The impact of emphysema in pulmonary fibrosis.

Several groups have described a syndrome in which idiopathic pulmonary fibrosis (IPF) coexists with pulmonary emphysema. This comes as no surprise since both diseases are associated with a history of exposure to cigarette smoke. The syndrome of combined pulmonary fibrosis and emphysema (CPFE) is characterised by upper lobe emphysema and lower lobe fibrosis. Physiological testing of these patients reveals preserved lung volume indices contrasted by markedly impaired diffusion capacity. The incidence of CPFE remains unknown but several case series suggest that this subgroup may comprise up to 35% of patients with IPF. CPFE is a strong determinant of associated pulmonary hypertension (PH). In addition, CPFE has major effects on measures of physiological function, exercise capacity and prognosis, and may affect the results of pulmonary fibrosis trials. Further studies are needed to ascertain the aetiology, morbidity, mortality and management of the CPFE syndrome, with or without PH, and to evaluate novel therapeutic options in CPFE.