Tsuchiya H, Migita M, Yamamori S, Kaneko Y, Adachi N, Nakamura T, Nobukuni Y, el-Sonbaty S S, Matsuda I
Department of Pediatrics, Kumamoto University School of Medicine, Japan.
Leukemia. 1995 Oct;9(10):1689-93.
We report two cases of acute lymphoblastic leukemia (ALL) with a late-appearing Philadelphia chromosome (Ph1), confirmed by the expression of BCR-ABL mRNA, using the reverse transcriptase/polymerase chain reaction (RT/PCR) technique. The first patient was a 10-year-old boy with precursor B cell type ALL-L1 (FAB classification). At diagnosis, no metaphase cells were found by chromosome analysis and BCR-ABL mRNA was not observed. At the beginning of relapse, which occurred after 7 months of complete remission, a normal karyotype was observed. At the terminal stage, leukemic cells with Ph1 and BCR-ABL mRNA for the P190 variety were observed. The second patient was a 12-year-old boy with immature T cell type ALL-L1. The metaphase cells showed a 9p- chromosome at diagnosis and Ph1 appeared in addition to 9p- at relapse. Hybrid mRNA for the P210 variety was detected only when Ph1 had developed. The blast cells with Ph1 were derived from the original leukemic clone through clonal evolution, since the same clonal rearrangements of IGH or TCRB were detected in leukemic cells obtained both at diagnosis and relapse in both patients. Thus, in both cases, Ph1 was detected only in the course of ALL along with expression of BCR-ABL mRNA. This observation also confirmed that, as in de novo Ph1-positive ALL, both the P190 and P210 varieties of BCR-ABL mRNA are observed in ALL with late-appearing Ph1.
我们报告了两例急性淋巴细胞白血病（ALL）伴费城染色体（Ph1）出现较晚的病例，通过逆转录酶/聚合酶链反应（RT/PCR）技术检测BCR-ABL mRNA的表达得以证实。首例患者是一名10岁男孩，为前体B细胞型ALL-L1（FAB分类）。诊断时，染色体分析未发现中期细胞，也未观察到BCR-ABL mRNA。在完全缓解7个月后出现复发时，观察到正常核型。在终末期，观察到具有Ph1和P190型BCR-ABL mRNA的白血病细胞。第二例患者是一名12岁男孩，为不成熟T细胞型ALL-L1。诊断时中期细胞显示9号染色体短臂缺失（9p-），复发时除9p-外还出现了Ph1。仅在Ph1出现时才检测到P210型的杂交mRNA。由于在两名患者诊断和复发时获得的白血病细胞中均检测到相同的IGH或TCRB克隆重排，因此具有Ph1的原始细胞是通过克隆进化从原始白血病克隆衍生而来。因此，在这两例病例中，仅在ALL病程中检测到Ph1，并伴有BCR-ABL mRNA的表达。这一观察结果还证实，与初发Ph1阳性ALL一样，在Ph1出现较晚的ALL中也观察到了BCR-ABL mRNA的P190和P210两种类型。
