Ultrasensitive PCR Detection of Tumor Cells in Myeloma

Chromosomal aberrations, such as translocations or inversions, described for a growing number of malignancies, are now widely used to detect tumor cells by polymerase chain reaction (PCR). However, in multiple myeloma (MM), no such ubiquitous PCR marker exists. Therefore, other means have been established to distinguish myeloma cells from normal cells. Because the plasma cells of a myeloma clone share an identical rearranged immunoglobulin gene sequence, it is possible to detect malignant cells with PCR primers specific for the VDJ rearrangement of the heavy chain of each myeloma clone. The sensitivity and specificity of this method, named allele-specific oligonucleotide (ASO) PCR, even with low proportions of malignant cells, has been proven (1 ).