Elevated sL1-CAM levels in BALF and serum of IPF patients

IPF is a form of interstitial pneumonia of unknown origin that has a poor prognosis for which current treatments are limited. Recent studies have shown that EMT plays a role in IPF and tumour metastasis. L1-CAM has also been linked to EMT during tumour development and tumour metastasis. Our aim was to determine prospectively the level of L1-CAM in IPF patients.

Forty consecutive Chinese patients (with IPF, 16; LC, 12; and CC, 12), but no apparent lung or other organ's diseases were enrolled. Soluble L1-CAM (sL1-CAM), TGF-β1, PDGF, γ-INF levels in BALF and serum sL1-CAM were measured using ELISA.

BALF sL1-CAM levels of IPF, LC and CC patients were 10.87 ± 0.88 ng/mL, 6.34 ± 0.67 ng/mL and 5.43 ± 0.65 ng/mL, respectively. BALF sL1-CAM concentration of IPF patients was significantly higher than that in LC and in CC patients. Besides, serum sL1-CAM levels in patients with IPF, LC and CC were 9.60 ± 1.41 ng/mL, 9.82 ± 0.72 ng/mL and 5.41 ± 1.07 ng/mL, respectively. The serum sL1-CAM levels in patients with IPF and LC were significantly higher than those in patients with CC (P < 0.001, respectively).

The concentrations of sL1-CAM both in BALF and in serum of patients with IPF are markedly increased compared with controls. This indicates that L1-CAM might be involved in the pathogenesis of IPF as well as that of LC.