Confirmation of monoclonality by fluorescent IgH-PCR analysis.

The detection of monoclonality by IgH-PCR analysis of 3 representative individuals is shown. DNA from samples containing CLL phenotype cells and from age- and sex-matched normal controls (2 controls per individual with CLL phenotype cells) was amplified using a fluorescent J_H primer and consensus primers to framework V_H regions. PCR products show a range of sizes with a normal distribution separated by 3 base pairs in normal individuals (A), a single peak in individuals whose B lymphocytes are all CLL phenotype (B), or a large single peak on an otherwise normal distribution in individuals with both CLL phenotype and polyclonal B lymphocytes (C). PCR results for patients with CLL-phenotype cells detectable by flow cytometry are shown (D). The flow assay is more sensitive than PCR detection20 and as such, IgH-PCR analysis rarely identified a monoclonal population in samples with low levels (< 0.5%) of CLL phenotype cells (D).