急性白血病膜结合L-选择蛋白与可溶性L-选择蛋白表达及临床意义的研究

为了探讨急性白血病患血浆可溶性L—选择蛋白(sL—selectin)水平和细胞膜结合L—选择蛋白(L—selectin)及其基因表达与急性白血病发病及病情变化的关系及对指导治疗、判断预后的临床意义，用酶联免疫吸附双技体夹心法(ELISA)、RT—PCR及免疫组化法，测定40例急性白血病患的血浆sL—selectin水平，L—selectin基因(lyarn-1)及细胞膜结合L—selectin分子的表达。结果显示：初治及难治性急性白血病患血浆sL—selectin水平较缓解及对照均显增高(P＜0．01)，而其mRNA及膜结合L—selectin表达和L—selectin阳性细胞百分率低于完全缓解组(P＜0．05)；伴有肝、脾肿大的急性白血病患较无此体征血浆sL—selectin水平明显增高(P＜0．01)；且sL—selectin水平与临床过程有关；急性白血病患L—selectin mRNA与膜结合L—selectin之间显示显相关性(γ＝0．782，P＜0．05)。结论：急性白血病患L—selectin基因的表达在mRNA水平及蛋白质水平均较对照减少，两有显相关性；监到患血浆sL—selectin水平对诊断急性白血病的复发及髓外浸润有一定竞义。

Study on Expression of Cell Surface L-Selectin and Soluble L-Selectin in Patients with Acute Leukemia

To study the relationship between the level of the soluble L-selectin (sL-selectin) in plasma and surface L-selectin expression on leukemic cells and episode and state of illness in acute leukemia patients, the plasma level of sL-selectin was measured by a sandwich enzyme-linked immunosorbent assay, and the expressions of surface L-selectin and its gene (lyam-1) were detected by immunohistochemistry and RT-PCR. The results showed that the levels of sL-selectin were significantly higher in untreated and therapy-resistant acute leukemia patients, and expression of L-selectin mRNA and cell surface L-selectinin in untreated and NR patients were significantly lower than that in CR patients and control group (P < 0.05). The plasma levels of sL-selectin were significantly increased in patients with splenomegaly and hepatomegaly (extramedullary infiltration). The levels of sL-selectin were related to the clinical course of the acute leukemia patients. A significant correalation existed between expressions of L-selectin mRNA and surface L-selectin in acute leukemia patients (gamma = 0.782, P < 0.05). It is concluded that expression of L-selectin gene was down-regulated in level of mRNA and protein in acute leukemia patients and both changes were highly correlated. Monitoring of the plasma level of sL-selectin is possibly useful for early diagnosis of relapse and extramedullary infiltration in acute leukemia.