[Serum α1-acid glycoprotein, imatinib concentration and efficacy in chronic myeloid leukemia patients]

To explore the relationship between serum α1-acid glycoprotein (AGP), disease progression, imatinib plasma trough concentration and efficacy in the patients with chronic myeloid leukemia (CML).

A total of 112 CML patients were recruited from August 2008 to February 2010 in our hospital. There were 72 males and 40 females with a median age of 39 years old (range: 6 - 76 years old). Among them, 102 patients were in chronic phase, 4 in accelerated phase and 6 in blastic phase. Ninety-nine patients were treated with imatinib while 13 patients received hydroxyurea. Twenty healthy blood donors were designated as the control group. The serum AGP levels of all patients were detected by immuno-turbidimetric assay. And the concentrations of AGP and imatinib were detected in 12 patients before and after 3 months of imatinib therapy respectively. For 84 CML patients, their plasma trough concentrations of imatinib were detected by high performance liquid chromatography-tandem mass spectrometry simultaneously. All patients were divided into 5 groups by efficacy to evaluate the significance of serum AGP and its relationship with imatinib concentration.

Serum AGP of no response (NR) group [(1.18 ± 0.26) g/L] was significant higher than that of complete cytogenetic response (CCR), complete hematologic response (CHR) and control group [(0.60 ± 0.21), (0.71 ± 0.17), (0.52 ± 0.15) g/L, all P < 0.05]. Serum AGP of accelerated/blastic phase group [(1.28 ± 0.50) g/L] was significant higher than CCR or control group (P < 0.05). Serum AGP of CHR group was higher than that of control group (P < 0.05). No significant difference existed between CCR, CHR or control group (P > 0.05). There were no significant differences between NR, relapse or accelerated/blastic phase group (P > 0.05). The serum AGP of 12 patients on a 3-month therapy of imatinib were lower than that of patients at pre-treatment [(0.54 ± 0.17) g/L vs (0.83 ± 0.31) g/L, P < 0.01]. The plasma trough concentration of imatinib was (1307 ± 586) µg/L (range: 109 - 3400 µg/L) in 84 patients. And it was positively correlated with the serum level of AGP (r = 0.443, P < 0.01).

The serum level of AGP can reflect the in vivo loads of leukemic cells for CML patients. There is a positive correlation between the serum level of AGP and the plasma trough concentration of imatinib. Serum AGP can be used as a monitoring index of efficacy for CML patients.