[Effectiveness of interferon alfa in different stages of thrombocythemia (preliminary report)]

In 6 women aged 38 to 68 years with thrombocythaemia during chronic myeloid leukaemia (4 cases), myelofibrosis (1 case), and idiopathic thrombocythaemia (1 case) the effects of recombinant human alpha-interferon (Intron A, rh IFN alpha -2b, Schering) were studied. The drug was given to all patients subcutaneously in one daily dose of 3 x 10(6) u, every day for 3 weeks, and then in the same doses twice weekly for 2 weeks (5 cases) and for 14 weeks (1 case). Intron A caused in all cases a fall of peripheral blood platelet count by 37% to 65.5% (mean 50%) in relation to the initial count (532 - 1,453 x 10(9)/l). The fall of the platelet count occurred usually after 7-10 days of this treatment, and the lowest count was noted usually after 24 days (10 to 42 days). During the treatment in 4 cases the peripheral leucocyte count dropped as well by 20-70%. In no cases exacerbation of chronic myeloid leukaemia was noted, and in the patient with myelofibrosis the enlarged spleen shrunk somewhat. These results of treatment and follow-up of patients with thrombocythaemia treated with Intron A indicate a significant although short-lasting effect of platelet count fall limited, however, to the time of the treatment. Side effects of the drug included mainly febrile conditions, myalgia and arthralgia.