Polycythemia vera: analysis of DNA from blood granulocytes using comparative genomic hybridization

Background and Objectives. The diagnosis of polycythemia vera (PV) is suppo rted by the finding of an abnormal karyotype in patients with erythrocytosi s. However, most W patients have normal marrow cytogenetics at presentation and there is reluctance to use this test routinely. Comparative genomic hy bridization (CGH) is a cytogenetic screening technique that analyzes interp hase cells. This approach offers practical advantages over conventional cyt ogenetics and interphase fluorescence insitu hybridization (IFISH), We have therefore evaluated the diagnostic utility of CGH applied to blood granulo cytes in W. Design and Methods. Blood granulocytes from 17 PV patients were analyzed us ing CGH and the results compared with those from previous conventional cyto genetics and IFISH studies. Results. Three patients had abnormal CGH profiles. One case had gain of 9p. This patient had normal IFISH results using a centromere-g probe. The seco nd case had complete gain of chromosomes 8 and 9 and the third had complete gain of chromosome 9, all confirmed by IFISH. Cytogenetics had not been pe rformed in two of these cases and had failed in the third. Three cases with 20q deletion according to cytogenetics and/or IFISH, were normal by CGH. T he remaining subjects were normal by all methods, Interpretation and Conclusions. CGH analysis of blood granulocytes can dete ct the chromosome gains commonly observed in PV. However, CGH cannot be rel ied on to detect 20q deletions, which are the most frequent cytogenetic abn ormality in W. Thus, CGH has a role in the diagnosis and follow-up of W pat ients, but must be used in conjunction with other methods. (C) 2001, Ferrat a Storti Foundation.