Quantitative Analysis of Fibroblastic Foci in Usual Interstitial Pneumonia: Study Population

We experienced consecutive 39 patients with interstitial pneumonia associated with CVD and 37 patients with idiopathic interstitial pneumonia who underwent open or thoracoscopic lung biopsy in our hospital between 1990 and 2003. Surgical lung biopsy slides were independently reviewed by two lung pathologists (S.I., N.E.) who were unaware of clinical or physiologic findings. When the classification differed between the pathologists, a consensus opinion on the overall histopathologic pattern was reached. Histologic features of UIP were based on a previously published report and the criteria in the American Thoracic Society/European Respiratory Society consensus classification. Of the patients, 17 with cVd and 20 with idiopathic interstitial pneumonia were histologically classified into UIP. Fifteen patients with CVD-UIP and 16 with IPF/UIP for whom clinical findings and lung specimens were available participated in the present study. The study protocol was approved by the Ethical Committee of the Hamamatsu University School of Medicine, and informed consent was obtained from all patients. No patients in an accelerated phase of interstitial pneumonia were included. The patients with CVD-UIP who all fulfilled the diagnostic criteria for their respective CVD included five patients with primary Sjogren syndrome; four patients with rheumatoid arthritis; two patients with systemic sclerosis; two patients with polymyositis/dermatomyositis; one patient with systemic lupus erythematosus and Sjogren syndrome; and one patient with rheumatoid arthritis and polymyositis/dermatomyositis. fully

Lung specimens were obtained from at least two lobes, and all available specimens were reviewed. Images of sections stained with hematoxylin-eosin were made using a microscope (Axio-photo; Carl Zeiss Corporation; Oberkochem, Germany) with a CCD camera (SPOT; Diagnostic Instruments; Sterling Heights, MI). At least 10 fields of imaged lesions at 100-fold magnification were randomly selected except for the areas of honeycombing. Briefly, we blindly moved the target fields in a CCD camera within the section. If honeycomb area was present in the target field, we moved the fields again until the field has no honeycombing area. In each selected field, the area of FF was measured using analytic software (Image-Pro Plus, version 4.5.0.24; Media Cybernetics; Atlanta, GA), and %FF was calculated by dividing the area of FF by that of the target field, as in Figure 1. Overall %FF, a quantitative %FF score, in each patient was defined as the average %FF in > 10 selected fields. To evaluate an intraobserver correlation of our quantitative scoring method, the same pathologist reviewed the same specimen on different days. Additionally, to evaluate an interobserver correlation of our method, the two pathologists (S.I., N.E.) independently reviewed the same specimen. The intraobserver and interobserver correlation were assessed using the Pearson correlation coefficient.

Figure-1

Figure 1. Images of sections made using a microscope with a CCD camera and image analysis software. Lung specimens were stained with hematoxylin-eosin, and at least 10 fields of imaged lesions at 100-fold magnification in each lobe were randomly selected. In each selected field, the %FF was calculated by dividing the area of FF (b) by that of the target field (a). The overall %FF and the quantitative %FF score in each patient are defined as the average of the %FF in > 10 selected fields.

This entry was posted in Pulmonary Function and tagged collagen vascular disease, fibroblastic foci, idiopathic interstitial pneumonia, quantitative analysis, usual interstitial pneumonia.