Collagen Vascular Disease Is an Important Condition in Patients with IPF

Commonly, interstitial pneumonia (IP) complicates collagen vascular disease (CVD) and IP may be the first or only manifestation of CVD. It is difficult to distinguish IP from CVD and many patients may be diagnosed with idiopathic IP. Similarly, there are few reports of patients who fulfill the criteria for a CVD after the diagnosis of idiopathic pulmonary fibrosis (IPF).

A recent study evaluated the cumulative incidence of CVD and the clinical features of patients who fulfilled the criteria for any CVD after an initial diagnosis of IPF [PLoS One. 2014;9(4):e94775].

This retrospective review followed 111 consecutive patients with IPF who were diagnosed clinically or underwent surgical lung biopsy between 1990 and 2007 at the Hamamatsu University School of Medicine, Japan. None of the patients fulfilled any of the CVD criteria from the American College of Rheumatology within ≥6 months after IPF diagnosis. The study participants’ medical records were analyzed. Laboratory findings, pulmonary function test results, and bronchoalveolar lavage were obtained at the time of initial diagnosis.

During the observation period, 10 patients (9%) developed CVD. Patients who were more likely to develop CVD were younger and female. Patients who developed CVD more likely had a better prognosis than those with IPF. The mean time until CVD diagnosis was 3.9 years. Of the 10 patients who developed CVD, 4 had rheumatoid arthritis, 4 had microscopic polyangitis, 1 had systemic sclerosis (SSc), and 1 had SSC and Sjogren’s syndrome. The cumulative incidences of CVD at 1, 5, and 10 years were 0.91%, 9.85%, and 15.5%, respectively.

Women with the presence of lymphoid aggregates with germinal centers were significantly associated with the occurrence of CVD in patients initially diagnosed with IPF.

All patients who developed CVD were treated with corticosteroids alone or in combination with immunosuppressive agents after their diagnosis of CVD. Patients with CVD were treated significantly more often than the patients with IPF (P=.01) and had a significantly higher rate of treatment with corticosteroids alone (P=.01; Please see Table below).

The study’s authors noted limitations. The IPF patients in the study were at a relatively early stage of disease progression and had longer survival than patients in other studies on this matter.

The study’s authors concluded that CVD is an important underlying condition in IPF that may have a better prognosis than IPF. The possibility of the development of CVD should remain a consideration in the follow-up treatment of IPF.