COMPARISON OF PCR WITH SOUTHERN HYBRIDIZATION FOR THE ROUTINE DETECTION OF IMMUNOGLOBULIN HEAVY-CHAIN GENE REARRANGEMENTS

The development of a reliable polymerase chain reaction (PCR) techniqu e for the routine detection of clonal immunoglobulin heavy chain (IgH) gene rearrangements would represent an attractive alternative to Sout hern hybridization analysis because of the relative simplicity of PCR protocols, and because the requirements for both quality and quantity of DNA would be considerably less stringent. To assess the utility of PCR for the routine detection of clonal IgH gene rearrangements, sampl es from 123 adult patients were evaluated and analysis by PCR amplific ation using IgH Framework 1 or Framework 3 variable region consensus p rimers was compared with analysis by restriction endonuclease digestio n and Southern hybridization with genomic, IgH probes. The authors fou nd that 90% of IgH genes found to be rearranged by Southern hybridizat ion are detected by the PCR technique. An additional 9 patient samples had clonal IgH gene rearrangements that were detectable by PCR alone. Eight of these nine patients had a history of a clonal hematopoietic process at either the morphologic or molecular level, and six had a hi story of a B-cell malignancy. It is likely that these specimens contai ned clonal lymphoid populations undetected by the Southern hybridizati on technique. Thus, the diagnostic sensitivity and specificity of the PCR method for the detection of B-cell tumors were 91% and 95%, respec tively. The combination of improved analytical sensitivity and specime n flexibility of the IgH PCR assay could make it the method of choice for the routine detection of clonal IgH gene rearrangements, if minor improvements in the diagnostic sensitivity of the assay can be achieve d.