tokens: On readmission , 11 patients received therapeutic heparin , which worsened the patients ' clinical condition and , in all 11 cases , decreased the platelet count ( mean at readmission , 143 x 10 ( 9 ) cells / L ; mean nadir after heparin re - exposure , 39 x 10 ( 9 ) cells / L ). Results of serologic tests for heparin - induced antibodies were positive in all patients .