[Children with acute lymphoblastic leukemia: prognostic significance of polymerase-chain-reaction analysis of minimal residual disease]

Abstract

Objective: Determination of the usefulness of polymerase chain reaction (PCR) for the detection of minimal residual disease (MRD) in bone marrow in children suffering from progenitor-B cell acute lymphoblastic leukaemia during and after treatment.

Design: Descriptive.

Setting: Emma's Children's Hospital, Academic Medical Centre, University of Amsterdam and Central Laboratory of the Dutch Red Cross, Amsterdam.

Method: Of 50 children suffering from progenitor-B cell ALL, stored bone marrow samples and bone marrow slides were investigated: 328 bone marrow samples were analysed by PCR for IgH/TCR delta; 34 patients were analysed at the end of induction therapy. Follow-up period was 20 to 133 months.

Results: Twenty-two patients stayed in continuous complete remission (CCR), 28 patients experienced a recurrence (REC). Reduction of tumour mass was higher in the CCR group. At the end of induction therapy 2/18 CCR patients and 10/16 REC patients were PCR positive (p = 0.005). PCR positivity was not related with known prognostic factors. After recurrence 6/8 patients, who became PCR negative, stayed in remission. All patients who stayed positive after treatment for their recurrence died from leukaemia (p = 0.006). All children who were only temporary PCR negative suffered a recurrence.

Conclusion: Analysis of MRD by means of PCR on bone marrow samples during and after treatment for progenitor-B cell ALL is of prognostic importance.