Hypermetaphase and interphase fluorescence in situ hybridisation for monitoring of remission status in Philadelphia chromosome positive chronic myeloid leukaemia.

ABSTRACT

Interferon (IFN) alone or in combination with cytostatic drugs, can induce major and durable cytogenetic remissions in chronic myelogenous leukaemia (CML) patients. Hypermetaphase (HMF) and interphase (IPF) fluorescence in situ hybridisation (FISH) have been described to be suitable for remission assessment. In the present study we applied HMF and IPF simultaneously to bone marrow (BM) probes from Ph-positive CML patients. As conventional cytogenetics (CC) is still deemed to be the <gold standard> for remission analysis we studied a group of patients analysed with this method as control. A mean of 50 metaphases was available for HMF analysis, whereas only an average of 18.7 metaphases could be analysed by CC. Remission assessment was frequently impossible by CC or HMF due to lack of metaphases, but always possible by applying IPF. Our results show that HMF should replace CC for routinely monitoring the remission status in Ph-positive CML patients and that in case of lack or insufficient number of metaphases in the majority of cases IPF is suitable for remission assessment.