Is fluorescence in situ hybridization a useful method in diagnosis of polycythemia vera patients?

Polycythemia vera (PV) is a clonal stem cell disease with trilineage myeloid involvement, characterized by a growth factor-independent erythroid proliferation. At the time of diagnosis, the percentage of cytogenetic abnormalities using conventional cytogenetic techniques is less than 20% of all PV patients. In the present study, we compare the results between conventional cytogenetic methods and fluorescence in situ hybridization (FISH) probes in 31 untreated PV patients. The karyotypes of all 31 cases were obtained from 24-hour bone marrow cell cultures. The fixed material, proceeding from conventional cytogenetics cultures, was analyzed with FISH, using centromeric probes for chromosomes 8 and 9 and locus-specific probes for 13q14 and 20q12 regions. Five cases (17.8%) showed an abnormal karyotype with conventional cytogenetics. When FISH probes were used, three alterations not detected with conventional cytogenetics, were found: two cases with D20S108 deletions and one with a D13S319 deletion, increasing the percentage of abnormal karyotypes to 19.3%. We conclude that, probably, the application of FISH with the mentioned probes, is not very useful to detect cytogenetic aberrations in untreated PV patients.