Diagnostic Utility of a Clonality Test for Lymphoproliferative Diseases in Koreans Using the BIOMED-2 PCR Assay

Abstract

Background: A clonality test for immunoglobulin (IG) and T cell receptor (TCR) is a useful adjunctive method for the diagnosis of lymphoproliferative diseases (LPDs). Recently, the BIOMED-2 multiplex polymerase chain reaction (PCR) assay has been established as a standard method for assessing the clonality of LPDs. We tested clonality in LPDs in Koreans using the BIOMED-2 multiplex PCR and compared the results with those obtained in European, Taiwanese, and Thai participants. We also evaluated the usefulness of the test as an ancillary method for diagnosing LPDs.

Methods: Two hundred and nineteen specimens embedded in paraffin, including 78 B cell lymphomas, 80 T cell lymphomas and 61 cases of reactive lymphadenitis, were used for the clonality test.

Results: Mature B cell malignancies showed 95.7% clonality for IG, 2.9% co-existing clonality, and 4.3% polyclonality. Mature T cell malignancies exhibited 83.8% clonality for TCR, 8.1% co-existing clonality, and 16.2% polyclonality. Reactive lymphadenitis showed 93.4% polyclonality for IG and TCR. The majority of our results were similar to those obtained in Europeans. However, the clonality for IGK of B cell malignancies and TCRG of T cell malignancies was lower in Koreans than Europeans.

Conclusions: The BIOMED-2 multiplex PCR assay was a useful adjunctive method for diagnosing LPDs.

Keywords: BIOMED-2 multiplex PCR assay; Gene rearrangement; Lymphoma, B-cell; Lymphoma, T cell.

Fig. 1

Detecting immunoglobulin (IG) and T cell receptor (TCR) gene rearrangement by 4% Metaphor agarose gel (A) and 8% non-denaturing polyacylamide gel (B) using the BIOMED-2 protocols. Results of IG/TCR gene clonality detection are indicated by the presence or absence of a PCR product of the expected size. All reactions on non-denaturing polyacrylamide gels and Metaphor agarose gels revealed the same results. The case of the photos showed positivity for TCRB_A and TCRB_C on both gels. The expected size of the PCR products were as follows: IGH_A 310-360 bp; IGH_B 250-295 bp; IGH_C 100-170 bp; IGH_D 110-290, 390-420 bp; IGH_E 100-130 bp; IGK_A 120-160, 190-210, 260-300 bp; IGK_B 201-250, 270-300, 350-390 bp; TCRB_A 240-285 bp; TCRB_B 240-285 bp; TCRB_C 170-210, 285-325 bp; TCRG_A 145-255; TCRG_B 80-220 bp. M, DNA size marker; PC, positive control; NC, negative control.