Absolute clone count by Vβ flow cytometry can be used to monitor therapy, and survival data suggest possible association with clone switching. Absolute clone size tends to decrease in responders to therapeutic intervention (n = 23) versus nonresponders (n = 26; matched pairs analysis, P = .024). Response was determine by hematologic improvement. (A) Patients with full hematologic remission (left panel broken lines) and patients with partial remission (left panel full lines) tend to demonstrate a decrease in absolute clone size. Patients who do not respond to therapy with no change in hematologic status (right panel broken lines) and patients whose condition deteriorated during treatment (right panel full lines) tend to exhibit an increase in absolute clone size. (B) Patients who displayed an increase in ANC as absolute clone count decreased. Although the proportion of clonal cells increased markedly after time point 6, the ACC increase was more modest and was accompanied by an increase in ANC by the most recent time point. (C) Subgroup analysis of patients with neutropenia who responded to various therapies (n = 23; cytoxan, cyclosporine, campath) demonstrate a significant increase in ANC. Clearly nonsignificant survival data are demonstrated for the presence of > 1 Vβ expansion (D bottom line), whereas patients with anemia (E bottom line) and lymphopenia (F bottom line) tend to do much worse. Clone switching (G bottom line) may have a relationship with survival, but at this analysis the data do not yield statistically significant results.