Objective: To determine whether a specific cytokine pattern (type 1 [Th1] or type 2 [Th2]) predominates in Wegener's granulomatosis (WG), by evaluating interferon-gamma (IFNgamma) 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 IFNgamma 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 IFNgamma (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 IFNgamma, while TCC, TCL, and CD4+ and CD8+ T cells from BAL and PB produced mainly IFNgamma.
Conclusion: Our data indicate that a Thl cytokine pattern predominates in the granulomatous inflammation in patients with WG.