[Molecular diagnostic tests in hematologic diseases].

Molecular diagnostic tests are widely performed in managing hematologic malignancies such as leukemia and lymphoma. In this article, we review the present application and problems of the tests. Karyotyping is performed at diagnosis of all kinds of hematologic malignancies. This method needs dividing cells as samples and skilled experts. Fluorescence in situ hybridization(FISH) analysis using cells in interphase is performed, for example, to monitor the effect of interferon on chronic myelogenous leukemia patients. The weak point of this method is that approximately 2% of false-positive cells are inevitable. Southern blot method is used for clonal analysis in some disease, for example, adult T-cell leukemia/lymphoma. Polymerase chain reaction(PCR) method using genomic DNA is performed for limited types of diseases such as lymphoma with bcl-2/IgH fusion gene. Reverse transcription(RT)-PCR method can detect fusion gene transcripts with high sensitivity. This method is useful for detecting minimal residual diseases after chemotherapy or bone marrow transplantation. To perform quantitative analysis, real-time PCR or competitive PCR must be done. In the near future, new technology such as gene expression profiling analysis using DNA microarrays or spectral karyotyping(SKY) method will be used in clinical practice.