5.2. Immunohistochemical expression of VEGF and bFGF (II)

5.2.1. VEGF and bFGF expression in intraluminal connective tissue

The percentage of VEGF and bFGF positive cells of the total number of cells is shown in Table 6. The cells of the newly formed connective tissue were more strongly positive for both VEGF antibodies in BOOP than in UIP (p < 0.001 for VEGF (C-1) and  < 0.004 for VEGF (A-20)). The staining pattern with both antibodies was mostly intracytoplasmic and granular, and particularly strong positivity was found for VEGF (C-1) in BOOP. The positive reaction was often pronounced in the fusiform cells underneath the epithelium. There was a positive correlation between the two VEGF stainings, Pearson’s correlation coefficient being 0.375 (p < 0.05).

The staining intensity of bFGF was mostly moderate and the location of the immunoreactivity was intracytoplasmic. The staining pattern in the intraluminal connective tissue lesions of BOOP and UIP varied greatly; some cells stained strongly, while others remained negative. Especially in BOOP there were cases in which fibroblasts remained negative, but the capillaries of the newly formed intraluminal connective tissue lesions stained positively. As a whole, expression of bFGF was wider in BOOP than in UIP (p < 0.02).

5.2.2. VEGF and bFGF expression outside the intraluminal connective tissue

The staining pattern of VEGF is shown in table 7. For bFGF, the localization of the immunohistochemical expression was parallel to the expression of VEGF, but as a whole, the staining intensity was somewhat stronger. The strongest expression for bFGF was seen in the basal cells of the bronchioles.