Pieters R, Huismans D R, Loonen A H, Peters G J, Hählen K, van der Does-van den Berg A, van Wering E R, Veerman A J
Department of Pediatrics, Free University Hospital, Amsterdam, The Netherlands.
Leukemia. 1992 May;6(5):375-80.
Many reports have described the relationship of adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP) activities with the immunological subclasses of acute lymphoblastic leukemia (ALL). The clinical significance of these enzymes in leukemias is not yet completely understood. We performed a study in 83 children with untreated ALL to establish the relationships of ADA and PNP to clinical outcome, in vitro drug resistance and differentiation stage of B-cell lineage ALL. ADA and PNP activities were determined radiochemically. In vitro resistance to 6-thioguanine (6-TG) was determined with the MTT assay. ADA activity was not different between proB- and cALL cases but decreased in the sequential differentiation stages cALL----preB-ALL----B-ALL. The PNP level was not different between the four stages of B-lineage ALL. Patients with cALL/preB ALL with low ADA activities had a significantly poorer probability of survival (p = 0.005) than patients with high ADA levels. Patients with cALL/preB ALL with low PNP activities showed a non-significant trend for a poorer prognosis (0.05 less than p less than 0.10) than patients with a high PNP level. Low ADA and PNP activities were not related to in vitro resistance to 6-TG. We conclude that ADA decreases and PNP remains constant in sequential differentiation stages of B-lineage ALL. Patients with precursor B-lineage ALL with low activities of ADA have a poorer prognosis than those with high activities of these enzymes. No relationship could be detected between ADA or PNP activity and resistance to 6-TG.
许多报告描述了腺苷脱氨酶（ADA）和嘌呤核苷磷酸化酶（PNP）活性与急性淋巴细胞白血病（ALL）免疫亚类之间的关系。这些酶在白血病中的临床意义尚未完全明确。我们对83例未经治疗的ALL患儿进行了一项研究，以确定ADA和PNP与临床结局、体外耐药性以及B细胞系ALL分化阶段之间的关系。采用放射化学法测定ADA和PNP活性。用MTT法测定对6-硫鸟嘌呤（6-TG）的体外耐药性。proB-ALL和cALL病例之间的ADA活性没有差异，但在cALL→preB-ALL→B-ALL的连续分化阶段ADA活性降低。B系ALL四个阶段之间的PNP水平没有差异。ADA活性低的cALL/preB ALL患者的生存概率明显低于ADA水平高的患者（p = 0.005）。PNP活性低的cALL/preB ALL患者的预后比PNP水平高的患者有较差的趋势，但差异无统计学意义（0.05＜p＜0.10）。ADA和PNP活性低与对6-TG的体外耐药性无关。我们得出结论，在B系ALL的连续分化阶段，ADA降低而PNP保持不变。ADA活性低的前体B系ALL患者的预后比这些酶活性高的患者差。未发现ADA或PNP活性与对6-TG的耐药性之间存在关联。
