Hatae Y, Nakadate H, Iizuka S, Takeda T, Shikano T, Imaizumi M
Sapporo National Hospital, Department of Pediatrics.
Rinsho Ketsueki. 1996 Dec;37(12):1410-5.
We treated two children with acute promyelocytic leukemia (APL) in whom complete remission was successfully induced by oral administration of all-trans retinoic acid (ATRA). We followed these patients with conventional chemotherapy. The first patient has remained in continuous complete remission. However, the other patient relapsed during the maintenance therapy and died of progressive disease in spite of a second treatment with ATRA and chemotherapy. From a clinical point of view, the latter case had a hyperleukocytosis on admission. Also morphologically speaking, this patient had a different M3 variant than the first case. There are two major isoforms of PML/RAR alpha transcripts, so called short and long type transcripts, according to the breakpoints in the PML genes. In the first case the "long type' isoform was detected by reverse transcriptase polymerase chain reaction (RT/PCR) amplification. On the other hand the "short type' isoform was observed in the latter case. Also the second case became PCR positive at relapse, although the detectable isoform was negative during remission. The "short type' isoform may be related to the poor prognosis and RT/PCR analyses may be a powerful to detect early relapse.
我们治疗了两名急性早幼粒细胞白血病（APL）患儿，通过口服全反式维甲酸（ATRA）成功诱导了完全缓解。我们采用常规化疗对这些患者进行随访。第一名患者持续处于完全缓解状态。然而，另一名患者在维持治疗期间复发，尽管再次接受了ATRA和化疗，仍因疾病进展而死亡。从临床角度来看，后一例患者入院时存在白细胞增多症。从形态学上讲，该患者与第一例患者的M3变异型不同。根据PML基因中的断点，PML/RARα转录本有两种主要的异构体，即所谓的短型和长型转录本。在第一例中，通过逆转录酶聚合酶链反应（RT/PCR）扩增检测到“长型”异构体。另一方面，在后一例中观察到“短型”异构体。此外，第二例患者在复发时PCR呈阳性，尽管在缓解期可检测到的异构体为阴性。“短型”异构体可能与预后不良有关，RT/PCR分析可能是检测早期复发的有力手段。
