RESUMO
<p><b>OBJECTIVE</b>To improve the techniques for minimal residual disease (MRD) detection in acute lymphoblastic leukemia (ALL).</p><p><b>METHODS</b>A real time quantitative PCR method was established for quantifying the clonal TCRVgammaI-Jgamma gene rearrangement in 36 ALL patients.</p><p><b>RESULTS</b>The sensitivity of the established real time quantitative PCR was at 10(-4) level. The amount of TCRVgammaI-Jgamma gene rearrangement in newly diagnosed group, complete remission (CR) group and post hematopoietic stem cell transplantation (HSCT) group was (7.38 +/- 6.65) x 10(-2), (1.02 +/- 1.08) x 10(-2) and (3.89 +/- 5.65) x 10(-3) level, respectively. and the amount in newly diagnosed group was higher than that in CR group and HSCT group (P = 0.001). The MRD level of ALL patients in CR group was higher than that in HSCT group (P = 0.022). MRD can be detected in 6 ALL patients after HSCT, 2 of them with low MRD level (< 1 x 10(-3)) survived long disease-free survival, the other 4 with high MRD level relapsed within one year.</p><p><b>CONCLUSION</b>The established real time quantitative PCR assay is simple, rapid, sensitive and specific. Use of this assay to evaluate MRD in the remission ALL cases is helpful for prognosis prediction.</p>