POLYCYTHEMIA-VERA TREATED WITH RECOMBINANT INTERFERON-ALPHA 2A - EVIDENCE OF A SELECTIVE EFFECT ON THE MALIGNANT CLONE

We periodically analyzed bone-marrow cytogenetic features in 8 patient s belonging to a series of 38 subjects with polycythemia vera (PV), al l treated with recombinant interferon-alpha 2a (rIFN-alpha) at a weekl y dose of 9,000,000 IU. Six out of these 8 patients never showed any c hromosome alterations, while 2 displayed at diagnosis the presence of trisomy 8 in all bone-marrow metaphases. interestingly enough, in thes e 2 patients rIFN-alpha treatment was able to induce not only complete hematological response but also the disappearance of trisomy 8, as sh own by conventional cytogenetic investigation and fluorescence in situ hybridization performed on bone-marrow cells after : year of treatmen t. This finding indicates that, as previously shown in chronic myeloid leukemia, in PV rIFN-alpha can also eradicate the malignant clone by means of a selective effect on hone-marrow transformed cells. (C) 1997 Wiley-Liss, Inc.