精准医学杂志 (Feb 2023)

MOLECULAR RELAPSE OF ACUTE PROMYELOCYTIC LEUKEMIA AFTER COMPLETE REMISSION: A CASE REPORT AND LITERATURE REVIEW

  • CHEN Junru, WANG Yilin, WANG Lingzhen, JIANG Jian, SUN Yan, LU Yuan

DOI
https://doi.org/10.13362/j.jpmed.202301014
Journal volume & issue
Vol. 38, no. 1
pp. 51 – 53

Abstract

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Objective To investigate the molecular biological changes of relapsed acute promyelocytic leukemia (APL), and to provide guidance for the clinical diagnosis and treatment of relapsed APL. Methods A retrospective analysis was performed on the clinical data of a pediatric patient with relapsed APL who was molecular relapse 8 months after drug withdrawal, and related literature was reviewed. Results The patient was a 1-year-old boy who initially presented with fever and hemorrhagic spots on the skin, and physical examination showed the appearance of anemia. The skin and mucosa of his whole body were covered with hemorrhagic spots and ecchymosis. Several enlarged lymph nodes that had fused together could be palpated on the left side of the neck, and the liver was palpable at 2 cm below the costal margin. The routine blood test showed low hemoglobin and platelet counts. The bone marrow smear showed that the proportion of promyelocytes was 75%, and POX was positive. The polymerase chain reaction and fluorescence in situ hybridization assay showed positive results for the PML/RARα fusion gene in the bone marrow smear. NRAS gene mutation was detected, and the initial diagnosis was APL. Following standard therapy, the patient’s bone marrow smear and minimal residual disease showed complete remission, and the PML/RARα fusion gene was no longer detectable. However, 8 months after drug withdrawal, the reexamination revealed that the L-type PML/RARα in the bone marrow of the child accounted for 4.51%. Therefore, the child was diagnosed with molecular relapse of APL and was given a chemotherapy regimen against relapsed APL. As a result, the PML/RARα of the child turned negative. Afterwards, the regular chemotherapy was continued. Meanwhile, autologous stem cell collection and regular reexamination were performed. Conclusion For relapsed APL, once molecular relapse is confirmed, treatment should be started as soon as possible, and regular detection of the PML/RARα fusion gene should be performed. Moreover, hematopoietic stem cell transplantation should be considered if second molecular remission cannot be achieved.

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