Validating a new plasma cell labeling technique for targeted fluorescence in situ hybridization assay in patients diagnosed with multiple myeloma.

Fluorescence in situ hybridization (FISH) is a useful tool in diagnosing multiple myeloma (MM), a disease involving abnormal clones of plasma cells. In a standard FISH procedure, all types of cells within the sample are analyzed and scored. A new method, cytoplasmic immunoglobulin (cIg) FISH, has recently been developed to specifically label the plasma cells by targeting the immunoglobulin light chains. This method allows the direct analysis and scoring of the plasma cells to give a more accurate result. If it is shown to reflect a more accurate result, it may be considered to be utilized in a routine laboratory. In this project, cIg FISH was carried out on 30 fixed bone marrow MM samples that had karyotyping and standard FISH done previously and results were compared. It was observed that cIg FISH enhanced the detection rate by an overall 16.7% for 1q21 amplifications and 3.4% for 15q22 amplification. The cIg procedure was also able to pick up abnormalities that standard FISH did not. This study showed that cIg FISH is an accurate and a more sensitive assay than standard FISH. However, optimization of this time-consuming procedure is required before cIg FISH can be considered for routine diagnostic application.Bachelor of Science in Biological Science

Cytogenetic and molecular aberrations of multiple myeloma patients : a single-center study in Singapore

Background-Much is known about the cytogenetic lesions that characterize multiple myeloma (MM) patients from the USA, Europe, and East Asia. However, little has been published about the disease among Southeast Asians. The aim of this study was to determine the chromosomal abnormalities of MM patients in our Singapore population. Methods-Forty-five newly-diagnosed, morphologically confirmed patients comprising 18 males and 27 females, aged 46-84 years (median 65 years) were investigated by karyotyping and fluorescence in situ hybridization (FISH). FISH employing standard panel probes and 1p36/1q21 and 6q21/15q22 probes was performed on diagnostic bone marrow samples. Results-Thirty-four cases (75.6%) had karyotypic abnormalities. Including FISH, a total detection rate of 91.1% was attained. Numerical and complex structural aberrations were common to both hyperdiploid and non-hyperdiploid patients. Numerical gains of several recurring chromosomes were frequent among hyperdiploid patients while structural rearrangements of several chromosomes including 8q24.1 and 14q32 characterized non-hyperdiploid patients. With FISH, immunoglobulin heavy chain (IGH) gene rearrangements, especially fibroblast growth factor receptor 3 (FGFR3)/IGH and RB1 deletion/monosomy 13 were the most common abnormalities (43.4%). Amplification 1q21 was 10 times more frequent (42.5%) than del(1p36) and del(6q21). Conclusions-We have successfully reported the comprehensive cytogenetic profiling of a cohort of newly-diagnosed myeloma patients in our population. This study indicates that the genetic and cytogenetic abnormalities, and their frequencies, in our study group are generally similar to other populations.Published versio