Factors affecting treatment outcome in patients with idiopathic nonspecific interstitial pneumonia: a nationwide cohort study.
BACKGROUND
The effects of corticosteroid-based therapy in patients with idiopathic nonspecific interstitial pneumonia (iNSIP), and factors affecting treatment outcome, are not fully understood. We aimed to investigate the long-term treatment response and factors affecting the treatment outcome in iNSIP patients from a multi-center study in Korea.


METHODS
The Korean interstitial lung disease (ILD) Study Group surveyed ILD patients from 2003 to 2007. Patients were divided into two groups to compare the treatment response: response group (forced vital capacity (FVC) improves ≥10% after 1 year) and non-response group (FVC <10%). Factors affecting treatment response were evaluated by multivariate logistic regression analysis.


RESULTS
A total of 261 patients with iNSIP were enrolled, and 95 patients were followed-up for more than 1 year. Corticosteroid treatment was performed in 86 patients. The treatment group showed a significant improvement in lung function after 1-year: FVC, 10.0%; forced expiratory volume (FEV1), 9.8%; diffusing capacity of the lung for carbon monoxide (DLco), 8.4% (p < 0.001). Sero-negative anti-nuclear antibody (ANA) was significantly related with lung function improvement. Sero-positivity ANA was significantly lower in the response group (p = 0.013), compared to that in the non-response group. A shorter duration of respiratory symptoms at diagnosis was significantly associated with a good response to treatment (p = 0.018).


CONCLUSION
Treatment with corticosteroids and/or immunosuppressants improved lung function in iNSIP patients, which was more pronounced in sero-negative ANA and shorter symptom duration patients. These findings suggest that early treatment should be considered in iNSIP patients, even in an early disease stage.
['Lee|Sang Hoon|SH|', 'Park|Moo Suk|MS|', 'Kim|Song Yee|SY|', 'Kim|Dong Soon|DS|', 'Kim|Young Whan|YW|', 'Chung|Man Pyo|MP|', 'Uh|Soo Taek|ST|', 'Park|Choon Sik|CS|', 'Park|Sung Woo|SW|', 'Jeong|Sung Hwan|SH|', 'Park|Yong Bum|YB|', 'Lee|Hong Lyeol|HL|', 'Shin|Jong Wook|JW|', 'Lee|Eun Joo|EJ|', 'Lee|Jin Hwa|JH|', 'Jegal|Yangin|Y|', 'Lee|Hyun Kyung|HK|', 'Kim|Yong Hyun|YH|', 'Song|Jin Woo|JW|', 'Park|Jong Sun|JS|']
D000305:Adrenal Cortex Hormones D000368:Aged D015331:Cohort Studies D005260:Female D005500:Follow-Up Studies D006801:Humans D054988:Idiopathic Interstitial Pneumonias D007166:Immunosuppressive Agents D008297:Male D008875:Middle Aged D056910:Republic of Korea D016896:Treatment Outcome
Treatment Non-specific interstitial pneumonia Pulmonary lung function