Detection of IgH and Cyclin D1 gene Rearrangement with Interphase FISH in Multiple Myeloma / 대한진단검사의학회지

ABSTRACT

BACKGROUND: The t(11;14)(q13;q32) is known to be one of the most frequent chromosomal abnor-malities found in multiple myeloma (MM). However, studies on t(11;14) in MM have been problemat-ic due to the fact that MM cells proliferate poorly in vitro. The purpose of our study is to evaluate inci-dence, clinical, and hematologic findings of MM with IgH and cyclin D1 gene rearrangement and to investigate the usefulness of interphase FISH (fluorescence in situ hybridization). METHODS: The study group included 36 patients (23 newly diagnosed MM, 8 relapsed MM, 5 per-sistent MM after treatment) admitted to Mokdong and Gil Hospital from November 1998 to July 2002. Interphase FISH was performed with IGH/CCND1 dual color, dual fusion translocation probe (Vysis Inc, Downers Grove, IL USA), using bone marrow mononuclear cells. RESULTS: Incidence of IgH and cyclin D1 gene rearrangement by interphase FISH was 19%. One patient with normal karyotype and another patient without any metaphase cells showed IgH and cyclin D1 gene rearrangement with interphase FISH. The lambda light chain subtype was more frequently found in patients with rearrangement (4/5, 80%) than those without rearrangement (6/23, 26%) (P<0.05). No significant differences were found in other clinical and hematologic findings in the two groups. CONCLUSIONS: We suggest that MM with IgH and cyclin D1 gene rearrangement is associated with the expression of lambda light chain. Interphase FISH may be helpful in samples with normal karyotype or no metaphase cells for detection of gene rearrangement of MM.