ABSTRACT
OBJECTIVE@#To analyze the correlation between the mutational status of immunoglobulin heavy chain variable (IGHV) gene with the prognosis of patients with Waldenström macroglobulinemia (WM).@*METHODS@#Immunoglobulin heavy chain gene (IGH) clonotypic sequence analysis was carried out to assess the mutational status of IGHV in the blood and/or bone marrow samples from 44 WM patients. The usage characteristics of IGHV-IGHD-IGHJ gene was explored.@*RESULTS@#The most common IGHV subgroup was IGHV3, which was similar to the data from the Institute of Hematology of Chinese Academy of Medical Science. IGHV3-23 (20.45% vs. 15.44%) and IGHV3-74 (11.36% vs. 7.35%) were the main fragments used, which was followed by IGHV4 gene family (15.91% vs. 24.26%). However, no significant correlation was found between the IGHV4 usage and the prognosis of the patients. Should 98% be taken as the cut-off value for the IGHV mutation status, only 5 patients had no IGHV variant, and there was no correlation with the prognosis. Based on the X-tile analysis, 92.6% was re-selected as the cut-off value for the IGHV variant status in such patients. LDH was increased in 26 patients (59.1%) without IGHV variant (P < 0.05), whilst progression-free survival (P < 0.05) and overall survival (P < 0.05) were significantly shorter compared with those with IGHV variants.@*CONCLUSION@#The usage characteristics of IGHV-IGHD-IGHJ in our patients was similar to reported by the Institute of Hematology of Chinese Academy of Medical Science, albeit that no correlation was found between the IGHV4 usage and the prognosis of the patients. Furthermore, 98% may not be appropriate for distinguishing the IGHV variant status in WM patients.
Subject(s)
Humans , Immunoglobulin Heavy Chains/genetics , Multigene Family , Mutation , Waldenstrom Macroglobulinemia/geneticsABSTRACT
Objective: To improve the positivity rate and accuracy of MYD88 mutation detection in patients with Waldenström macroglobulinemia (WM) . Methods: MYD88 mutation status was retrospectively evaluated in 66 patients diagnosed with WM in Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from June 2017 to June 2021. The positivity rate and accuracy of the different methods and specimens for MYD88 mutation detection were analyzed. Results: MYD88 mutations were detected in 51 of 66 patients with WM, with an overall positivity rate of 77%. The positivity rate of the next-generation sequencing (NGS) or allele-specific polymerase chain reaction (AS-PCR) was significantly higher than that of the first-generation Sanger sequencing (84% vs 71% vs 46%, P<0.05) . For the different specimens, the positivity rate for the lymph nodes or bone marrow was significantly higher than that of peripheral blood (79% vs 84% vs 52%, P<0.05) . The positivity rate of the MYD88 mutation in the lymph nodes, bone marrow, and peripheral blood determined by NGS was 86%, 90%, and 67%, respectively. The positivity rate in the lymph nodes, bone marrow, and peripheral blood detected by AS-PCR was 78%, 81%, and 53%, respectively. Thirty-nine patients with WM underwent ≥ 2 MYD88 mutation detections. The final MYD88 mutational status for each patient was used as the standard to determine the accuracy of the different methods and in different specimens. The accuracy of MYD88 mutation detection in the lymph nodes (n=18) and bone marrow (n=13) by NGS was significantly higher than that in the peripheral blood (n=4) (100% vs 100% vs 75%, P<0.05) . There was no statistically significant difference in the accuracy of MYD88 mutation detection by AS-PCR in the lymph nodes (n=15) , bone marrow (n=11) , or peripheral blood (n=16) (93% vs 91% vs 88%, P>0.05) . Conclusions: In the detection of the MYD88 mutation in patients diagnosed with WM, NGS or AS-PCR is more sensitive than Sanger sequencing. Lymph nodes and bone marrow specimens are better than peripheral blood specimens.