Clonality by SSCP analysis. Healthy peripheral blood mononucler cells (PBMC) as a control were investigated. Lane 2 (Vβ5a-Cβ) and lane 10 (Vβ13-Cβ); lane 8, Vβ4-Jβ1.4 of healthy PBMC stimulated with TSST1; lane 1, Vβ13-Jβ1.2 in patient no. 1; lanes 3, 4, and 5, Vβ5a-Cβ, Vβ5a-Jβ1.6, and Vβ5b-Jβ1.2 in patient no. 2, respectively; lanes 6 and 12, Vβ6-Jβ1.1 and Vβ13-Cβ in patient no. 4, respectively; lane 7, Vβ6-Jβ1.1 of bone marrow in patient no. 5; lanes 9 and 11, Vβ4-Jβ1.4 and Vβ13-Cβ in patient no. 3, respectively. Smears are shown in lanes 2, 5, 8, 10, 11, and 12. Distinct bands are observed in lanes 3, 4, 6, 7, 9, and 1, suggesting clonal expansion.