The role of interferon-alpha in the treatment of myeloproliferative disorders.

The interferons are cytokines with a wide array of biological properties. In hematological malignancies the most used IFN class is -alpha; it has been used for thirty years but the mode of action is still not absolutely clear. Nevertheless, the benefits of IFN-alpha for the treatment of CMD have been described in particular for CML and less for PV, ET and MMM. IFN-alpha is presently considered the golden standard of therapy for CML patients not eligible for SCT; the antileukemic effect has been well documented by hematological and cytogenetic response. The survival advantage for IFN treated patients is remarkable in comparison with patients treated with conventional chemotherapy. Recently, the combination IFN-alpha plus Ara-C has demonstrated to increase the rate of major cytogenetic response and to prolong survival. To date, there is not a generally accepted treatment for ET, PV and MMM, which can reduce the risk of thromboembolism and/or hemorragic events. In several subsets of ET and PV patients, IFN-alpha can be considered as first line therapy. IFN-alpha is usually associated with the development of early and later side effects, that reduce the enthusiasm for its use. In the future PEG-IFN-alpha would improve the quality of life of IFN-treated CMD patients.