- Progressive lymphocytosis with an increase >50% over a 2-month period or an anticipated doubling time of less than 6 months. In patients with initial blood lymphocyte counts of less than 30x10^9/L LDT should not be used as a single parameter to define treatment indication. Marked hypogammaglobulinemia or the development of a monoclonal protein in the absence of any of the above criteria for active disease is not sufficient for protocol therapy.