Investigation of minimal residual disease in adult Ph1 positive acute lymphoblastic leukemia by a combination of cell sorting and fluorescence in situ hybridization: a preliminary study on 6 cases.

We studied minimal residual disease in 6 patients with Philadelphia positive acute lymphoblastic leukemia (Ph1 ALL) in remission by using a combination of cell sorting (CD34 + ) and FISH. The detection of residual leukemic cells in Ph1 ALL by using this method is much more sensitive than conventional morphology and cytogenetic analyses.