PURPOSE: Acute exacerbation (AE) of idiopathic pulmonary fibrosis (IPF) is increasingly recognized as a commonly occurring clinical event. The mortality of AE of IPF is high, ranging from 20% to 100%. In contrast, there have been anecdotal case reports on AE of nonspecific interstitial pneumonia (NSIP).
METHODS: Between January 1997 and December 2006, seventy-six consecutive patients were diagnosed as idiopathic NSIP by surgical lung biopsy. Among them, 11 patients satisfied the clinical criteria of AE of IPF by Kondoh et al (Acute exacerbation in idiopathic pulmonary fibrosis. Analysis of clinical and pathologic findings in three cases. Chest 1993;103:1808-12.).
RESULTS: The median age of 11 patients (9 female) was 66 years (range, 55 to 72 years). The median symptom duration of AE prior to hospital visit was 11 days (range, 4 to 28 days). Surgery for lung cancer, bronchoalveolar lavage (BAL) and relapse of NSIP were thought to be the triggering factors of AE in three patients, respectively. Initial PaO2/FiO2 was 140mmHg (range, 64 to 213mmHg). Mechanical ventilation was applied to 6 patients. Bilateral diffuse ground-glass opacity (GGO) was the most common finding on chest HRCT. Surgical lung biopsy was performed in 9 patients at the time of AE. Diffuse alveolar damage (DAD) (n=5) or focal bronchoiolitis obliterance organizing pneumonia (BOOP) (n=4) was superimposed on NSIP background. With corticosteroids and/or cytotoxic agents, 30-days mortality was 36.4%. Treatment response was better in those with focal BOOP pattern (4/4, 100%) than those with DAD pattern (1/5, 25%) (p = 0.048).
CONCLUSION: Pathologic finding of focal BOOP pattern rather than DAD pattern may be a good prognostic factor in AE of NSIP.
CLINICAL IMPLICATIONS: Clinical outcome of acute exacerbation of NSIP is likely to be determined by the histopathologic findings.
DISCLOSURE: Hae Seong Nam, No Product/Research Disclosure Information; No Financial Disclosure Information