Objective:To explore the effect of TP53 mutation variant allele frequency(VAF)on the prognosis of diffuse large B-cell lymphoma(DLBCL)patients.Methods:This study included 155 patients with DLBCL who were first diagnosed in the People's Hospital of Xinjiang Uygur Autonomous Region from March 2009 to March 2022. Complete clinical data and paraffin-embedded tumor tissue samples were obtained,and DNA was extracted from tumor tissues.The gene mutation profile of DLBCL patients was detected and analyzed by second-generation sequencing technology.Kaplan-Meier method was used to analyze the mutation status of TP53 gene and the relationship between mutation VAF and OS.Cox regression univariate and multivariate analysis was use to analyze the independent factors affecting OS.A nornogram model for predicting 1,3,and 5 years OS in DLBCL patients were established to evaluated the performance of the model based on C-index and calibration curves.Results:The average value of TP53 mutation VAF in male DLBCL patients was significantly higher than that in female patients (P<0.05 ).Patients with TP53 mutantion had shorter OS than those with wild-type patients (P=0.030).The optimal VAF threshold for TP53 mutation based on OS stratification was 33.61％(P<0.001),and patients with TP53 mutation VAF≥34％had shorter OS than those with TP53 mutation VAF<34％and wild-type patients (P<0.001).Multivariate Cox analysis showed that TP53 mutation VAF≥34％ was an independent poor predictor of OS (HR=4.05,P<0.001),and IPI score ≥3 was an independent predictor of OS poor (HR=2.27,P=0.008).In combination with factors with independent prognostic significance obtained from multi-factor analysis,we constructed a nomogram model for predicting 1-year,3-year,5-year OS in DLBCL patients.The results showed that the C index of TP53-mutated VAF combined with IPI model was 0.743,which predicted the value of 1-year,3-year,and 5-year OS in DLBCL patients.Calibration curves show that the model has good agreement between predicted and actual survival of DLBCL patients at 1-year,3-year,and 5-year. Conclusion:TP53 mutant VAF has prognostic value in DLBCL patients,and TP53 mutant VAF≥34％ is an independent risk factor for OS in DLBCL patients.The prognosis model of TP53 mutation VAF combined with IPI nomogram constructed in this study has good predictive performance for DLBCL patients.

Objective To explore the clinical characteristics of patients with diffuse large B-cell lymphoma (DLBCL) accompanied with KMT2D gene mutation and the impact of its co-mutated genes on prognosis. Methods Clinical data of 155 newly diagnosed DLBCL patients were obtained. The second-generation sequencing method was used to detect 475 hotspot genes, including KMT2D mutation. Patients were divided into the KMT2D mutation group and KMT2D wild-type group based on the presence or absence of KMT2D gene mutation. Clinical characteristics, differences in co-mutated genes, and survival differences between the two groups were compared. Results The frequency of KMT2D mutation was 31%, which is predominantly observed in elderly patients (P=0.07) and less in the double-expressor phenotype (P=0.07). Compared with the KMT2D wild-type group, KMT2D gene mutation was associated with higher co-mutation rates of CDKN2A (OR=2.82, P=0.01) and BCL2 (OR=3.84, P=0.016), while being mutually exclusive with MYC gene mutation (OR=0.11, P=0.013). In univariate survival analysis, no statistically significant difference in overall survival (OS) was found between the KMT2D mutation group and the wild-type group (P=0.54). Further analysis of the prognostic significance of KMT2D with other gene mutations indicated that patients with KMT2D^mutBTG2^mut had poorer OS than those with KMT2D^wt BTG2^mut (P=0.07) and KMT2D^wt BTG2^wt (P=0.05). On the contrary, patients with KMT2D^mut CD79B^mut had better OS than those with KMT2D^mut CD79B^wt (P=0.09), with no prognostic impact observed for other co-mutated genes. Multivariate Cox regression analysis revealed that Ann Arbor stages Ⅲ and Ⅳ (HR=2.751, 95%CI: 1.169-6.472, P=0.02), elevated LDH levels (HR=2.461, 95%CI: 1.396-4.337, P=0.002), Ki-67 index>80% (HR=1.875, 95%CI: 1.066-3.299, P=0.029), and KMT2D^mutBTG2^mut(HR=4.566, 95%CI: 1.348-15.471, P=0.015) were independent risk factors for OS in patients with DLBCL (P<0.05). Conclusion DLBCL patients with KMT2D mutation often have multiple gene mutations, among which patients with a co-mutated BTG2 gene have poor prognosis.