[Application of CD138 Immunomagnetic Bead Sorting Combined with Fluorescence in Situ Hybridization in Multiple Myeloma].

Objective: To compare the effects of direct fluorescence in situ hybridization (D-FISH) detection without sorting and CD138 immunomagnetic bead sorting technology combined with FISH (MACS-FISH) on cytogenetic analysis of patients with multiple myeloma (MM).

Methods: FISH test results of 229 patients with initial MM were retrospectively analyzed. The patients were divided into two groups, 140 patients were tested with D-FISH and 89 patients with MACS-FISH. The combination probe was designed as P53, D13S319, RB1, 1q21, and IgH. Cytogenetic detection results were compared between the two groups.

Results: The total detection rate of cytogenetic abnormalities in D-FISH group was 52.9%, and that in MACS-FISH group was 79.8%. There was a significant difference in the cytogenetic abnormality rate between the two groups (P=0.020). The abnormal genes with the highest detection rate in the two groups were 1q21 and IgH, respectively, while the lowest was P53. There was no significant difference in the percentage of P53 positive cells (positive rate) between the two groups, while D13S319, RB1, 1q21, and IgH showed significant difference in positive cell rate (P=0.0002, P<0.0001, P=0.0033, P=0.0032). There was no significant correlation between the proportion of plasma cells (PC) detected by bone marrow morphology and cytogenetic abnormality rate in the D-FISH group, while there was a correlation between the proportion of PC detected by flow cytometry and cytogenetic abnormality rate (r=0.364). The PC proportion detected by bone marrow morphology and flow cytometry in the MACS-FISH group had no correlation with the cytogenetic abnormality rate and positive cell rate of the 5 genes mentioned above. Additionally, the PC proportion detected by bone marrow morphology and flow cytometry showed significant difference (P<0.0001).

Conclusion: CD138 immunomagnetic bead sorting combined with FISH technology can significantly improve the abnormality detection rate of MM cytogenetics.