Expression of CD14 correlates with lung function impairment in pulmonary sarcoidosis

CD14 expression on alveolar macrophages (AM) was studied in patients with sarcoidosis using immunocytochemistry and cytometric analysis. Compared with healthy control donors, patients had elevated percentages of CD14-positive AM (22 percent vs 34 percent), and the antigen density was threefold higher (92 vs 297 channels). Furthermore, soluble serum CD14 (ssCD14) was significantly elevated in patients with sarcoidosis with an average of 5.3 +/- 1.6 mg/L vs 3.2 +/- 0.7 mg/L in healthy control subjects. Follow-up of one patient, whose lung function test results improved during therapy with corticosteroids, revealed a concomitant decrease of CD14 staining on AM and of ssCD14. Statistical analysis revealed a negative correlation between CD14 expression on AM and PO2 at rest (p = 0.0005), and after labor (p = 0.02). Levels of ssCD14 gave a positive correlation to reduction of Dco (p = 0.006) and VC (p = 0.05). These data suggest that CD14 expression is related to severity of disease and that it may be useful for monitoring in sarcoidosis.