A prospective survey of idiopathic interstitial pneumonias in a web registry in Japan

There have been no prospective large-scale multicenter epidemiological studies on the clinical course and treatment from the time of diagnosis of idiopathic interstitial pneumonias (IIPs) in Japan. The purpose of this study was to clarify the current clinical situation of IIP in Japan.

This study was supported by a grant from the Ministry of Health, Labour and Welfare to the Diffuse Lung Diseases Research Group. Data including clinical findings, course, and treatment of IIP from a web database created by a collaborative effort of medical institutions across Japan that specialize in the care of interstitial pneumonias were collected and analyzed.

A total of 436 IIP patients from 19 institutions were newly registered during a 5-year period. Idiopathic pulmonary fibrosis (IPF) was the most frequently encountered IIP, and 28% of the IPF cases were initially diagnosed by abnormal chest X-ray or CT in asymptomatic patients. Until the 2008 fiscal year, no treatment was given for most cases of IPF. After the end of 2008, when pirfenidone was approved for manufacture, the number of patients for whom no treatment was recommended declined, and pirfenidone therapy was initiated in 32.9% of cases in 2009. The median survival times for IPF from the onset symptoms and from the initial visit were 105 months and 69 months, respectively.

This study should provide valuable information for understanding the current state of IIP in Japan.