A clinical, radiographic, and physiologic scoring system for the longitudinal assessment of patients with idiopathic pulmonary fibrosis

In order to develop a reproducible, quantifiable means of assessment of the clinical status of patients with idiopathic pulmonary fibrosis (IPF), a composite clinical-radiographic-physiologic (CRP) scoring system was devised, using 7 variables: dyspnea, chest radiograph, spirometry, lung volume, diffusion capacity, resting alveolar-arterial PO₂, and exercise O₂ saturation. To assess this scoring system, we examined the relationships between CRP scores and histopathologic findings, including a cellular pathology score composed of abnormalities deemed to be potentially reversible, a fibrotic pathology score based on abnormalities felt to be essentially irreversible, and an index of overall pathologic derangement (total pathology score), derived from the sum of the cellular and fibrotic scores. The initial CRP determination at the time of open lung biopsy correlated significantly with the total pathology score (r = 0.61, p < 0.001). The CRP score determined after 6 months of corticosteroid therapy showed a significant correlation with the fibrotic pathology score present on open lung biopsy (r = 0.76, p < 0.001). The change in CRP after 6 months of corticosteroid therapy tended to reflect the cellular histopathologic component of the open lung biopsy (r = -0.43, p < 0.10). Moreover, in none of these relationships did any individual component of the CRP score correlate better with the respective histopathologic index than did the CRP score itself. These data suggest that this CRP score is useful for the estimation of the severity of underlying pathologic derangement and for the longitudinal quantitative assessment of clinical impairment in patients with IPF.