INTRODUCTION

Minimal residual disease (MRD), detected based on immunoglobulin and T-cell receptor (Ig/TCR) gene rearrangements as markers of residual leukemic cells, is currently the most reliable prognostic factor in acute lymphoblastic leukemia (ALL). A feasibility study is presented of the standard strategy for the identification of Ig/TCR targets for MRD diagnostics in Polish ALL patients by identifying Ig/TCR gene rearrangement pattern using standard primer sets and protocols.

MATERIALS AND METHODS

The PCR-heteroduplex approach based on BIOMED-1 and BIOMED-2 protocols (recommended as the European standard) was used to detect IGH, IGK-Kde, TCRD, TCRG, and TCRB rearrangements in 58 Polish B-cell precursor ALL patients. Sequencing and homology analysis between the obtained and germline Ig/TCR sequences enabled identification of the rearrangements. The U-Gauss test was used for statistical analysis of the Ig/TCR rearrangement pattern in Polish patients compared with relevant data on other nationalities.

RESULTS

The following pattern was identified: IGH: 83% (VH-JH: 74%, DH-JH: 9%), IGK-Kde: 41%, TCRD: 78% (incomplete TCRD: 55%, Vdelta2-Ddelta3: 45%, Ddelta2-Ddelta3: 21%, Vdelta2-Jalpha: 35%), TCRG: 50%, and TCRB: 13%. Considerable convergence of the Ig/TCR pattern in Polish patients and those of other nationalities (mainly West Europeans) was demonstrated. Statistically relevant differences were only found between the incidence of DH-JH in Polish (9%) and Dutch patients (24%; p<0.05) and Polish and Italian patients (19%; p<0.05), VH-JH in Polish (74%) and Chilean patients (100%; p<0.05), and TCRG in Polish (50%) and Brazilian patients (69%; p<0.05).

CONCLUSIONS

The convergence of Ig/TCR patterns in Polish and European patients indicates that the strategy for Ig/TCR target identification based on standard primers and protocols might be directly used for the construction of Polish standards and recommendations for MRD diagnostics.