Objective:To investigate the clinical, genetic, and clonality related aspects of individuals with Richter transformation (RT) .Methods:From January 2019 to December 2021, 18 RT patients with diagnoses at the First Affiliated Hospital of Nanjing Medical University (Pukou CLL center) were retrospectively examined. The immunoglobin heavy variable (IGHV) gene usage and IGHV-D-J rearrangement pattern of diagnosed CLL/SLL and transformed diffuse large B-cell lymphoma (DLBCL) were compared to determine the clonality relatedness. To investigate the risk factors of RT, Clinical and laboratory data from patients with newly diagnosed CLL/SLL and transformed DLBCL were gathered.Results:The median age of RT was 56.5 (41-75) years old. 17 patients transformed to DLBCL and 1 transformed to Hodgkin lymphoma (HL) . Of 17 individuals who had DLBCL transformation, 15 had CLL/SLL-related clonality and 2 had unrelated clonality. Next-generation sequencing (NGS) analysis of 11 paired initially diagnosed treatment-naive CLL/SLL and RT DLBCL found that EGR2、TP53 and NOTCH1 were among the most frequently mutated genes both in treatment-naive CLL/SLL and in RT DLBCL. In several cases, specific mutations were gained or lost throughout RT, indicating clonal evolution. Among 10 patients before exposure to BTK inhibitors before RT, four patients acquired BTK mutation. The aforementioned mutations should be considered high-risk variables for transformation; in addition, TP53 and EGR2 mutations could be linked to a poor prognosis following RT in patients receiving a cocktail of new medicines.Conclusion:Most RT DLBCL patients in our center are clonality related (15/17, 88.2% ) and we recommend all qualified centers to evaluate clonality relatedness of RT DLBCL patients. There was some variability in the mutational landscape between DLBCL that had undergone a transformation and initially diagnosed, treatment-naive CLL/SLL. The underlying molecular mechanism of RT needs more research.

Chronic lymphocytic leukemia (CLL) is the most common leukemia in the Western adults, although the incidence of CLL is relatively low in Asian populations. However, with the aging population, the incidence of CLL is increasing in China. The interaction between CLL cells and the microenvironment plays a crucial role in the recognition of antigens by the B-cell receptor immunoglobulin (BCR IG). The mutational status of the immunoglobulin heavy variable region (IGHV) is a classical prognostic marker for CLL. Over 40% of CLL patients exhibit biased usage of IGHV and highly similar amino acid sequences in the heavy complementarity-determining region 3 (HCDR3), known as the BCR stereotypy. Different subgroups of stereotyped BCR exhibit distinct biological and clinical features. Among them, subset #2 with mutated IGHV and poor prognosis, as well as the subset #8 with a high risk of Richter transformation, have been recommended by the European Research Initiative on CLL to be included in clinical reports on IGHV mutational status. This review summarizes the definition, distribution, biological characteristics, and clinical significance of clonality patterns of the BCR in CLL.

Objective:To investigate the vaccination status, characteristics and prognosis of patients suffering from a combination of COVID-19 and chronic lymphocytic anemia (CLL) in China.Methods:Clinical data of 328 patients with chronic lymphocytic leukemia (CLL) who were first diagnosed with COVID-19 and treated in the Department of Hematology of Jiangsu Provincial People’s Hospital between November 2022 and February 2023 were retrospectively analyzed. Univariate and multivariate analysis of data of patients with severe/critical COVID-19 were conducted by applying the binary logistic regression model.Results:The median age of the CLL patients was 60 (24-87) years. 23.5% (77/328) of these patients suffered from severe/critical COVID-19 infection. Univariate analysis of the data demonstrated that a combination of factors including age >67 years ( OR=2.15, 95% CI 1.24- 3.73, P=0.006), diabetes ( OR=2.09, 95% CI 1.05-4.20, P=0.037), chronic hepatitis B ( OR=2.91, 95% CI 1.30-6.51, P=0.010), CLL progressive ( OR=3.79, 95% CI 1.57-9.15, P=0.003) and CD20 antibody-based treatments within three months prior to the COVID-19 infection ( OR=2.79, 95% CI 1.35-5.77, P=0.006) were the risk factors for severe/critical COVID-19. According to the multivariate analysis, CLL progressive ( OR=2.98, 95% CI 1.10-8.10, P=0.033) was an independent risk factor for severe/critical COVID-19 and administration of the BTK (Bruton tyrosine kinase) inhibitor monotherapy might exert a protective effect and influence a positive outcome of the COVID-19 infection ( OR=0.38, 95% CI 0.16-0.90, P=0.028). Among the 242 patients who were followed up until October 2023, 9.1% (22/242) had multiple subsequent COVID-19 infections (≥3), and 2.1% (5/242) had persistent COVID-19 infections (patients with persistent positive test for the SARS-CoV-2 antigen testing until missing follow-up for any reason). The peak value of the anti-SARS-CoV-2-IgG titres was observed between three and four months post symptom onset (median: 3.511 S/CO vs 1.047 S/CO, P<0.05). The levels of immunoglobulin A gradually decreased following infection with COVID-19, and its trough levels were attained between two to four weeks post infection (median: 0.30 g/L vs 0.74 g/L, P<0.05). According to this study the mortality of patients suffering from a combination of COVID-19 infection and CLL was 2.7% (9/328), and the main reason for their death was respiratory failure and heart failure. Conclusions:A low rate of COVID-19 vaccination and a high rate of severe/critical COVID-19 infection was observed in the CLL patients. CLL progressive was associated with severe/critical COVID-19. Anti-CD20-based treatments received within the past three months might be a risk factor for exacerbation of COVID-19 infection, whereas a monotherapy with BTK inhibitors exert a protective effect and improve outcome of COVID-19 infection.