Platelet-derived growth factor in bronchiolitis obliterans-organizing pneumonia.
Bronchiolitis obliterans-organizing pneumonia (BOOP) is a disorder characterized by intraluminal proliferation of connective tissue in distal air spaces. As part of a general investigation of the role of growth factors in this process, the present study examined the expression of the mitogen, platelet-derived growth factor (PDGF), and one of its receptors, PDGFR-beta, in this disease. Serial sections of lung biopsy specimens from 20 patients with BOOP and 10 control subjects were stained with antibodies against PDGF, PDGFR-beta, and the monocyte/macrophage marker CD68. Stereologic point counting showed that PDGF+ cells represented 4.6 +/- 1.6% (mean +/- SD) of the volume occupied by lung tissue in BOOP and 2.1 +/- 0.7% in the control subjects (p < 0.0001). In both groups the positive cells were tissue macrophages, and CD68+ macrophages accounted for 10.7 +/- 4.7% of the lung tissue in BOOP as compared with 5.4 +/- 3.7% in the control subjects (p < 0.005). PDGFR-beta immunoreactivity was present in some alveolar epithelial cells in BOOP, but was absent in control subjects. We conclude that PDGF+ cells and CD68+ macrophages are found in greater numbers in lungs with BOOP, and an increased expression of PDGFR-beta epitopes was observed in some patients with BOOP. We speculate that these molecules are important in the pathogenesis of the destructive fibroproliferative process that characterizes this disease.
Aubert
J D
JD
University of British Columbia Pulmonary Research Laboratory, St. Paul's Hospital, Vancouver, Canada.
Paré
P D
PD
Hogg
J C
JC
Hayashi
S
S
D000368:Aged; D018549:Cryptogenic Organizing Pneumonia / Q000276:immunology* / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010982:Platelet-Derived Growth Factor / Q000276:immunology* / Q000302:isolation & purification; D012129:Respiratory Function Tests
D010982:Platelet-Derived Growth Factor