) or azathioprine (AZA) on lung function in patients with cHP.



Patients with cHP treated with either MMF or AZA were retrospectively identified from four interstitial lung disease centers. Change in lung function before and after treatment initiation was analyzed using linear mixed-effects modeling (LMM), adjusting for age, sex, smoking history, and prednisone use.



Seventy patients were included: 51 were treated with MMF and 19 with AZA. Median follow-up after treatment initiation was 11 months. Prior to treatment initiation, FVC and diffusion capacity of the lung for carbon monoxide (Dlco) % predicted were declining at a mean rate of 0.12% (P < .001) and 0.10% (P < .001) per month, respectively. Treatment with either MMF or AZA was not associated with improved FVC (0.5% at 1 year; P = .46) but was associated with a statistically significant improvement in Dlco of 4.2% (P < .001) after 1 year of treatment. Results were similar in the subgroup of patients treated with MMF for 1 year; the FVC increased nonsignificantly by 1.3% (P = .103) and Dlco increased by 3.9% (P < .001).



Treatment with MMF or AZA is associated with improvements in Dlco in patients with cHP. Prospective randomized trials are needed to validate their effectiveness for cHP.
Department of Medicine, University of California, San Francisco, San Francisco, CA; Department of Medicine, Centre Hospitalier de l'Université de Montréal, Montreal, QC, Canada. Electronic address: julie.morisset@umontreal.ca.
Julie
J
Morisset
Department of Medicine, University of Calgary, Calgary, AB, Canada.
Kerri A
KA
Johannson
Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA.
Eric
E
Vittinghoff
Department of Respiratory Diseases, Pontifical Catholic University of Chile, Santiago, Chile.
Carlos
C
Aravena
Department of Radiology, University of California, San Francisco, San Francisco, CA.
Brett M
BM
Elicker
Department of Pathology, University of California, San Francisco, San Francisco, CA.
Kirk D
KD
Jones
Department of Medicine, University of Calgary, Calgary, AB, Canada.
Charlene D
CD
Fell
Department of Medicine, Centre Hospitalier de l'Université de Montréal, Montreal, QC, Canada.
Helene
H
Manganas
Department of Medicine, Centre Hospitalier de l'Université de Montréal, Montreal, QC, Canada.
Bruno-Pierre
BP
Dubé
Department of Medicine, University of California, San Francisco, San Francisco, CA.
Paul J
PJ
Wolters
Department of Medicine, University of California, San Francisco, San Francisco, CA.
Harold R
HR
Collard
Department of Medicine and Centre for Heart Lung Innovation, University of British Columbia, Vancouver, BC, Canada.
Christopher J
CJ
Ryerson
Department of Medicine, University of California, San Francisco, San Francisco, CA.
Brett
B
Ley
D000368:Aged; D000542:Alveolitis, Extrinsic Allergic / Q000188:drug therapy* / Q000503:physiopathology; D001379:Azathioprine / Q000627:therapeutic use*; D002248:Carbon Monoxide; D002908:Chronic Disease; D005260:Female; D005938:Glucocorticoids / Q000627:therapeutic use; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009173:Mycophenolic Acid / Q000627:therapeutic use*; D011241:Prednisone / Q000627:therapeutic use; D011653:Pulmonary Diffusing Capacity; D012189:Retrospective Studies; D016896:Treatment Outcome; D014797:Vital Capacity
D005938:Glucocorticoids; D007166:Immunosuppressive Agents; D002248:Carbon Monoxide; D009173:Mycophenolic Acid; D001379:Azathioprine; D011241:Prednisone
azathioprine; hypersensitivity pneumonitis; interstitial lung disease; mycophenolate mofetil