Comparison of clinicoradiologic manifestation of nonspecific interstitial pneumonia and usual interstitial pneumonia/idiopathic pulmonary fibrosis: A report from NRITLD

Abstract

BACKGROUND:Ever since Katzenstein and Fiorelli introduced the term nonspecific interstitial pneumonia (NSIP) to denote those cases of interstitial pneumonia that cannot be categorized as any of the other types of idiopathic interstitial pneumonias (IIP), there has been continuing debate on whether it is a real clinical entity or not. The American Thoracic Society/European Respiratory Symposium task group tried to identify idiopathic NSIP as a separate disease and exclude it from the category of IIP. However, it appears that the clinical presentation of NSIP and usual interstitial pneumonia (UIP) are the same.OBJECTIVE:To show that the radiologic features of NSIP and UIP should be relied upon, instead of clinical presentation and pathologic findings, to differentiate between the two.MATERIALS AND METHODS:Consecutive patients who had received a diagnosis of either NSIP or UIP on the basis of open lung biopsy between January 2001 and December 2007 were identified for inclusion in this retrospective review. The study included 61 subjects: 32 men and 29 women with a mean age of 59.39 ± 14.5 years. Chest computed tomography images of all the cases were collected for a review. High resolution computed tomography (HRCT) and all pathologic specimens were also evaluated. A weighted kappa coefficient was used to evaluate whether radiology can be used instead of biopsy for the diagnosis of NSIP and UIP. Comparison of the mean ages and the time intervals (i.e., interval between symptom onset and the time of diagnosis) in the UIP and NSIP groups was done using the Mann-Whitney U test. Association between gender and biopsy result was evaluated by the Fisher exact test. Data were evaluated using SPSS, v.13.RESULTS:Sixty-one patients were included in this study, 32 were male and 29 were female. On the basis of biopsy findings, 50 (82%) patients had UIP and 11 (18%) had NSIP. Thirty (60%) of the 50 patients who had UIP were male and 20 (40%) were female; 2 (18.2%) of the 11 patients who suffered from NSIP were male and 9 (81.8%) were female. Based on HRCT findings, 36 (60%) patients were diagnosed to have UIP and 24 (40%) were diagnosed with NSIP. When diagnosis was based on biopsy findings, the time interval in the UIP group was 13.59 ± 8.29 months and in the NSIP group it was 7.90 ± 4.18 months. When diagnosed on the basis of HRCT findings, the time interval in the UIP group was 14.22 ± 8.94 months and in the NSIP group it was 10.54 ± 5.78 months. When diagnosis was on the basis of biopsy, the mean age in the UIP group was 61.30 ± 14.18 years and in the NSIP group it was 50.73 ± 13.14 years.CONCLUSION:HRCT can be used instead of invasive methods like lung biopsy to differentiate between UIP and NSIP.

Significance of connective tissue disease features in idiopathic interstitial pneumonia

“…24 (24%) patients fulfilled the criteria for this algorithm, which was associated with a 10-fold increase in likelihood of NSIP. The striking demographic associations with NSIP observed in the present study mirror previous observations [17,[46][47][48][49], and lend further support for the inclusion of a typical demographic profile in diagnostic and prognostic algorithms. The age threshold of 50 yrs in females evaluated in our study was based upon the statement by an expert group that age ,50 yrs is an atypical feature in IPF and the fact that 50 yrs was the mean age for females in this study [23].…”

State of the art in the diagnosis and management of interstitial lung disease

“…Nonspecific interstitial pneumonia (NSIP) is a chronic interstitial lung disease characterized by relatively homogeneous expansion of the alveolar walls by inflammation and/or fibrosis. NSIP may be idiopathic, but more commonly occurs as a manifestation of CTD; it can be associated with toxic effects of drugs, occupational exposure, hypersensitivity pneumonitis, infections, chronic aspiration, granulomatous disease or chronic interstitial lung disease complicating diffuse alveolar damage [ 8 , 10 , 27 ].…”

“…The histology ranges from a predominantly inflammatory process (cellular NSIP) to predominant fibrosis (fibrotic NSIP) [ 10 ]. The diagnosis of NSIP without biopsy is highly inaccurate, with ~50% of cases being missed [ 27 ]. Ground-glass attenuation alone or mixed with consolidation is the most common CT feature.…”

Nonspecific interstitial pneumonia: clinical associations and outcomes

“…The histopathologic pattern of nonspecific interstitial pneumonitis (NSIP) has been found in a wide variety of clinical contexts, including chronic hypersensitivity pneumonitis, drug-related interstitial pneumonia, and connective tissue disease (CTD) [ 1 – 5 ]. NSIP has been identified as one of the most common pathologic patterns in patients with CTD [ 6 – 11 ]. Recent studies have shown that NSIP, even when initially diagnosed as an idiopathic form of NSIP, might be associated with an autoimmune background that later reveals itself as an organ-specific or a systemic autoimmune disease [ 12 – 14 ].…”