OBJECTIVETo investigate the changes of thrombospondin 1(TSP1) level and von Willebrand factor cleaving protease(ADAMTS13) activity in the patients with hematologic malignancies before and after treatment and to evaluate their clinical significance.

METHODSEighty-two patients with hematologic malignancies were enrolled in this study, among them 20 patients were with acute leukemia, 48 patients were with lymphoma and 14 patients were with multiple myeloma. The plasma samples of 82 patients with hematologic malignancies and 45 healthy controls were collected. The activities of ADAMTS13 were evaluated by residue collagen binding assay(R-CBA), the levels of TSP1 and vWF antigen were measured by enzyme-linked immunosorbent assay(ELISA).

RESULTSThe activity of plasma ADAMTS13 in patients with hematologic malignancies was lower than that of normal controls(P<0.05). The levels of vWF antigen and TSP1 in the patients with hematologic malignancies were higher than those in normal controls(P<0.05). After standard induction chemotherapy, the ADAMTS13 activity of the patients with hematologic malignancies at the complete remission was higher than that before therapy(P<0.05); the vWF antigen level was significantly lower than that in the patients with hematologic malignancies before therapy(P<0.05), but still higher than that in controls(P<0.05). There were 25 infection patients in 82 cases of hematologic malignancies, and the ADAMTS13 activity in the patients with newly diagnosed hematologic malignancies complicated with infection before therapy was obviously lower than that in the patients with hematologic malignancies without infection(P<0.05), the levels of vWF antigen and TSP1 were significantly lower than that in patients without infection (P<0.05). In the process of treatment, 8 patients have been speculated to suffer from thrombus, and the ADAMTS13 activity in the patients with thrombus was obviously lower than that in the patients without thrombus(P<0.05).

CONCLUSIONLow ADAMTS13 activity and high TSP1 level may participate in the progress of hematologic malignancies, the infection and thrombotic events may lead to further reduction of the ADAMTS13 activity. Assaying the level of ADAMTS13 activity in the patients with malignant tumor may be helpful to prevent the infection and thrombosis in the patients with hematologic malignancies.