Etiology of thrombocytopenia in all patients treated with heparin products.
OBJECTIVE
To characterize the cause of thrombocytopenia in all patients treated with heparin products, to determine the incidence of heparin-induced thrombocytopenia (HIT) in unselected hospitalized patients, and to have modern data of the magnitude of this problem.


METHODS
Retrospective hospital-based cohort study. During a random 2-month period, we reviewed the medical records of all patients treated with heparin agents, screened them for thrombocytopenia, and determined the cause of it.


RESULTS
Out of 674 patients who received heparin products, 110 (16%) had thrombocytopenia. The most common causes included cancer chemotherapy, surgery, sepsis, and medications. Three patients met the clinical criteria for HIT. One had antibodies for heparin-platelet factor-4, and received a direct thrombin inhibitor. The other two individuals had a clinical syndrome that resembled immune HIT, but were not tested for HIT antibodies. One suffered a thrombotic episode that led to the death of her fetus. The other died of a possible thromboembolism.


CONCLUSIONS
This study provides evidence-based data for the differential diagnosis of thrombocytopenia after treatment with heparin products. Our findings suggest that increased awareness of the HIT syndrome might reduce morbidity and mortality. Patients exposed to heparin products, who develop thrombocytopenia, should not be overlooked.
Division of Hematology and Medical Oncology, University of Louisville, J.G. Brown Cancer Center, Louisville, KY 40202, USA. damianla@ulh.org
Damian A
DA
Laber
Monte E
ME
Martin
D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000009:adverse effects; D001323:Autoantibodies / Q000097:blood; D003937:Diagnosis, Differential; D064420:Drug-Related Side Effects and Adverse Reactions; D005260:Female; D006493:Heparin / Q000009:adverse effects* / Q000276:immunology / Q000627:therapeutic use; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010978:Platelet Factor 4; D011183:Postoperative Complications; D011247:Pregnancy; D012189:Retrospective Studies; D018805:Sepsis / Q000150:complications; D013921:Thrombocytopenia / Q000139:chemically induced / Q000175:diagnosis / Q000209:etiology*
D000970:Antineoplastic Agents; D001323:Autoantibodies; D010978:Platelet Factor 4; D006493:Heparin