Chronic lymphocytic leukemia in a Japanese population

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BlankChronic lymphocytic leukemia in a Japanese population: varied

immunophenotypic profile, distinctive usage of frequently mutated IGH gene, and

indolent clinical behavior.

J Tomomatsu, Y Isobe, K Oshimi, Y Tabe, K Ishii, M Noguchi, T Hirano, N Komatsu,

and K Sugimoto

Leuk Lymphoma, November 11, 2010;

Department of Hematology, Juntendo University School of Medicine, Tokyo, Japan.

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.

PMID: 21067444