The Risk Factors of Exacerbation in Interstitial Pneumonia With Autoimmune Features: A Single-Center Observational Cohort Study

Okinori Murata, Katsuya Suzuki, Tsutomu Takeuchi, Makoto Maemondo

Research output: Contribution to journalArticlepeer-review


Objectives: To investigate the long-term outcomes, including risk factors, for exacerbation between monotherapy and combination therapy in patients with interstitial pneumonia with autoimmune features (IPAF). Methods: We assessed 672 patients between April 2009 and March 2019 who were evaluated using high-resolution computed tomography (HRCT) of the chest. We applied the IPAF criteria. Fifty-two patients who visited our department for at least 6 months were diagnosed with IPAF. Clinical, laboratory, and imaging data were collected from medical records and statistically analyzed. Results: Among the 52 cases of IPAF, we compared the characteristics at diagnosis between treated (n = 28) and untreated patients (n = 24). The exacerbation rates were 42.9% (n = 12) and 8.3% (n = 2) (P = 0.0051), respectively. Among the treated patients, smoking history, high titer of KL-6, and the duration from diagnosis to the start of treatment were significant risk factors for exacerbation (P = 0.0062, 0.011, and 0.019, respectively). The number of risk factors was significantly and positively associated with exacerbation rate (P = 0.0053). Among the treated patients, glucocorticoid (GC) monotherapy was used in 13 cases, and GC and immunosuppressant (IS) combination therapy was used in 14 patients. There was no significant difference in the treatment methods between patients with and without risk factors (P = 0.47). When comparing the long-term outcomes between the monotherapy and combination therapy groups, the 3-year non-exacerbation rates were 72.9 and 45.9% (P = 0.020), respectively. Conclusions: IPAF patients with risk factors had a high exacerbation rate, regardless of the type of treatment. New interventions aimed at preventing exacerbations in these patients are required.

Original languageEnglish
Pages (from-to)1693-1710
Number of pages18
JournalRheumatology and Therapy
Issue number4
Publication statusPublished - 2021 Dec


  • Interstitial pneumonia with autoimmune features
  • Long-term outcomes
  • Prognosis
  • Risk factors
  • Treatment methods

ASJC Scopus subject areas

  • Rheumatology
  • Immunology and Allergy


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