OBJECTIVETo investigate the effects of chronic mercury poisoning on blood coagulation and fibrinolysis systems, and the possible mechanism.

METHODSTwenty-seven patients with chronic mercury poisoning were studied with 30 healthy people as control. Thrombomodulin (TM), tissue plasminogen activator (t-PA), plasminogen activator inhibitor (PAI), interleukin-13 (IL-13), interleukin-18 (IL-18), soluble intercellular adhesion molecule-1 (SICAM-1) were examined with ELISA methods, and superoxide dismutase (SOD) and lipid peroxidation (LPO) was examined with chemical catalysis methods. Two to three weeks after treatment with reduced glutathione, tiopronin and daidzein, blood was used for determin the above items again.

RESULTS(1) The concentration of TM in patients [(2.36 +/- 0.16) ng/ml] was significantly lower than in the control [(4.36 +/- 0.24) ng/ml] (P < 0.01), while TM tended to be higher after treatment [(4.82 +/- 0.34) ng/ml] (P < 0.05). (2) The concentration of t-PA in patients [(3.44 +/- 0.34) ng/ml] was significantly lower than in the control [(4.52 +/- 0.16) ng/ml] (P < 0.05), and was higher significantly [(5.63 +/- 0.58) ng/ml] after treatment (P < 0.05); The concentration of PAI in patients [(48.23 +/- 3.59) ng/ml] was significantly higher than in the control [(31.59 +/- 2.13) ng/ml] (P < 0.05), but after treatment no significant change [(50.71 +/- 4.29) ng/ml] was found (P > 0.05). (3) The activity of SOD in patients [(953.85 +/- 9.56) U/g Hb] was significantly lower than in the control [(1,308.75 +/- 10.21) U/g Hb] (P < 0.01), and was higher significantly [(1,217.95 +/- 6.29) U/g Hb] after treatment (P < 0.05); and the concentration of LPO in patients [(9.53 +/- 0.26) nmol/ml] was significantly higher than in the control (P < 0.05), and significantly lower [(7.29 +/- 0.35) nmol/ml] after treatment (P < 0.05). (4) The concentrations of IL-13 [(35.93 +/- 5.28) pg/ml], IL-18 [(28.79 +/- 2.53) pg/ml], SICAM-1 [(603.16 +/- 29.12) ng/ml] were significantly higher than those in the controls (P < 0.05, P < 0.01), but no significant difference was found after treatment.

CONCLUSIONDysfunction of the TM/protein C system and t-PA/PAI system (i.e. the decrease of anti-coagulation activity and the inhibition of the function for the fibrolysis system) may play a key role in the secondary hypercoagulable state induced by chronic mercury poisoning.