circulating heparan sulfate chains and body weight contribute to anti-xa levels in cancer patients using the prophylactic dose of enoxaparin

Hospitalized cancer patients are at increased risk of thrombosis and prophylaxis with heparin is recommended. heparanase is a protein capable of degrading heparan sulfate (hs) chains. the first objective of the study was to examine the effects of weight on anti-xa levels in cancer patients treated with a fixed dose of enoxaparin as thromboprophylaxis. the second aim was to assess a potential correlation between plasma pre-treatment coagulation parameters and anti-xa levels in an assumption that heparanase degradation activity towards heparins and hs chains could affect anti-xa levels. two blood samples (prior to and 3 h after drug injection) of 76 cancer patients with an indication for prophylaxis with enoxaparin (40 mg) were evaluated for coagulation markers. sub-prophylactic levels of anti-xa (< 0.2 u/ml) were found in 16/76 (21%) patients; in 13/76 (13%) patients the values were supra-prophylactic (> 0.5 u/ml). in the subgroup of patients weighing > 80 kg, 7/14 (50%) individuals had a sub-prophylactic level. overall, anti-xa levels appeared to correlate with patient's weight (r = − 0.48, p < 0.0001), pre-treatment partial thromboplastin time (ptt), d-dimer, hs, heparanase levels and procoagulant activity. we concluded that plasma anti-xa levels correlated with patient's weight. a substantial portion of cancer patients receiving enoxaparin prophylaxis was undertreated. for patients > 80 kg, a weight-adjusted prophylactic dose of enoxaparin could be considered. elevated enoxaparin anti-xa levels correlated with pre-treatment parameters of coagulation system activation. high pre-treatment hs and elevated plasma anti-xa levels potentially serve as biomarkers for the identification of patients at increased thrombosis risk.