Cytokine profiles in Wegener's granulomatosis: Predominance of type 1 (Th1) in the granulomatous inflammation

Objective. To determine whether a specific cytokine pattern (type 1 [Th1] or type 2 [Th2]) predominates in Wegener's granulomatosis (WG), by evaluating interferon-γ (IFNγ) and interleukin-4 (IL-4) expression in different compartments of the body (i.e., biopsied nasal mucosal tissue [NBS], bronchoalveolar lavage [BAL] fluid, and peripheral blood [PB]) and comparing the findings with those in disease and healthy control subjects. Methods. Competitive reverse transcriptase-polymerase chain reaction (RT- PCR) and enzyme-linked immunosorbent assay were used to assess IFNγ and IL- 4 expression in T cell clones (TCC), T cell lines (TCL), and polyclonal CD4+ and CD8+ cells derived from NBS, BAL, and PB. Results. Patients with WG and chronic rhinitis were found to share in situ production of messenger RNA (mRNA) specific for IFNγ (Th1). Only 2 patients with WG expressed IL-4, whereas IL-4 mRNA PCR products were found in inflamed tissues of the disease control patients. The granuloma-derived T cells of WG patients produced only IFNγ, while TCC, TCL, and CD4+ and CD8+ T cells from BAL and PB produced mainly IFNγ. Conclusion. Our data indicate that a Th1 cytokine pattern predominates in the granulomatous inflammation in patients with WG.