Case report: Mutation evolution in a patient with TdT positive high grade B cell lymphoma with MYC and BCL2 rearrangements following the treatment of concurrent follicular lymphoma and diffuse large B-cell lymphoma

BACKGROUND

Concurrent follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL)was reported in some studies, while the diagnosis of TdT (terminal deoxynucleotydil transferase) positive high grade B cell lymphoma (HGBL) with MYC and BCL2 rearrangements ("double hit") transformed from FL/DLBCL has been rarely reported. Herein, we described the clinical features and mutation profiles of a case diagnosed with TdT positive "double hit" HGBL following the treatment of FL/DLBCL.

CASE PRESENTATION

This is a 43-year-old Chinese man who was diagnosed with low grade FL (account for 80%) combined with DLBCL (20%) at a stage of IVB. The patient presented with BCL2/IGH translocation without MYC rearrangement, as well as the expressions of CD20, CD19, CD10 and BCL2 at the initial diagnosis of FL/DLBCL. MYC rearrangement and TdT expression occurred after the treatment. The targeted sequencing revealed mutations in KMT2D, FOXO1, CREBBP, ATM, STAT6, BCL7A, DDX3X, MUC4, FGFR3, ARID5B, DDX11 and PRKCSH genes were the co-mutations shared by the FL/DLBCL and TdT positive "double hit" HGBL, while CCND3, BIRC6, ROBO1 and CHEK2 mutations specifically occurred after the treatment. The overall survival time was 37.8 and 17.8 months after the initial diagnosis of FL/DLBCL and TdT positive "double hit" HGBL, respectively.

CONCLUSION

This study reports a rare case of TdT positive "double hit" HGBL following the treatment of concurrent FL/DLBCL and highlights the mutation characteristics. Collectively, this study will help enrich the knowledge of TdT positive "double hit" HGBL transformed from FL/DLBCL.

Genomic and structural mechanistic insight to reveal the differential infectivity of omicron and other variants of concern

BACKGROUND

The genome of SARS-CoV-2, is mutating rapidly and continuously challenging the management and preventive measures adopted and recommended by healthcare agencies. The spike protein is the main antigenic site that binds to the host receptor hACE-2 and is recognised by antibodies. Hence, the mutations in this site were analysed to assess their role in differential infectivity of lineages having these mutations, rendering the characterisation of these lineages as variants of concern (VOC) and variants of interest (VOI).

METHODS

In this work, we examined the genome sequence of SARS-CoV-2 VOCs and their phylogenetic relationships with the other PANGOLIN lineages. The mutational landscape of WHO characterized variants was determined and mutational diversity was compared amongst the different severity groups. We then computationally studied the structural impact of the mutations in receptor binding domain of the VOCs. The binding affinity was quantitatively determined by molecular dynamics simulations and free energy calculations.

RESULTS

The mutational frequency, as well as phylogenetic distance, was maximum in the case of omicron followed by the delta variant. The maximum binding affinity was for delta variant followed by the Omicron variant. The increased binding affinity of delta strain followed by omicron as compared to other variants and wild type advocates high transmissibility and quick spread of these two variants and high severity of delta variant.

CONCLUSION

This study delivers a foundation for discovering the improved binding knacks and structural features of SARS-CoV-2 variants to plan novel therapeutics and vaccine candidates against the virus.

Multimodal data analysis reveals that pancreatobiliary-type ampullary adenocarcinoma resembles pancreatic adenocarcinoma and differs from cholangiocarcinoma

BACKGROUND

Ampullary adenocarcinoma (AAC) arises from the ampulla of Vater where the pancreatic duct and bile duct join and empty into the duodenum. It can be classified into intestinal and pancreatobiliary types based on histopathology or immunohistochemistry. However, there are no biomarkers for further classification of pancreatobiliary-type AAC which has important implications for its treatment. We aimed to identify the tumor origin of pancreatobiliary-type AAC by systematically analyzing whole-slide images (WSIs), survival data, and genome sequencing data collected from multiple centers.

METHODS

This study involved three experiments. First, we extracted quantitative and highly interpretable features from the tumor region in WSIs and constructed a histologic classifier to differentiate between pancreatic adenocarcinoma (PAC) and cholangiocarcinoma. The histologic classifier was then applied to patients with pancreatobiliary-type AAC to infer the tumor origin. Secondly, we compared the overall survival of patients with pancreatobiliary-type AAC stratified by the adjuvant chemotherapy regimens designed for PAC or cholangiocarcinoma. Finally, we compared the mutation landscape of pancreatobiliary-type AAC with those of PAC and cholangiocarcinoma.

RESULTS

The histologic classifier accurately classified PAC and cholangiocarcinoma in both the internal and external validation sets (AUC > 0.99). All pancreatobiliary-type AACs (n = 45) were classified as PAC. The patients with pancreatobiliary-type AAC receiving regimens designed for PAC showed more favorable overall survival than those receiving regimens designed for cholangiocarcinoma in a multivariable Cox regression (hazard ratio = 7.24, 95% confidence interval: 1.28-40.78, P = 0.025). The results of mutation analysis showed that the mutation landscape of AAC was very similar to that of PAC but distinct from that of cholangiocarcinoma.

CONCLUSIONS

This multi-center study provides compelling evidence that pancreatobiliary-type AAC resembles PAC instead of cholangiocarcinoma in different aspects, which can guide the treatment selection and clinical trials planning for pancreatobiliary-type AAC.