Clinical and Laboratory Features.*

Abbreviations: WBC, white blood cell; Hgb, hemoglobin; Prolymphs, prolymphocytes; LDH, serum lactate dehydrogenase; β2M, serum β2 microglobulin; serum Ig, serum immunoglobulin levels; surface IgL, surface immunoglobulin light chain isotype; IGHV SM status, immunoglobulin heavy chain variable region gene somatic mutation status.*Rai stage, splenomegaly, WBC count, Hgb, Prolymphs, Platelets, LDH, β2M, serum Ig were determined at the time the sample was obtained. The CLL score, surface IgL, IGHV SM status, ZAP70, and karyotype were determined on samples obtained before treatment was initiated.†All p values were calculated using the two-sided Fisher's Exact test except for age in years, which was calculated using the two-sided t-test, and time-to-event parameters (log-rank test).‡The normal ranges are: WBC, 4–11×109/L; Hgb, 14.0–18.0 g/dL, platelets, 140–440×109/L; LDH, 313–618 U/L; β2M, 0.7–1.8 mg/L; serum Ig, IgM 29–214 g/dL, IgA 74–327 g/dL, IgG 624–1680 g/dL. Serum Ig are considered decreased (hypogammaglobulinemia) if ≥2 immunoglobulin fractions are below the normal range. CD38 is low if