Autologous transplantation of in vivo purged PBSC in CML: Comparison of FISH, cytogenetics, and PCR detection of Philadelphia chromosome in leukapheresis products

To determine the effectiveness of different methods for the detection of tu mor cell contamination of collected peripheral stem cells, we performed a s tudy on 39 chronic myelogenous leukemia (CML) patients who were consecutive ly treated at our department. Analyses of tumor cell contamination by fluor escence in situ hybridization (FISH), conventional cytogenetics, and polyme rase chain reaction (PCR) showed marked differences in the percentage of ev aluable results: Quantitative analysts of tumor cell contamination was feas ible in 60 of 105 (57%) samples evaluated with the use of conventional cyto genetic analysis and in 105 of 107 (98%) samples analyzed by FISH. PCR was evaluable in all 85 samples tested (100%). Both methods were shown to be ad equate overall in determining the number of BCR-ABL positive cells, althoug h cytogenetics tended to produce slightly higher percentages. Based on thes e results, we conclude that FISH performed on leukapheresis products is a r apid and reliable method for assessing the quality of these products and sh ould be used for routine evaluation of tumor cell contamination of CML stem cell products. (C) Elsevier Science Inc., 2000. All rights reserved.