Idiopathic Pulmonary Fibrosis Acute Exacerbations Are Challenging To Diagnose
A new study on acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) entitled “Autopsy analyses in acute exacerbation of idiopathic pulmonary fibrosis” was published in Respiratory Research by Keishi Oda, part of Dr. Hiroshi Mukae’s group from the Department of Respiratory Medicine at University of Occupational and Environmental Health in Kitakyushu City, Japan.
Idiopathic Pulmonary Fibrosis (IPF) is characterized by a progressive scarring of the lung tissue that leads to a decrease of functional lung volume and oxygen uptake. The origin of IPF is not known; many people live only for 3 to 5 years after diagnosis, and the disease has no cure. The main cause of death of IPF is respiratory failure. Acute exacerbation of IPF (AE-IPF) has an extremely poor prognosis and is believed to occur in 5-10% of IPF patients per year. The most common histopathological pattern found in lung tissue removed from patients with IPF is called interstitial pneumonia (UIP), which includes the presence of fibroblastic foci. Additionally, the most commonly described pathological features of AE-IPF after surgical lung biopsies is consistent with diffuse alveolar damage (DAD) superimposed on underlying UIP.
In the present study, researchers made a retrospective review of a series of autopsies of 52 patients with AE-IPF performed at five university hospitals and one municipal hospital between 1999 and 2013. They analyzed medical records such as demographic and clinical data, autopsy findings, and complications during the clinical course until death. Importantly, they characterized and evaluated the pathological features, including concomitant and infectious diseases, observed in AE-IPF patients during their clinical course until death.
The authors found that the median age of the subjects at autopsy was 71 years, with a range of ages from 47 to 86 years, wherein 38 (73.1%) of the subjects were males. 45 (86.5%) patients after being diagnosed with AE-IPF initiated a treatment based on high-dose corticosteroid therapy. This type of therapy and the use of immunosuppressive agents are generally used by clinicians; however, there is a previous study that suggested that these drugs increase the rates of infectious complications. In all cases, the usual interstitial pneumonia (UIP) pattern was found in the fibrotic lesion.
The authors acknowledge several limitations associated with their study, such as the fact that patients that survived after AE-IPF were not included, therefore, the present observations may not reflect all aspects of the AE-IPF condition. Second, only Japanese IPF patients were included in the study, thus interpretation of the results must take into account racial and institutional specificity. Third, 52% of the patients with AE-IPF required mechanical ventilation upon hospital admission, suggesting a more severe condition. Thus, the results of this study may not be extrapolated to all cases of AE-IPF.
Overall, the authors concluded that the pathological findings of AE-IPF included diffuse alveolar damage (DAD) as well as a series of other pathological conditions, thus making it very difficult to arrive at an accurate diagnosis of AE-IPF. As a result, there is a risk of death among patients with AE-IPF due to the incidence of many complications during their clinical course, such as the effects of therapy with high-dose of corticosteroids. For these reasons, it is crucial to treat patients with AE-IPF by intervening on-time with appropriate treatment, and monitoring the health condition of the patient.