Cytogenetic remission induced by interferon-alpha in a myeloproliferative disorder with trisomy 8.

We report a case of an unusual myeloproliferative disorder with trisomy of chromosome 8 characterized by peripheral blood thrombocythaemia and pronounced bone marrow myelodysplastic features. Treatment with interferon-alpha at intermediate dosages, together with a complete bone marrow and peripheral blood haematology remission, was able to induce a cytogenetic remission, shown by the complete disappearance at the conventional cytogenetic analysis of trisomy 8 abnormality characterizing the neoplastic clone at diagnosis. However, trisomy 8 was still detectable by FISH in a small proportion of cells, showing that profound suppression of, but not complete eradication of, the neoplastic clone had occurred. The ability of interferon-alpha to induce a major cytogenetic remission in a +8, Philadelphia-chromosome negative, myeloproliferative disorder has not previously been documented and may provide further indications for the use of this drug in these disorders.