Rapid improvement in a terminal case of hairy cell leukemia treated with a new human recombinant interferon, IFN-α-C

A new type of human interferon (IFN), IFN-α-C, produced in Escherichia coli and purified on monoclonal antibodies, was given at a dose of 3 x 10⁶ u (3 μg)/day to a terminally ill unsplenectomized patient with hairy cell leukemia, who had had severe recurrent infections and pancytopenia. There was marked reduction in the size of the spleen after 2 weeks, and platelet counts returned to normal after 1 month of treatment. The IFN treatment also raised the granulocyte counts and hemoglobin levels, improved the normal repopulation of the bone marrow, and restored resistance to infections. IFN-α-C was well tolerated, without serious side effects, and treatment has been continued for 10 months.