[Expression Level and Target Gene Prediction of miR-181b in Patients with Chronic Lymphocytic Leukemia]

To analyze the diagnostic value of multiple reverse transcription-polymerase chain reaction (RT-PCR) for detecting different fusion genes in children with primary acute lymphoblastic leukemia (ALL).

The clinical data of 80 children with ALL treated in the 2^nd affiliated hospital of Xi'an Medical College from September 2012 to September 2017 were collected and retrospectively analyzed. Immunophenotype, chromosome karyotype and fusion gene were analyzed.

Immunophenotyping showed that there were 2 cases of mixed expression of myeloid + B system, 2 cases with pre- B expression, 58 cases with former B expression, 11 cases with CD13 combined with pre- B expression, 4 cases with CD5 combined with pre- B expression, and 3 cases with CD2 combined with pre- B expression. The results of chromosome karyotype analysis showed that among 72 cases of karyotype analysts 5 cases could not be analyzed, 27 cases were determined to be normal karyotype, 11 cases with abnormal karyotype and 29 cases without mitotic phase. Six fusion genes were expressed in 30 cases (37.50%) of 80 ALL children, including MLL/AF9, CBF/MYH 11, BCR/ABL, TLS/ERG, MLL/ENL and TEL/AML1. Among the 3 cases with MLL/AF9 fusion gene expression [t(9;11)], 2 cases showed a poor response to early treatment, but achieved complete remission after intensive chemotherapy, and 1 case accepted bone marrow transplantation; in 1 case with CBF/MYH 11 fusion gene expression, treatment was abandoned by family members, and 4 cases with BCR/ABL fusion gene expression [t (9;22) (q34; q11)] were all showed poor response to early treatment, and achieved complete remission after intensive chemotherapy. All the fusion genes were positive during remission, including 2 cases of bone marrow transplantation; 1 case with TLS/ERG fusion gene expression [t (16;21)] displayed poor response to early treatment, and completely remitted after intensive chemotherapy; 2 cases with MLL/ENL fusion gene expression [t (11;19)] recurred during chemotherapy; 19 cases with TEL/AML1 fusion gene expression [t (12;21)] also achieved complete remission. 4 cases achieved a partial remission.

Genotyping can make up for the insufficiency of MICM typing, and multiplex RT-PCR can be used to rapidly detect the fusion genes caused by chromosomal aberration in children with ALL.