Concentrations of IL4Rα and TNFα in bronchoalveolar lavage fluid can distinguish hypersensitivity pneumonitis from other fibrosing interstitial lung diseases

Abstract

Objectives: Fibrosing interstitial lung diseases (ILDs), namely hypersensitivity pneumonitis (HP), idiophatic intersticial fibrosis(IPF), non-specific intestitial pneumoias(NSIP) and ILDs accompanying connective tissue diseases (ILD-CTDs), could be difficult to differentiate from each other. Aim: To compare interleukin- 4 receptor alpha (IL4Rα), tumor necrosis factor alpha (TNFα), matrix metalloproteinase 7(MMP7), proteinase activated receptor 2(PAR-2) values and differential cell counts in bronchoalveolar lavage fluid (BALF) of HP, IPF, NSIP and ILD-CTD patients. Material and methods: 80 patients were enrolled (20 ILD-CTDs/18IPF/6NSIP/36HP, 38men/42women, 7smokers/34non-smokers/39exsmokers). Measurements of vital capacity (VC) %PV and diffusing capacity for carbon monoxide(DLco) %PV and BAL were performed. Differential cell counts in BALF were measured. Concentrations of IL4Rα, TNFα, PAR-2 and MMP7 in BALF were assesed by ELISA. Analysis of Variance was used to state statistically significant data. Results: In IPF patients were men (N=15, p Conclusion: HP is characterised in our study by higher lymphocyte counts and concentrations of IL4Rα, TNFα in BALF, which could reflect active inflammation and granuloma formation. It seems that these cytokines in BALF might help to differentiate HP (including chronic HP with fibrosis) from other fibrosing ILDs. Supported by F.Hoffmann-LaRoche grant