T-cell clonality determination using polymerase chain reaction (PCR) amplification of the T-cell receptor gamma-chain gene and capillary electrophoresis of fluorescently labeled PCR products

We compared the effectiveness of polymerase chain reaction (PCR) and DNA bl ot analysis (DBA) for detecting clonal T-cell populations and investigated whether a nonradioactive PCR method could be used in routine clinical diagn osis. We analyzed DNA from 117 cases for T-cell clonality by PCR amplificat ion. DBA was performed on 77 of these cases. Denaturing polyacrylamide gel electrophoresis (PCR-PAGE) of radiolabeled PCR products and capillary elect ophoresis (PCR-CE) of fluorescently labeled PCR products were used for PCR products separation and quantitation. Complete agreement was obtained betwe en PCR-PAGE and DBA in 67 of 77 cases. One case was positive by DBA and neg ative by PCR-PAGE, and 2 cases were positive by PAGE and negative by DBA. F ive cases indeterminate by DBA were positive by PCR-PAGE, and 1 indetermina te cases was negative by PCR-PAGE. In the comparison of PCR-PAGE and PCR-CE , of 63 cases with height ratios less than 2.0, all were negative by PCR-PA GE. OF 53 cases with height ratios of 2.0 or more, 50 were positive by PCR- PAGE. We conclude that PCR-CE is analytically equivalent to DBA and PCR-PAG E for detecting clonal T-cell populations. The PCR-CE method is semiquantit ative and, therefore, may be more objective than gel-based methods.