Immunohistochemical Analysis of the Bullae in Patients with Primary Spontaneous Pneumothorax / 대한흉부외과학회지

ABSTRACT

BACKGROUND: Bulla is an air-filled space within the lung parenchyma resulting from deterioration of the alveolar tissue. Molecular mechanism of the formation of the bulla is not well described. Fibroblast growth factor(FGF)-7, bone morphogenetic protein(BMP) receptor, and transforming growth factor(TGF)-beta receptor are known to have a stimulatory or inhibitory role in the lung formation. We investigated to see if these growth factor or cytokine receptors are involved in the bulla formation by immunohistochemical staining of bullous lung tissues from patients with primary spontaneous pneumothorax. MATERIAL AND METHOD: Bullous lung tissues were obtained from 31 patients with primary spontaneous pneumothorax, including 30 males and 1 female from 15 to 39 years old. The bullous tissues were obtained by video-thoracoscopic surgery and/or mini-thoracotomy and fixed in formalin. Blocks of the specimens were embedded with paraffin and cut into 5~6 micrometer thick slices. The sections were deparaffinized and hydrated and then incubated with primary antibodies against FGF-7, BMP-RII, or TGF-RII. RESULT: Of the 31 patients, 24 were TGF-RII positive including 18 strong and 6 weak positives. Observation with high magnification showed that strong immunostaining was detected in the boundary region between bullous and normal lung tissues. In contrast, all of the sections were negative with FGF-7 or BMP-RII antibodies. CONCLUSION: These results suggest that overexpression of TGF-beta RII may be involved in the formation of bulla, although further molecular studies are needed to find out more detailed molecular mechanisms.