Chronic lymphocytic leukemia in a Japanese population: varied immunophenotypic profile, distinctive usage of frequently mutated IGH gene, and indolent clinical behavior.
Chronic lymphocytic leukemia (CLL) is relatively rare in Japan. Among 46 cases of mature B-cell leukemia, we identified 28 Japanese patients with CLL, including prolymphocytoid and lymphoplasmacytoid morphological variants. Compared with Western patients with CLL, only 52.0% of cases showed the typical immunophenotypic profile. IgG-bearing (15.4%) and clearly CD20-expressing (71.4%) cases were frequently observed. Most cases harbored a mutated immunoglobulin heavy-chain (VH) gene (88.5%) and commonly used a VH3 family member (61.5%) other than VH3-21. During the median follow-up period of 64 months, 20 cases (71.4%) showed an indolent clinical course without any treatment, and six cases (21.4%) were accompanied by other malignancies. Binet A stage (p = 0.003), low-risk category according to the modified Rai classification (p = 0.016), and ≤ 15 U/mL level of serum thymidine kinase activity (p = 0.016) were associated with prolongation of treatment-free status. Although Japanese cases of CLL showed heterogeneity in morphology and immunophenotype, most cases arose from post-antigen-selected B cells and presented with indolent clinical behavior.
Department of Hematology, Juntendo University School of Medicine, Tokyo, Japan.
Junichi
J
Tomomatsu
Yasushi
Y
Isobe
Kazuo
K
Oshimi
Yoko
Y
Tabe
Kiyoshi
K
Ishii
Masaaki
M
Noguchi
Takao
T
Hirano
Norio
N
Komatsu
Koichi
K
Sugimoto
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People; D018450:Disease Progression; D005260:Female; D005787:Gene Frequency; D050438:Genes, Immunoglobulin Heavy Chain / Q000235:genetics; D019254:Genes, bcl-2 / Q000235:genetics; D006801:Humans; D007135:Immunoglobulin Variable Region / Q000235:genetics; D016130:Immunophenotyping; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000175:diagnosis* / Q000453:epidemiology / Q000235:genetics* / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D015514:Oncogene Proteins, Fusion / Q000032:analysis / Q000235:genetics*; D011153:Population; D011379:Prognosis
C529133:IGH-CCND1 fusion protein, human; D007135:Immunoglobulin Variable Region; D015514:Oncogene Proteins, Fusion