Clonal CD8+ TCR-Vβ expanded populations with effector memory phenotype in Churg Strauss Syndrome

Churg Strauss Syndrome (CSS) is a systemic vasculitis in which oligoclonal T cell expansions might be involved in the pathogenesis. Combined analysis of TCR-Vβ expression profile by flow cytometry and of TCR gene rearrangement by heteroduplex PCR was used to detect and characterize T cell expansions in 8 CSS patients, 10 asthmatics and 42 healthy subjects. In all CSS patients one or two Vβ families were expanded among CD8+ cells, with an effector memory phenotype apt to populate tissues and inflammatory sites. Heteroduplex PCR showed the presence of one or more clonal TCR rearrangements, which reveals monoclonal or oligoclonal T cells subpopulations. After purification with a Vβ specific monoclonal antibody, each CD8+/Vβ+ expanded family showed a single TCR rearrangement, clearly suggestive of monoclonality. All CD8+ expansions were detectable throughout the disease course. TCR-Vβ expanded or deleted populations were not observed in asthmatic patients. Clonal CD8+/Vβ+ T cell expansions might be useful as a disease marker.