SESSION TYPE: ILD - Bench to Bedside
PRESENTED ON: Wednesday, October 24, 2012 at 02:45 PM - 04:15 PM
PURPOSE: Interstitial lung diseases (ILD) are a heterogeneous group of illnesses characterized by variable degrees of fibrosis and an imbalance of pro-inflammatory cytokines. Hyaluronan (HA) is a glycosaminoglycan which plays an important role in certain inflammatory diseases. We previously reported a significant increase in HA levels in bronchoalveolar lavage (BAL) from ILD patients compared with healthy subjects. In vitro studies have shown that HA induces the expression of pro-inflammatory genes in alveolar macrophages. In the present study we quantified HA and cytokine levels in BAL and evaluated lung function parameters in ILD patients and control subjects.
METHODS: Patient population: idiopathic pulmonary fibrosis/usual interstitial pneumonia (IPF/UIP: n=6); non-specific interstitial pneumonia (NSIP: n=4); sarcoidosis (n= 6); hypersensitivity pneumonitis (HP: n=12) and pulmonary Langerhans cell histiocytosis (Hx: n=3). Controls were individuals with healthy lungs (n=13). Cytokine and HA levels in BAL samples were determined by enzyme immunoassay. Pulmonary function tests included lung diffusing capacity for carbon monoxide (DLCO) and alveolar volume (VA).
RESULTS: We found a significant increase of HA levels in BAL from patients with NSIP (2.057,00 ± 419,90 ng/mL, p<0,01); HP (1.975,00 ± 199,30 ng/mL, p<0,001); Sarcoidosis (1.839,00 ± 47,90 ng/mL, p<0,01) and Hx (1.918,00 ± 404,20 ng/mL; p<0,05) compared with controls (623,50±48,10 ng/mL). However, there were not differences between IPF/UIP (961,90 ± 118,79 ng/mL) and the control group. When we analyzed the levels of proinflammatory cytokines (IL-1β, IL-6, TNF-α and IL-8) in BAL we observed no significant differences between ILD patients and control subjects. However, there was a correlation between IL-6 and HA levels in BAL (Spearman r = 0,57 and p<0,01). Moreover, we observed an inverse correlation between the concentrations of HA and lung functional parameters: patients with higher concentrations of HA had lower values of DLCO/VA (Spearman r = -0,28).
CONCLUSIONS: Our results show a relationship between BAL HA levels and the severity of ILD.
CLINICAL IMPLICATIONS: HA could be a marker of ILD progression.
DISCLOSURE: The following authors have nothing to disclose: Glenda Ernst, Pedro Grynblat, Carolina Jancic, Auteri Santiago, Fernando Galíndez, Juan Carlos Moncalvo, Jorge Geffner, Silvia Hajos
No Product/Research Disclosure InformationMaría Ferrer Hospital, Buenos Aires, Argentina