Genetic and Clinical Characteristics of Korean Chronic Lymphocytic Leukemia Patients with High Frequencies of MYD88 Mutations

Inferior Outcomes of Fludarabine-Cyclophosphamide-Rituximab Chemotherapy in Korean Chronic Lymphocytic Leukemia Patients with Concurrent Thrombocytopenia and Anemia

Background/Objectives: Anti-CD20 monoclonal antibodies combined with alkylator-based chemotherapy enhance survival in chronic lymphocytic leukemia (CLL). However, the risks of infection and bone marrow suppression may mean that new, targeted therapies are more appropriate for some patients than fludarabine-cyclophosphamide-rituximab (FCR). In the Republic of Korea, where insurance limits coverage to novel agents, FCR therapy should be carefully considered for patients with CLL. Methods: Using clinical data from 144 FCR-treated patients with CLL, we retrospectively analyzed clinical characteristics impacting survival outcomes, the impact of cytopenia after FCR, and the durable remission status in terms of measurable residual disease (MRD). We compared the impact of bicytopenia with those of other hematologic conditions. Results: The 5-year overall survival (OS) and 5-year progression-free survival (PFS) for all patients were 84.4% and 68.3%, respectively. FCR-treated patients in the bicytopenia and TP53-positive groups exhibited poor OS and PFS; in particular, the bicytopenia group often experienced prolonged anemia and thrombocytopenia (6-12 months). The responder group achieved sustained remission for a median of 5 years for MRD negativity. Conclusions: In bicytopenia, FCR can induce prolonged cytopenia, making it difficult to switch to second-line therapy or complete cycles of chemoimmunotherapy, directly affecting poor survival outcomes. The cautious application of FCR therapy in CLL without bicytopenia or TP53 positivity can achieve long-term remission.

Next-Generation Integrated Sequencing Identifies Poor Prognostic Factors in Patients with MYD88-Mutated Chronic Lymphocytic Leukemia in Taiwan

INTRODUCTION

Chronic lymphocytic leukemia (CLL) is the most common type of leukemia in the Western countries and is very rare in Asia.

METHODS

Peripheral blood or bone marrow mononuclear cells obtained at initial diagnosis from 215 patients with CLL were analyzed by using next-generation sequencing to investigate the ethnic differences in genetic abnormalities.

RESULTS

Whole-genome sequencing and whole-exome sequencing analyses on 30 cases showed that 9 genes, including IGLL5, MYD88, TCHH, DSCAM, AXDND1, BICRA, KMT2D, MYT1L, and RBM43, were more frequently mutated in our Taiwanese cohort compared with those of the Western cohorts. IGLL5, MYD88, and KMT2D genes were further analyzed by targeted sequencing in another 185 CLL patients, unraveling frequencies of 29.3%, 20.9%, and 15.0%, respectively. The most frequent positional mutation of MYD88 was V217F (26/45, 57.8%), followed by L265P (9/45, 20.0%). MYD88 mutations were significantly associated with IGLL5 mutations (p = 0.0004), mutated IGHV (p < 0.0001) and 13q deletion (p = 0.0164). CLL patients with co-occurrence of MYD88 mutations with KMT2D or/and IGLL5 mutations were associated with a significantly inferior survival compared to those with MYD88 mutation alone (not reached vs. 131.8 months, p = 0.007). In multivariate analysis, MYD88 mutation without KMT2D or IGLL5 mutations was an independently favorable predictor.

CONCLUSIONS

IGLL5, MYD88, and KMT2D mutations were enriched in Taiwanese CLL, and co-occurrence of MYD88 mutations with KMT2D or/and IGLL5 mutations was associated with a poorer prognosis.

Characteristics of chronic lymphocytic leukemia in Japan: Comprehensive analysis of the CLLRSG-01 study

Chronic lymphocytic leukemia (CLL) is rare in Japan. We conducted the nationwide, prospective observational study CLLRSG-01 to clarify the current state of CLL in Japan and to make accurate international comparisons by preparing naturally air-dried smears like those used in other countries. Of the 201 untreated patients enrolled and evaluated, 119 were diagnosed with CLL and 82 with non-CLL mature B-cell neoplasms, based on the WHO classification. Of the 119 CLL patients, 90 were classified as typical and 29 as atypical according to FAB classification morphology, with the proportion of atypical CLL consistent with reports from other countries. Immunophenotypic analyses by flow cytometry showed that 55% of Japanese CLL patients had a Matutes score of 4 or higher, which is lower than the rate of about 90% in Europeans. Mutated IGHV was identified in 80% of Japanese CLL patients, which is a higher rate than in Western patients. The most frequent IGHV gene was VH3-30 (15%), followed by VH3-23 (12%) and VH4-34 (10%). VH1-69, the most common gene in Western countries, was identified in only one patient. These results indicate that the pattern of immunophenotypes and IGHV gene usage in Japanese CLL patients differs from that in Western patients.

Molecular characteristics in Chinese with chronic lymphocytic leukemia by next-generation sequencing: A single-center retrospective analysis

INTRODUCTION

Although the prevalence of Asian chronic lymphocytic leukemia (CLL) patients is not as high as that of Caucasians, there are more atypical CLLs in Asia whose genetic characteristics and their clinical significance are distinct and remain unclear.

METHODS

A retrospective analysis of 85 CLL samples in our center was conducted from 2019 to 2022. We used next-generation sequencing with a 172 gene panel to explore the multi-gene mutational data and the mutational status of immunoglobulin heavy variable (IGHV) gene.

RESULTS

MYD88 (20.0%) was the most frequently mutated gene, much higher than in Europe, followed in order by TP53 (18.8%), NOTCH1 (14.1%), IGLL5 (11.8%), and DNMT3A (8.2%). In addition, the incidence of ATM and SF3B1 mutations was relatively lower in our centre compared to Europe. Mutated (M)-IGHV patients were more likely to have a cooccurrence of MYD88 mutation, while complex karyotype and DNMT3A mutation were more common in the unmutated (U)-IGHV group. MYD88 mutated CLL was characterized by prevalence in young males in high-risk staging, with isolated 13q deletion and concomitant mutation of IGLL5. CLL patients with MYD88 and TP53 mutation showed an unfavorable prognosis.

CONCLUSION

These results would be valuable in helping to understand the characteristics and significance of cytogenetic genetics in Chinese patients with CLL.

A case of cold agglutinin syndrome associated with chronic lymphocytic leukaemia harbouring mutations in CARD11 and KMT2D

Cold agglutinin disease (CAD) is a rare cold autoimmune haemolytic anaemia (cAIHA) caused by IgM antibodies recognizing I antigens on erythrocytes. cAIHA is now mainly classified into two types: primary CAD and cold agglutinin syndrome (CAS). CAS develops in association with the underlying disease, which is most commonly malignant lymphoma. Recent studies have identified gene mutations in CARD11 and KMT2D in a high proportion of patients with CAD, which has led to recognition of CAD as an indolent lymphoproliferative disorder. We herein report a case of cAIHA without lymphocytosis or lymphadenopathy in whom bone marrow was infiltrated by a small population of clonal lymphocytes (6.8%) expressing cell surface markers consistent with chronic lymphocytic leukaemia (CLL). Whole-exome sequencing of bone marrow mononuclear cells revealed mutations in the CARD11 and KMT2D genes. This patient also had somatic hypermutation with overrepresentation of IGHV4-34, which is prevalent in CLL harbouring the KMT2D mutation. These observations suggest that CAS caused by early-phase CLL could be misinterpreted as primary CAD.

Genetic markers of chronic lymphocytic leukemia: a retrospective study of 312 patients from a reference center in Lebanon

Aim: Chronic lymphocytic leukemia (CLL) is a highly heterogenous hemopathy. Genetic stratification of CLL patients has important prognostic and therapeutic values - mainly immunoglobulin heavy chain variable region gene (IGHV) mutational status and the presence of cytogenetic abnormalities. The genetics of CLL in Lebanon is scarcely described in the literature. Patients & methods: In this work, we studied the genetic biomarkers of 312 Lebanese CLL patients. Results: Prominent IGHV genes were IGHV4-34, IGHV1-69 and IGHV3-30; and CLL #1 and #5 presented major subsets. Some similarities as well as major differences were highlighted when comparing our data with previously published data. Conclusion: The distribution of IGHV alleles in our series differed from previously described distributions, suggesting involvement of antigenic selection and regional variables in CLL pathogenesis.