21例伴有4号染色体三体细胞的急性白血病的分析

目的探讨伴有4号染色体三体细胞的急性白血病（acute leukemia，AL）的临床和实验室特点。方法对21例伴有4号染色体三体细胞的AL患者的临床和实验室资料进行回顾性分析。21例均采用骨髓细胞直接法或短期培养法制备染色体，用R显带技术进行核型分析；其中5例核型分析揭示t（8；21）易位者，采用AMLl／EqO双色探针和间期荧光原位杂交技术进行AMLl／ETO重排检测；应用SpectrumGreen标记的4号着丝粒探针，对其中13例AL患者进行荧光原位杂交检测。结果21例AL中2例为继发性白血病，其余均为原发性白血病。4号染色体三体异常主要见于AML-M2（9／21例），21例中7例为单纯4号染色体三体，14例同时伴有其他异常，以t（8；21）最常见（8／14例）；临床上16例初诊白细胞计数大于10×10^9／L；15例有不同程度的肝、脾和淋巴结肿大；进行免疫表型分析的15例患者中6例为髓系和淋系抗原共表达，11例有CD34表达。双色荧光原位杂交研究揭示其中5例核型分析显示t（8；21）者均有AMLl／EqO重排，单色荧光原位杂交也证实14例为4号染色体三体阳性。结论伴有4号染色体三体异常的急性白血病有着独特的临床和实验室特点，其预后不良。

Clinical and experimental retrospective analysis on acute leukemia with trisomy 4 cell

OBJECTIVE: To explore the clinical and experimental features of acute leukemia (AL) with trisomy 4. METHODS: A retrospective analysis on the clinical and laboratory data of 21 cases of AL with trisomy 4 was performed. Chromosomes were prepared using direct method and/or short-term (24 h) cultures of bone marrow cells. Karyotypic analysis was carried out by using R-banding technique. Thirteen cases were studied by interphase fluorescence in situ hybridization (FISH) by using a chromosome 4-specific alpha -satellite DNA probe labeled by spectrum Green to ascertain the presence of a clone with trisomy 4. Five cases with t (8; 21) revealed by karyotypic analysis were detected by dual-color FISH using t (8; 21) translocation probe to confirm the AML1/ETO rearrangement. RESULTS: All the patients with AL and trisomy 4 were with de novo AL except two cases with secondary AL. M2 was the most frequent Franch-American-British(FAB) subtype in this series (9/21 cases). The initial leukocyte count more than 10x 10(9)/L was seen in 16 cases. An enlargement of liver, spleen and/or lymph nodes in varying degrees was found in 15 cases. Among 15 cases received immunophenotypic analysis, 11 cases showed CD34 positivity and 6 cases co-expressed myeloid and lymphocyte antigens. Karyotypic analysis disclosed clonal trisomy 4 in 18 cases and one cell with +4 in 3 cases. Isolated trisomy 4 was found in 7 cases, while 14 cases had other abnormalities besides trisomy 4 among which t (8; 21) was found in 8 cases. Dual-color FISH confirmed that all 13 cases including 3 cases having one cell with +4 on karyotypic analysis had clonal trisomy 4. Dual-color FISH confirmed that all 5 cases with t (8; 21) had AML1/ETO rearrangement. CONCLUSION: AL patients with trisomy 4 have unique clinical and experimental features and a poor prognosis.