COMPARISON OF FLUORESCENT CONSENSUS IGH PCR AND ALLELE-SPECIFIC OLIGONUCLEOTIDE PROBING IN THE DETECTION OF MINIMAL RESIDUAL DISEASE IN CHILDHOOD ALL

The sensitivity of detection of residual disease by two IgH PCR strate gies, fluorescent framework 3 (Ffr3) and allele-specific oligonucleoti de probing (ASOP), was compared in 57 'remission' BM samples obtained from 19 children with B-lineage acute lymphoblastic leukaemia (ALL). O ligonucleotide probing was more sensitive than FFr3 PCR in 10/16 cases , achieving a sensitivity of 0.01% or greater in 15/16 cases. Comparab le sensitivities were obtained in the six remaining cases; the FFr3 PC R achieving a sensitivity of 0.1% or greater in 14/16 cases. 39/57 're mission' BM samples analysed showed no evidence of MRD by either techn ique although 18 were positive by ASOP and 14 positive by FFr3 PCR. Th e level of disease was estimated to be 0.01% or less in the four false negative samples.