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Interferon alpha‐2 for hairy cell leukemia: Evidence for induction of RNA synthesis in hairy cells and failure to correlate enhancement of natural killer cells with elimination of hairy cells
Author(s) -
Schwarzmeier Josef D.,
Schwabe Michael,
Prischl Friedrich,
Wagner Ludwig,
Lion Thomas,
Micksche Michael,
Köller Ursula
Publication year - 1987
Publication title -
european journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.904
H-Index - 84
eISSN - 1600-0609
pISSN - 0902-4441
DOI - 10.1111/j.1600-0609.1987.tb01449.x
Subject(s) - hairy cell leukemia , hairy cell , interferon , monoclonal antibody , biology , uridine , microbiology and biotechnology , natural killer t cell , in vitro , immunology , leukemia , cytotoxic t cell , antibody , rna , biochemistry , gene
The effect of human recombinant interferon α 2 (IFNα 2 ) on hairy cells obtained from 16 patients was evaluated. All patients promptly responded to induction of remission with 2 times 10 6 U/m 2 interferon α 2b , three times a week, sc. In order to achieve a more detailed insight into the mode of action of interferon in this disease, we determined the influence of IFNα 2 on the incorporation of radiolabeled thymidine and uridine into hairy cells. While both 3 H‐thymidine and 3 H‐uridine incorporation were unaffected by IFNα 2 in a 3‐hour incubation period, a significant increase in uridine incorporation into hairy cells, but not CLL cells, was observed after 24 h. Cell surface marker analysis performed with monoclonal antibodies did not reveal a quantitative alteration of the immunophenotype of hairy cells in vitro. In addition, natural killer cells, assessed by monoclonal antibodies and a cytotoxicity assay against K 562 cells, were found to be decreased in 9 out of 10 patients prior to therapy. Although IFNα 2 could stimulate natural killer cells in vivo, we did not find a consistent correlation between the activation of these cells and the response to therapy. We conclude, therefore, that NK cells play no major role in the regression of hairy cells. Furthermore, IFNα 2 does not alter antigenic determinants in vitro, but leads to an enhanced incorporation of 3 H‐uridine into hairy cells in vitro, thus indicating a possible role for the induction of RNA synthesis in vivo.