In vitro production of myeloperoxidase anti-neutrophil cytoplasmic antibody and establishment of Th1-type T cell lines from peripheral blood lymphocytes of patients.

OBJECTIVE: To investigate the pathogenic role of T cells in the development of anti-neutrophil cytoplasmic antibody (ANCA) associated vasculitis.
METHODS: Peripheral blood lymphocytes (PBL) were isolated from myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA) associated vasculitis patients and cultured in medium. The production of MPO-ANCA in the medium of PBL stimulated with Concanavalin-A (Con-A), with or without cyclosporin (CyA), was measured by enzyme-linked immunosorbent assay (ELISA) on MPO coated plates. RNA isolated from PBMC of one patient was used for polymerase chain reaction (PCR) and single stranded conformational polymorphism (SSCP) studies, and MPO-specific T cell lines (TCL) were established by antigen stimulation techniques.
RESULTS: PBL of patients with MPO-ANCA-associated vasculitis produced MPO-ANCA following Con-A stimulation, and this effect was inhibited by treatment with cyclosporin A (CyA) or elimination of CD4 cells. PCR-SSCP showed autoantigen-reactive oligoclonal T-cell accumulation in PBMC of one of these patients. We established MPO-specific TCL which secreted interferon-gamma (IFN-gamma), but not interleukin-4 (IL-4); all TCL were CD4 positive, CD8 negative, and HLA-DR restricted.
CONCLUSIONS: Our results suggest that Th1-type T cells may mediate MPO-ANCA production, and may play a role in the onset of MPO-ANCA vasculitis.