Yoo Eun-Hyung, Kim Hee-Jin, Lee Seung-Tae, Kim Won-Seog, Kim Sun-Hee
Department of Laboratory Medicine & Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Korean J Lab Med. 2009 Dec;29(6):491-6. doi: 10.3343/kjlm.2009.29.6.491.
Aggressive natural killer-cell leukemia (ANKL) is a rare neoplasm characterized by systemic proliferation of NK cells. However, the differential diagnosis of NK lymphoproliferative disorders is difficult because of the absence of a distinct diagnostic hallmark. Therefore, to identify diagnostic markers for ANKL, we analyzed the clinical data and laboratory findings obtained for 20 patients with ANKL.
From January 2000 to July 2007, 20 patients were diagnosed with ANKL on the basis of bone marrow studies. We retrospectively analyzed the clinical features and laboratory findings, including the complete blood count, Epstein-Barr virus status, immunophenotype, and the cytogenetic results.
The subjects included 6 women and 14 men (median age, 44 yr; range, 2-70 yr). Cytogenetic studies were performed in 18 patients, and karyotypic abnormalities were observed in 9 patients (50%). None of the cytogenetic abnormalities were constantly observed in all the patients. However, 6q abnormalities were observed in 4 patients (4/18, 22%). The immunophenotype of the leukemic NK-cells was cytoplasmic CD3(+), surface CD3(-), CD16/56(+), CD2(+), and CD5(-). Notably, the CD7 antigen was absent in 10 patients (50%). When the CD7 loss was combined with cytogenetic abnormalities, clonal markers could be identified in 75% of the ANKL cases.
The CD7 antigen loss was frequently observed in our series of ANKL patients. In conjunction with the cytogenetic findings, this characteristic immunophenotypic finding can serve as a reliable marker for the timely diagnosis of ANKL. Therefore, immunophenotypic analysis of CD7 expression should be included in the diagnosis of NK cell neoplasms.
侵袭性自然杀伤细胞白血病（ANKL）是一种罕见的肿瘤，其特征为NK细胞的系统性增殖。然而，由于缺乏明确的诊断标志，NK淋巴细胞增殖性疾病的鉴别诊断较为困难。因此，为了确定ANKL的诊断标志物，我们分析了20例ANKL患者的临床资料和实验室检查结果。
2000年1月至2007年7月，20例患者经骨髓检查确诊为ANKL。我们回顾性分析了其临床特征和实验室检查结果，包括全血细胞计数、EB病毒状态、免疫表型和细胞遗传学结果。
研究对象包括6名女性和14名男性（中位年龄44岁；范围2 - 70岁）。18例患者进行了细胞遗传学研究，9例患者（50%）观察到核型异常。并非所有患者都持续观察到相同的细胞遗传学异常。然而，4例患者（4/18，22%）观察到6号染色体异常。白血病NK细胞的免疫表型为胞质CD3(+)、表面CD3(-)、CD16/56(+)、CD2(+)和CD5(-)。值得注意的是，10例患者（50%）缺失CD7抗原。当CD7缺失与细胞遗传学异常相结合时，75%的ANKL病例可识别出克隆标志物。
在我们的ANKL患者系列中经常观察到CD7抗原缺失。结合细胞遗传学结果，这一特征性免疫表型发现可作为及时诊断ANKL的可靠标志物。因此，NK细胞肿瘤的诊断应包括CD7表达的免疫表型分析。
