Clinical utility of immunoglobulin heavy chain gene rearrangement identification for tumour cell detection in multiple myeloma

In an attempt to define the clinical utility of immunoglobulin heavy chain (IgH) gene rearrangement identification for tumour cell detection in multip le myeloma, we investigated 36 consecutive newly diagnosed patients intende d for high-dose chemotherapy in a study protocol. After identification of t he IgH rearrangement, an allele specific oligonucleotide (ASO) was construc ted and used in a semiquantative PCR for minimal residual disease (MRD) eva luation. The myeloma-specific IgH gene rearrangement could be identified an d an ASO primer constructed in 24 (67%) of the patients. All of these patie nts underwent transplantation; 22 were autologous, of whom three had PCR-ne gative stem cell harvests, and two were allogeneic. 10 patients achieved a clinical complete response (CR) and five were PCR negative in sequential bo ne marrow analyses, In patients not achieving CR, PCR negativity was occasi onally found, but in general the PCR results reflected the clinical status of the patients. No consistent relationship between the bone marrow MRD sta tus and the clinical course was found, and early relapses occurred also in PCR-negative patients.