[Detection and application of bcl-2/IgH gene translocation and immunoglobulin gene rearrangement in follicular lymphoma]

Objective: To evaluate the application of FISH testing of bcl-2/IgH gene translocation and IgH/L gene rearrangement in different stages of follicular lymphoma. Methods: In 32 follicular lymphoma cases, which were collected at Guangdong General Hospital from September 2014 to December 2016, the bcl-2/IgH gene ectopic state was detected by FISH while the IgH/L gene rearrangement was tested using PCR-GeneScan to analyze the relationship between bcl-2/IgH gene translocation, different stages of follicular lymphoma and clonal immunoglobulin (IgH/L) gene rearrangements. Results: From the paraffin sections of all 32 follicular lymphomas, 17 cases showed bcl-2/IgH gene translocation, and the percentages of FL1, FL2 and FL3 translocation were 12/13, 3/5 and 2/14, respectively. Among the 24 cases of IgH/L gene arrangements identified from the total sample, the occurrence rates of FL1, FL2 and FL3 gene arrangement were 7/13, 4/5 and 13/14, respectively. Spearman's rank correlation analysis and χ(2) analysis showed that bcl-2/IgH gene translocation was negatively correlated with follicular lymphoma stage and the association was statistically significant. In more advanced stages of follicular lymphoma, the occurrence of bcl-2/IgH gene translocation tended to decrease with distinct FL1, FL2 and Fl3 gene expression (P<0.05). As IgH/L gene rearrangement in FL3 was higher than that in FL1 and FL2, its detection may be complimentary to FISH test for bcl-2/IgH gene translocation in diagnosing follicular lymphoma. Conclusions: The combined use of FISH and PCR-GeneScan increases the positive rate of follicular lymphoma diagnosis, and this combination is more sensitive than FISH or clonal analysis only to detect the chromosomal abnormality or the gene rearrangement.