Radiological and histopathological features of Early Idiopathic Pulmunary Fibrosis (Early IPF)

<bold>Introduction:</bold> IPF is defined according to current ATS/ERS guidelines as a chronic, fibrosing interstitial pneumonia of unknown cause associated with radiological and histologic features of usual interstitial pneumonia (UIP).“Early Interstitial Lung Disease” (ILD) refers to ILD in asymptomatic patients with normal pulmonary function tests. <bold>Objectives:</bold> The aim of our study is to compare the prevalence of some radiological and histopathologic features in patients with early and more advanced forms of IPF. Patients with early IPF had both FVC and DLCO values >80%. <bold>Methods:</bold> We collected radiological and histopathological data of 326 consecutive patients diagnosed with IPF at AOU Careggi, Florence. Student t-test or Mann-Whitney test were used to compare continuous variables. Categorical variables were compared with Fisher’s exact test. Significance was set at p<0,05. <bold>Results:</bold> From a radiological point of view, patients with early IPF have a significantly higher percentage of indeterminate UIP patterns (31,43%). From a histopathological point of view, early IPF have significantly lower prevalence of some patterns most associated with IPF (fibroblastic foci, honeycombing), while the pattern of "patchy" fibrosis variously associated with inflammatory infiltrate, bronchiolar metaplasia, and reactive pneumocytic hyperplasia is more common. <bold>Conclusions:</bold> Compared with advanced disease, early IPF presents some distinctive radiologic and histopathologic features. These preliminary results strengthen the need for further evaluation of possible differential pathogenetic mechanisms, leading hopefully to innovative targeted therapeutic approaches in the early phase of the disease.