Cytokine levels in the sera of patients with idiopathic pulmonary fibrosis

Summary

Background

Idiopathic pulmonary fibrosis (IPF) is a fibroproliferative disorder. Cytokines contribute an important but yet undefined role to its pathogenesis.

Objectives

The present study aims to compare serum levels of cytokines involved in Th-1 and Th-2 immunity, such as interleukins (IL) IL-2, IL-4, IL-8, IL-10, interferon-γ (IFN-γ) and IL-12 (p40) in patients with IPF and healthy volunteers. Twenty patients with IPF and 40 healthy controls (HC) participated.

Methods

Cytokines were assessed by enzyme-linked immunoabsorbent assay (ELISA).

Results

Median values of serum IL-2, IL-8, IL-10, IL-12 (p40) were higher in the IPF than the control group: IPF group: 1.05 U/ml, 12.55, 10.13, 44.17 pg/ml; control group: 0.05 U/ml, 6.91, 0.75, 4.51 pg/ml, respectively $(P<0.05)$. IFN-γ serum levels were lower in the IPF (0.19 pg/ml) than in the control group (0.49 pg/ml). IL-4 values did not differ in a statistically significant way among the groups: 8.40 pg/ml in the IPF group, and 7.46 pg/ml in the control group $(P>0.05)$. IL-4 positively correlated to fast expiratory volume in 1 s (FEV₁%) and forced vital capacity (FVC%), while IL-8 negatively correlated to the respective values $(P<0.005)$.

Conclusions

IL-2, IL-8, IL-10 and IL-12 (p40) were found to be elevated in the sera of patients with IPF. IFN-γ was found to be decreased in the sera of patients with IPF.