Boccuni P, Di Noto R, Lo Pardo C, Villa M R, Ferrara F, Rotoli B, Del Vecchio L
Divisione di Ematologia, Università Frederico II, Napoli, Italy.
Tissue Antigens. 1998 Jul;52(1):1-8. doi: 10.1111/j.1399-0039.1998.tb03017.x.
CD66c is a surface (and intracellular) molecule bound to the membrane by a glycosyl-phosphatidylinositol anchor. While its expression on peripheral granulocytes is well recognized, less is known about its distribution in early steps of normal and neoplastic hematopoiesis. We analyzed by flow cytometry cell surface expression of CD66c on bone marrow cells from 4 healthy subjects and on bone marrow or peripheral blood cells from 127 patients with newly diagnosed hematologic malignancies: 70 de novo acute myeloid leukemias (AML), 6 refractory anemias with excess of blasts in transformation, 3 myeloid and 3 lymphoid blastic phases of chronic myelogenous leukemia, 33 B-lineage and 6 T-lineage acute lymphoblastic leukemias (B- and T-ALL), and 3 B-cell and 3 T-cell non-Hodgkin's lymphomas in the leukemic phase. We found that in normal bone marrow CD66c expression was myeloid restricted, reaching its highest level on promyelocytes. As for de novo AML, slight expression of CD66c was found on 6/25 (24%) AML-M4 and only occasionally in other subgroups. In 9 out of 10 cases of acute promyelocytic leukemia, CD66c was totally absent, but antigen expression was easily detectable following in vitro exposure to all-trans retinoic acid. Among lymphoid malignancies, CD10+ early-B-ALL consistently expressed the molecule (20/23 cases, or 87%) whereas both CD10- early-B ALL and SmIg+ B-ALL completely lacked it. Finally, dual staining with CD66c and CD10 proved to be a suitable tool for distinguishing even low percentages of residual leukemic cells (CD10+/CD66c+) from normal regenerating early-B cells (CD10+/CD66c ) in CD10+ early-B-ALL induced into remission.
CD66c是一种通过糖基磷脂酰肌醇锚定与细胞膜结合的表面（及细胞内）分子。虽然其在外周粒细胞上的表达已广为人知，但对于其在正常和肿瘤性造血早期阶段的分布了解较少。我们通过流式细胞术分析了4名健康受试者骨髓细胞以及127例新诊断血液系统恶性肿瘤患者的骨髓或外周血细胞表面CD66c的表达情况，这些患者包括：70例初发急性髓系白血病（AML）、6例转化型难治性贫血伴原始细胞增多、3例慢性粒细胞白血病的髓系和3例淋巴系原始细胞期、33例B系和6例T系急性淋巴细胞白血病（B-ALL和T-ALL），以及3例处于白血病期的B细胞和3例T细胞非霍奇金淋巴瘤。我们发现，在正常骨髓中，CD66c表达局限于髓系，在早幼粒细胞上达到最高水平。对于初发AML，在6/25（24%）的AML-M4中发现CD66c有轻微表达，在其他亚组中仅偶尔出现。在10例急性早幼粒细胞白血病病例中有9例完全没有CD66c，但在体外暴露于全反式维甲酸后抗原表达易于检测到。在淋巴系统恶性肿瘤中，CD10+早期B-ALL持续表达该分子（20/23例，即87%），而CD10-早期B-ALL和SmIg+ B-ALL则完全缺乏该分子。最后，在诱导缓解的CD10+早期B-ALL中，用CD66c和CD10进行双重染色被证明是一种合适的工具，可用于区分低比例的残留白血病细胞（CD10+/CD66c+）与正常再生早期B细胞（CD10+/CD66c-）。
