Flow cytometry in hairy cell leukemia before and during interferon alfa-2b therapy

Cancer. 1987 Jun 15;59(12):1987-91. doi: 10.1002/1097-0142(19870615)59:12<1987::aid-cncr2820591203>3.0.co;2-k.


Mononuclear cells from 15 patients with hairy cell leukemia were studied before and during therapy with interferon alfa-2b (IFN) by regular peripheral blood differential counts and flow cytometry, using a panel of monoclonal antibodies (Moab). Seven leukemic phase patients (Group 1) had a mean leukocyte count of 48,870/microliter at entry with a mean absolute hairy cell (HC) count of 40,100/microliter. After 3 months on IFN, both parameters decreased significantly (WBC 3,500/microliter; HC count 130/microliter). In eight patients with a cytopenic form of the disease (Group 2) the mean leukocyte count rose from 2950/microliter to 3890/microliter while the mean absolute HC count decreased from 300/microliter to 120/microliter. The morphologic shifts correlated well with changes in the Moab reaction pattern. In Group 1 the activity of all Moab decreased significantly. In Group 2, only cells expressing Leu 3a and Leu 11a (a marker of natural killer cells) showed a significant shift, the latter increasing from 170/microliter to 360/microliter. This increase in natural killer cell antigen expression was not obvious based on routine morphologic observations alone. We show that flow cytometry may be a useful adjunct in monitoring the response of HCL to therapy. Changes in populations of cells that may be difficult to discriminate on morphologic grounds alone may be observed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Monoclonal
  • Antigens, Neoplasm / analysis*
  • Antigens, Surface / analysis*
  • B-Lymphocytes / immunology
  • Flow Cytometry
  • Humans
  • Interferon Type I / therapeutic use*
  • Killer Cells, Natural / immunology
  • Leukemia, Hairy Cell / pathology*
  • Leukemia, Hairy Cell / therapy
  • Leukocyte Count
  • Monocytes / immunology
  • T-Lymphocytes / immunology


  • Antibodies, Monoclonal
  • Antigens, Neoplasm
  • Antigens, Surface
  • Interferon Type I